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WO2025093767A1 - Absorbent article with improved attachment zone - Google Patents

Absorbent article with improved attachment zone Download PDF

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Publication number
WO2025093767A1
WO2025093767A1 PCT/EP2024/081052 EP2024081052W WO2025093767A1 WO 2025093767 A1 WO2025093767 A1 WO 2025093767A1 EP 2024081052 W EP2024081052 W EP 2024081052W WO 2025093767 A1 WO2025093767 A1 WO 2025093767A1
Authority
WO
WIPO (PCT)
Prior art keywords
channel
absorbent
channel portion
width
core wrap
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/EP2024/081052
Other languages
French (fr)
Inventor
Werner Van Ingelgem
Tom Derycke
Steven Smet
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Drylock Technologies NV
Original Assignee
Drylock Technologies NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Drylock Technologies NV filed Critical Drylock Technologies NV
Publication of WO2025093767A1 publication Critical patent/WO2025093767A1/en
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00Bandages or dressings; Absorbent pads
    • A61F13/15Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F13/531Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having a homogeneous composition through the thickness of the pad
    • A61F13/532Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having a homogeneous composition through the thickness of the pad inhomogeneous in the plane of the pad
    • A61F13/533Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having a homogeneous composition through the thickness of the pad inhomogeneous in the plane of the pad having discontinuous areas of compression
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00Bandages or dressings; Absorbent pads
    • A61F13/15Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/45Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape
    • A61F13/47Sanitary towels, incontinence pads or napkins
    • A61F13/475Sanitary towels, incontinence pads or napkins characterised by edge leakage prevention means
    • A61F13/4751Sanitary towels, incontinence pads or napkins characterised by edge leakage prevention means the means preventing fluid flow in a transversal direction
    • A61F13/4756Sanitary towels, incontinence pads or napkins characterised by edge leakage prevention means the means preventing fluid flow in a transversal direction the means consisting of grooves, e.g. channels, depressions or embossments, resulting in a heterogeneous surface level
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00Bandages or dressings; Absorbent pads
    • A61F13/15Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F13/531Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having a homogeneous composition through the thickness of the pad
    • A61F13/532Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having a homogeneous composition through the thickness of the pad inhomogeneous in the plane of the pad
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00Bandages or dressings; Absorbent pads
    • A61F13/15Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F13/534Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having an inhomogeneous composition through the thickness of the pad
    • A61F13/535Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having an inhomogeneous composition through the thickness of the pad inhomogeneous in the plane of the pad, e.g. core absorbent layers being of different sizes
    • A61F13/536Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having an inhomogeneous composition through the thickness of the pad inhomogeneous in the plane of the pad, e.g. core absorbent layers being of different sizes having discontinuous areas of compression

Definitions

  • the present invention pertains to the technical field of absorbent articles, more preferably disposable personal care articles such as diapers, baby pants, adult incontinent garments, and the like, and to absorbent structures for use in such absorbent articles. More specifically the present invention relates to an absorbent article comprising an absorbent core with at least one channel, the absorbent core being arranged between a topsheet and a backsheet. The present invention also relates to methods for manufacturing such an absorbent article.
  • Absorbent articles comprising an absorbent core with one or more channels between a topsheet and a backsheet are well known. Examples of such absorbent articles are described for example in patents EP 3 403 630 Bl, EP 3 403 632 Bl and EP 3 403 631 Al in the name of the applicant, which are incorporated herein by reference.
  • ADL liquid distribution and acquisition layer
  • capillary acceleration sheet it is known to provide a liquid distribution and acquisition layer (ADL) or capillary acceleration sheet between the topsheet and the absorbent core in order to take up and distribute the liquid from the topsheet towards the absorbent core.
  • ADL or capillary acceleration sheet extends over an area where liquid insult is to be expected.
  • Such layers are chosen to reduce the time needed to obtain a dry feeling at the topsheet surface after a liquid insult and to reduce rewetting.
  • the at least one channel in the absorbent core mainly serves the purpose of achieving a fast distribution of the liquid by mass flow after a liquid insult.
  • the top core wrap sheet and the back core wrap sheet are attached to each other at least in a portion of the at least one channel.
  • the object of embodiments of the invention is to provide an absorbent article of the type stated in the preamble, with an improved attachment zone, and more in particular an attachment zone which is well aligned with the at least one channel.
  • an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet and an absorbent core positioned between the liquid pervious topsheet and the liquid impervious backsheet.
  • the absorbent core comprises a bottom core wrap sheet, a top core wrap sheet and absorbent material between the bottom core wrap sheet and the top core wrap sheet. It is noted that the bottom and top core wrap sheets may be part of a single integral sheet wrapping the absorbent material or may be separate sheets, optionally having different properties.
  • the absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp and is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel.
  • the at least one channel comprises a first channel portion extending in a longitudinal direction of the absorbent core and a second channel portion extending at an angle with respect to the first channel portion.
  • the first channel portion has a first channel width (wcl) seen in a transverse direction of the absorbent core and comprises a first attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet.
  • the first attachment zone has a first attachment width (wbl) seen in the transverse direction.
  • the second channel portion has a second channel width (wc2) seen in a direction perpendicular on a centre line of the second channel portion and comprises a second attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet.
  • the second attachment zone has a second attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion.
  • a first ratio (wbl/wcl) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.
  • Embodiments of the invention are based inter alia on the insight that a transport means, such as drum, on which the absorbent articles are typically produced typically operates at very high speed.
  • an attachment means such as a sealing bar
  • the channel portion may be shifted relative to the attachment zone.
  • problems resulted in an attachment zone extending in areas outside of the channel portion and covering less area within the channel portion.
  • the misalignment problem is addressed by choosing first ratio (wbl/wcl) of the first attachment width relative to the first channel width which larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width. In this way, in the second channel portion, which is the channel portion extending at an angle relative to the longitudinal direction, even in cases of a small misalignment, the second attachment zone will still be located substantially within the second channel portion.
  • the first and second attachment zones are distinguishable zones and may either be continuous attachment zone or discontinuous attachment zones.
  • the attachment zone may be defined as a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines, wherein the average width (wb) of each attachment zone is an average of the width of the polygon measured in a direction perpendicular on a centre line of the attachment zone.
  • the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy.
  • the sealing is done in accordance with a sealing pattern. In the area of the first and second channel position outside of the first and second attachment zone the top core wrap sheet is not sealed to the bottom core wrap sheet.
  • the sealing pattern covers less than 80%, preferably less than 70%, more preferably less than 60%, even more preferably less than 50%, most preferably between 1 and 50% of the surface area of the at least one channel.
  • the sealing pattern covers between 1 and 50% of the total surface area of the at least one channel, or between 1 and 40%, or between 1 and 30%, or between 1 and 25%, or between 2 and 25%, or between 3 and 25%, or between 4 and 25%.
  • the sealing pattern comprises a plurality of discrete sealing areas
  • the total surface area of those discrete sealing areas is preferably less than 80% of the surface area of the at least one channel.
  • Such sealing pattern can provide a good resistance against the swell forces generated by liquid being captured in the superabsorbent particles by hydrogen bonds, but the sealing pattern equally can provide resistance against dry and wet superabsorbent particles trying to penetrate through the core wrap and through the sealing pattern after as well as during the sealing step of the manufacturing process. In that manner, any risk of dry or wet SAP particles coming into contact with sensitive skin upon wearing is avoided or reduced. Further, by having a reduced surface area that is being sealed in accordance with a pattern, any particles remaining in the one or more channel zones can easily migrate to a non-sealing area so that the risk of creating holes in the one or more channel zones is reduced or avoided.
  • the sealing pattern is a regular pattern, such as a line pattern such as a grid, a pattern of dots, etc.
  • the dots may have any shape, e.g. round, polygonal, etc.
  • the line pattern may comprise one or more sets of parallel lines. When a first set of parallel lines and a second set of parallel lines is included, the lines of the first set may be oriented at a non-zero angle with respect to the lines of the second set.
  • the sealing pattern comprises a large number of distinct sealing areas spread across the first and second attachment zone.
  • the large number is larger than 10, more preferably larger than 20.
  • the sealing pattern comprises a plurality of discrete elements, and each discrete element has a first dimension in a first direction and a second dimensions in a direction perpendicular to the first direction.
  • the first dimension is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm or between 0.2 and 0.7 mm, or between 0.3 and 0.6 mm.
  • sealing patterns such as grids, dots, polygons, etc.
  • fine single bonding areas e.g. having a surface area smaller than 2 mm 2 or a line thickness lower than 1 mm
  • individual superabsorbent particles will find easier their way to nonsealed zones in order not to create any hole.
  • the first channel portion and the second channel portion are interconnected, so that liquid can flow from the first channel portion into the second channel portion and vice versa without being hindered by absorbent material in between the first and second channel portion.
  • the at least one channel comprises a further channel portion extending in a longitudinal direction of the absorbent core, said further channel portion having a further channel width (wcf) seen in a transverse direction of the absorbent core and comprising a further attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet, said further attachment zone having a further attachment width (wbf) seen in the transverse direction, wherein the first channel portion is connected to a first end of the second channel portion and the further channel portion is connected to a second opposite end of the second channel portion.
  • first and the further channel portion i.e. two channel portions extending in the longitudinal direction, may be interconnected by the second channel portion so that mass flow is possible between the first and further channel portion, wherein a robust attachment zone is present in the second channel portion.
  • the first and further channel width are substantially the same.
  • the second channel portion may be a straight portion or a curved portion.
  • the at least one channel comprises a first channel and a second channel, said first channel including the first and second channel portion, said first and second channel being arranged so as to be mirror images relative to a longitudinal central axis of the absorbent core.
  • the second channel includes first and second channel portions.
  • the first and second channel each have a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length of the absorbent core, preferably at least 30% of the length of the absorbent core (La).
  • the at least one channel comprises, preferably consists of, an interconnected channel comprising the first and second channel portion, wherein the first channel portion extends along a longitudinal central axis (A) of the absorbent core and the second channel portion is connected to the first channel portion and diverges away from the longitudinal central axis, wherein the interconnected channel comprises a third channel portion which is arranged to be a mirror image of the second channel portion relative to the longitudinal central axis of the absorbent core, said third channel portion having a third attachment zone.
  • the interconnected channel has a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length (La) of the absorbent core, preferably at least 30% of the length of the absorbent core.
  • the interconnected channel comprises a further channel portion and a second further channel portion, wherein the first channel portion is connected to a first end of the second and third channel portion, the further channel portion is connected to a second end of the second channel portion and the second further channel portion is connected to a second end of the third channel portion.
  • the first and the second attachment zone include the same type of attachment.
  • the first attachment zone is a permanent attachment zone and the second attachment zone is a permanent attachment zone.
  • the first attachment zone is a permanent attachment zone and the second attachment zone is a permanent attachment zone or comprises one or more semipermanent attachment zones configured to release after having been in contact with liquid, for example after having been in contact with the liquid for a time period of less than 2 minutes.
  • the first and/or second channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
  • an average length (lb) of the first attachment zone is smaller than an average length (1c) of the first channel portion.
  • the first attachment width (wbl) of is less than 90% of the first channel width (wcl), preferably less than 80%, more preferably less than 70%, and more than 25%.
  • the first and second attachment zone may comprise a single continuous attached portion or a plurality of discrete attached portions.
  • the first and second attachment zone may comprise one or more permanent attachment portions which remain attached after wetting and/or one or more semipermanent attachment portions which detach after wetting and/or one or more unattached portions.
  • An unattached portion or a semi-permanent attachment portion allows for an increased swelling of the absorbent material after the one or more channels have fulfilled their function of distributing the liquid, as wet absorbent material is allowed to extend/swell into the channel area in case of an unattached or detached portion.
  • the average width of the first attachment zone is less than 90% of the average width of the first channel portion, preferably less than 80%, more preferably less than 70%, and more than 25% of the average width of the first channel portion.
  • the average length of the first attachment zone is less than 99%, more preferably less than 98% of the average length of the first channel portion, e.g. less than 97% or even 95%, and/or more than 80% of the average length of the channel.
  • an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet and an absorbent core positioned between the liquid pervious topsheet and the liquid impervious backsheet.
  • the absorbent core comprises a bottom core wrap sheet, a top core wrap sheet and absorbent material between the bottom core wrap sheet and the top core wrap sheet.
  • the absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp, wherein the absorbent material is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel.
  • the at least one channel comprises a channel portion extending at an angle with respect to a longitudinal direction of the absorbent core.
  • This channel portion may be similar to the second channel portion discussed in the embodiments above.
  • the channel portion has a channel width (wc2) seen in a direction perpendicular on a centre line of the channel portion and comprises an attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet, said attachment zone having an attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion.
  • the attachment width is less than 80% of the channel width (wb2 ⁇ 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
  • embodiments of the invention may also comprise at least one channel having only channel portions which are not aligned along the longitudinal direction, such as two elongate curved portions, or with a channel portion which is not aligned along the longitudinal direction in combination with channel portions which are aligned in the longitudinal direction but which have different properties than those described in accordance with the first aspect.
  • the problem of misalignment between the area of the channel portion and the associated attachment zone is particularly relevant for a channel portion extending at an angle relative to the longitudinal direction of the absorbent core because for such channel portion typically a misalignment will be present across the entire channel portion, whilst for a channel portion extending in the longitudinal direction, i.e. in the transport direction, the problem will only be present for the longitudinal ends of the channel and have less impact.
  • the misalignment problem is addressed by choosing a width of the attachment zone which is significantly smaller than the channel width. In this way, in the channel portion extending at an angle relative to the longitudinal direction, even in cases of a small misalignment, the attachment zone will still be located substantially within the channel portion, resulting in a good attachment and thus improved liquid distribution characteristics.
  • the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy.
  • the bottom core wrap sheet is not sealed to the top core wrap sheet.
  • the channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30% of the width of the absorbent core.
  • the width of the absorbent core is measured in a transverse direction of the absorbent core, in an area where the respective channel is present, between two end points where absorbent material is present, i.e. it is the width of the absorbent material deposition area of the absorbent core.
  • the top core wrap sheet and/or the back core wrap sheet may extend over a width which is larger than the width of the absorbent core, as they may be attached along a periphery where no absorbent material is present.
  • the width of the absorbent core may vary between a minimum width and a maximum width, and preferably the above defined channel width is valid both for the minimum and the maximum width.
  • the absorbent material deposition area may thus have a width which varies e.g.
  • a width of the absorbent material deposition area measured at a front end of the absorbent core may be above 100 mm, or even above 105 mm and a width measured at a rear end of the absorbent core may be below 100 mm, or even below 95 mm.
  • the channel width may be constant through substantially the whole length of the channel portion or may vary along its length. When the width varies along the length, then the above specified width percentages apply for the average width of the respective channel portion.
  • the channel portion is formed by one or more absorbent material-free zones within the absorbent material deposition area of the absorbent core, and the channel width is considered to be the width of the material-free zone, disregarding the possible presence of core wrap within the channel. If the channel portion is formed by one or more absorbent material zones where less absorbent material per surface area is present as compared to an area adjacent the channel portion, the channel width is the width of the absorbent material zone where less absorbent material per surface area is present.
  • the absorbent core periphery which may be the periphery of the top/bottom core wrap, may define any suitable shape, such as a "T,” “Y,” “hour-glass,” or “dog-bone” shape, for example.
  • a “T shape may have a larger width in the front portion than in the rear portion of the absorbent core.
  • An absorbent core periphery having a generally “dog bone” or “hour-glass” shape may taper along its width towards the middle or "crotch” region of the core. In this way, the absorbent core may have a relatively narrow width in an area of the absorbent core intended to be placed in the crotch region of an absorbent article.
  • the attachment zone includes all permanent attachment portions within the respective channel portion, i.e. outside of the attachment zone no further permanent attachment bonds are present in the corresponding channel portion.
  • Each attachment zone may be either a continuous attachment zone or a discontinuous attachment zone including a plurality of bonding spots at a distance of each other.
  • the average width is the average of the width (measured in perpendicular on a centre line of the attachment zone) along its full length (along the centre line of the attachment zone) of the attachment zone.
  • the attachment zone may be defined as a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines, wherein the average width (wb) of each attachment zone is an average of the width of the polygon measured in a direction perpendicular on a centre line of the attachment zone, across the full length of the attachment zone. This may equally apply for the first and second attachment zone of the first aspect.
  • a permanent attachment zone is an attachment zone which remains attached when wetted. This may be tested by applying 200 ml liquid substantially equally across the absorbent core and evaluating the attachment zone after 10 minutes. If the attachment zone remains intact, the attachment zone is a permanent attachment zone. More preferably, a permanent attachment zone is an attachment zone which remains intact after submerging the absorbent core in the liquid and waiting for 10 minutes.
  • each permanent attachment zone is an elongate attachment zone.
  • each permanent attachment zone is centred with respect to the corresponding channel.
  • no permanent bonds are present in an area of the channel surrounding the permanent attachment zone.
  • the absorbent material can easily expand into that surrounding area upon wetting of the absorbent material.
  • one or more semi-permanent attachment portions may be present in an area of the channel surrounding the permanent attachment zone. Such semipermanent attachment portions are configured to loosen upon wetting of the absorbent article.
  • adhesive is arranged between the bottom core wrap sheet and the top core wrap sheet at least in a portion of the at least one channel, within and/or outside of the first and second attachment zone.
  • the adhesive may create the distinguishable attachment zone(s), but may also be included on top of the distinguishable attachment zone(s).
  • the distinguishable attachment zone(s) may be formed by sealing, but in addition adhesive may be present in the entire channel portion(s).
  • the distinguishable attachment zone(s) may be formed by adhesive, and no adhesive is present outside of the distinguishable attachment zone(s).
  • adhesive may be applied in one or more lanes or in a swirl pattern or on the entire surface on the top core wrap sheet and/or on the bottom core wrap sheet.
  • the bottom core wrap sheet is a spunbond meltblown spunbond nonwoven comprising a first spunbond layer, a meltblown layer and a second spunbond layer on the other side of the meltblown layer, wherein preferably the second spunbond layer comprises polypropylene fibres.
  • the absorbent article further comprises a capillary acceleration sheet between the absorbent core and the liquid pervious topsheet.
  • the capillary acceleration sheet is a through-air-bonded nonwoven having a basis weight between 15 and 50 g/m2, more preferably between 15 and 30 g/m2.
  • a good topsheet dryness and in particular a fast topsheet dryness after liquid insult, and a good rewetting behaviour, is obtained.
  • a fast dryness feeling and a low rewetting at the level of the topsheet can be ensured, whilst at the same time providing a good liquid distribution through the one or more channels resulting in improved leakage protection.
  • the bottom core wrap sheet has a basis weight which is larger than the basis weight of the top core wrap sheet and/or the capillary acceleration sheet.
  • the bottom core wrap can be used for distribution purposes, distributing the liquid from the one or more channels to the absorbent material, whilst the providing integrity to the absorbent article.
  • the liquid may be transported from the one or more channels through the bottom core wrap, along areas where the absorbent material is saturated, e.g. areas close to the one or more channels, to other areas where the absorbent material is not yet saturated.
  • a relatively light top core wrap and/or capillary acceleration sheet it takes less time before a dry feeling is obtained at the topsheet surface and any rewetting is reduced or avoided.
  • the at least one channel comprises one or more elongated channels each having a channel length measured in a longitudinal direction of the absorbent core, said channel length being at least 10% of the length of the absorbent core, preferably at least 15% of the length of the absorbent core, the one or more elongated channels comprising the channel portion(s).
  • the one or more elongated channels comprise at least a first and a second elongated channel extending at a distance of each other in a substantially longitudinal direction of the absorbent core.
  • the bottom core wrap sheet consists of a single sheet. In that way the bottom core wrap can be easily transported in a machine for producing the absorbent articles. Further, the strength and/or integrity of the absorbent article may be increased.
  • the bottom core wrap sheet comprises a through-air bonded non-woven, wherein preferably the bottom core wrap sheet consists of a through-air bonded non-woven.
  • the bottom core wrap has a basis weight between 18 and 80 g/m2, preferably between 20 and 75 g/m2, more preferably between 25 and 70 g/m2, even more preferably between 30 and 65 g/m2.
  • the top core wrap sheet comprises at least one spunbond and optionally at least one meltblown layer, wherein for example the top core wrap consists of a spunbond layer.
  • the top core wrap has a basis weight between 8 and 30 g/m2.
  • an amount of cellulosic fluff pulp in the absorbent material is below 250 g/m2, preferably below 200 g/m2, more preferably below 180 g/m2, even more preferably below 160 g/m2, e.g. between 60 g/m2 and 180 g/m2 or between 70 g/m2 and 170 g/m2.
  • an amount of superabsorbent particles in the absorbent material is above 300 g/m2, preferably above 320 g/m2, more preferably above 340 g/m2, e.g. between 300 g/m2 and 400 g/m2 or between 320 g/m2 and 390 g/m2.
  • the superabsorbent particles have a permeability SFC which is higher than 10 x 10-7 cm3.S.g-l and/or a permeability GBP which is higher than 20 Da, preferably higher than 25 Da.
  • the absorbent material comprises more than 60 weight%, preferably more than 70 weight% superabsorbent particles.
  • the bottom core wrap sheet is a through-air bonded non-woven.
  • This may be a spunbond/spunbond through-air-bonded nonwoven, or a classical through-air bonded nonwoven obtained by sequentially feeding the fibres of a first and second layer.
  • the bottom core wrap sheet comprises a first layer and a second layer, wherein said first layer has a first density between 20 and 150 kg/m3 and said second layer has a second density between 100 and 400 kg/m3, said second density being higher than the first density, wherein said first layer is closer to the absorbent material than said second layer.
  • a difference between the first and the second density is higher than 20 kg/m3, more preferably higher than 30 kg/m3 even more preferably higher than 40 kg/m2, even more preferably between 50 and 150 kg/m3, most preferably between 60 and 140 kg/m3, e.g. between 70 and 130 kg/m3.
  • the first layer is a through-air-bonded carded non-woven and the second layer is a spunbond layer, e.g. a PP spunbond layer.
  • the first layer is a spunbond layer and the second layer is a spunbond layer.
  • the first and second layer may be obtained using multiple spinning column, whereupon the assembly is interconnected using e.g. through-air- bonding.
  • the first layer has a first basis weight and the second layer has a second basis weight, said second basis weight being lower than said first basis weight.
  • the second layer may be a rather thin layer as it does not have to contribute to the distribution.
  • the difference between the first layer and the second layer is larger than 1 g/m2, more preferably larger than 2 g/m2, even more preferably larger than 3 g/m2, or even larger than 5 g/m2, for example between 1 and 10 g/m2.
  • the first layer has a first basis weight between 15 and 80 g/m2, preferably between 25 and 80 g/m2, and/or the second layer has a second basis weight between 8 and 35 g/m2, preferably between 8 and 25 g/m2.
  • the first layer and/or the second layer comprise more than 90weight% of synthetic fibres, preferably more than 95weight% of synthetic fibres.
  • the first layer comprises polyester fibres. Polyester fibres have the advantage of being capable of providing a highly voluminous first layer, resulting in good distribution properties.
  • the second layer comprises any one of the following fibres or a combination thereof: polyethylene, polyester, copolyester, polypropylene, polyactic acid (PLA).
  • the second density is selected such that it forms a barrier for the superabsorbent particles.
  • the second layer may have a mean flow pore size below a predetermined value, and the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material.
  • PDS particle size distribution
  • traditional blend polymerization superabsorbent particles can serve for this purpose, with sieve selection.
  • drop polymerization superabsorbent particles e.g. SAVIVA® superabsorbent of the company BASF
  • solvent polymerized superabsorbent particles can have such a narrow PDS.
  • the mean flow pore size of the bottom core wrap is below 200 micron, more preferably below 150 micron, even more preferably between 10 and 150 micron, and most preferably between 20 and 150 micron. These values may be achieved thanks to the presence of the second layer.
  • the bottom distribution sheet is attached along a periphery to the bottom core wrap sheet and/or the top core wrap sheet and/or the capillary acceleration sheet.
  • the mass per unit area may be measured using NWSP 130.1.R0 (20) and the nonwoven thickness may be measured using NWSP 120.6.R0 (15). The density can then be calculated as the mass per unit area divided by the thickness.
  • the capillary acceleration sheet has a mean flow pore size below a predetermined value
  • the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material.
  • PDS particle size distribution
  • traditional blend polymerization superabsorbent particles can serve for this purpose, with sieve selection.
  • drop polymerization superabsorbent particles e.g. SAVIVA® superabsorbent of the company BASF
  • solvent polymerized superabsorbent particles can have such a narrow PDS.
  • the capillary acceleration sheet may have a mean flow pore size below 50 micron, preferably between 5 and 50 micron, more preferably between 10 and 50 micron, e.g. between 10 and 40 micron or between 20 and 40 micron.
  • the absorbent material, and in particular super absorbent particles can be well maintained in the absorbent article without requiring an adapted topsheet.
  • the capillary acceleration sheet can fulfil its capillary acceleration function, and will allow liquid to pass through the capillary acceleration sheet.
  • the topsheet may be an apertured topsheet as the low mean flow pore size of the capillary acceleration sheet will avoid that any significant amounts of absorbent material, and in particular of superabsorbent particles, escape through the topsheet.
  • the measure "mean flow pore size” refers to a measure of average pore diameter as determined by a liquid displacement technique utilizing a Coulter Porometer and Coulter POROFIL® test liquid available from Coulter Electronics Limited, Luton, England. The mean flow pore size is determined by wetting a test sample with a liquid having a very low surface tension (i.e., Coulter POROEIL®). Air pressure is applied to one side of the sample.
  • a flow versus pressure relationship for the wet sample can be established and compared to the results for the dry sample.
  • the mean flow pore size is measured at the point where the curve representing 50% of the dry sample flow versus pressure intersects the curve representing wet sample flow versus pressure.
  • the capillary acceleration sheet may have a mean flow pore size below a predetermined value, and the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material.
  • any escaping of absorbent material through the topsheet can be avoided or reduced.
  • traditional blend polymerization superabsorbent particles can serve for this purpose, wherein a sieve selection is used to obtain the desired PDS.
  • drop polymerization superabsorbent particles e.g. SAVIVA® superabsorbent of the company BASF
  • solvent polymerized superabsorbent particles can have such a narrow PDS.
  • the mean flow pore size is between 10 and 200 micron, more preferably between 10 and 150 micron, even more preferably between 20 and 150 micron, and most preferably between 30 and 150 micron.
  • the mean flow pore size is between 30 and 120 micron or between 30 and 100 micron.
  • the capillary acceleration sheet is sealed to the top core wrap sheet according to the sealing pattern, and optionally also to the bottom core wrap sheet through the top core wrap sheet.
  • the sealing is realized by heat and/or pressure and/or ultrasonic energy.
  • the sealing is done by pressing one or more sealing bars against one or more zones overlapping with the one or more channels, said sealing bars being provided with protrusions according to the sealing pattern.
  • the capillary acceleration sheet is a nonwoven comprising fibres having an average diameter between 10 and 35 micron, more preferably between 15 and 30 micron, even more preferably between 17 and 27 micron.
  • the capillary acceleration sheet may have a fineness which results in a high capillary suction of liquid towards the absorbent material, where the liquid is further distributed through the at least one channel and absorbed by the absorbent material.
  • the capillary acceleration sheet pulls liquid to the absorbent material in a very fast manner, resulting in a fast dryness at top sheet level.
  • the capillary acceleration sheet has an average fineness which is between 2-6 dtex, i.e. between 1.8 and 5.4 den. It is noted that instead of or in addition to defining the average diameter of the capillary acceleration sheet, this sheet may also be defined using a fineness value, such as a dtex value or a den value. A den value may be determined using test method ASTM 1577.
  • the capillary acceleration sheet is attached to the bottom core distribution assembly at least in a portion of the one or more channels.
  • the capillary acceleration sheet is a nonwoven with polypropylene (PP) fibres.
  • PP polypropylene
  • the topsheet is an apertured topsheet having apertures with a surface area larger than 0.1 mm2, preferably larger than 0.5 mm2. This allows liquid to pass easily through the topsheet towards the capillary acceleration sheet.
  • the capillary acceleration sheet comprises a blend of fibres having different diameters.
  • the fibres are intermingled, i.e. preferably the different fibres are not arranged in layers but mixed with each other to form the capillary acceleration sheet.
  • a blend of polypropylene (PP) fibres is used.
  • PE polyethylene
  • PET polyethyleneterephthalate
  • PE/PP PE/PP bi-component fibres
  • PE/PLA bi-component fibres etc.
  • the fibres may be continuously crimped fibres.
  • the capillary acceleration sheet comprises a blend of first fibres having an average first diameter above 20 micron, preferably above 22 micron, more preferably above 24 micron, and second fibres having an average second diameter below 20 micron, preferably below 19 micron, more preferably below 18 micron.
  • the fine second fibres will contribute to the fast capillary suction whilst the coarser first fibres will ensure a good distribution of the liquid, also by mass flow.
  • the first fibres represent less than 50 weight% of the capillary acceleration sheet, more preferably less than 45 weight%
  • the second fibres represent more than 50 weight% of the capillary acceleration sheet, more preferably more than 55 weight%.
  • Such a distribution provides a good balance between suction and migration by capillary flow promoted by the finer second fibres and liquid distribution by mass flow promoted by the coarser first fibres.
  • the capillary acceleration sheet is a continuous filament web.
  • the capillary acceleration sheet may be a spunbond nonwoven, a carded nonwoven, a spunlace nonwoven.
  • the capillary acceleration sheet may be made by spunbonding, carding, or spunlacing (hydro-entangling), or a combination thereof. If the capillary acceleration sheet is a spunbond web, it may be a caelered (i.e. a point bonded) spunbond web, preferably with a bonding area between 10 and 30%.
  • the capillary acceleration sheet comprises a fraction of fibres having an average diameter which is at least 10% lower than an average diameter of the fibres of the liquid pervious topsheet, preferably at least 20% lower than an average diameter of the fibres of the liquid pervious topsheet.
  • the topsheet has a basis weight between 10 and 30 g/m2, preferably between 15 and 25 g/m2.
  • the fibres of the topsheet have an average fineness between 1-3 dtex.
  • the topsheet is any one of the following: a spunbond nonwoven, a through air bonded carded web (TABCW).
  • TABCW through air bonded carded web
  • the through air bonded carded web comprises polyethylene/polypropylene bi-component staple fibres.
  • At least a portion of the topsheet is bonded to the capillary acceleration sheet, preferably at least in a portion of the one or more channels.
  • the capillary acceleration sheet extends over at least 15%, preferably at least 20%, more preferably at least 45% of an upper surface area of the bottom core wrap; and/or the capillary acceleration sheet extends over at least 25%, preferably at least 30%, more preferably at least 35% of a length of the bottom core wrap; and/or wherein the capillary acceleration sheet extends over at least 25%, preferably at least 30%, more preferably at least 35% of a width of the bottom core wrap.
  • the bottom core wrap has a first and second longitudinal edge and a first and second transverse edge and the at least one channel comprise at least one elongate channel extending from a crotch region in the direction of the first and/or second transverse edge.
  • This elongate channel may then comprise the first and second attachment zone of the first aspect or the attachment zone of the second aspect.
  • Such channels will allow a good liquid distribution by mass flow between the first and second transverse edge.
  • the first and second channel width in accordance with the first aspect or the channel width in accordance with the second aspect is at least 4 mm, preferably at least 6 mm, more preferably at least 8 mm, most preferably at least 9 mm, e.g. between 10 mm and 20 mm or between 12 mm and 20 mm.
  • the channel width may be constant through substantially the whole length of the channel portion or may vary along its length. When the width varies along the length, then the above specified channel width values apply for the average width of the respective channel portion.
  • the at least one channel comprise a first channel and a second channel portion which extend next to each other and are each extending in the direction of a first and/or second transverse edge of the bottom core wrap.
  • the first and second channel portion each comprise a first and second attachment zone as defined in accordance with the first aspect or an attachment zone as defined in accordance with the second aspect.
  • the capillary acceleration sheet at least partially covers the first and second channel. In that manner, the capillary acceleration sheet can suck liquid towards the two channels portions.
  • the distance, measured at a front edge, between the first and the second channel portion is between 10 mm and 50 mm, e.g. between 15 mm and 30 mm; and/or the length of the first and the second channel is larger than 60 mm, preferably larger than 70 mm.
  • Such dimensions will typically result in a good distribution. The skilled person understands that the dimensions will be dependent on the size of the absorbent article, and thus one the size of the bottom core wrap.
  • the at least one channel further comprise a third and a fourth channel portion located at a distance of each other preferably connected to the first and second channel portion, respectively, said third and fourth channel portion each extending in the direction of the first and/or second transverse edge.
  • the capillary acceleration sheet at least partially covers the third and fourth channel.
  • the distance between the first and the second channel is different from the distance between the third and the fourth channel.
  • the distance between the first and the second channel portion is between 20 mm and 50 mm, and, measured at a rear edge the distance between the third and the fourth channel is between 10 mm and 30 mm.
  • the bottom core wrap sheet has a front portion extending at one side of a transverse crotch line and a rear portion extending at the other side of the transverse crotch line; wherein the first and second channel portion extend at least in the front portion of the bottom core wrap sheet; and wherein the third and fourth channel portion extend at least in the rear portion of the bottom core wrap sheet.
  • the distance between the first and the second channel portion is smaller than the distance between the third and the fourth channel portion.
  • a position and/or shape of the at least one channel is indicated by means of a distinguishable colour and/or coloured pattern, e.g. by a printed ink layer.
  • the distinguishable colour and/or coloured pattern may be provided on at least one of the topsheet, the capillary acceleration sheet, the backsheet and the bottom core wrap.
  • the at least one channel together extend over a channel length which is at least 20 %, preferably at least 30%, preferably at least 40%, more preferably at least 50% of a length of the absorbent core.
  • the at least one channel and the capillary acceleration sheet are arranged symmetrically with respect to a longitudinal centre line of the bottom core wrap.
  • the absorbent material comprises cellulosic fluff pulp made up of cellulose fibres and superabsorbent particles.
  • the fibres can be natural or synthetic.
  • the absorbent material is substantially fluffless.
  • absorbent material refers to a material that is applied in bulk, i.e. a 3D absorbent material, i.e. not as a sheet.
  • the absorbent material may comprise more than 20 weight% superabsorbent particles or more than 40 weight% superabsorbent particles or more than 60 weight% superabsorbent particles, or more than 80 weight% superabsorbent particles.
  • the absorbent material may also be fluffless, i.e. with substantially without cellulose fibres.
  • a method for manufacturing an absorbent article comprising the steps of providing a liquid pervious topsheet and a liquid impervious backsheet; arranging an absorbent material comprising at least one of superabsorbent particles and cellulosic fluff pulp, between a bottom core wrap sheet and a top core wrap sheet, such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to areas around the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel; and arranging the liquid pervious topsheet at the side of top core wrap sheet and the liquid impervious backsheet at the side of the bottom core wrap sheet.
  • Figures 1-5 illustrate top views of various embodiments of absorbent cores for an absorbent article
  • Figure 6 is a schematic cross-section of an exemplary embodiment of an absorbent article with an absorbent core
  • figures 7A and 7B are cross-sections of exemplary embodiments of an absorbent article with an absorbent core
  • figure 7C is a detailed view of the bottom core wrap of figure 7B;
  • Figures 8A-8B are schematic top views of the absorbent core of the exemplary embodiments of figures 6 and 7A, respectively;
  • Figures 9-16 are schematic top plan views of exemplary embodiments of a diaper
  • Figure 17 is a schematic top plan view of another exemplary embodiment of a diaper with four channels.
  • Figure 18 is a perspective view of an exemplary embodiment of a diaper in the wetted state
  • Figure 19 illustrates schematically an exemplary embodiment of a method and apparatus for manufacturing an absorbent article
  • Figure 21 A and 21B illustrate an embodiment of a channel, as seen in a cross section, in a dry state and in a wet state, respectively.
  • a first channel 1000 comprises a first channel portion 140 extending in a longitudinal direction L of the absorbent core 100, here in a front portion of the absorbent core 100, a second channel portion 180 extending at an angle with respect to the first channel portion 140, and a further channel portion 160 extending in a longitudinal direction L of the absorbent core.
  • the first channel portion 140 is connected to a first end, here a front end, of the second channel portion 180 and the further channel portion 160 is connected to a second opposite end, here a rear end, of the second channel portion 180.
  • the first and second channel 1000, 2000 are arranged so as to be mirror images relative to a longitudinal central axis A of the absorbent core 1000.
  • the second channel 1000 comprises a first channel portion 150 extending in a longitudinal direction L of the absorbent core 100, here in a front portion of the absorbent core 100, a second channel portion 190 extending at an angle with respect to the first channel portion 150, and a further channel portion 170 extending in the longitudinal direction L of the absorbent core 100.
  • the second channel 2000 will not be described in detail below as its properties are identical to the properties of the first channel 1000 except from being mirrored with respect to the first channel 1000.
  • the first channel portion 140 has a first channel width wcl seen in a transverse direction of the absorbent core.
  • the first channel portion 140 comprises a first attachment zone 145 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120.
  • the first attachment zone 145 has a first attachment width wbl seen in the transverse direction T.
  • the second channel portion 180 has a second channel width wc2 seen in a direction perpendicular on a center line C of the second channel portion 180.
  • the second channel portion 180 comprises a second attachment zone 185 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120.
  • the second attachment zone 185 has a second attachment width wb2 seen in the direction perpendicular on the center line C of the second channel portion 180.
  • the further channel portion 160 has a further channel width wcf seen in a transverse direction T of the absorbent core and comprises a further attachment zone 165 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120.
  • the further attachment zone 165 has a further attachment width wbf seen in the transverse direction T.
  • a first ratio wbl /wcl of the first attachment width relative to the first channel width is larger than a second ratio wb2/wc2 of the second attachment width relative to the second channel width.
  • the second attachment width wb2 is less than 80% of the channel width wc2 (wb2 ⁇ 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
  • the top core wrap sheet 110 is attached to the bottom core wrap sheet 120 by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy.
  • the sealing is only applied in the attachment zones 145, 185, 165 and not in the full area of the channel 1000.
  • the first, second and further channel width wcl, wc2, wcf may be substantially the same, meaning that the difference between those values is less than 10% of wcl. However, those values may also be different.
  • the first channel width wcl could be larger than wcf to allow more liquid mass flow in the front side of the absorbent core 100.
  • wc2 could be larger than wcl and/or wcf so as to be able to increase the attachment width wb2.
  • the second channel portion 180 is a straight portion, but this could also be a curved portion interconnecting the first and further channel portions 140, 160.
  • the first and second channel 1000, 2000 each have a length Lc measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length of the absorbent core, preferably at least 30% of the length of the absorbent core La.
  • the first, second and further attachment zone 145, 185, 165 include the same type of attachment, here an attachment by sealing, optionally in combination with gluing. If a combination of sealing and gluing is used, an adhesive might also be applied outside of the first, second and further attachment zone 145, 185, 165. In another embodiment, only gluing is used and a certain type of adhesive is only applied in the first, second and further attachment zone 145, 185, 165.
  • each of the first, second and further attachment zone 145, 185, 165 may comprises a plurality of discrete bonding spots.
  • Each attachment zone 145, 185, 165 may be considered to be delimited by a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and straight lines interconnecting said adjacent peripheral bonding points or edges.
  • this pattern may simply continue at an edge between adjacent attachment zones, resulting in a combined attachment area 145, 185, 165 with a regular sealing pattern.
  • the sealing pattern may be a regular pattern, such as a line pattern or a pattern of dots and/or the sealing pattern may comprise a large number of distinct sealing areas, such as dots or lines, spread across the first, second and further attachment zones, wherein the large number is larger than 10 and/or the sealing pattern may comprise a plurality of discrete elements, and wherein each element has a first dimension in a first direction and a second dimensions in a direction perpendicular to the first direction, wherein the first dimension is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm.
  • the first, second and further attachment zones are permanent attachment zones.
  • the first, second and further channel width wcl, wc2, wcf is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
  • an average length lb of the first attachment zone 145 is smaller than an average length 1c of the first channel portion 140.
  • an average length of the further attachment zone 165 may be smaller than an average length of the further channel portion 140. In this way, also the first and further attachment zones 145, 165 will allow some misalignment whilst still being within the area of the channel 1000’.
  • the first attachment width wbl is less than 90% of the first channel width wcl, preferably less than 80%, more preferably less than 70%, and more than 25%.
  • FIG. 2 illustrates a second embodiment which is similar to the embodiment of Figure 1 and the same or similar parts have been indicated with the same reference numeral and will not be described again.
  • the interconnected channel (1000’) comprises the first, second and further channel portion 140, 180, 160.
  • the first channel portion 140 extends along a longitudinal central axis A of the absorbent core 100, here mainly in the rear part of the absorbent core 100 but the structure could also be inverted.
  • the second channel portion 180 is connected to the first channel portion 140 and diverges away from the longitudinal central axis A.
  • the interconnected channel 1000’ comprises a third channel portion 190 which is arranged to be a mirror image of the second channel portion 180 relative to the longitudinal central axis A of the absorbent core 100, said third channel portion having a third attachment zone and having identical properties as the second channel portion 180.
  • the interconnected channel 1000’ comprises a second further channel portion 170 which is arranged to be a mirror image of the further channel portion 160 relative to the longitudinal central axis A of the absorbent core 100, said second further channel portion 170 having identical properties as the further channel portion 160.
  • the first channel portion 140 is connected to a first end, here a rear end, of the third channel portion 190 and the second further channel portion 170 is connected to a second end, here a front end, of the third channel portion 190.
  • the interconnected channel 1000’ has a length Lc measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length La of the absorbent core, preferably at least 30% of the length of the absorbent core.
  • the embodiment of Figure 4 is similar to the embodiment of Figure 3 and the same or similar parts have been indicated with the same reference numeral and will not be described again.
  • the curved second channels portions 180, 190 join at their front ends and are connected to a single further channel portions 160 which extends along the central axis A of the absorbent core 100.
  • the embodiment of Figure 5 shows some similarity to the embodiment of Figure 1 and the same or similar parts have been indicated with the same reference numeral and will not be described again.
  • the channels 1000, 2000 are curved over their entire length and each contain a single attachment zone 185 having a reduced attachment width wb2.
  • the attachment width wb2 is less than 80% of the channel width wc2 (wb2 ⁇ 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
  • Figures 6 and 8A show a cross section and top view of an exemplary embodiment of an absorbent article comprising with an absorbent core 100 similar to the embodiment of Figure 1 with multiple channel portions 140, 150, 160, 170, 180, 190.
  • the upper side of the absorbent article generally has a topsheet 300 that can be liquid pervious (not shown in figure 8 A for clarity reasons).
  • the lower side has a backsheet 200 (not shown in figure 8A for clarity reasons) that can generally be liquid impervious and is joined with the topsheet 300 at the edges of the absorbent article (not shown). In some embodiments of adult incontinence products, the topsheet 300 and the backsheet 200 are not joined at the edges.
  • An absorbent core 100 is positioned between the topsheet 300 and the backsheet 200.
  • the absorbent core 100 comprises absorbent material 130 arranged between a bottom core wrap sheet 120 and a top core wrap sheet 110, in such a manner that one or more channels 1000, 2000 with channel portions 140, 150, 160, 170, 180, 190 are formed, wherein less absorbent material 130 per surface area is present in the one or more channels 1000, 2000 compared to an area around the one or more channels.
  • An acquisition and distribution layer (ADL) 600 is provided at the top of the absorbent core 100, beneath the topsheet 300.
  • the topsheet 300, the backsheet 200, and the absorbent core 100 can be assembled in a variety of well-known configurations.
  • the topsheet 300 and the backsheet 200 can be joined to each other by adhesive, by heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, a crimp seal, or by any other suitable securing method.
  • the ADL 600 is typically a relatively thick layer (basis weight above 50 g/m 2 ) and comprises a coarse fibre.
  • a liquid-impermeable, either hydrophilic or hydrophobic, distribution or wicking layer 700 is included between the absorbent core 100 and the backsheet 200. This distribution or wicking layer 700 helps to wick and transport liquids and having a capability to disperse the liquid over the surface of said wicking layer from the less absorbent area’s (e.g.
  • the liquid in the one or more channels will be drawn up into the distribution layer and will spread out throughout the rest of the distribution layer. In that way, the distribution, transport and absorption of the liquid can be improved.
  • the capillary acceleration sheet 400 may take on any suitable shape.
  • the capillary acceleration sheet 400 may follow more or less the contours of the absorbent core 100.
  • the capillary acceleration sheet may comprise a rectangular shape regardless of the shape of the absorbent core 100.
  • the capillary acceleration sheet may be longer in length than the absorbent core 100 or shorter than the absorbent core 100.
  • the capillary acceleration sheet 400 may be positioned in a specific location on the absorbent core 100.
  • the through air bonded carded web comprises polyethylene/polypropylene bi-component staple fibres.
  • “Bonded carded web” refers to webs that are made from staple fibres that are sent through a combing or carding unit, which breaks apart and aligns the staple fibres in the machine direction to form a generally machine direction-oriented fibrous nonwoven web. This web may then be drawn through a heated drum, creating bonds throughout the fabric without applying specific pressure (through air bonding process).
  • the “Through air bonded carded web”, TABCW material provides a relatively low density, lofty web.
  • the topsheet has a basis weight between 10 and 30 g/m 2 , preferably between 15 and 25 g/m 2 .
  • the fibres of the topsheet have an average fineness between 1-3 dtex.
  • Lofty apertured formed film topsheets with appreciable topsheet texture (nubs, microtexture or with filament-like protrusions on the body-facing surface that can trap bodily discharges and hinder low fluid flows towards the body) that may be hydrophobic or hydrophilic in nature, can also be used.
  • topsheet 300 directly or indirectly to the underlying capillary acceleration sheet 400.
  • These layers may be bonded by any known bonding means, such as slot gluing, spiral gluing, fusion point bonding, sealing according to a sealing pattern, or otherwise attached.
  • a distribution layer may be present between the absorbent core 100 and the capillary acceleration sheet 400. However, preferably no distribution layer is present between the capillary acceleration sheet 400 and the absorbent core 100.
  • the function of a distribution layer is to spread the insulting fluid liquid over a larger surface within the article so that the absorbent capacity of the absorbent core 100 can be more efficiently used.
  • the distribution layer is made of a nonwoven material based on synthetic or cellulosic fibres and having a relatively low density.
  • Figure 7C illustrates in more detail a possible bottom core wrap 800 comprising a first layer 801 and a second layer 802, wherein said first layer has a first density between 20 and 150 kg/m3 and said second layer has a second density between 100 and 400 kg/m3, said second density being higher than the first density.
  • the first layer 801 is closer to the absorbent material 130 than said second layer 802 which faces the backsheet 200.
  • the absorbent article of figure 7B may comprise a capillary acceleration sheet 400 and/or a top core wrap 110. As shown the capillary acceleration sheet 400 and/or the top core wrap 110 may be attached through the first layer 801 to the second layer 802 of the bottom core wrap 800 in the channel areas 160, 170.
  • the topsheet 300 and/or the backsheet 200 may be attached at least in a portion of the channels 1000, 2000 to the bottom core wrap 800 (not shown).
  • the bottom core wrap 800 is attached along a periphery to the bottom core wrap 110 and/or the capillary acceleration sheet 400.
  • the bottom core wrap may be glued and/or sealed to the top core wrap 110 and/or the capillary acceleration 400 at least in a portion of the one or more channels.
  • the bottom core wrap 800 may consist of a single sheet.
  • the bottom core wrap 800 is in direct contact with the superabsorbent particles of the absorbent material 130.
  • a difference between the first and the second density is higher than 20 kg/m3, preferably higher than 30 kg/m3 more preferably higher than 40 kg/m2, even more preferably between 50 and 150 kg/m3, most preferably between 60 and 140 kg/m3.
  • the second density is selected such that it forms a barrier for the super absorbent particles.
  • the bottom core wrap 800 is a through-air bonded non-woven.
  • the first layer 801 is a through-air-bonded carded non-woven and the second layer 802 is a spunbond layer.
  • the first layer 801 has a first basis weight and the second layer 802 has a second basis weight, said second basis weight being lower than said first basis weight.
  • the difference between the first layer and the second layer may be larger than 1 g/m2, preferably larger than 2 g/m2, more preferably larger than 5 g/m2.
  • the first layer may have a first basis weight between 15 and 80 g/m2, preferably between 25 and 80 g/m2, and/or the second layer may have a second basis weight between 8 and 35 g/m2, preferably between 8 and 25 g/m2.
  • the first layer and/or the second layer comprise more than 90weight% of synthetic fibres, preferably more than 95weight% of synthetic fibres.
  • the first layer comprises polyester fibres
  • the second layer comprises any one of the following fibres or a combination thereof: polyethylene, polyester, copolyester, polypropylene, polyactic acid (PL A).
  • the attachment between the top core wrap sheet 110 and the bottom core wrap sheet 800 may be a continuous or discontinuous attachment.
  • the top core wrap sheet 110 may be attached to the bottom core wrap 800 along a portion of the one or more channels 1000, 2000 with optionally one or more unattached portions being present between attached portions.
  • the one or more channels 1000, 2000 may comprise one or more permanent attachment portions which remain attached after wetting and/or one or more semi-permanent attachment portions which detach after wetting and/or one or more unattached portions.
  • An unattached portion or a semi-permanent attachment portion allows for an increased swelling of the absorbent material 130 after the one or more channels 1000, 2000 have fulfilled their function of distributing the liquid. Indeed, wet absorbent material 130 is allowed to extend/swell into a portion of the channel area 1000, 2000 in case of an unattached or detached portion.
  • the capillary acceleration sheet 400 covers entirely the one or more channels 1000, 2000. Such an arrangement leads to a substantial improvement in the distribution of fluids over the complete absorbent core 100. Nevertheless, other arrangements also provide a good distribution of liquids.
  • the capillary acceleration sheet 400 may only partially overlap with the one or more channels 1000, 2000 or may be located between two longitudinal channels or between two lateral channels.
  • the one or more channels may extend in a front portion of the absorbent core 100 beyond a front edge of the capillary acceleration sheet 400 and/or in a rear portion of the absorbent core 100, beyond a rear edge of the capillary acceleration sheet 400. Because the capillary acceleration sheet 400 does not cover a front and/or rear end of the one or more channels, fluid in-flow and/or fluid out-flow may be increased.
  • Figure 9 illustrates an exemplary embodiment of an absorbent article with an absorbent core 100 with a single channel 1000’ with a first channel portion extending in a longitudinal direction of the absorbent core 100 and a second and third channel portion extending at an angle, similarly to the embodiment of Figures 2 and 3.
  • the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
  • the channel 1000’ extends over at least 20% of the length of the absorbent core 100, more preferably at least 30%, even more preferably at least 40%.
  • the capillary acceleration sheet 400 may be attached to the bottom core wrap 800 through one or more permanent or semi-permanent attachment portions.
  • the semi-permanent portions may be configured to release after having been in contact with liquid whilst said permanent portions may be configured not to release after having been in contact with liquid. It is noted that different types of semi-permanent attachment portions may be used in the same absorbent article so as to achieve a gradual loosening of the attachments upon wetting.
  • the absorbent material in the absorbent core 100 preferably comprises cellulosic fluff pulp and/or superabsorbent particles. However, the absorbent material may be substantially fluffless.
  • substantially no absorbent material is present in the channel 1000’.
  • a position and/or shape of the channel 1000’ may be indicated by means of a distinguishable colour and/or coloured pattern.
  • a position and/or shape of the channel 180 may be indicated by means of a printed ink layer.
  • the distinguishable colour and/or coloured pattern may be provided on at least one of the topsheet, the top core wrap, the capillary acceleration sheet 400, the backsheet and the bottom core wrap.
  • the absorbent core has a maximum thickness and the channel 1000’ extends through at least 90 % of the maximum thickness of the absorbent core, more preferably through substantially 100% of the thickness of the absorbent core 100 such that in the first and second attachment zone substantially no absorbent material is present between the capillary acceleration sheet 400 and the bottom core wrap.
  • the attachment between the capillary acceleration sheet 400 and the bottom core wrap sheet is any one of the following or a combination thereof: pressure bonding, thermal bonding, sonic bonding, chemical bonding, adhesive.
  • the attachment may be a direct or indirect attachment.
  • an adhesive and/or other intermediate material may be inserted between the capillary acceleration sheet 400 and the bottom core wrap.
  • Figure 10 and figure 11 illustrate exemplary embodiments with two channels 1000, 2000.
  • the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
  • the absorbent core 100 has a first and second longitudinal edge and a first and second transverse edge and the channels 1000, 2000 are elongate channels extending from a crotch region in the direction of the first and second transverse edge.
  • the channels 1000, 2000 may comprise one or more channel portions 140, 180 and associated attachment zones 145, 185 as discussed in connection with Figures 1-5.
  • the one or more attachment zones are formed by any one of the following or a combination thereof: pressure bonding, thermal bonding, sonic bonding, chemical bonding, adhesive.
  • the channels 1000, 2000 may comprise any one or more of the following: one or more permanent attachment zones, one or more semi-permanent attachment zones configured to release after having been in contact with liquid, one or more unattached zones.
  • the channels 1000, 2000 extend next to each other and are each extending in the direction of a first and/or second transverse edge.
  • the capillary acceleration sheet 400 at least partially covers both channels 1000, 2000.
  • the capillary acceleration sheet 400 partially covers the channels 1000, 2000, whilst in Figure 11 the channels are fully covered.
  • the distance between the channels 1000, 2000 is between 10 mm and 50 mm, preferably between 15 mm and 30 mm; and the length of the first and the second channel is larger than 60 mm, preferably larger than 70 mm.
  • the absorbent core 100 has a front portion extending at one side of a transverse crotch line and a rear portion extending at the other side of the transverse crotch line.
  • the front portion corresponds with an upper portion of the absorbent core 100
  • the front portion 100a corresponds with the lower portion of the absorbent core 100.
  • Figure 12 and Figure 18 illustrate another embodiment with two channels 1000, 2000 similar to the embodiment of Figure 1.
  • the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
  • the channel portions 160, 170 are located at a distance of each other.
  • the capillary acceleration sheet 400 may covers all four channel portions 140, 150, 160, 170.
  • the distance between the channel portion 140, 150 is different from the distance between the channel portions 160, 170.
  • the channel portions 140, 150 extend at least in the front portion 100a of the absorbent core 100, and the channel portions 160, 170 extend at least in the rear portion 100b of the absorbent core 100, wherein preferably the distance between the channel portions 140, 150 is bigger than the distance between the channel portions 160, 170.
  • the channel portion 140 is connected to the channel portion 160 through a channel portion 180 and the channel portion 150 is connected to the channel portion 170 through a channel portion 190.
  • the channel portions 140, 150, 160, 170, 180, 190 comprise permanent attachment zones.
  • the channel portions 140, 150 extend longitudinally between respective ends 141, 142, 151, 152, and the channel portions 160, 170 extend longitudinally between respective ends 161, 162, 171, 172.
  • the absorbent core 100 has a front edge 133, a rear edge 134, and opposite longitudinal side edges 131, 132 which define an area Al.
  • the absorbent material 130 is deposited in an area A2 within the area Al.
  • the length and width of the absorbent core refer to the length La and width Wai, Wa2 of the area A2.
  • the area A2 may be slightly smaller than the area Al.
  • a position and/or shape of one or more channels is indicated by means of a distinguishable colour and/or coloured pattern, e.g. by a printed ink layer, wherein preferably the distinguishable colour and/or coloured pattern is provided on at least one of the topsheet, the capillary acceleration sheet 400, the backsheet and the bottom core wrap.
  • the channels and the capillary acceleration sheet 400 are arranged symmetrically with respect to a longitudinal centre line of the bottom core wrap.
  • the channel portions 140, 150 may extend over a length 11 which is less than the length 13 of the channel portions 160, 170.
  • the channel portions 160, 170 which are closer to each other may be longer to extend over a longer part of the crotch region, for example the channel portions 160, 170 may extend both in the front and the rear portion 100a, 100b of the absorbent core 100.
  • the channel portions 140, 150 extend over a length 11 which is at least 5% less, more preferably at least 10% less than the length 13 of the channel portions 160, 170.
  • the channel portions 140, 150 extend over a length 11 which is at least 25%, more preferably at least 35%, even more preferably at least 45% of the length 13 of the channel portions 160, 170.
  • the first and second channels comprise permanent attachment zones which remain attached upon wetting, or semi-permanent attachment zones configured to release after having been in contact with liquid for a predetermined period of time, wherein said predetermined period of time is preferably smaller than 30 s.
  • the at least one connecting channel 1045, 1045’ comprises any one or more of: a permanent attachment portion which remains attached upon wetting, a semi-permanent attachment portion configured to release after having been in contact with liquid for a predetermined period of time, wherein said predetermined period of time is preferably smaller than 30s, and unattached portion.
  • Attachment portion/zone refers to a portion/zone where the capillary acceleration sheet 400 and/or the top core wrap is attached to the bottom core wrap.
  • the channel portions 140, 150 are substantially parallel and extend in a longitudinal direction of the absorbent core 100 and second channel portions 180, 190 may diverge in the direction of the front edge of the absorbent core 100, see Figure 13.
  • the second channel portions 180, 190 may be implemented as described in connection with Figures 1-5.
  • the largest distance between the channel in the transverse direction is between 15 and 70% of the width of the absorbent core, more preferably between 20 and 50%; wherein preferably the largest distance between the first and the second channel in the transverse direction is between 10 mm and 100 mm, more preferably between 20 mm and 80 mm, even more preferably between 30 mm and 70 mm.
  • Figure 15 illustrates an embodiment with an X-shaped channel area.
  • the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
  • channel portions which are crossing the longitudinal center line upon wetting of the absorbent core 100, liquid is guided in the first and/or second elongate channel from left to right and/or from right to left, respectively, whilst flowing towards the crotch region or away from the crotch region, improving the liquid distribution, whereupon the liquid can be absorbed by the absorbent material.
  • the channel portions may be longer compared to similar channel portions extending parallel to the longitudinal center line, resulting in a larger liquid distribution zone.
  • the channel portions 180, 190 extend both in the front portion and in the rear portion. In that manner a good liquid distribution from left to right and from front to rear can be obtained.
  • the first elongate and the second elongate channels are arranged symmetrically with respect to the longitudinal center line of the absorbent core.
  • a maximum distance between the elongate channel portions 180, 190 is between 15 and 70% of the width of the absorbent core, more preferably between 20 and 50%.
  • a maximum distance between the channel portions in the front portion is different from a maximum distance between the channel portions in the rear portion.
  • the liquid distribution zone may be better adapted to the type of person wearing the absorbent article. For example, for a male person, a maximum distance between the distance between the channel portions near a front transverse edge may be larger than a maximum distance between the channel portions in a rear portion.
  • the length of the channel portions 180, 190 is larger than 10% of the length of the absorbent core, more preferably larger than 30%, even more preferably larger than 50%.
  • the channel portions together form a substantially X-shaped zone.
  • the legs of the “X” may be interrupted to create one or more bridging zones.
  • Figure 16 illustrates an embodiment of an absorbent article with an absorbent core 100 comprising channel portions 140, 150, 160, 180, 190 similar to the embodiment of Figure 2.
  • the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
  • the channels comprise second channel portions 140, 150 similar to the channel portions of Figure 2, and a channel portion 160 extending from the crotch region in the direction of the second transverse edge, wherein seen in a projection on a transverse direction the channel portion 160 is located between the channel portions 140, 150.
  • a channel portions 140, 150 in the front or rear portion and a channel portion 160 in the rear or front portion, respectively, it is possible to tailor the absorbent article to the wearer.
  • the channel portions 140, 150 may be in the front portion and the channel portion 160 may be in the rear portion
  • the channel portions 140, 150 may be in the rear portion and the channel portion 160 in the front portion.
  • the channel portions 140, 150 may extend over a length which is less than the length of the channel portion 160.
  • the channel portion 160 may be longer to extend over a longer part of the crotch region, for example the channel portion 160 may extend both in the front and the rear portion of the absorbent core.
  • the channel portions 140, 150 extend over a length which is at least 5% less, more preferably at least 10% less than the length of the channel portion 160.
  • the first and the second channel extend over a length which is at least 25%, more preferably at least 35%, even more preferably at least 45% of the length of the channel portion 160.
  • each channel portion has a width, said width being at least 5% of the width (varies between Wai and Wa2 in the embodiment of Figure 17) of the absorbent core 100, preferably at least 7%, e.g. at least 10%, e.g. at least 15% or even at least 20%.
  • the channel width may be between 9 and 20 mm and the width of the absorbent material deposition area A2 (indicated in Figure 17) may be between 80 and 200 mm, e.g. between 90 and 150 mm.
  • the width of each channel is less than 30% of the width of the absorbent core, e.g. less than 25%.
  • the width of the absorbent core is measured in a transverse direction of the absorbent core, in an area where the respective one or more channels are present, between two end points where absorbent material is present, i.e. the width of the absorbent core is defined as the width of the absorbent material deposition area A2 of the absorbent core 100.
  • the top core wrap sheet and/or the back core wrap sheet may extend in an area Al over a width Wa’ (as indicated in Figure 17) which is larger than the width of the absorbent core and a length La’ which is larger than the length of the absorbent core, as they may be attached along a periphery where no absorbent material is present.
  • the width of the absorbent core may vary between a minimum width and a maximum width (varies between Wai and Wa2 in the embodiment of Figure 17; not indicated in the other figures but may vary in a similar way or may be constant or may vary in a different way), and preferably the above specified minimum width of each channel is valid both for the minimum and the maximum width of the absorbent core.
  • the absorbent material deposition area A2 may thus have a width which varies e.g. between a value above 100 mm and a value below 100 mm. Preferably the difference is at least 5 mm.
  • a width Wai of the absorbent material deposition area measured at a front end of the absorbent core 100 may be above 100 mm, or even above 105 mm and a width Wa2 measured at a rear end of the absorbent core 100 may be below 100 mm, or even below 95 mm.
  • the width wc of the channel may be constant through substantially the whole length of a channel portion (as shown in the Figures) or may vary along its length. When the width varies along the length, then the above specified width percentages and values apply for the average width of the respective channel.
  • the one or more channel portions are formed by one or more absorbent material-free zones within the absorbent material deposition area of the absorbent core, and the width of a channel is considered to be the width of the material-free zone, disregarding the possible presence of core wrap within the channel.
  • the absorbent core periphery which may be the periphery of the top/bottom core wrap, may define any suitable shape, such as a "T,” “Y,” “hour-glass,” or “dog-bone” shape, for example.
  • a “T shape may have a larger width in the front portion than in the rear portion of the absorbent core.
  • An absorbent core periphery having a generally “dog bone” or “hour-glass” shape may taper along its width towards the middle or "crotch” region of the core. In this way, the absorbent core may have a relatively narrow width in an area of the absorbent core intended to be placed in the crotch region of an absorbent article.
  • the one or more channels cover together at least 20%, preferably at least 30 %, more preferably at least 40%, more preferably at least 50%, e.g. at least 60%, or at least 70%, or 80% or at least 90% of a total length La of the absorbent core.
  • the covered length may be realized with a single channel or with a combination of two or more channels. This will allow a good distribution over the entire absorbent core as well as a good formation of the channels/embankments and will give the absorbent article a tub-shape upon swelling of the absorbent core.
  • the length of the absorbent core is defined as the length La of the absorbent material deposition area A2 indicated in Figure 17.
  • the length la of the bottom core wrap and/or of the top core wrap may be slightly larger than the length 1 of the absorbent material deposition area A2.
  • the absorbent article 100 may further comprise a wetness indicator preferably placed between two channels and/or in one or more channels and/or between a channel and an edge of the absorbent core.
  • the wetness indicator may change appearance when contacted with liquid, e.g. the wetness indicator may be configured to generate a colour change signal that changes appearance when contacted with liquid.
  • the wetness indicator may comprise a composition that changes appearance when contacted with liquid, in particular a composition comprising a pH indicator and/or a water soluble dye.
  • the composition may comprise a stabilizer, a colorant, and a matrix.
  • Figure 19 illustrates an embodiment of a method for manufacturing an absorbent article.
  • the method comprises in a first step guiding a first sheet material 110, 400 along an optional guide roller 5, and further along a rotating member 10, wherein a surface 15 of said rotating member 10 is provided with a pattern with suction zones 13, 13’ and non-suction zones 11, 12; 11’, 12’.
  • the first sheet material 110, 400 is shown in a transparent manner to reveal the suction and non-suction zones of the rotating member 10.
  • the suction zones 13, 13’ may be provided with holes, and the non-suction zones 11, 12; 11’, 12’ are formed of closed material.
  • the non-suction zones 11, 12; 11’, 12’ may be provided with inserts.
  • the inserts 11, 12; 11’, 12’ may have a trapezoidal cross section.
  • Figure 16 shows an insert pattern with four non-suction zones per absorbent core, but it will be understood that the number of inserts depends on the number of channels to be realized.
  • the inserts may be fixed e.g. with screws on the rotating member 10.
  • a vacuum is applied, see VACUUM 1.
  • the non-suction zones 11, 12; 11’, 12’ comprise at least a first elongate zone 11, 11’ and a second elongate zone 12, 12’ extending in a circumferential direction of the rotating member 10.
  • an absorbent material F is applied via a hopper 40 on said first sheet material 110, 400 on the rotating member 10 such that the suction zones 13, 13’ are covered with absorbent material and substantially no absorbent material is present on the non-suction zones 11, 12; 11’, 12’.
  • a second sheet material 800 is applied on top of the absorbent material on the first sheet material 110, 400, e.g. using a further rotating member 20.
  • the first sheet material 110, 400 may be a combination of the capillary acceleration sheet material 400 and the top core wrap material 110, and the second sheet material 800 may be bottom core wrap.
  • the second sheet material is a combination of the top core wrap material and the capillary acceleration sheet material
  • the first sheet material may be the bottom core wrap.
  • the first sheet material 110 is attached to the second sheet material 800 at least in the areas where substantially no absorbent material is present, and such that one or more channels are formed.
  • the attaching may be done by applying pressure and/or heat and/or ultrasonic energy on the sandwich formed by the first sheet material 110, 400 and on the second sheet material 800, especially in the one or more channels where substantially no absorbent material is present, e.g. by a rotating member 30 and/or opposite rotating member 30’ which is provided with at least a first and a second seal rib or bar 31, 32 dimensioned for applying pressure and heat in the areas where substantially no absorbent material is present in order to create the channels, respectively.
  • the capillary acceleration sheet 140, the bottom core wrap 800 and the top core wrap 110 may have any one of the features described above or described in the summary.
  • the first sheet material and the second sheet material may be additionally attached using a binder, such as glue, to strengthen the bond between the first and second sheet material.
  • a binder such as glue
  • gluing may be performed as described in patent EP 3 453 368 Bl in the name of the applicant, which is included herein by reference.
  • the capillary acceleration sheet material 400 may also be first laminated, e.g. adhered, to a topsheet material, and the combination of the capillary acceleration sheet 400 and the topsheet may then be arranged against the top core wrap 110, wherein optionally the capillary acceleration sheet 400 may be glued to the top core wrap 110.
  • Figures 20A-E illustrate an example of a set of sealing bars 31 , 31’ , 31” having a first sealing pattern.
  • the sealing bars 31, 31’, 31” may be intended to seal portions of e.g. channels 1000, 2000.
  • the sealing bars 31, 31’, 31” comprise respective sealing portions 145’, 165’, 185’ intended to seal permanent attachment zones 145, 165, 185 of a channel 1000.
  • These permanent attachment zones 145, 165, 185 are smaller than the area of the channel 1000, as described in connection with Figure 1.
  • further respective sealing portions 147’, 167’, 187’ intended to create semi-permanent attachment zones around the permanent attachment zones 145, 165, 185 may be provided.
  • Such further respective sealing portions may have a height which is lower than the height of sealing portions 145’, 165’, 185’ such that less pressure is applied.
  • the temperature of the further respective sealing portions may be controlled during sealing such that it is lower than the temperature of sealing portions 145’, 165’, 185’.
  • Such measures will allow to generate a permanent attachment zone surrounded by a semi-permanent attachment zone which is such that it releases upon wetting.
  • one or more sealing bars may be used in accordance with the one or more channels to be sealed.
  • a detail of the sealing pattern is visible in the top view of figure 20B and in figure 20D which illustrates the areas where sealing will take place.
  • the sealing pattern is a regular pattern of square shaped dots 3000.
  • FIG 20E shows a cross section and illustrates that the dots are achieved by protrusions 1010.
  • Each protrusion 1010 preferably has a flat top surface forming a dot 3000 of the sealing pattern, and an inclined peripheral surface. If an absorbent particle were to be present near the flat top surface it can easily migrate in a recess delimited by the inclined peripheral wall.
  • the sealing pattern (i.e. the total surface area of the dots 3000) covers less than 80%, preferably less than 70%, more preferably less than 60%, even more preferably less than 50%, most preferably between 1 and 50% of the surface area of the one or more channels.
  • the sealing pattern covers between 1 and 50% of the total surface area of the one or more channels, or between 1 and 40%, or between 1 and 30%, or between 1 and 25%, or between 2 and 25%, or between 3 and 25%, or between 4 and 25%.
  • Such sealing pattern may also be used in the optional further sealing portions.
  • Such sealing pattern can provide a good resistance against the swell forces generated by liquid being captured in the superabsorbent particles by hydrogen bonds, but the sealing pattern equally can provide resistance against dry and wet superabsorbent particles trying to penetrate through the capillary acceleration sheet and through the sealing pattern after as well as during the sealing step of the manufacturing process. In that manner, any risk of dry or wet SAP particles coming into contact with sensitive skin upon wearing is avoided or reduced. Further, by having a reduced surface area that is being sealed in accordance with a pattern, any particles remaining in the one or more channel zones can easily migrate to a non-sealing area so that the risk of creating holes in the one or more channel zones is reduced or avoided.
  • the sealing pattern comprises a large number of distinct sealing areas (here dots 3000) spread across the one or more channels.
  • the large number is larger than 10, more preferably larger than 20.
  • the sealing pattern comprises a plurality of discrete elements (here dots 3000), and each discrete element has a first dimension dl in a first direction and a second dimension d2 in a direction perpendicular to the first direction.
  • the first dimension dl is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm or between 0.2 and 0.7 mm, or between 0.3 and 0.6 mm, e.g. 0.5 mm as illustrated.
  • the second dimension d2 is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g.
  • the second distance d2 may be much longer than the first distance dl.
  • the distance d4 between adjacent discrete elements is smaller than 10 mm, preferably smaller than 5 mm, more preferably smaller than 2 mm, e.g. between 0.1 and 2.0 mm or between 0.2 and 1.5 mm, or between 0.3 and 1.0 mm, e.g. 0.7 mm as illustrated.
  • the angle a between adjacent inclined surfaces of the protrusions 1010 is between 60 and 120 degrees, more preferably between 70 and 110 degrees, even more preferably between 80 and 100 degrees.
  • plurality of discrete elements is aligned along lines oriented at an angle
  • 3 is between 20 and 160 degrees, more preferably between 30 and 150 degrees.
  • the width wb of the attachment zone 145 (here a rectangle including the dots and contacting the most peripheral points of the peripheral dots) is smaller than the channel width wc.
  • the width (wb) of the permanent attachment zone 145 is less than 80% of the width (wc) of the corresponding channel, preferably less than 70%, e.g. less than 60%.
  • the length of the permanent attachment zone 145 is at least 5 mm less than the average length of the associated channel portion, preferably at least 7 mm less.
  • the average length of the permanent attachment zone 145 is more than 80% of the average length of the associated channel portion.
  • no permanent bonds are present in an area 147 of the channel portion 140 surrounding the permanent attachment zone 145 no permanent bonds are present.
  • one or more semi-permanent attachment zones may be present in the area 147.
  • a shortest distance (y) between a periphery of the channel portion 140 and a periphery of the corresponding attachment zone 145 is larger than 2 mm, preferably larger than 3 mm, e.g. larger than 4 mm.
  • the permanent attachment zone as defined here has a polygon shape, said polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines.
  • the adjacent left edges or points are interconnected through straight lines
  • adjacent rear edges or points are interconnected through straight lines
  • adjacent right edges or points are interconnected through straight lines
  • adjacent rear edges or points are interconnected through straight lines, such that a polygon is formed which includes all permanent bonding spots and touches the most peripheral edges or points thereof.
  • an edge barrier refers to one or more than one edge barrier.
  • Absorbent article refers to devices that absorb and contain bodily exudates, and more specifically, refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the various liquids discharged from the body.
  • Absorbent articles include but are not limited to feminine hygiene garments, baby diapers and pants, adult incontinence garments, various diaper and pants holders, liners, towels, absorbent inserts and the like.
  • “Absorbent core” as used herein refers to a three-dimensional part of the absorbent structure, comprising liquid-absorbing material, useful to permanently absorb and/or retain bodily exudates.
  • Absorbent component refers to a structural constituent of an absorbent article, e.g., a piece of an absorbent core, such as one of multiple pieces in a multi-piece absorbent core.
  • Absorbent element refers to a part of a functional constituent of an absorbent structure, e.g., an acquisition layer, a dispersion layer, core layer or a release structure formed of a material or materials having particular liquid handling characteristics suitable for the specific function.
  • Absorbent fibrous polymer material refers to an absorbent polymer material which is in threadlike from such as fibers, filaments, and the like so as to be less flowable in the dry state than particulates.
  • Absorbent insert refers to a device adapted for insertion into an "Absorbent layer” as used herein refers to a term referring to a discrete, identifiable sheet-like or web-like element of an absorbent article which may remain detached and relatively movable with respect to another such element or may be attached or joined so as to remain permanently associated with another such element.
  • Each absorbent layer may itself include a laminate or combination of several layers, sheets and/or webs of similar or diverse compositions.
  • ABSAP Absorbent polymer material
  • AGM absorbent gelling material
  • AGM absorbent gelling material
  • SAP super absorbent material
  • EDANA 441.2-01 any suitable particulate (e.g., flaked, particulate, granular, or powdered) or fibrous cross linked polymeric materials that can absorb at least 5 times and preferably at least about 10 times or more its weight of an aqueous 0.9% saline solution as measured using the Centrifuge Retention Capacity test (EDANA 441.2-01).
  • Absorbent polymer material area refers to the area of the absorbent structure wherein adjacent layers are separated by a multiplicity of absorbent polymer material. Incidental contact areas between these adjacent layers within the absorbent particulate polymer material area may be intentional (e.g bond area's) or unintentional (e.g. manufacturing artifacts).
  • Absorbent particulate polymer material refers to an absorbent polymer material which is in particulate form such as powders, granules, flakes and the like so as to be flowable in the dry state.
  • Absorption refers to the process by which a liquid is taken up within a material.
  • Absorption rate refers to the rate of absorption of liquid, i.e. the amount of liquid which is absorbed per unit of time, typically by an absorbent component, element and/or absorbent layer of the absorbent article, structure and/or core.
  • Acquisition layer refers to the layer overlying the absorbent core having a faster liquid uptake and/or distribution capability.
  • Absorbency is the ability of a material to take up fluids by various means including capillary, osmotic, solvent, chemical and/or other action.
  • “Adult incontinence garment” as used herein refers to absorbent articles intended to be worn by incontinent adults, for absorbing and containing bodily exudates.
  • Adhesion refers to the force that holds different materials together at their interface.
  • Adhesive refers to a material, which may or may not be flowable in solution or when heated, that is used to bond materials together.
  • Adsorption refers to the process by which a liquid is taken up by the surface of a material.
  • Airlaying refers to forming a web by dispersing fibers or particles in an air stream and condensing them from the air stream onto a moving screen by means of a pressure and/or vacuum; a web of fibers produced by airlaying is herein referred to an "airlaid”; an airlaid web bonded by one or more techniques to provide fabric integrity is herein referred to an "airlaid non wo ven".
  • Apparent density refers to the basis weight of the sample divided by the caliper with appropriate unit conversions incorporated therein. Apparent density used herein has the unit g/cm3.
  • Body pants refers to absorbent articles marketed for use in transitioning children from diapers to underwear intended to cover the lower torso of children, so as to absorb and contain body exudates which article is generally configured like a panty garment and manufactured with a completed waist encircling portion, thereby eliminating the need for the user to fasten the article about the waist of the wearer.
  • Back region refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the back of a wearer.
  • Backing refers to a web or other material that supports and reinforces the back of a product.
  • Basis weight is the weight per unit area of a sample reported in grams per square meter, g/m2 or gsm.
  • Bodily exudates "body exudates”, “bodily fluids”, “body fluids”, “bodily discharges”, “body discharges”, “fluid(s)”, “ liquid(s)”, “fluid(s) and liquid(s) and the like as used herein are used interchangeably and refer to, but are not limited to urine, blood, vaginal discharges, breast milk, sweats and fecal matter.
  • Binder "adhesive”, “glue”, “resins”, “plastics” and the like as used herein are used interchangeably and refer to substances, generally in a solid form (e.g. powder, film, fiber) or as a foam, or in a liquid form (e .g. emulsion, dispersion, solution) used for example by way of impregnation, spraying, printing, foam application and the like used for attaching or bonding functional and/or structural components, elements and materials, for example including heat and/or pressure sensitive adhesives, hot-melts, heat activated adhesives, thermoplastic materials, chemical activated adhesives/solvents, curable materials and the like.
  • Bond strength refers to the amount of adhesion between bonded surfaces. It is a measure of the stress required to separate a layer of material from the base to which it is bonded.
  • “Capillary action”, “capillarity”, or “capillary motion” and the like as used herein are used to refer to the phenomena of the flow of liquid through porous media.
  • “Chassis” as used herein refers to a foundational constituent of an absorbent article upon which the remainder of the structure of the article is built up or overlaid, e.g., in a diaper, the structural elements that give the diaper the form of briefs or pants when configured for wearing, such as a backsheet, a topsheet, or a combination of a topsheet and a backsheet.
  • Cellulose fibers refers to naturally occurring fibers based on cellulose, such as, for example cotton, linen, etc; wood pulp fibers are one example of cellulose fibers; man-made fibers derived from cellulose, such as regenerated cellulose (rayon), or partially or fully acetylated cellulose derivatives (e.g. cellulose acetate or triacetate) are also considered as cellulose fibers.
  • Cluster or the like as used herein refers to an agglomeration of particles and/or fibers.
  • “Chemically stiffened fibers”, chemically modified fibers”, “chemically cross-linked fibers”, “curly fibers” and the like as used herein are used interchangeably and refer to any fibers which have been stiffened by chemical means to increase stiffness of the fibers under both dry and aqueous conditions, for example by way of addition of chemical stiffening agents (e.g. by coating, impregnating, etc), altering the chemical structure of the fibers themselves (e.g. by cross-linking polymer chains, etc) and the like.
  • Cohesion refers to the resistance of similar materials to be separated from each other.
  • Computer refers to chambers, cavities, pockets and the like.
  • Crossstock refers to a lightweight non-woven material used to contain and conceal an underlying absorbent core material; examples are the facing layer or materials that cover the absorbent cores of feminine hygiene garment s, baby diapers and pants and adult incontinence garments.
  • “Crotch region” of an absorbent article as used herein refers to about 50% of the absorbent article's total length (i.e., in the y-dimension), where the crotch point is located in the longitudinal center of the crotch region. That is, the crotch region is determined by first locating the crotch point of the absorbent article, and then measuring forward and backward a distance of 25% of the absorbent article's total length.
  • Cross direction (CD) Cross direction
  • lateral lateral
  • transverse and the like as used herein are used interchangeably and refer to a direction which is orthogonal to the longitudinal direction and includes directions within ⁇ 45° of the transversal direction.
  • “Curing” as used herein refers to a process by which resins, binders or plastics are set into or onto fabrics, usually by heating, to cause them to stay in place; the setting may occur by removing solvent or by cross-linking so as to make them in soluble.
  • Diaper "Diaper”, "conventional diaper”, “diaper-like”, “diaper-like garment” and the like as used herein are used interchangeably and refer to disposable absorbent articles, which typically include a front waist portion and a back waist portion which may be releasable connected about the hips of the wearer during use by conventional fasteners such as adhesive tape fasteners or hook and loop type fasteners.
  • conventional fasteners such as adhesive tape fasteners or hook and loop type fasteners.
  • the article is positioned between the legs of the wearer and the fasteners are releasable attached to secure the back waist portion to the front waist portion of the diaper, thereby securing the diaper about the waist of the wearer.
  • the front waist portion and a back waist portion are connected by relatively non-stretchable or stretchable members (the term “stretchable” as used herein refers to materials that are extensible when forces are applied to the material, and offer some resistance to extension). Hence, such articles are generally not configured to be pulled up or down over the hips of the wearer when the fasteners are attached.
  • Dispossion layer refers to the layer overlying the absorbent core having a faster liquid uptake and dispersion capability.
  • Disposable is used herein to describe articles that are generally not intended to be laundered or otherwise restored or reused (i.e., they are intended to be discarded after a single use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
  • “Drylaying” as used herein refers to a process for making a nonwoven web from dry fiber; these terms apply to the formation of carded webs, as well as to the air laying formation of random webs; a web of fibers produced by drylaying is herein referred to as a "drylaid”; a drylaid web bonded by one or more techniques to provide fabric integrity is herein referred to a “drylaid nonwoven”.
  • “Dry strength” as used herein refers to the strength of ajoint determined in dry state conditions, immediately after drying under specified conditions or after a period of conditioning in the standard laboratory atmosphere.
  • Essentially cellulose free refers to an absorbent article, structure, core component and/or element containing less than 20% by weight cellulosic fibers, less than 10% cellulosic fibers, less than 5% cellulosic fibers, no cellulosic fibers, or no more than an immaterial amount of cellulosic fibers which do not materially affect the thinness, flexibility or absorbency thereof.
  • Essentially fluffless or “little to no fluff pulp” as used herein refers to an absorbent article, structure, core, component and/or element containing less than 20% by weight fluff pulp, less than 10% fluff pulp, less than 5% fluff pulp, no fluff pulp, or no more than an immaterial amount of fluff pulp which do not materially affect the thinness, flexibility or absorbency thereof.
  • Fabric refers to a sheet structure made from fibers, filaments and/or yarns.
  • “Feminine hygiene garments” as used herein refer to absorbent hygiene articles intended to be worn by woman, for absorbing and containing body exudates.
  • Fiber refers to the basic threadlike structure from which nonwovens, yarns and textiles are made. It differs from a particle by having a length at least 4 times its width; "Natural fibers” are either of animal (wool, silk), vegetable (cotton, flax, jute) or mineral (asbestos) origin, while “Man-made fibers” may be either polymers synthesized from chemical compounds (polyester, polypropylene, nylon, acrylic etc.) or modified natural polymers (rayon, acetate) or mineral (glass). "Fiber” and “filament” are used interchangeably.
  • Fiber pulp or "Pulp fluff” as used herein refers to wood pulp specially prepared to be drylaid.
  • the fibers can be either natural or synthetic or a combination thereof.
  • Front region refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the front of a wearer.
  • Garment facing layer refers to elements of the chassis that form the outer surface of the absorbent article, such as the backsheet, the side panels, the waist fasteners, and the like, when such elements are present.
  • Heat activated adhesive refers to a dry adhesive that is rendered tacky or fluid by application of heat or heat and pressure to the assembly.
  • Heat sealing adhesive refers to a thermoplastic adhesive which is melted between the adherent surfaces by heat application to one or both of the adjacent adherent surfaces.
  • High loft refers to general term of low density, thick or bulky fabrics.
  • Hot-melt adhesive refers to a solid material that melts quickly upon heating, then sets to a firm bond upon cooling; used for almost instantaneous bonding.
  • Hydrophilic refers to having an affinity for being wetted by water or for absorbing water.
  • Hydrophilic refers to lacking the affinity for being wetted by water or for absorbing water.
  • Immobilization layer refers to a layer able to be applied to the absorbent polymer material or absorbent polymer material area with the intent to gather, bond and/or immobilize absorbent material and/or absorbent layer.
  • Join, “joined” and “joining” as used herein refers to encompassing configurations wherein an element is directly secured to another element by affixing the element directly to the other element, as well as configurations wherein the element is indirectly secured to the other element by affixing the element to an intermediate member or members which in turn is or are affixed to the other element.
  • “Knitting” as used herein refers to the technique for interlocking loops of fibers with needles or similar devices.
  • Layer refers to identifiable components of the absorbent article, and any part referred to as a “layer” may actually comprise a laminate or combination of several sheets or webs of the requisite type of materials.
  • the term “layer” includes the terms “layers” and “layered.”
  • “Upper” refers to the layer of the absorbent article which is nearest to and/ or faces the wearer facing layer; conversely, the term “lower” refers to the layer of the absorbent article which is nearest to and/or faces the garment facing layer.
  • “Layer” is three dimensional structure with a x dimension width, y dimension length, and z-dimensions thickness or caliper, said x-y dimensions being substantially in the plane of the article, however it should be noted that the various members, layers, and structures of absorbent articles according to the present invention may or may not be generally planar in nature, and may be shaped or profiled in any desired configuration.
  • Machine direction (MD) "longitudinal” and the like as used herein are used interchangeably and refer to a direction running parallel to the maximum linear dimension of the structure and includes directions within ⁇ 45° of the longitudinal direction.
  • Major surface refers to a term used to describe the surfaces of greatest extent of a generally planar or sheet-like structural element and to distinguish these surfaces from the minor surfaces of the end edges and the side edges, i.e., in an element having a length, a width, and a thickness, the thickness being the smallest of the three dimensions, the major surfaces are those defined by the length and the width and thus having the greatest extent.
  • Mass flow refers to the flow of a liquid from one absorbent element or component to another absorbent element or component by channel flow action.
  • Mechanism bonding refers to a method of bonding fibers by entangling them. This can be achieved by needling, stitching with fibers or by the use of high-pressure air or water jets and the like.
  • Nonwoven refers to manufactured sheet, web or batt of directionally or randomly orientated fibers, bonded by friction, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted, tufted, stitch-bonded incorporating binding yarns or filaments, or felted by wet-milling, whether or not additionally needled.
  • the fibers may be of natural or man-made origin and may be staple or continuous filaments or be formed in situ.
  • Non wo ven fabrics can be formed by many processes such as melt blowing, spun bonding, solvent spinning, electrospinning, and carding.
  • the basis weight of non wo ven fabrics is usually expressed in grams per square meter (gsm).
  • Pant "training pant”, “closed diapers”, “prefastened diapers”, “pull-on diapers” and “diaper-pants” and the like as used herein are used interchangeably and refer to absorbent articles which are typically applied to the wearer by first leading the feet into the respective leg openings and subsequently pulling the pants from the feet to waist area over the hips and buttocks of the wearer and which are capable of being pulled up or down over the hips of the wearer.
  • Such articles may include a front waist portion and a back waist portion which may be connected about the hips of the wearer by integral or releasable members.
  • a pant may be preformed by any suitable technique including, but not limited to, joining together portions of the article using refastenable and/or nonrefastenable bonds (e.g., seam, weld, adhesive, cohesive bond, fastener, etc.).
  • a pant may be preformed anywhere along the circumference of the article (e.g., side fastened, front waist fastened).
  • Polymer refers to but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Unless otherwise specifically limited, the term “polymer” includes all possible spatial configurations of the molecule and include, but are not limited to isotactic, syndiotactic and random symmetries.
  • Rear refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the back of the wearer.
  • Release structure As used herein are used interchangeably and refer to a structure in fluid communication with the absorbent core having a larger relative liquid absorption capacity and/or rate allowing it to quickly take up, temporarily hold and releasing liquids.
  • Resin refers to a solid or semisolid polymeric material.
  • Thermobonding refers to a method of bonding fibers by the use of heat and/or high- pressure.
  • Thermoplastic refers to polymeric materials that have a melting temperature and can flow or be formed into desired shapes on the application of heat at or below the melting point.
  • Ultrasonic refers to the use of high frequency sound to generate localized heat through vibration thereby causing thermoplastic fibers to bond to one another.
  • Water-absorbing “liquid-absorbing”, “absorbent”, “absorbing” and the like as used herein are used interchangeably and refer to compounds, materials, products that absorb at least water, but typically also other aqueous fluids and typically other parts of bodily exudates such as at least urine or blood.
  • Weight facing layer refers to elements of the chassis that form the inner surface of the absorbent article, such as the topsheet, the leg cuffs, and the side panels, etc., when such elements are present.
  • Weighting refers to the process of interlacing two or more sets of yarns at right angles to form a fabric; a web of fibers produced by weaving is herein referred to as a "woven".
  • Web material refers to an essentially endless material in one direction, i.e. the longitudinal extension or the length, or the x- direction in Cartesian coordinates relative to the web material. Included in this term is an essentially unlimited sequence of pieces cut or otherwise separated from an essentially endless material.
  • the web materials will have a thickness dimension (i.e. the z-direction) which is significantly smaller than the longitudinal extension (i.e. in x-direction).
  • the width of web materials (they-direction) will be significantly larger than the thickness, but less than the length.
  • the thickness and the width of such materials is essentially constant along the length of the web.
  • such web materials may be cellulosic fiber materials, tissues, woven or nonwoven materials and the like.
  • web materials are supplied in roll form, or on spools, or in a folded state in boxes. The individual deliveries may then be spliced together to form the essentially endless structure.
  • a web material may be composed of several web materials, such as multilayer non-woven, coated tissues, nonwoven/film laminates. Web materials may comprise other materials, such as added binding material, particles, hydrophilizing agents and the like.
  • Weight burst strength is a measure of a layer's ability to absorb energy, when wet and subjected to deformation normal to the plane of the web.
  • Weight refers to the strength of a joint determined immediately after removal from a liquid in which it has been immersed under specified conditions of time, temperature and pressure. The term is commonly used in the art to designate strength after immersion in water.
  • Weighting refers to the forming a web from an aqueous dispersion of fibers by applying modified paper making techniques; a web of fibers produced by wetlaying is herein referred to as a "wetlaid”.
  • Wood pulp refers to cellulosic fibers used to make viscose rayon, paper and the absorbent cores of products such as feminine hygiene garments, baby diapers and pants and adult incontinence garments.
  • X-y dimension refers to the plane orthogonal to the thickness of the article, structure or element.
  • the x- and y-dimensions correspond generally to the width and length, respectively, of the article, structure or element.
  • Z-dimension refers to the dimension orthogonal to the length and width of the article, structure or element.
  • the z-dimension corresponds generally to the thickness of the article, structure or element.

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Abstract

An absorbent article comprising a liquid pervious topsheet (300), a liquid impervious backsheet (200), an absorbent core (100) positioned between the liquid pervious topsheet and the liquid impervious backsheet, said absorbent core comprising a bottom core wrap sheet (120), a top core wrap sheet (110) and absorbent material (130) between the bottom core wrap sheet and the top core wrap sheet, wherein said at least one channel comprises a first channel portion (140) extending in a longitudinal direction of the absorbent core and a second channel portion (180) extending at an angle with respect to the first channel portion, said first channel portion comprising a first attachment zone (145) where the top core wrap sheet is attached to the bottom core wrap sheet, and said second channel portion comprising a second attachment zone (185) where the top core wrap sheet is attached to the bottom core wrap sheet, wherein a first ratio (wb1/wc1) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.

Description

ABSORBENT ARTICLE WITH IMPROVED ATTACHMENT ZONE
TECHNICAL FIELD
The present invention pertains to the technical field of absorbent articles, more preferably disposable personal care articles such as diapers, baby pants, adult incontinent garments, and the like, and to absorbent structures for use in such absorbent articles. More specifically the present invention relates to an absorbent article comprising an absorbent core with at least one channel, the absorbent core being arranged between a topsheet and a backsheet. The present invention also relates to methods for manufacturing such an absorbent article.
BACKGROUND
Absorbent articles comprising an absorbent core with one or more channels between a topsheet and a backsheet are well known. Examples of such absorbent articles are described for example in patents EP 3 403 630 Bl, EP 3 403 632 Bl and EP 3 403 631 Al in the name of the applicant, which are incorporated herein by reference.
It is known to provide a liquid distribution and acquisition layer (ADL) or capillary acceleration sheet between the topsheet and the absorbent core in order to take up and distribute the liquid from the topsheet towards the absorbent core. Typically, an ADL or capillary acceleration sheet extends over an area where liquid insult is to be expected. Such layers are chosen to reduce the time needed to obtain a dry feeling at the topsheet surface after a liquid insult and to reduce rewetting.
The at least one channel in the absorbent core mainly serves the purpose of achieving a fast distribution of the liquid by mass flow after a liquid insult. In order to maintain the channel integrity of the at least one channel, it is preferred that the top core wrap sheet and the back core wrap sheet are attached to each other at least in a portion of the at least one channel.
SUMMARY
The object of embodiments of the invention is to provide an absorbent article of the type stated in the preamble, with an improved attachment zone, and more in particular an attachment zone which is well aligned with the at least one channel.
Aspect 1 According to a first aspect of the invention, there is provided an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet and an absorbent core positioned between the liquid pervious topsheet and the liquid impervious backsheet. The absorbent core comprises a bottom core wrap sheet, a top core wrap sheet and absorbent material between the bottom core wrap sheet and the top core wrap sheet. It is noted that the bottom and top core wrap sheets may be part of a single integral sheet wrapping the absorbent material or may be separate sheets, optionally having different properties. The absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp and is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel. The at least one channel comprises a first channel portion extending in a longitudinal direction of the absorbent core and a second channel portion extending at an angle with respect to the first channel portion. The first channel portion has a first channel width (wcl) seen in a transverse direction of the absorbent core and comprises a first attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet. The first attachment zone has a first attachment width (wbl) seen in the transverse direction. The second channel portion has a second channel width (wc2) seen in a direction perpendicular on a centre line of the second channel portion and comprises a second attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet. The second attachment zone has a second attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion. A first ratio (wbl/wcl) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.
Embodiments of the invention are based inter alia on the insight that a transport means, such as drum, on which the absorbent articles are typically produced typically operates at very high speed. In order to create an attachment zone in a channel portion an attachment means, such as a sealing bar, need to be controlled in an accurate manner to obtain a proper alignment between a channel portion, i.e. an area where less or no absorbent material is present, and the attachment zone. For example, if the rotation of the drum is not well synchronised with the rotation of a sealing bar, seen in the transport direction, the channel portion may be shifted relative to the attachment zone. In prior art products, such problems resulted in an attachment zone extending in areas outside of the channel portion and covering less area within the channel portion. This problem is particularly relevant for a channel portion extending at an angle relative to the longitudinal direction of the absorbent core because for such channel portion the misalignment will be present across the entire channel portion, whilst for a channel portion extending in the longitudinal direction, i.e. in the transport direction, the problem will only be present for the longitudinal ends of the channel and have less impact. In embodiments of the invention, the misalignment problem is addressed by choosing first ratio (wbl/wcl) of the first attachment width relative to the first channel width which larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width. In this way, in the second channel portion, which is the channel portion extending at an angle relative to the longitudinal direction, even in cases of a small misalignment, the second attachment zone will still be located substantially within the second channel portion.
The first and second attachment zones are distinguishable zones and may either be continuous attachment zone or discontinuous attachment zones. For a discontinuous attachment zone including a plurality of bonding spots at a distance of each other, the attachment zone may be defined as a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines, wherein the average width (wb) of each attachment zone is an average of the width of the polygon measured in a direction perpendicular on a centre line of the attachment zone.
Preferably, the first ration is at least 5% larger than the second ratio (wbl/wcl >= 1.05*wb2/wc2), preferably at least 10% larger, more preferably at least 20% larger.
Preferably, in the first and the second attachment zone, the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy. Preferably, the sealing is done in accordance with a sealing pattern. In the area of the first and second channel position outside of the first and second attachment zone the top core wrap sheet is not sealed to the bottom core wrap sheet.
Preferably, the sealing pattern covers less than 80%, preferably less than 70%, more preferably less than 60%, even more preferably less than 50%, most preferably between 1 and 50% of the surface area of the at least one channel. For example, the sealing pattern covers between 1 and 50% of the total surface area of the at least one channel, or between 1 and 40%, or between 1 and 30%, or between 1 and 25%, or between 2 and 25%, or between 3 and 25%, or between 4 and 25%. For example, when the sealing pattern comprises a plurality of discrete sealing areas, the total surface area of those discrete sealing areas is preferably less than 80% of the surface area of the at least one channel.
Such sealing pattern can provide a good resistance against the swell forces generated by liquid being captured in the superabsorbent particles by hydrogen bonds, but the sealing pattern equally can provide resistance against dry and wet superabsorbent particles trying to penetrate through the core wrap and through the sealing pattern after as well as during the sealing step of the manufacturing process. In that manner, any risk of dry or wet SAP particles coming into contact with sensitive skin upon wearing is avoided or reduced. Further, by having a reduced surface area that is being sealed in accordance with a pattern, any particles remaining in the one or more channel zones can easily migrate to a non-sealing area so that the risk of creating holes in the one or more channel zones is reduced or avoided.
Preferably, the sealing pattern is a regular pattern, such as a line pattern such as a grid, a pattern of dots, etc. The dots may have any shape, e.g. round, polygonal, etc. The line pattern may comprise one or more sets of parallel lines. When a first set of parallel lines and a second set of parallel lines is included, the lines of the first set may be oriented at a non-zero angle with respect to the lines of the second set.
Preferably, the sealing pattern comprises a large number of distinct sealing areas spread across the first and second attachment zone. Preferably, the large number is larger than 10, more preferably larger than 20.
Preferably, the sealing pattern comprises a plurality of discrete elements, and each discrete element has a first dimension in a first direction and a second dimensions in a direction perpendicular to the first direction. The first dimension is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm or between 0.2 and 0.7 mm, or between 0.3 and 0.6 mm.
By providing well selected sealing patterns, such as grids, dots, polygons, etc., that have a limited total bonding area with fine single bonding areas, e.g. having a surface area smaller than 2 mm2 or a line thickness lower than 1 mm, individual superabsorbent particles will find easier their way to nonsealed zones in order not to create any hole.
In an exemplary embodiment, the first and second channel width are substantially the same, wherein preferably the second channel width is less than 10% smaller or larger than the first channel width (wc2 = wcl +/- 10%).
Preferably, the first channel portion and the second channel portion are interconnected, so that liquid can flow from the first channel portion into the second channel portion and vice versa without being hindered by absorbent material in between the first and second channel portion. Optionally, the at least one channel comprises a further channel portion extending in a longitudinal direction of the absorbent core, said further channel portion having a further channel width (wcf) seen in a transverse direction of the absorbent core and comprising a further attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet, said further attachment zone having a further attachment width (wbf) seen in the transverse direction, wherein the first channel portion is connected to a first end of the second channel portion and the further channel portion is connected to a second opposite end of the second channel portion. In this way, the first and the further channel portion, i.e. two channel portions extending in the longitudinal direction, may be interconnected by the second channel portion so that mass flow is possible between the first and further channel portion, wherein a robust attachment zone is present in the second channel portion.
Preferably, the first and further channel width are substantially the same. Preferably the further channel width is less than 10% smaller or larger than the first channel width (wcf = wcl +/- 10%).
The second channel portion may be a straight portion or a curved portion.
In an exemplary embodiment, the at least one channel comprises a first channel and a second channel, said first channel including the first and second channel portion, said first and second channel being arranged so as to be mirror images relative to a longitudinal central axis of the absorbent core. Thus, also the second channel includes first and second channel portions. Preferably, the first and second channel each have a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length of the absorbent core, preferably at least 30% of the length of the absorbent core (La).
In an exemplary embodiment, the at least one channel comprises, preferably consists of, an interconnected channel comprising the first and second channel portion, wherein the first channel portion extends along a longitudinal central axis (A) of the absorbent core and the second channel portion is connected to the first channel portion and diverges away from the longitudinal central axis, wherein the interconnected channel comprises a third channel portion which is arranged to be a mirror image of the second channel portion relative to the longitudinal central axis of the absorbent core, said third channel portion having a third attachment zone. Preferably, the interconnected channel has a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length (La) of the absorbent core, preferably at least 30% of the length of the absorbent core. Optionally, the interconnected channel comprises a further channel portion and a second further channel portion, wherein the first channel portion is connected to a first end of the second and third channel portion, the further channel portion is connected to a second end of the second channel portion and the second further channel portion is connected to a second end of the third channel portion.
Preferably, the first and the second attachment zone include the same type of attachment.
Preferably, the first attachment zone is a permanent attachment zone and the second attachment zone is a permanent attachment zone.
According to another exemplary embodiment, the first attachment zone is a permanent attachment zone and the second attachment zone is a permanent attachment zone or comprises one or more semipermanent attachment zones configured to release after having been in contact with liquid, for example after having been in contact with the liquid for a time period of less than 2 minutes.
Preferably, the first and/or second channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
Preferably, seen in a longitudinal direction of the absorbent core, an average length (lb) of the first attachment zone is smaller than an average length (1c) of the first channel portion.
Preferably, the first attachment width (wbl) of is less than 90% of the first channel width (wcl), preferably less than 80%, more preferably less than 70%, and more than 25%.
The first and second attachment zone may comprise a single continuous attached portion or a plurality of discrete attached portions. The first and second attachment zone may comprise one or more permanent attachment portions which remain attached after wetting and/or one or more semipermanent attachment portions which detach after wetting and/or one or more unattached portions. An unattached portion or a semi-permanent attachment portion allows for an increased swelling of the absorbent material after the one or more channels have fulfilled their function of distributing the liquid, as wet absorbent material is allowed to extend/swell into the channel area in case of an unattached or detached portion. Preferably, the average width of the first attachment zone is less than 90% of the average width of the first channel portion, preferably less than 80%, more preferably less than 70%, and more than 25% of the average width of the first channel portion.
Preferably, the average length of the first attachment zone is less than 99%, more preferably less than 98% of the average length of the first channel portion, e.g. less than 97% or even 95%, and/or more than 80% of the average length of the channel.
Aspect 2
According to a second aspect there is provided an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet and an absorbent core positioned between the liquid pervious topsheet and the liquid impervious backsheet. The absorbent core comprises a bottom core wrap sheet, a top core wrap sheet and absorbent material between the bottom core wrap sheet and the top core wrap sheet. The absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp, wherein the absorbent material is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel. The at least one channel comprises a channel portion extending at an angle with respect to a longitudinal direction of the absorbent core. This channel portion may be similar to the second channel portion discussed in the embodiments above. The channel portion has a channel width (wc2) seen in a direction perpendicular on a centre line of the channel portion and comprises an attachment zone where the top core wrap sheet is attached to the bottom core wrap sheet, said attachment zone having an attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion. The attachment width is less than 80% of the channel width (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
Thus, embodiments of the invention may also comprise at least one channel having only channel portions which are not aligned along the longitudinal direction, such as two elongate curved portions, or with a channel portion which is not aligned along the longitudinal direction in combination with channel portions which are aligned in the longitudinal direction but which have different properties than those described in accordance with the first aspect.
As explained in connection with the first aspect, the problem of misalignment between the area of the channel portion and the associated attachment zone is particularly relevant for a channel portion extending at an angle relative to the longitudinal direction of the absorbent core because for such channel portion typically a misalignment will be present across the entire channel portion, whilst for a channel portion extending in the longitudinal direction, i.e. in the transport direction, the problem will only be present for the longitudinal ends of the channel and have less impact. In embodiments of the invention, the misalignment problem is addressed by choosing a width of the attachment zone which is significantly smaller than the channel width. In this way, in the channel portion extending at an angle relative to the longitudinal direction, even in cases of a small misalignment, the attachment zone will still be located substantially within the channel portion, resulting in a good attachment and thus improved liquid distribution characteristics.
Preferably, in the attachment zone, the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy. In the area of the channel portion outside of the attachment zone, the bottom core wrap sheet is not sealed to the top core wrap sheet.
Preferably, the channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30% of the width of the absorbent core.
The width of the absorbent core is measured in a transverse direction of the absorbent core, in an area where the respective channel is present, between two end points where absorbent material is present, i.e. it is the width of the absorbent material deposition area of the absorbent core. Thus, the top core wrap sheet and/or the back core wrap sheet may extend over a width which is larger than the width of the absorbent core, as they may be attached along a periphery where no absorbent material is present. In the area where the at least one channel is present, the width of the absorbent core may vary between a minimum width and a maximum width, and preferably the above defined channel width is valid both for the minimum and the maximum width. The absorbent material deposition area may thus have a width which varies e.g. between a value above 100 mm and a value below 100 mm. Preferably the difference is at least 5 mm. For example, a width of the absorbent material deposition area measured at a front end of the absorbent core may be above 100 mm, or even above 105 mm and a width measured at a rear end of the absorbent core may be below 100 mm, or even below 95 mm.
The channel width may be constant through substantially the whole length of the channel portion or may vary along its length. When the width varies along the length, then the above specified width percentages apply for the average width of the respective channel portion. Preferably, the channel portion is formed by one or more absorbent material-free zones within the absorbent material deposition area of the absorbent core, and the channel width is considered to be the width of the material-free zone, disregarding the possible presence of core wrap within the channel. If the channel portion is formed by one or more absorbent material zones where less absorbent material per surface area is present as compared to an area adjacent the channel portion, the channel width is the width of the absorbent material zone where less absorbent material per surface area is present.
The absorbent core periphery, which may be the periphery of the top/bottom core wrap, may define any suitable shape, such as a "T," "Y," "hour-glass," or "dog-bone" shape, for example. A “T shape may have a larger width in the front portion than in the rear portion of the absorbent core. An absorbent core periphery having a generally "dog bone" or "hour-glass" shape may taper along its width towards the middle or "crotch" region of the core. In this way, the absorbent core may have a relatively narrow width in an area of the absorbent core intended to be placed in the crotch region of an absorbent article.
In a possible embodiment, the attachment zone includes all permanent attachment portions within the respective channel portion, i.e. outside of the attachment zone no further permanent attachment bonds are present in the corresponding channel portion. Each attachment zone may be either a continuous attachment zone or a discontinuous attachment zone including a plurality of bonding spots at a distance of each other. For a continuous attachment zone, the average width is the average of the width (measured in perpendicular on a centre line of the attachment zone) along its full length (along the centre line of the attachment zone) of the attachment zone. For a discontinuous attachment zone including a plurality of bonding spots at a distance of each other, the attachment zone may be defined as a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines, wherein the average width (wb) of each attachment zone is an average of the width of the polygon measured in a direction perpendicular on a centre line of the attachment zone, across the full length of the attachment zone. This may equally apply for the first and second attachment zone of the first aspect.
A permanent attachment zone is an attachment zone which remains attached when wetted. This may be tested by applying 200 ml liquid substantially equally across the absorbent core and evaluating the attachment zone after 10 minutes. If the attachment zone remains intact, the attachment zone is a permanent attachment zone. More preferably, a permanent attachment zone is an attachment zone which remains intact after submerging the absorbent core in the liquid and waiting for 10 minutes.
Preferably, each permanent attachment zone is an elongate attachment zone. Preferably, each permanent attachment zone is centred with respect to the corresponding channel.
Preferably, in an area of the channel surrounding the permanent attachment zone no permanent bonds are present. In that manner, the absorbent material can easily expand into that surrounding area upon wetting of the absorbent material. Optionally, in an area of the channel surrounding the permanent attachment zone one or more semi-permanent attachment portions may be present. Such semipermanent attachment portions are configured to loosen upon wetting of the absorbent article.
Common
Below some preferred features are described which may be used both in embodiments of the first and second aspect.
Optionally, adhesive is arranged between the bottom core wrap sheet and the top core wrap sheet at least in a portion of the at least one channel, within and/or outside of the first and second attachment zone. The adhesive may create the distinguishable attachment zone(s), but may also be included on top of the distinguishable attachment zone(s). For example, in one embodiment, the distinguishable attachment zone(s) may be formed by sealing, but in addition adhesive may be present in the entire channel portion(s). In another embodiment, the distinguishable attachment zone(s) may be formed by adhesive, and no adhesive is present outside of the distinguishable attachment zone(s).
For example, adhesive may be applied in one or more lanes or in a swirl pattern or on the entire surface on the top core wrap sheet and/or on the bottom core wrap sheet.
Preferably, the bottom core wrap sheet is a spunbond meltblown spunbond nonwoven comprising a first spunbond layer, a meltblown layer and a second spunbond layer on the other side of the meltblown layer, wherein preferably the second spunbond layer comprises polypropylene fibres.
Preferably, the absorbent article further comprises a capillary acceleration sheet between the absorbent core and the liquid pervious topsheet.
Preferably, the capillary acceleration sheet is a through-air-bonded nonwoven having a basis weight between 15 and 50 g/m2, more preferably between 15 and 30 g/m2. By using such relatively light but dense through-air-bonded nonwoven a good topsheet dryness, and in particular a fast topsheet dryness after liquid insult, and a good rewetting behaviour, is obtained. By combining at least one channel with a capillary acceleration sheet a fast dryness feeling and a low rewetting at the level of the topsheet can be ensured, whilst at the same time providing a good liquid distribution through the one or more channels resulting in improved leakage protection.
Preferably, the capillary acceleration sheet has been subjected to a hydrophilic spin finish treatment. This further improves the topsheet dryness.
Optionally, the bottom core wrap sheet has a basis weight which is larger than the basis weight of the top core wrap sheet and/or the capillary acceleration sheet. By providing a bottom core wrap having a basis weight which is larger than the basis weight of the top core wrap and/or larger than the basis weight of the capillary acceleration sheet, the bottom core wrap can be used for distribution purposes, distributing the liquid from the one or more channels to the absorbent material, whilst the providing integrity to the absorbent article. The liquid may be transported from the one or more channels through the bottom core wrap, along areas where the absorbent material is saturated, e.g. areas close to the one or more channels, to other areas where the absorbent material is not yet saturated. Further, by using a relatively light top core wrap and/or capillary acceleration sheet it takes less time before a dry feeling is obtained at the topsheet surface and any rewetting is reduced or avoided.
Preferably, the at least one channel comprises one or more elongated channels each having a channel length measured in a longitudinal direction of the absorbent core, said channel length being at least 10% of the length of the absorbent core, preferably at least 15% of the length of the absorbent core, the one or more elongated channels comprising the channel portion(s).
Preferably, the one or more elongated channels comprise at least a first and a second elongated channel extending at a distance of each other in a substantially longitudinal direction of the absorbent core.
Preferably, the bottom core wrap sheet consists of a single sheet. In that way the bottom core wrap can be easily transported in a machine for producing the absorbent articles. Further, the strength and/or integrity of the absorbent article may be increased.
Preferably, the bottom core wrap sheet comprises a through-air bonded non-woven, wherein preferably the bottom core wrap sheet consists of a through-air bonded non-woven. Preferably, the bottom core wrap has a basis weight between 18 and 80 g/m2, preferably between 20 and 75 g/m2, more preferably between 25 and 70 g/m2, even more preferably between 30 and 65 g/m2. Preferably, the top core wrap sheet comprises at least one spunbond and optionally at least one meltblown layer, wherein for example the top core wrap consists of a spunbond layer. Preferably, the top core wrap has a basis weight between 8 and 30 g/m2.
Preferably, an amount of cellulosic fluff pulp in the absorbent material is below 250 g/m2, preferably below 200 g/m2, more preferably below 180 g/m2, even more preferably below 160 g/m2, e.g. between 60 g/m2 and 180 g/m2 or between 70 g/m2 and 170 g/m2.
Preferably, an amount of superabsorbent particles in the absorbent material is above 300 g/m2, preferably above 320 g/m2, more preferably above 340 g/m2, e.g. between 300 g/m2 and 400 g/m2 or between 320 g/m2 and 390 g/m2.
Preferably, the superabsorbent particles have a permeability SFC which is higher than 10 x 10-7 cm3.S.g-l and/or a permeability GBP which is higher than 20 Da, preferably higher than 25 Da.
Preferably, the absorbent material comprises more than 60 weight%, preferably more than 70 weight% superabsorbent particles.
In an exemplary embodiment, the bottom core wrap sheet is a through-air bonded non-woven. This may be a spunbond/spunbond through-air-bonded nonwoven, or a classical through-air bonded nonwoven obtained by sequentially feeding the fibres of a first and second layer.
In an exemplary embodiment, the bottom core wrap sheet comprises a first layer and a second layer, wherein said first layer has a first density between 20 and 150 kg/m3 and said second layer has a second density between 100 and 400 kg/m3, said second density being higher than the first density, wherein said first layer is closer to the absorbent material than said second layer. Preferably, a difference between the first and the second density is higher than 20 kg/m3, more preferably higher than 30 kg/m3 even more preferably higher than 40 kg/m2, even more preferably between 50 and 150 kg/m3, most preferably between 60 and 140 kg/m3, e.g. between 70 and 130 kg/m3. By using such differences in density a good balance between distribution and integrity properties can be achieved.
In an exemplary embodiment, the first layer is a through-air-bonded carded non-woven and the second layer is a spunbond layer, e.g. a PP spunbond layer. In another exemplary embodiment, the first layer is a spunbond layer and the second layer is a spunbond layer. Thus, the first layer may be a more porous spunbond layer than the second layer. The first and second layer may be obtained using multiple spinning column, whereupon the assembly is interconnected using e.g. through-air- bonding. In a preferred embodiment, the first layer has a first basis weight and the second layer has a second basis weight, said second basis weight being lower than said first basis weight. Thus, the second layer may be a rather thin layer as it does not have to contribute to the distribution. Preferably, the difference between the first layer and the second layer is larger than 1 g/m2, more preferably larger than 2 g/m2, even more preferably larger than 3 g/m2, or even larger than 5 g/m2, for example between 1 and 10 g/m2. In an exemplary embodiment, the first layer has a first basis weight between 15 and 80 g/m2, preferably between 25 and 80 g/m2, and/or the second layer has a second basis weight between 8 and 35 g/m2, preferably between 8 and 25 g/m2.
Preferably, the first layer and/or the second layer comprise more than 90weight% of synthetic fibres, preferably more than 95weight% of synthetic fibres. In a preferred embodiment, the first layer comprises polyester fibres. Polyester fibres have the advantage of being capable of providing a highly voluminous first layer, resulting in good distribution properties. In a possible embodiment, the second layer comprises any one of the following fibres or a combination thereof: polyethylene, polyester, copolyester, polypropylene, polyactic acid (PLA).
Preferably, the second density is selected such that it forms a barrier for the superabsorbent particles. For example, the second layer may have a mean flow pore size below a predetermined value, and the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material. By using absorbent material comprising absorbent particles with a well-defined particle size distribution (PDS) adapted to the flow pore size of the bottom core wrap, and in particular the second layer thereof, any escaping of absorbent material can be reduced. Topping of the fines (e.g. a “dust-fraction” < 50 pm) away may be advantageous, as well as the removal of large fraction (e.g. >600 pm). For example, traditional blend polymerization superabsorbent particles can serve for this purpose, with sieve selection. According to another example drop polymerization superabsorbent particles (e.g. SAVIVA® superabsorbent of the company BASF) with a narrow PDS can be used. Also solvent polymerized superabsorbent particles can have such a narrow PDS.
In an exemplary embodiment, the mean flow pore size of the bottom core wrap is below 200 micron, more preferably below 150 micron, even more preferably between 10 and 150 micron, and most preferably between 20 and 150 micron. These values may be achieved thanks to the presence of the second layer. Preferably, the bottom distribution sheet is attached along a periphery to the bottom core wrap sheet and/or the top core wrap sheet and/or the capillary acceleration sheet.
For determining the density of the bottom core wrap, the mass per unit area may be measured using NWSP 130.1.R0 (20) and the nonwoven thickness may be measured using NWSP 120.6.R0 (15). The density can then be calculated as the mass per unit area divided by the thickness.
In an exemplary embodiment, the capillary acceleration sheet has a mean flow pore size below a predetermined value, and the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material. By using absorbent material comprising absorbent particles with a well-defined particle size distribution (PDS) adapted to the flow pore size of the capillary acceleration sheet, any escaping of absorbent material through the topsheet can be further reduced. Topping of the fines (e.g. a “dust-fraction” < 50 pm) away may be advantageous, as well as the removal of large fraction (e.g. >600 pm). For example, traditional blend polymerization superabsorbent particles can serve for this purpose, with sieve selection. According to another example drop polymerization superabsorbent particles (e.g. SAVIVA® superabsorbent of the company BASF) with a narrow PDS can be used. Also solvent polymerized superabsorbent particles can have such a narrow PDS.
The capillary acceleration sheet may have a mean flow pore size below 50 micron, preferably between 5 and 50 micron, more preferably between 10 and 50 micron, e.g. between 10 and 40 micron or between 20 and 40 micron.
By having a capillary acceleration sheet with a mean flow pore size below 50 micron, the absorbent material, and in particular super absorbent particles can be well maintained in the absorbent article without requiring an adapted topsheet. On the other hand, the capillary acceleration sheet can fulfil its capillary acceleration function, and will allow liquid to pass through the capillary acceleration sheet. By combining at least one channel with a capillary acceleration sheet a fast dryness feeling and a low rewetting at the level of the topsheet can be ensured, whilst at the same time providing a good liquid distribution through the one or more channels resulting in improved leakage protection. Also, the topsheet may be an apertured topsheet as the low mean flow pore size of the capillary acceleration sheet will avoid that any significant amounts of absorbent material, and in particular of superabsorbent particles, escape through the topsheet. The measure "mean flow pore size" refers to a measure of average pore diameter as determined by a liquid displacement technique utilizing a Coulter Porometer and Coulter POROFIL® test liquid available from Coulter Electronics Limited, Luton, England. The mean flow pore size is determined by wetting a test sample with a liquid having a very low surface tension (i.e., Coulter POROEIL®). Air pressure is applied to one side of the sample. Eventually, as the air pressure is increased, the capillary attraction of the fluid in the largest pores is overcome, forcing the liquid out and allowing air to pass through the sample. With further increases in the air pressure, progressively smaller and smaller holes will clear. A flow versus pressure relationship for the wet sample can be established and compared to the results for the dry sample. The mean flow pore size is measured at the point where the curve representing 50% of the dry sample flow versus pressure intersects the curve representing wet sample flow versus pressure. The diameter of the pore which opens at that particular pressure (i.e., the mean flow pore size) can be determined from the following expression: pore diameter pm = 40 r / pressure, where r = surface tension of the fluid expressed in units of mN/M; the pressure is the applied pressure expressed in millibars (mbar); and the very low surface tension of the liquid used to wet the sample allows one to assume that the contact angle of the liquid on the sample is about zero.
The capillary acceleration sheet may have a mean flow pore size below a predetermined value, and the absorbent material comprises superabsorbent particles prepared such that substantially no superabsorbent particles having dimensions smaller than said mean flow pore size are present in the absorbent material.
By using a capillary acceleration sheet having a mean flow pore size below a predetermined value in combination with absorbent particles with a well-defined particle size distribution (PDS) adapted to the predetermined value, any escaping of absorbent material through the topsheet can be avoided or reduced. For example, traditional blend polymerization superabsorbent particles can serve for this purpose, wherein a sieve selection is used to obtain the desired PDS. According to another example drop polymerization superabsorbent particles (e.g. SAVIVA® superabsorbent of the company BASF) with a narrow PDS can be used. Also solvent polymerized superabsorbent particles can have such a narrow PDS.
Preferably, the mean flow pore size is between 10 and 200 micron, more preferably between 10 and 150 micron, even more preferably between 20 and 150 micron, and most preferably between 30 and 150 micron. For example, the mean flow pore size is between 30 and 120 micron or between 30 and 100 micron. In an exemplary embodiment, the capillary acceleration sheet is sealed to the top core wrap sheet according to the sealing pattern, and optionally also to the bottom core wrap sheet through the top core wrap sheet.
Preferably, the sealing is realized by heat and/or pressure and/or ultrasonic energy. Preferably, the sealing is done by pressing one or more sealing bars against one or more zones overlapping with the one or more channels, said sealing bars being provided with protrusions according to the sealing pattern.
Preferably, the capillary acceleration sheet is a nonwoven comprising fibres having an average diameter between 10 and 35 micron, more preferably between 15 and 30 micron, even more preferably between 17 and 27 micron.
More in particular, the capillary acceleration sheet may have a fineness which results in a high capillary suction of liquid towards the absorbent material, where the liquid is further distributed through the at least one channel and absorbed by the absorbent material. Thus, the capillary acceleration sheet pulls liquid to the absorbent material in a very fast manner, resulting in a fast dryness at top sheet level.
In an exemplary embodiment, the capillary acceleration sheet has an average fineness which is between 2-6 dtex, i.e. between 1.8 and 5.4 den. It is noted that instead of or in addition to defining the average diameter of the capillary acceleration sheet, this sheet may also be defined using a fineness value, such as a dtex value or a den value. A den value may be determined using test method ASTM 1577.
Optionally, the capillary acceleration sheet is attached to the bottom core distribution assembly at least in a portion of the one or more channels.
According to an exemplary embodiment, the capillary acceleration sheet is a nonwoven with polypropylene (PP) fibres. The advantage of PP is that it can be easily shaped.
According to an exemplary embodiment, the topsheet is an apertured topsheet having apertures with a surface area larger than 0.1 mm2, preferably larger than 0.5 mm2. This allows liquid to pass easily through the topsheet towards the capillary acceleration sheet. Especially for embodiments where the capillary acceleration sheet forms a barrier for superabsorbent particles such an embodiment is advantageous. According to an exemplary embodiment, the capillary acceleration sheet comprises a blend of fibres having different diameters. Preferably, the fibres are intermingled, i.e. preferably the different fibres are not arranged in layers but mixed with each other to form the capillary acceleration sheet. Preferably, a blend of polypropylene (PP) fibres is used. However, it is also possible to use other single component or bi-component fibres, such as polyethylene (PE) fibres, polyethyleneterephthalate (PET) fibres, PE/PP bi-component fibres, PE/PLA bi-component fibres, etc. The fibres may be continuously crimped fibres.
According to an exemplary embodiment, the capillary acceleration sheet comprises a blend of first fibres having an average first diameter above 20 micron, preferably above 22 micron, more preferably above 24 micron, and second fibres having an average second diameter below 20 micron, preferably below 19 micron, more preferably below 18 micron. In that manner, the fine second fibres will contribute to the fast capillary suction whilst the coarser first fibres will ensure a good distribution of the liquid, also by mass flow. Preferably, the first fibres represent less than 50 weight% of the capillary acceleration sheet, more preferably less than 45 weight%, and the second fibres represent more than 50 weight% of the capillary acceleration sheet, more preferably more than 55 weight%. Such a distribution provides a good balance between suction and migration by capillary flow promoted by the finer second fibres and liquid distribution by mass flow promoted by the coarser first fibres.
According to an exemplary embodiment, the capillary acceleration sheet is a continuous filament web. The capillary acceleration sheet may be a spunbond nonwoven, a carded nonwoven, a spunlace nonwoven. The capillary acceleration sheet may be made by spunbonding, carding, or spunlacing (hydro-entangling), or a combination thereof. If the capillary acceleration sheet is a spunbond web, it may be a calandered (i.e. a point bonded) spunbond web, preferably with a bonding area between 10 and 30%.
According to an exemplary embodiment, the capillary acceleration sheet comprises a fraction of fibres having an average diameter which is at least 10% lower than an average diameter of the fibres of the liquid pervious topsheet, preferably at least 20% lower than an average diameter of the fibres of the liquid pervious topsheet. By having finer fibres in the capillary acceleration sheet than in the topsheet, the liquid will pass fast through the topsheet and the main capillary suction will take place in the capillary acceleration sheet. Preferably, the topsheet has a basis weight between 10 and 30 g/m2, preferably between 15 and 25 g/m2. Preferably, the fibres of the topsheet have an average fineness between 1-3 dtex. Preferably, the topsheet is any one of the following: a spunbond nonwoven, a through air bonded carded web (TABCW). Preferably, the through air bonded carded web comprises polyethylene/polypropylene bi-component staple fibres.
According to an exemplary embodiment, at least a portion of the topsheet is bonded to the capillary acceleration sheet, preferably at least in a portion of the one or more channels.
According to an exemplary embodiment, the capillary acceleration sheet extends over at least 15%, preferably at least 20%, more preferably at least 45% of an upper surface area of the bottom core wrap; and/or the capillary acceleration sheet extends over at least 25%, preferably at least 30%, more preferably at least 35% of a length of the bottom core wrap; and/or wherein the capillary acceleration sheet extends over at least 25%, preferably at least 30%, more preferably at least 35% of a width of the bottom core wrap.
According to an exemplary embodiment, the bottom core wrap has a first and second longitudinal edge and a first and second transverse edge and the at least one channel comprise at least one elongate channel extending from a crotch region in the direction of the first and/or second transverse edge. This elongate channel may then comprise the first and second attachment zone of the first aspect or the attachment zone of the second aspect. Such channels will allow a good liquid distribution by mass flow between the first and second transverse edge.
According to an exemplary embodiment, the first and second channel width in accordance with the first aspect or the channel width in accordance with the second aspect, is at least 4 mm, preferably at least 6 mm, more preferably at least 8 mm, most preferably at least 9 mm, e.g. between 10 mm and 20 mm or between 12 mm and 20 mm. In that manner, it can be ensured that a sufficient amount of liquid can be distributed and any leakage can be limited or avoided. Further, by having wider channels, the risk of getting fluff material in the one or more channels may be reduced. The channel width may be constant through substantially the whole length of the channel portion or may vary along its length. When the width varies along the length, then the above specified channel width values apply for the average width of the respective channel portion.
According to an exemplary embodiment, the at least one channel comprise a first channel and a second channel portion which extend next to each other and are each extending in the direction of a first and/or second transverse edge of the bottom core wrap. Preferably, the first and second channel portion each comprise a first and second attachment zone as defined in accordance with the first aspect or an attachment zone as defined in accordance with the second aspect. Preferably, the capillary acceleration sheet at least partially covers the first and second channel. In that manner, the capillary acceleration sheet can suck liquid towards the two channels portions.
According to an exemplary embodiment, the distance, measured at a front edge, between the first and the second channel portion is between 10 mm and 50 mm, e.g. between 15 mm and 30 mm; and/or the length of the first and the second channel is larger than 60 mm, preferably larger than 70 mm. Such dimensions will typically result in a good distribution. The skilled person understands that the dimensions will be dependent on the size of the absorbent article, and thus one the size of the bottom core wrap.
According to an exemplary embodiment, the at least one channel further comprise a third and a fourth channel portion located at a distance of each other preferably connected to the first and second channel portion, respectively, said third and fourth channel portion each extending in the direction of the first and/or second transverse edge. Preferably, the capillary acceleration sheet at least partially covers the third and fourth channel. By adding such a third and fourth channel the distribution can be further enhanced. Preferably, the distance between the first and the second channel is different from the distance between the third and the fourth channel.
Preferably, measured at a front edge, the distance between the first and the second channel portion is between 20 mm and 50 mm, and, measured at a rear edge the distance between the third and the fourth channel is between 10 mm and 30 mm. Preferably, the bottom core wrap sheet has a front portion extending at one side of a transverse crotch line and a rear portion extending at the other side of the transverse crotch line; wherein the first and second channel portion extend at least in the front portion of the bottom core wrap sheet; and wherein the third and fourth channel portion extend at least in the rear portion of the bottom core wrap sheet. Preferably, the distance between the first and the second channel portion is smaller than the distance between the third and the fourth channel portion.
According to an exemplary embodiment, a position and/or shape of the at least one channel is indicated by means of a distinguishable colour and/or coloured pattern, e.g. by a printed ink layer. For example, the distinguishable colour and/or coloured pattern may be provided on at least one of the topsheet, the capillary acceleration sheet, the backsheet and the bottom core wrap. According to an exemplary embodiment, the at least one channel together extend over a channel length which is at least 20 %, preferably at least 30%, preferably at least 40%, more preferably at least 50% of a length of the absorbent core.
According to an exemplary embodiment, the at least one channel and the capillary acceleration sheet are arranged symmetrically with respect to a longitudinal centre line of the bottom core wrap.
Preferably, the absorbent material comprises cellulosic fluff pulp made up of cellulose fibres and superabsorbent particles. The fibres can be natural or synthetic. According to another exemplary embodiment, the absorbent material is substantially fluffless. Typically, absorbent material refers to a material that is applied in bulk, i.e. a 3D absorbent material, i.e. not as a sheet. In some embodiments, the absorbent material may comprise more than 20 weight% superabsorbent particles or more than 40 weight% superabsorbent particles or more than 60 weight% superabsorbent particles, or more than 80 weight% superabsorbent particles. The absorbent material may also be fluffless, i.e. with substantially without cellulose fibres.
Preferably, a shortest distance between a periphery of each channel portion and a periphery of the corresponding attachment zone is larger than 2 mm, preferably larger than 3 mm, e.g. larger than 4 mm. In that way absorbent material may expand into a portion of the channel along the full periphery of the channel.
Any of the features described above to characterize the at least one channel, the bottom core wrap and/or the top core wrap and/or the capillary acceleration sheet, may also be combined with the third and fourth aspect described below.
Aspect 3
According to a third aspect there is provided a method for manufacturing an absorbent article, comprising the steps of providing a liquid pervious topsheet and a liquid impervious backsheet; arranging an absorbent material comprising at least one of superabsorbent particles and cellulosic fluff pulp, between a bottom core wrap sheet and a top core wrap sheet, such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to areas around the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel; and arranging the liquid pervious topsheet at the side of top core wrap sheet and the liquid impervious backsheet at the side of the bottom core wrap sheet. The arranging is such that the at least one channel comprises a first channel portion extending in a longitudinal direction of the absorbent core and a second channel portion extending at an angle with respect to the first channel portion. The method further comprising attaching the top core wrap sheet to the bottom core wrap sheet in a first attachment zone of the first channel portion and in a second attachment zone of the second channel portion; said first channel portion having a first channel width (wcl) seen in a transverse direction of the absorbent core and said first attachment zone having a first attachment width (wbl) seen in the transverse direction, and said second channel portion having a second channel width (wc2) seen in a direction perpendicular on a centre line of the second channel portion and said second attachment zone having a second attachment width seen in the direction perpendicular on the centre line of the second channel portion. The attaching is done such that a first ratio (wbl /wcl) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.
Aspect 4
According to a fourth aspect, there is provided a method for manufacturing an absorbent article, comprising the steps of providing a liquid pervious topsheet and a liquid impervious backsheet; arranging an absorbent material comprising at least one of superabsorbent particles and cellulosic fluff pulp, between a bottom core wrap sheet and a top core wrap sheet, such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to areas around the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel; and arranging the liquid pervious topsheet at the side of top core wrap sheet and the liquid impervious backsheet at the side of the bottom core wrap sheet, wherein said at least one channel comprises a channel portion extending at an angle with respect to the longitudinal direction of the absorbent core, the method further comprising attaching the top core wrap sheet to the bottom core wrap sheet in an attachment zone of the channel portion; said channel portion having a channel width (wc2) seen in a direction perpendicular on a centre line of the channel portion and said attachment zone having an attachment width (wb2) seen in the direction perpendicular on the centre line of the channel portion, wherein the attaching is done such that the attachment width is less than 80% of the channel width (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
Common
Below some preferred feature of the third and fourth aspect are set out.
Preferably, the attaching is done by sealing.
Preferably, the sealing is done in accordance with a sealing pattern comprising a number of discrete sealed elements. Preferably, the method is done such as to result in an absorbent articles of any one of the embodiments discussed above.
Preferably, the arranging of the absorbent material comprises the steps of guiding a first sheet material along a rotating member, wherein a surface of said rotating member is provided with a pattern with suction zones and non-suction zones; wherein said non-suction zones are intended to form the one or more channels; applying an absorbent material on said first sheet material on the rotating member such that the suction zones are covered with absorbent material and substantially no absorbent material is present on the non-suction zones; and applying a second sheet material on top of the absorbent material on the first sheet material; and at least partially attaching said first sheet material to said second sheet material in the areas where substantially no absorbent material is present, such that one or more attachment zones in said at least one channel are formed. One of said first and second sheet material is a material for forming the top core wrap sheet, and the other one is a material for forming the bottom core wrap sheet.
Preferably, the attaching is done by applying pressure and/or heat and/or ultrasonic energy on the bottom core wrap and the capillary acceleration sheet material and/or the top core wrap material in the areas where substantially no absorbent material is present. For example, a sealing pattern as described above may be used for the attaching. Optionally the sealing with a sealing pattern may be combined with applying an adhesive between the top core wrap and the bottom core wrap. For example, adhesive may be applied on the first sheet in an area outside the at least one channel, and adhesive may be applied across the entire surface of the second sheet.
Any of the features described above in connection with the absorbent article are also applicable for embodiments of the method.
BRIEF DESCRIPTION OF FIGURES
The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of devices of the present invention. The above and other advantages of the features and objects of the invention will become more apparent and the invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which:
Figures 1-5 illustrate top views of various embodiments of absorbent cores for an absorbent article; Figure 6 is a schematic cross-section of an exemplary embodiment of an absorbent article with an absorbent core; figures 7A and 7B are cross-sections of exemplary embodiments of an absorbent article with an absorbent core; figure 7C is a detailed view of the bottom core wrap of figure 7B;
Figures 8A-8B are schematic top views of the absorbent core of the exemplary embodiments of figures 6 and 7A, respectively;
Figures 9-16 are schematic top plan views of exemplary embodiments of a diaper;
Figure 17 is a schematic top plan view of another exemplary embodiment of a diaper with four channels; and
Figure 18 is a perspective view of an exemplary embodiment of a diaper in the wetted state;
Figure 19 illustrates schematically an exemplary embodiment of a method and apparatus for manufacturing an absorbent article;
Figures 20A-E illustrate an example of a set of sealing bars having a sealing pattern;
Figure 21 A and 21B illustrate an embodiment of a channel, as seen in a cross section, in a dry state and in a wet state, respectively.
DESCRIPTION OF EMBODIMENTS
Figure 1
Figure 1 illustrates a top view of a first exemplary embodiment of an absorbent core 100 for being inserted between a liquid pervious topsheet and a liquid impervious backsheet in order to obtain an embodiment of absorbent article. The absorbent core 100 comprises a top core wrap sheet 110, a bottom core wrap sheet 120 and absorbent material (not indicated but present between the bottom core wrap sheet 120 and the top core wrap sheet 110 in areas outside the channels 1000, 2000). The absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp. The absorbent material is arranged such that channels 1000, 2000 are formed, wherein less absorbent material per surface area is present in channels 1000, 2000 compared to an area surrounding the channels 1000, 2000, wherein preferably substantially no absorbent material is present in the channels 1000, 2000.
A first channel 1000 comprises a first channel portion 140 extending in a longitudinal direction L of the absorbent core 100, here in a front portion of the absorbent core 100, a second channel portion 180 extending at an angle with respect to the first channel portion 140, and a further channel portion 160 extending in a longitudinal direction L of the absorbent core. The first channel portion 140 is connected to a first end, here a front end, of the second channel portion 180 and the further channel portion 160 is connected to a second opposite end, here a rear end, of the second channel portion 180. The first and second channel 1000, 2000 are arranged so as to be mirror images relative to a longitudinal central axis A of the absorbent core 1000. The second channel 1000 comprises a first channel portion 150 extending in a longitudinal direction L of the absorbent core 100, here in a front portion of the absorbent core 100, a second channel portion 190 extending at an angle with respect to the first channel portion 150, and a further channel portion 170 extending in the longitudinal direction L of the absorbent core 100. The second channel 2000 will not be described in detail below as its properties are identical to the properties of the first channel 1000 except from being mirrored with respect to the first channel 1000.
The first channel portion 140 has a first channel width wcl seen in a transverse direction of the absorbent core. The first channel portion 140 comprises a first attachment zone 145 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120. The first attachment zone 145 has a first attachment width wbl seen in the transverse direction T. The second channel portion 180 has a second channel width wc2 seen in a direction perpendicular on a center line C of the second channel portion 180. The second channel portion 180 comprises a second attachment zone 185 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120. The second attachment zone 185 has a second attachment width wb2 seen in the direction perpendicular on the center line C of the second channel portion 180. The further channel portion 160 has a further channel width wcf seen in a transverse direction T of the absorbent core and comprises a further attachment zone 165 where the top core wrap sheet 110 is attached to the bottom core wrap sheet 120. The further attachment zone 165 has a further attachment width wbf seen in the transverse direction T.
A first ratio wbl /wcl of the first attachment width relative to the first channel width is larger than a second ratio wb2/wc2 of the second attachment width relative to the second channel width. Preferably, the first ration is at least 5% larger than the second ratio (wbl/wcl >= 1.05*wb2/wc2), more preferably at least 10% larger, even more preferably at least 20% larger. Preferably, the second attachment width wb2 is less than 80% of the channel width wc2 (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
In the first, second and further attachment zones 145, 185, 165, preferably, the top core wrap sheet 110 is attached to the bottom core wrap sheet 120 by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy. The sealing is only applied in the attachment zones 145, 185, 165 and not in the full area of the channel 1000.
The first, second and further channel width wcl, wc2, wcf may be substantially the same, meaning that the difference between those values is less than 10% of wcl. However, those values may also be different. For example the first channel width wcl could be larger than wcf to allow more liquid mass flow in the front side of the absorbent core 100. Also, wc2 could be larger than wcl and/or wcf so as to be able to increase the attachment width wb2.
In the illustrated embodiment, the second channel portion 180 is a straight portion, but this could also be a curved portion interconnecting the first and further channel portions 140, 160.
The first and second channel 1000, 2000 each have a length Lc measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length of the absorbent core, preferably at least 30% of the length of the absorbent core La.
Preferably, the first, second and further attachment zone 145, 185, 165 include the same type of attachment, here an attachment by sealing, optionally in combination with gluing. If a combination of sealing and gluing is used, an adhesive might also be applied outside of the first, second and further attachment zone 145, 185, 165. In another embodiment, only gluing is used and a certain type of adhesive is only applied in the first, second and further attachment zone 145, 185, 165.
When sealing is used, each of the first, second and further attachment zone 145, 185, 165 may comprises a plurality of discrete bonding spots. Each attachment zone 145, 185, 165 may be considered to be delimited by a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and straight lines interconnecting said adjacent peripheral bonding points or edges. When a regular sealing pattern is used, this pattern may simply continue at an edge between adjacent attachment zones, resulting in a combined attachment area 145, 185, 165 with a regular sealing pattern.
As will be further explained below referring to Figures 20A-20D, the sealing pattern may be a regular pattern, such as a line pattern or a pattern of dots and/or the sealing pattern may comprise a large number of distinct sealing areas, such as dots or lines, spread across the first, second and further attachment zones, wherein the large number is larger than 10 and/or the sealing pattern may comprise a plurality of discrete elements, and wherein each element has a first dimension in a first direction and a second dimensions in a direction perpendicular to the first direction, wherein the first dimension is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm.
Preferably, the first, second and further attachment zones are permanent attachment zones. Preferably, the first, second and further channel width wcl, wc2, wcf is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
Preferably, seen in the longitudinal direction L of the absorbent core, an average length lb of the first attachment zone 145 is smaller than an average length 1c of the first channel portion 140. Similarly, seen in the longitudinal direction L of the absorbent core, an average length of the further attachment zone 165 may be smaller than an average length of the further channel portion 140. In this way, also the first and further attachment zones 145, 165 will allow some misalignment whilst still being within the area of the channel 1000’.
Preferably, the first attachment width wbl is less than 90% of the first channel width wcl, preferably less than 80%, more preferably less than 70%, and more than 25%.
Preferably, the channel widths wcl, wc2, wcf are at least 1 mm, preferably at least 3 mm, more preferably at least 4 mm, even more preferably at least 5 mm, most preferably at least 6 mm. The length Lc of the channels 1000, 2000 may be larger than 30 mm, preferably larger than 40 mm, more preferably larger than 50 mm. Preferably, each channel width is at least 5% of the width of the absorbent core 100, preferably at least 7%, e.g. at least 10%, e.g. at least 15% or even at least 20%. For example, the channel widths may be between 9 and 20 mm and the width of the absorbent material deposition area may be between 80 and 200 mm, e.g. between 90 and 150 mm. Preferably, the width of each channel is less than 30% of the width of the absorbent core, e.g. less than 25%. By having wider channels, the risk of getting fluff material in the one or more channels may be reduced.
Figure 2
Figure 2 illustrates a second embodiment which is similar to the embodiment of Figure 1 and the same or similar parts have been indicated with the same reference numeral and will not be described again. In the embodiment of Figure 2, instead of two channels, a single interconnected channel 1000’ is included. The interconnected channel (1000’) comprises the first, second and further channel portion 140, 180, 160. The first channel portion 140 extends along a longitudinal central axis A of the absorbent core 100, here mainly in the rear part of the absorbent core 100 but the structure could also be inverted. The second channel portion 180 is connected to the first channel portion 140 and diverges away from the longitudinal central axis A. The interconnected channel 1000’ comprises a third channel portion 190 which is arranged to be a mirror image of the second channel portion 180 relative to the longitudinal central axis A of the absorbent core 100, said third channel portion having a third attachment zone and having identical properties as the second channel portion 180. The interconnected channel 1000’ comprises a second further channel portion 170 which is arranged to be a mirror image of the further channel portion 160 relative to the longitudinal central axis A of the absorbent core 100, said second further channel portion 170 having identical properties as the further channel portion 160. The first channel portion 140 is connected to a first end, here a rear end, of the third channel portion 190 and the second further channel portion 170 is connected to a second end, here a front end, of the third channel portion 190.
The interconnected channel 1000’ has a length Lc measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length La of the absorbent core, preferably at least 30% of the length of the absorbent core.
Figure 3
The embodiment of Figure 3 is similar to the embodiment of Figure 2 and the same or similar parts have been indicated with the same reference numeral and will not be described again. In the embodiment of Figure 3, instead of straight second channel portions 180, 190, those second channels portions 180, 190 are curved and longer and there are no further and second further channel portions 160, 170.
Figure 4
The embodiment of Figure 4 is similar to the embodiment of Figure 3 and the same or similar parts have been indicated with the same reference numeral and will not be described again. In the embodiment of Figure 4, the curved second channels portions 180, 190 join at their front ends and are connected to a single further channel portions 160 which extends along the central axis A of the absorbent core 100.
Figure 5
The embodiment of Figure 5 shows some similarity to the embodiment of Figure 1 and the same or similar parts have been indicated with the same reference numeral and will not be described again. In the embodiment of Figure 5, the channels 1000, 2000 are curved over their entire length and each contain a single attachment zone 185 having a reduced attachment width wb2. The attachment width wb2 is less than 80% of the channel width wc2 (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
The preferred features set out in connection with Figure 1 , also apply to the embodiments of Figures 2-5 where applicable.
Figures 6 and 8A Figures 6 and 8A show a cross section and top view of an exemplary embodiment of an absorbent article comprising with an absorbent core 100 similar to the embodiment of Figure 1 with multiple channel portions 140, 150, 160, 170, 180, 190. The upper side of the absorbent article generally has a topsheet 300 that can be liquid pervious (not shown in figure 8 A for clarity reasons). The lower side has a backsheet 200 (not shown in figure 8A for clarity reasons) that can generally be liquid impervious and is joined with the topsheet 300 at the edges of the absorbent article (not shown). In some embodiments of adult incontinence products, the topsheet 300 and the backsheet 200 are not joined at the edges. An absorbent core 100 is positioned between the topsheet 300 and the backsheet 200. The absorbent core 100 comprises absorbent material 130 arranged between a bottom core wrap sheet 120 and a top core wrap sheet 110, in such a manner that one or more channels 1000, 2000 with channel portions 140, 150, 160, 170, 180, 190 are formed, wherein less absorbent material 130 per surface area is present in the one or more channels 1000, 2000 compared to an area around the one or more channels. An acquisition and distribution layer (ADL) 600 is provided at the top of the absorbent core 100, beneath the topsheet 300. The topsheet 300, the backsheet 200, and the absorbent core 100 can be assembled in a variety of well-known configurations. For example, the topsheet 300 and the backsheet 200 can be joined to each other by adhesive, by heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, a crimp seal, or by any other suitable securing method. In prior art embodiment the ADL 600 is typically a relatively thick layer (basis weight above 50 g/m2) and comprises a coarse fibre. Further, a liquid-impermeable, either hydrophilic or hydrophobic, distribution or wicking layer 700 is included between the absorbent core 100 and the backsheet 200. This distribution or wicking layer 700 helps to wick and transport liquids and having a capability to disperse the liquid over the surface of said wicking layer from the less absorbent area’s (e.g. saturated) to the more absorbent area’s (e.g. unsaturated). Due to the specific absorbent capacity of the distribution or wicking layer 700, the liquid in the one or more channels will be drawn up into the distribution layer and will spread out throughout the rest of the distribution layer. In that way, the distribution, transport and absorption of the liquid can be improved.
Figures 7A, 7B, 8B
Figures 7A and 8B show a cross section and top view of another exemplary embodiment of an absorbent article comprising with an absorbent core 100 similar to the embodiment of Figure 1. The absorbent article comprises a liquid pervious topsheet 300, a liquid impervious backsheet 200, an absorbent core 100 comprising absorbent material 130, and a capillary acceleration sheet 400 between the absorbent core 100 and the liquid pervious topsheet 300. The absorbent core 100 is positioned between the liquid pervious topsheet 300 and the liquid impervious backsheet 200. The absorbent material 130 is arranged between a bottom core wrap sheet 800 and a top core wrap sheet 110, such that one or more channel portions 140, 150, 160, 170, 180, 190 are formed, wherein less absorbent material 130 per surface area is present in the one or more channel portions 140, 150, 160, 170, 180, 190 compared to an area around the one or more channels, wherein preferably substantially no absorbent material is present in the one or more channel portions 140, 150, 160, 170, 180, 190. The top core wrap 110, the bottom core wrap 800 and the capillary acceleration sheet 400 may have any one or more of the features disclosed above in the summary.
The top core wrap 110 is attached to the bottom core wrap 800 at least in the attachment zones 145, 165, 185 of the first channel 1000 and in the corresponding attachment zones of the second channel 2000, see Figure 1 , and preferably the capillary acceleration sheet 400 is attached to the top core wrap 110 in at least a portion of the channels 1000, 2000. This is not shown in figure 7A but the skilled person understands that the capillary acceleration sheet 400 may be attached to the top core wrap 110 at the level of the channels 1000, 2000.
The capillary acceleration sheet 400 may take on any suitable shape. For example, the capillary acceleration sheet 400 may follow more or less the contours of the absorbent core 100. In other forms, the capillary acceleration sheet may comprise a rectangular shape regardless of the shape of the absorbent core 100. In some forms, the capillary acceleration sheet may be longer in length than the absorbent core 100 or shorter than the absorbent core 100. In other forms, the capillary acceleration sheet 400 may be positioned in a specific location on the absorbent core 100.
To provide for softness next to the body, the topsheet 300 can be formed from a soft, smooth, flexible, porous material that is non-irritating to the user's skin. The topsheet 300 is permeable to the body fluids to be collected by the absorbent article. Generally, topsheets for absorbent articles can be made from a wide range of materials such as woven and non wo ven materials; polymeric materials such as apertured formed thermoplastic films, apertured plastic films, and hydroformed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. Suitable woven and nonwoven materials can be comprised of natural fibres (e.g., wood or cotton fibres), synthetic fibres (e.g., polymeric fibres such as polyester, polypropylene, or polyethylene fibres) or from a combination of natural and synthetic fibres.
Hydrophobic topsheets or topsheets with a low hydrophilicity have a reduced tendency to allow fluids to pass back through and rewet the wearer's skin. Thus, the surface of the topsheet that is in contact with the body remains dry, thereby reducing body soiling and creating a more comfortable feel for the wearer. Example topsheets are topsheets selected from typical nonwoven forming approaches such as spunbonded, through-air bonded (TAB), carded, hydro-entangled, needled, or high loft nonwoven topsheets, and apertured 2-dimensional or 3-dimensional film topsheets. Spunbonded or through-air bonded (TAB) webs or through-air bonded carded (TABC) webs are preferred. Preferably, the through air bonded carded web comprises polyethylene/polypropylene bi-component staple fibres. “Bonded carded web” refers to webs that are made from staple fibres that are sent through a combing or carding unit, which breaks apart and aligns the staple fibres in the machine direction to form a generally machine direction-oriented fibrous nonwoven web. This web may then be drawn through a heated drum, creating bonds throughout the fabric without applying specific pressure (through air bonding process). The “Through air bonded carded web”, TABCW material provides a relatively low density, lofty web.
Preferably, the topsheet has a basis weight between 10 and 30 g/m2, preferably between 15 and 25 g/m2. Preferably, the fibres of the topsheet have an average fineness between 1-3 dtex.
Lofty apertured formed film topsheets, with appreciable topsheet texture (nubs, microtexture or with filament-like protrusions on the body-facing surface that can trap bodily discharges and hinder low fluid flows towards the body) that may be hydrophobic or hydrophilic in nature, can also be used.
It is possible and advantageous to bond the topsheet 300 directly or indirectly to the underlying capillary acceleration sheet 400. These layers may be bonded by any known bonding means, such as slot gluing, spiral gluing, fusion point bonding, sealing according to a sealing pattern, or otherwise attached.
Optionally, a distribution layer may be present between the absorbent core 100 and the capillary acceleration sheet 400. However, preferably no distribution layer is present between the capillary acceleration sheet 400 and the absorbent core 100. The function of a distribution layer is to spread the insulting fluid liquid over a larger surface within the article so that the absorbent capacity of the absorbent core 100 can be more efficiently used. Typically the distribution layer is made of a nonwoven material based on synthetic or cellulosic fibres and having a relatively low density.
The capillary acceleration sheet 400 is positioned at the body-facing side of the absorbent core 100, between the topsheet 300 and the absorbent core 100 of the absorbent article, and preferably in close proximity or even in good contact with the body-facing side of the absorbent core 100. The use of a capillary acceleration sheet 400 in combination with the one or more channels in the absorbent core 100 leads to a very good distribution of fluids from a discharge area to the entire absorbent core 100 and an increased dryness feeling at the level of topsheet 300, and this shortly after liquid insult. Figure 7C illustrates in more detail a possible bottom core wrap 800 comprising a first layer 801 and a second layer 802, wherein said first layer has a first density between 20 and 150 kg/m3 and said second layer has a second density between 100 and 400 kg/m3, said second density being higher than the first density. As shown in the embodiment of figure 7B, the first layer 801 is closer to the absorbent material 130 than said second layer 802 which faces the backsheet 200. The absorbent article of figure 7B may comprise a capillary acceleration sheet 400 and/or a top core wrap 110. As shown the capillary acceleration sheet 400 and/or the top core wrap 110 may be attached through the first layer 801 to the second layer 802 of the bottom core wrap 800 in the channel areas 160, 170. Optionally also the topsheet 300 and/or the backsheet 200 may be attached at least in a portion of the channels 1000, 2000 to the bottom core wrap 800 (not shown). Further, the bottom core wrap 800 is attached along a periphery to the bottom core wrap 110 and/or the capillary acceleration sheet 400. The bottom core wrap may be glued and/or sealed to the top core wrap 110 and/or the capillary acceleration 400 at least in a portion of the one or more channels.
The bottom core wrap 800 may consist of a single sheet. Preferably, the bottom core wrap 800 is in direct contact with the superabsorbent particles of the absorbent material 130. Preferably, a difference between the first and the second density is higher than 20 kg/m3, preferably higher than 30 kg/m3 more preferably higher than 40 kg/m2, even more preferably between 50 and 150 kg/m3, most preferably between 60 and 140 kg/m3. Preferable, the second density is selected such that it forms a barrier for the super absorbent particles.
Preferably, the bottom core wrap 800 is a through-air bonded non-woven. In an example, the first layer 801 is a through-air-bonded carded non-woven and the second layer 802 is a spunbond layer.
The first layer 801 has a first basis weight and the second layer 802 has a second basis weight, said second basis weight being lower than said first basis weight. The difference between the first layer and the second layer may be larger than 1 g/m2, preferably larger than 2 g/m2, more preferably larger than 5 g/m2. The first layer may have a first basis weight between 15 and 80 g/m2, preferably between 25 and 80 g/m2, and/or the second layer may have a second basis weight between 8 and 35 g/m2, preferably between 8 and 25 g/m2. Preferably, the first layer and/or the second layer comprise more than 90weight% of synthetic fibres, preferably more than 95weight% of synthetic fibres.
In an example, the first layer comprises polyester fibres, and the second layer comprises any one of the following fibres or a combination thereof: polyethylene, polyester, copolyester, polypropylene, polyactic acid (PL A). The attachment between the top core wrap sheet 110 and the bottom core wrap sheet 800 may be a continuous or discontinuous attachment. For example, the top core wrap sheet 110 may be attached to the bottom core wrap 800 along a portion of the one or more channels 1000, 2000 with optionally one or more unattached portions being present between attached portions. More generally, the one or more channels 1000, 2000 may comprise one or more permanent attachment portions which remain attached after wetting and/or one or more semi-permanent attachment portions which detach after wetting and/or one or more unattached portions. An unattached portion or a semi-permanent attachment portion allows for an increased swelling of the absorbent material 130 after the one or more channels 1000, 2000 have fulfilled their function of distributing the liquid. Indeed, wet absorbent material 130 is allowed to extend/swell into a portion of the channel area 1000, 2000 in case of an unattached or detached portion.
In the embodiment of figures 7A and 8B, the capillary acceleration sheet 400 covers entirely the one or more channels 1000, 2000. Such an arrangement leads to a substantial improvement in the distribution of fluids over the complete absorbent core 100. Nevertheless, other arrangements also provide a good distribution of liquids. For example, the capillary acceleration sheet 400 may only partially overlap with the one or more channels 1000, 2000 or may be located between two longitudinal channels or between two lateral channels. For example, the one or more channels may extend in a front portion of the absorbent core 100 beyond a front edge of the capillary acceleration sheet 400 and/or in a rear portion of the absorbent core 100, beyond a rear edge of the capillary acceleration sheet 400. Because the capillary acceleration sheet 400 does not cover a front and/or rear end of the one or more channels, fluid in-flow and/or fluid out-flow may be increased.
Now a series of variants will be illustrated with reference to Figures 9-16.
Figure 9
Figure 9 illustrates an exemplary embodiment of an absorbent article with an absorbent core 100 with a single channel 1000’ with a first channel portion extending in a longitudinal direction of the absorbent core 100 and a second and third channel portion extending at an angle, similarly to the embodiment of Figures 2 and 3. In Figure 9 the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
Preferably, the channel 1000’ extends over at least 20% of the length of the absorbent core 100, more preferably at least 30%, even more preferably at least 40%. In the channel 180 the capillary acceleration sheet 400 may be attached to the bottom core wrap 800 through one or more permanent or semi-permanent attachment portions. The semi-permanent portions may be configured to release after having been in contact with liquid whilst said permanent portions may be configured not to release after having been in contact with liquid. It is noted that different types of semi-permanent attachment portions may be used in the same absorbent article so as to achieve a gradual loosening of the attachments upon wetting. The absorbent material in the absorbent core 100 preferably comprises cellulosic fluff pulp and/or superabsorbent particles. However, the absorbent material may be substantially fluffless.
Preferably, substantially no absorbent material is present in the channel 1000’. A position and/or shape of the channel 1000’ may be indicated by means of a distinguishable colour and/or coloured pattern. E.g., a position and/or shape of the channel 180 may be indicated by means of a printed ink layer. The distinguishable colour and/or coloured pattern may be provided on at least one of the topsheet, the top core wrap, the capillary acceleration sheet 400, the backsheet and the bottom core wrap.
According to a preferred embodiment, outside of the channel 1000’ the absorbent core has a maximum thickness and the channel 1000’ extends through at least 90 % of the maximum thickness of the absorbent core, more preferably through substantially 100% of the thickness of the absorbent core 100 such that in the first and second attachment zone substantially no absorbent material is present between the capillary acceleration sheet 400 and the bottom core wrap.
According to a preferred embodiment, the attachment between the capillary acceleration sheet 400 and the bottom core wrap sheet is any one of the following or a combination thereof: pressure bonding, thermal bonding, sonic bonding, chemical bonding, adhesive. The attachment may be a direct or indirect attachment. E.g. an adhesive and/or other intermediate material may be inserted between the capillary acceleration sheet 400 and the bottom core wrap.
Figures 10 and 11
Figure 10 and figure 11 illustrate exemplary embodiments with two channels 1000, 2000. In Figures 10 and 11 the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
The absorbent core 100 has a first and second longitudinal edge and a first and second transverse edge and the channels 1000, 2000 are elongate channels extending from a crotch region in the direction of the first and second transverse edge. The channels 1000, 2000 may comprise one or more channel portions 140, 180 and associated attachment zones 145, 185 as discussed in connection with Figures 1-5. Preferably the one or more attachment zones are formed by any one of the following or a combination thereof: pressure bonding, thermal bonding, sonic bonding, chemical bonding, adhesive. The channels 1000, 2000 may comprise any one or more of the following: one or more permanent attachment zones, one or more semi-permanent attachment zones configured to release after having been in contact with liquid, one or more unattached zones.
The channels 1000, 2000 extend next to each other and are each extending in the direction of a first and/or second transverse edge. Preferably, the capillary acceleration sheet 400 at least partially covers both channels 1000, 2000. In Figure 10 the capillary acceleration sheet 400 partially covers the channels 1000, 2000, whilst in Figure 11 the channels are fully covered. Preferably, the distance between the channels 1000, 2000 is between 10 mm and 50 mm, preferably between 15 mm and 30 mm; and the length of the first and the second channel is larger than 60 mm, preferably larger than 70 mm.
The absorbent core 100 has a front portion extending at one side of a transverse crotch line and a rear portion extending at the other side of the transverse crotch line. In Figures 9-16, the front portion corresponds with an upper portion of the absorbent core 100, whilst in Figures 17 and 18 the front portion 100a corresponds with the lower portion of the absorbent core 100.
In Figures 10 and 11, the illustrated channels 1000, 2000 comprise straight channel portions but it will be understood that the channels may also be curved channels, wherein the distance between the channels increases toward the front transverse edge and/or towards the rear transverse edge of the absorbent core 100.
Figures 12, 17, 18
Figure 12, Figure 17 and Figure 18 illustrate another embodiment with two channels 1000, 2000 similar to the embodiment of Figure 1. In Figures 12, 17 and 18, the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
The channel portions 160, 170 are located at a distance of each other. As illustrated, the capillary acceleration sheet 400 may covers all four channel portions 140, 150, 160, 170. Preferably, as illustrated in Figures 17 and 18, the distance between the channel portion 140, 150 is different from the distance between the channel portions 160, 170. Preferably, the channel portions 140, 150 extend at least in the front portion 100a of the absorbent core 100, and the channel portions 160, 170 extend at least in the rear portion 100b of the absorbent core 100, wherein preferably the distance between the channel portions 140, 150 is bigger than the distance between the channel portions 160, 170. The channel portion 140 is connected to the channel portion 160 through a channel portion 180 and the channel portion 150 is connected to the channel portion 170 through a channel portion 190. Preferably, the channel portions 140, 150, 160, 170, 180, 190 comprise permanent attachment zones.
Preferably, the channel portions 140, 150 extend longitudinally between respective ends 141, 142, 151, 152, and the channel portions 160, 170 extend longitudinally between respective ends 161, 162, 171, 172.
As illustrated in Figure 17, the absorbent core 100 has a front edge 133, a rear edge 134, and opposite longitudinal side edges 131, 132 which define an area Al. The absorbent material 130 is deposited in an area A2 within the area Al. In the present application the length and width of the absorbent core refer to the length La and width Wai, Wa2 of the area A2. The area A2 may be slightly smaller than the area Al.
Optionally, a position and/or shape of one or more channels is indicated by means of a distinguishable colour and/or coloured pattern, e.g. by a printed ink layer, wherein preferably the distinguishable colour and/or coloured pattern is provided on at least one of the topsheet, the capillary acceleration sheet 400, the backsheet and the bottom core wrap. Preferably, the channels and the capillary acceleration sheet 400 are arranged symmetrically with respect to a longitudinal centre line of the bottom core wrap.
A first distance between the channel portions 140, 150 may be at least 5%, preferably at least 10% bigger, even more preferably at least 20% bigger than a second distance between the channel portions 160, 170. This difference may be optimized in function of the desired used. For example, for male persons the difference may be bigger.
Seen in a projection on the longitudinal direction of the absorbent core 100, the channel portions 140, 150 may extend over a length 11 which is less than the length 13 of the channel portions 160, 170. To fit better to the body the channel portions 160, 170 which are closer to each other may be longer to extend over a longer part of the crotch region, for example the channel portions 160, 170 may extend both in the front and the rear portion 100a, 100b of the absorbent core 100. Preferably, the channel portions 140, 150 extend over a length 11 which is at least 5% less, more preferably at least 10% less than the length 13 of the channel portions 160, 170. Preferably the channel portions 140, 150 extend over a length 11 which is at least 25%, more preferably at least 35%, even more preferably at least 45% of the length 13 of the channel portions 160, 170.
Figures 13 and 14
Figures 13 and 14 illustrate an absorbent article comprising an absorbent core 100 having a first and second longitudinal edge and a front and rear transverse edge. The absorbent core is provided with two interconnected elongate channel portions 140, 150 extending next to each other from a crotch region in the direction of the front and/or rear transverse edge and at least one connecting channel 1045, 1045’ connecting the first channel with the second channel portions. By providing a first and a second elongate channel portions which are interconnected by at least one connecting channel, upon wetting of the absorbent core, liquid can flow from the first elongate channel portion to the second elongate channel portion and vice versa, improving the liquid distribution, whereupon the liquid can be absorbed by the absorbent material. In Figures 13 and 14, the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
In Figure 13 the channel comprises a rear connecting channel portion 1045 which connects a rear end portion of the channel portion 140 to a corresponding rear end portion of the channel portion 150. The channel portions 140, 150 may be implemented as the first channel portion described in connection with Figures 1-5, and the channel portion 1045 may be implemented as the second channel portion 160 described in Figures 1-5. In Figure 14 both a rear connecting channel 1045 and a front connecting channel 1045’ which connects a front end portion of the channel portion 140 to a corresponding front end portion of the channel portion 150, are provided. In that manner a good distribution is obtained in the front portion and/or in the rear portion. Especially for a male person, it may be desirable to have a front connecting channel. The channel portions 140, 150 may be implemented as the first channel portion described in connection with Figures 1-5, and the channel portion 1045, 1045’ may be implemented as the second channel portion 160 described in Figures 1- 5.
The absorbent core 100 has a transverse crotch line dividing the absorbent core in a front portion and a rear portion on either side of the transverse crotch line. Preferably, the front connecting channel is located in the front portion and/or the rear connecting channel is located in the rear portion.
Preferably, the absorbent core 100 is substantially symmetrical with respect to a longitudinal center axis. For example, the channel area 140, 150, 1045, 1045’ may be substantially V-shaped or U- shaped or O-shaped, wherein the V-shape or U-shape is arranged such that it is symmetrical with respect to the longitudinal center axis of the absorbent core.
In an exemplary embodiment, the first and second channels comprise permanent attachment zones which remain attached upon wetting, or semi-permanent attachment zones configured to release after having been in contact with liquid for a predetermined period of time, wherein said predetermined period of time is preferably smaller than 30 s. In a preferred embodiment the at least one connecting channel 1045, 1045’ comprises any one or more of: a permanent attachment portion which remains attached upon wetting, a semi-permanent attachment portion configured to release after having been in contact with liquid for a predetermined period of time, wherein said predetermined period of time is preferably smaller than 30s, and unattached portion. Attachment portion/zone refers to a portion/zone where the capillary acceleration sheet 400 and/or the top core wrap is attached to the bottom core wrap.
In an exemplary embodiment, the channel portions 140, 150 are substantially parallel and extend in a longitudinal direction of the absorbent core 100 and second channel portions 180, 190 may diverge in the direction of the front edge of the absorbent core 100, see Figure 13. The second channel portions 180, 190 may be implemented as described in connection with Figures 1-5.
In an exemplary embodiment, the largest distance between the channel in the transverse direction is between 15 and 70% of the width of the absorbent core, more preferably between 20 and 50%; wherein preferably the largest distance between the first and the second channel in the transverse direction is between 10 mm and 100 mm, more preferably between 20 mm and 80 mm, even more preferably between 30 mm and 70 mm.
Figure 15
Figure 15 illustrates an embodiment with an X-shaped channel area. In Figure 15, the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
The absorbent core 100 has a first and second longitudinal edge and a first and second transverse edge, and a longitudinal center line dividing the absorbent core in a first longitudinal portion and a second longitudinal portion on either side of the longitudinal center line, and a transverse crotch line dividing the absorbent core in a front portion and a rear portion on either side of the transverse crotch line. The absorbent core is provided with a plurality of channel portions 180, 190. The channel portions 180, 190 cross the longitudinal center line in a crossing point, from a first longitudinal portion to a second longitudinal portion. The channel portions 180, 190 may be implemented as described in connection with Figures 1-5. By providing channel portions which are crossing the longitudinal center line, upon wetting of the absorbent core 100, liquid is guided in the first and/or second elongate channel from left to right and/or from right to left, respectively, whilst flowing towards the crotch region or away from the crotch region, improving the liquid distribution, whereupon the liquid can be absorbed by the absorbent material. Further, by making the channel portions cross the longitudinal center line, the channel portions may be longer compared to similar channel portions extending parallel to the longitudinal center line, resulting in a larger liquid distribution zone.
Preferably, the channel portions 180, 190 extend both in the front portion and in the rear portion. In that manner a good liquid distribution from left to right and from front to rear can be obtained. Preferably, the first elongate and the second elongate channels are arranged symmetrically with respect to the longitudinal center line of the absorbent core. Preferably, a maximum distance between the elongate channel portions 180, 190 is between 15 and 70% of the width of the absorbent core, more preferably between 20 and 50%.
In an exemplary embodiment a maximum distance between the channel portions in the front portion is different from a maximum distance between the channel portions in the rear portion. In that manner the liquid distribution zone may be better adapted to the type of person wearing the absorbent article. For example, for a male person, a maximum distance between the distance between the channel portions near a front transverse edge may be larger than a maximum distance between the channel portions in a rear portion.
Preferably, the length of the channel portions 180, 190 is larger than 10% of the length of the absorbent core, more preferably larger than 30%, even more preferably larger than 50%.
In an exemplary embodiment, the channel portions together form a substantially X-shaped zone. Optionally the legs of the “X” may be interrupted to create one or more bridging zones.
Figure 16
Figure 16 illustrates an embodiment of an absorbent article with an absorbent core 100 comprising channel portions 140, 150, 160, 180, 190 similar to the embodiment of Figure 2. In Figure 16, the capillary acceleration sheet 400 is shown to extend over only a portion of the surface area of the absorbent core 100, but it will be understood that it can also extend over the entire surface area of the absorbent core 100.
The channels comprise second channel portions 140, 150 similar to the channel portions of Figure 2, and a channel portion 160 extending from the crotch region in the direction of the second transverse edge, wherein seen in a projection on a transverse direction the channel portion 160 is located between the channel portions 140, 150. By having a channel portions 140, 150 in the front or rear portion and a channel portion 160 in the rear or front portion, respectively, it is possible to tailor the absorbent article to the wearer. For example, for a male person the channel portions 140, 150 may be in the front portion and the channel portion 160 may be in the rear portion, whilst for a female person the channel portions 140, 150 may be in the rear portion and the channel portion 160 in the front portion. Further it is possible to optimize the difference between the front and the rear portion for obtaining a unisex absorbent article.
Seen in a projection on the longitudinal direction of the absorbent core, the channel portions 140, 150 may extend over a length which is less than the length of the channel portion 160. To fit better to the body the channel portion 160 may be longer to extend over a longer part of the crotch region, for example the channel portion 160 may extend both in the front and the rear portion of the absorbent core. Preferably, the channel portions 140, 150 extend over a length which is at least 5% less, more preferably at least 10% less than the length of the channel portion 160. Preferably the first and the second channel extend over a length which is at least 25%, more preferably at least 35%, even more preferably at least 45% of the length of the channel portion 160.
In all embodiments described above, and in particular in the embodiments of Figures 9-18, preferably, each channel portion has a width, said width being at least 5% of the width (varies between Wai and Wa2 in the embodiment of Figure 17) of the absorbent core 100, preferably at least 7%, e.g. at least 10%, e.g. at least 15% or even at least 20%. For example, the channel width may be between 9 and 20 mm and the width of the absorbent material deposition area A2 (indicated in Figure 17) may be between 80 and 200 mm, e.g. between 90 and 150 mm. Preferably, the width of each channel is less than 30% of the width of the absorbent core, e.g. less than 25%. By having wider channels, the risk of getting fluff material in the one or more channels may be reduced.
The width of the absorbent core is measured in a transverse direction of the absorbent core, in an area where the respective one or more channels are present, between two end points where absorbent material is present, i.e. the width of the absorbent core is defined as the width of the absorbent material deposition area A2 of the absorbent core 100. Thus, the top core wrap sheet and/or the back core wrap sheet may extend in an area Al over a width Wa’ (as indicated in Figure 17) which is larger than the width of the absorbent core and a length La’ which is larger than the length of the absorbent core, as they may be attached along a periphery where no absorbent material is present. In the area where the one or more channels are present, the width of the absorbent core may vary between a minimum width and a maximum width (varies between Wai and Wa2 in the embodiment of Figure 17; not indicated in the other figures but may vary in a similar way or may be constant or may vary in a different way), and preferably the above specified minimum width of each channel is valid both for the minimum and the maximum width of the absorbent core. The absorbent material deposition area A2 may thus have a width which varies e.g. between a value above 100 mm and a value below 100 mm. Preferably the difference is at least 5 mm. For example, a width Wai of the absorbent material deposition area measured at a front end of the absorbent core 100 may be above 100 mm, or even above 105 mm and a width Wa2 measured at a rear end of the absorbent core 100 may be below 100 mm, or even below 95 mm.
The width wc of the channel may be constant through substantially the whole length of a channel portion (as shown in the Figures) or may vary along its length. When the width varies along the length, then the above specified width percentages and values apply for the average width of the respective channel. Preferably, the one or more channel portions are formed by one or more absorbent material-free zones within the absorbent material deposition area of the absorbent core, and the width of a channel is considered to be the width of the material-free zone, disregarding the possible presence of core wrap within the channel.
The absorbent core periphery, which may be the periphery of the top/bottom core wrap, may define any suitable shape, such as a "T," "Y," "hour-glass," or "dog-bone" shape, for example. A “T shape may have a larger width in the front portion than in the rear portion of the absorbent core. An absorbent core periphery having a generally "dog bone" or "hour-glass" shape may taper along its width towards the middle or "crotch" region of the core. In this way, the absorbent core may have a relatively narrow width in an area of the absorbent core intended to be placed in the crotch region of an absorbent article.
For all embodiments described above, preferably, the one or more channels cover together at least 20%, preferably at least 30 %, more preferably at least 40%, more preferably at least 50%, e.g. at least 60%, or at least 70%, or 80% or at least 90% of a total length La of the absorbent core. The covered length may be realized with a single channel or with a combination of two or more channels. This will allow a good distribution over the entire absorbent core as well as a good formation of the channels/embankments and will give the absorbent article a tub-shape upon swelling of the absorbent core. The length of the absorbent core is defined as the length La of the absorbent material deposition area A2 indicated in Figure 17. The length la of the bottom core wrap and/or of the top core wrap may be slightly larger than the length 1 of the absorbent material deposition area A2.
The absorbent article 100 may further comprise a wetness indicator preferably placed between two channels and/or in one or more channels and/or between a channel and an edge of the absorbent core. The wetness indicator may change appearance when contacted with liquid, e.g. the wetness indicator may be configured to generate a colour change signal that changes appearance when contacted with liquid. The wetness indicator may comprise a composition that changes appearance when contacted with liquid, in particular a composition comprising a pH indicator and/or a water soluble dye. The composition may comprise a stabilizer, a colorant, and a matrix.
Figure 19
Figure 19 illustrates an embodiment of a method for manufacturing an absorbent article. The method comprises in a first step guiding a first sheet material 110, 400 along an optional guide roller 5, and further along a rotating member 10, wherein a surface 15 of said rotating member 10 is provided with a pattern with suction zones 13, 13’ and non-suction zones 11, 12; 11’, 12’. The first sheet material 110, 400 is shown in a transparent manner to reveal the suction and non-suction zones of the rotating member 10. The suction zones 13, 13’ may be provided with holes, and the non-suction zones 11, 12; 11’, 12’ are formed of closed material. For example, the non-suction zones 11, 12; 11’, 12’ may be provided with inserts. The inserts 11, 12; 11’, 12’, may have a trapezoidal cross section. Figure 16 shows an insert pattern with four non-suction zones per absorbent core, but it will be understood that the number of inserts depends on the number of channels to be realized. The inserts may be fixed e.g. with screws on the rotating member 10. At an inner area of the rotating member 10 a vacuum is applied, see VACUUM 1. The non-suction zones 11, 12; 11’, 12’ comprise at least a first elongate zone 11, 11’ and a second elongate zone 12, 12’ extending in a circumferential direction of the rotating member 10. In a second step an absorbent material F is applied via a hopper 40 on said first sheet material 110, 400 on the rotating member 10 such that the suction zones 13, 13’ are covered with absorbent material and substantially no absorbent material is present on the non-suction zones 11, 12; 11’, 12’. In a third step a second sheet material 800 is applied on top of the absorbent material on the first sheet material 110, 400, e.g. using a further rotating member 20. The first sheet material 110, 400 may be a combination of the capillary acceleration sheet material 400 and the top core wrap material 110, and the second sheet material 800 may be bottom core wrap. However, in another embodiment, the second sheet material is a combination of the top core wrap material and the capillary acceleration sheet material, and the first sheet material may be the bottom core wrap. In a fourth step the first sheet material 110 is attached to the second sheet material 800 at least in the areas where substantially no absorbent material is present, and such that one or more channels are formed. The attaching may be done by applying pressure and/or heat and/or ultrasonic energy on the sandwich formed by the first sheet material 110, 400 and on the second sheet material 800, especially in the one or more channels where substantially no absorbent material is present, e.g. by a rotating member 30 and/or opposite rotating member 30’ which is provided with at least a first and a second seal rib or bar 31, 32 dimensioned for applying pressure and heat in the areas where substantially no absorbent material is present in order to create the channels, respectively.
The capillary acceleration sheet 140, the bottom core wrap 800 and the top core wrap 110 may have any one of the features described above or described in the summary.
While the above-described method of manufacturing absorbent articles has good results, the first sheet material and the second sheet material may be additionally attached using a binder, such as glue, to strengthen the bond between the first and second sheet material. For example, gluing may be performed as described in patent EP 3 453 368 Bl in the name of the applicant, which is included herein by reference.
The capillary acceleration sheet material 400 may also be first laminated, e.g. adhered, to a topsheet material, and the combination of the capillary acceleration sheet 400 and the topsheet may then be arranged against the top core wrap 110, wherein optionally the capillary acceleration sheet 400 may be glued to the top core wrap 110.
Figures 20A-E
Figures 20A-E illustrate an example of a set of sealing bars 31 , 31’ , 31” having a first sealing pattern. The sealing bars 31, 31’, 31” may be intended to seal portions of e.g. channels 1000, 2000. The sealing bars 31, 31’, 31” comprise respective sealing portions 145’, 165’, 185’ intended to seal permanent attachment zones 145, 165, 185 of a channel 1000. These permanent attachment zones 145, 165, 185 are smaller than the area of the channel 1000, as described in connection with Figure 1. Optionally further respective sealing portions 147’, 167’, 187’ intended to create semi-permanent attachment zones around the permanent attachment zones 145, 165, 185 may be provided. Such further respective sealing portions may have a height which is lower than the height of sealing portions 145’, 165’, 185’ such that less pressure is applied. In addition or alternatively the temperature of the further respective sealing portions may be controlled during sealing such that it is lower than the temperature of sealing portions 145’, 165’, 185’. Such measures will allow to generate a permanent attachment zone surrounded by a semi-permanent attachment zone which is such that it releases upon wetting. It will be understood that one or more sealing bars may be used in accordance with the one or more channels to be sealed. A detail of the sealing pattern is visible in the top view of figure 20B and in figure 20D which illustrates the areas where sealing will take place. Here the sealing pattern is a regular pattern of square shaped dots 3000. Figure 20E shows a cross section and illustrates that the dots are achieved by protrusions 1010. Each protrusion 1010 preferably has a flat top surface forming a dot 3000 of the sealing pattern, and an inclined peripheral surface. If an absorbent particle were to be present near the flat top surface it can easily migrate in a recess delimited by the inclined peripheral wall.
Preferably, the sealing pattern (i.e. the total surface area of the dots 3000) covers less than 80%, preferably less than 70%, more preferably less than 60%, even more preferably less than 50%, most preferably between 1 and 50% of the surface area of the one or more channels. For example, the sealing pattern covers between 1 and 50% of the total surface area of the one or more channels, or between 1 and 40%, or between 1 and 30%, or between 1 and 25%, or between 2 and 25%, or between 3 and 25%, or between 4 and 25%. Such sealing pattern may also be used in the optional further sealing portions.
Such sealing pattern can provide a good resistance against the swell forces generated by liquid being captured in the superabsorbent particles by hydrogen bonds, but the sealing pattern equally can provide resistance against dry and wet superabsorbent particles trying to penetrate through the capillary acceleration sheet and through the sealing pattern after as well as during the sealing step of the manufacturing process. In that manner, any risk of dry or wet SAP particles coming into contact with sensitive skin upon wearing is avoided or reduced. Further, by having a reduced surface area that is being sealed in accordance with a pattern, any particles remaining in the one or more channel zones can easily migrate to a non-sealing area so that the risk of creating holes in the one or more channel zones is reduced or avoided.
Although a pattern of dots 3000 is illustrated, the skilled person understands that other sealing patterns are possible, such as a line pattern e.g. a grid, etc. Also, the dots may have any shape, e.g. round, polygonal, etc. The line pattern may comprise one or more sets of parallel lines. When a first set of parallel lines and a second set of parallel lines are included, the lines of the first set may be oriented at a non-zero angle with respect to the lines of the second set. Preferably, the sealing pattern comprises a large number of distinct sealing areas (here dots 3000) spread across the one or more channels. Preferably, the large number is larger than 10, more preferably larger than 20.
Preferably, the sealing pattern comprises a plurality of discrete elements (here dots 3000), and each discrete element has a first dimension dl in a first direction and a second dimension d2 in a direction perpendicular to the first direction. The first dimension dl is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm or between 0.2 and 0.7 mm, or between 0.3 and 0.6 mm, e.g. 0.5 mm as illustrated. Preferably also the second dimension d2 is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm or between 0.2 and 0.7 mm, or between 0.3 and 0.6 mm, e.g. 0.5 mm as illustrated. However, also line patterns are possible in which case the second distance d2 may be much longer than the first distance dl.
Preferably, the distance d4 between adjacent discrete elements (here dots 3000) is smaller than 10 mm, preferably smaller than 5 mm, more preferably smaller than 2 mm, e.g. between 0.1 and 2.0 mm or between 0.2 and 1.5 mm, or between 0.3 and 1.0 mm, e.g. 0.7 mm as illustrated. Preferably, the pitch distance d3 (=dl+d4) of the dot pattern is smaller than 10 mm, preferably smaller than 5 mm, more preferably smaller than 2 mm, e.g. 1.2 mm as illustrated.
Preferably, the angle a between adjacent inclined surfaces of the protrusions 1010 is between 60 and 120 degrees, more preferably between 70 and 110 degrees, even more preferably between 80 and 100 degrees.
Preferably, plurality of discrete elements (here dots 3000) is aligned along lines oriented at an angle |3 with respect to a longitudinal direction of the absorbent core. Preferably, the angle |3 is between 20 and 160 degrees, more preferably between 30 and 150 degrees.
Figure 21
As illustrated in Figure 21, the width wb of the attachment zone 145 (here a rectangle including the dots and contacting the most peripheral points of the peripheral dots) is smaller than the channel width wc. Preferably, the width (wb) of the permanent attachment zone 145 is less than 80% of the width (wc) of the corresponding channel, preferably less than 70%, e.g. less than 60%. Preferably, the length of the permanent attachment zone 145 is at least 5 mm less than the average length of the associated channel portion, preferably at least 7 mm less. Preferably, the average length of the permanent attachment zone 145 is more than 80% of the average length of the associated channel portion. Preferably, in an area 147 of the channel portion 140 surrounding the permanent attachment zone 145 no permanent bonds are present. Optionally one or more semi-permanent attachment zones may be present in the area 147. Preferably, a shortest distance (y) between a periphery of the channel portion 140 and a periphery of the corresponding attachment zone 145 is larger than 2 mm, preferably larger than 3 mm, e.g. larger than 4 mm.
As illustrated in all embodiments of Figures 20-21 , in the context of the application, when a plurality of discrete permanent bonding spots is included, the permanent attachment zone as defined here has a polygon shape, said polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and interconnecting said adjacent peripheral bonding points or edges through straight lines. Stated differently, the adjacent left edges or points are interconnected through straight lines, adjacent rear edges or points are interconnected through straight lines, adjacent right edges or points are interconnected through straight lines and adjacent rear edges or points are interconnected through straight lines, such that a polygon is formed which includes all permanent bonding spots and touches the most peripheral edges or points thereof.
Glossary
As used in the present application, the following terms have the following meanings:
"A", "an", and "the" as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, "an edge barrier" refers to one or more than one edge barrier.
"About" as used herein referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/-20% or less, preferably +/-10% or less, more preferably +1-5% or less, even more preferably +7-1% or variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier "about" refers is itself also specifically disclosed.
"Absorbent article", "absorbent garment", "absorbent product", "absorbing article", "absorbing garment", "absorbing product" and the like as used herein are used interchangeably and refer to devices that absorb and contain bodily exudates, and more specifically, refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the various liquids discharged from the body. Absorbent articles include but are not limited to feminine hygiene garments, baby diapers and pants, adult incontinence garments, various diaper and pants holders, liners, towels, absorbent inserts and the like. "Absorbent core" as used herein refers to a three-dimensional part of the absorbent structure, comprising liquid-absorbing material, useful to permanently absorb and/or retain bodily exudates.
"Absorbent component" as used herein refers to a structural constituent of an absorbent article, e.g., a piece of an absorbent core, such as one of multiple pieces in a multi-piece absorbent core.
"Absorbent element" as used herein refers to a part of a functional constituent of an absorbent structure, e.g., an acquisition layer, a dispersion layer, core layer or a release structure formed of a material or materials having particular liquid handling characteristics suitable for the specific function.
"Absorbent fibrous polymer material" as used herein refers to an absorbent polymer material which is in threadlike from such as fibers, filaments, and the like so as to be less flowable in the dry state than particulates.
"Absorbent insert" as used herein refers to a device adapted for insertion into an "Absorbent layer" as used herein refers to a term referring to a discrete, identifiable sheet-like or web-like element of an absorbent article which may remain detached and relatively movable with respect to another such element or may be attached or joined so as to remain permanently associated with another such element. Each absorbent layer may itself include a laminate or combination of several layers, sheets and/or webs of similar or diverse compositions.
"Absorbent polymer material", "absorbent gelling material", "AGM", "superabsorbent", "super absorbent material", "super absorbent polymer", "SAP" and the like as used herein are used interchangeably and refer to any suitable particulate (e.g., flaked, particulate, granular, or powdered) or fibrous cross linked polymeric materials that can absorb at least 5 times and preferably at least about 10 times or more its weight of an aqueous 0.9% saline solution as measured using the Centrifuge Retention Capacity test (EDANA 441.2-01).
"Absorbent polymer material area" as used herein refers to the area of the absorbent structure wherein adjacent layers are separated by a multiplicity of absorbent polymer material. Incidental contact areas between these adjacent layers within the absorbent particulate polymer material area may be intentional (e.g bond area's) or unintentional (e.g. manufacturing artifacts).
"Absorbent particulate polymer material" as used herein refers to an absorbent polymer material which is in particulate form such as powders, granules, flakes and the like so as to be flowable in the dry state.
Absorption" as used herein refers to the process by which a liquid is taken up within a material. "Absorption rate" as used herein refers to the rate of absorption of liquid, i.e. the amount of liquid which is absorbed per unit of time, typically by an absorbent component, element and/or absorbent layer of the absorbent article, structure and/or core.
"Acquisition layer", "acquisition region", "acquisition surface" or "acquisition material" and the like as used herein refer to the layer overlying the absorbent core having a faster liquid uptake and/or distribution capability.
"Absorbency" is the ability of a material to take up fluids by various means including capillary, osmotic, solvent, chemical and/or other action.
"Adult incontinence garment" as used herein refers to absorbent articles intended to be worn by incontinent adults, for absorbing and containing bodily exudates.
"Adhesion" as used herein refers to the force that holds different materials together at their interface.
"Adhesive" as used herein refers to a material, which may or may not be flowable in solution or when heated, that is used to bond materials together.
"Adsorption" as used herein refers to the process by which a liquid is taken up by the surface of a material.
"Airlaying" as used herein refers to forming a web by dispersing fibers or particles in an air stream and condensing them from the air stream onto a moving screen by means of a pressure and/or vacuum; a web of fibers produced by airlaying is herein referred to an "airlaid"; an airlaid web bonded by one or more techniques to provide fabric integrity is herein referred to an "airlaid non wo ven".
"Apparent density", "density" as used herein refers to the basis weight of the sample divided by the caliper with appropriate unit conversions incorporated therein. Apparent density used herein has the unit g/cm3.
"Attach", "attached" and "attachment" as used herein are synonymous with their counterparts of the terms "fasten", "affix", "secure", "bind", "join" and "link". "Baby diaper" as used herein refers to absorbent articles intended to be worn by children, for absorbing and containing bodily exudates which the user draws up between the legs and fastens about the waist of the wearer.
"Baby pants" as used herein refers to absorbent articles marketed for use in transitioning children from diapers to underwear intended to cover the lower torso of children, so as to absorb and contain body exudates which article is generally configured like a panty garment and manufactured with a completed waist encircling portion, thereby eliminating the need for the user to fasten the article about the waist of the wearer.
"Back region" as used herein refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the back of a wearer.
"Backing" as used herein refers to a web or other material that supports and reinforces the back of a product.
"Basis weight" is the weight per unit area of a sample reported in grams per square meter, g/m2 or gsm.
"Bodily exudates", "body exudates", "bodily fluids", "body fluids", "bodily discharges", "body discharges", "fluid(s)", " liquid(s)", "fluid(s) and liquid(s) and the like as used herein are used interchangeably and refer to, but are not limited to urine, blood, vaginal discharges, breast milk, sweats and fecal matter.
"Binder", "adhesive", "glue", "resins", "plastics" and the like as used herein are used interchangeably and refer to substances, generally in a solid form (e.g. powder, film, fiber) or as a foam, or in a liquid form (e .g. emulsion, dispersion, solution) used for example by way of impregnation, spraying, printing, foam application and the like used for attaching or bonding functional and/or structural components, elements and materials, for example including heat and/or pressure sensitive adhesives, hot-melts, heat activated adhesives, thermoplastic materials, chemical activated adhesives/solvents, curable materials and the like.
"Bond strength" as used herein refers to the amount of adhesion between bonded surfaces. It is a measure of the stress required to separate a layer of material from the base to which it is bonded.
"Capillary action", "capillarity", or "capillary motion" and the like as used herein are used to refer to the phenomena of the flow of liquid through porous media. "Chassis" as used herein refers to a foundational constituent of an absorbent article upon which the remainder of the structure of the article is built up or overlaid, e.g., in a diaper, the structural elements that give the diaper the form of briefs or pants when configured for wearing, such as a backsheet, a topsheet, or a combination of a topsheet and a backsheet.
"Cellulose fibers" as used herein refers to naturally occurring fibers based on cellulose, such as, for example cotton, linen, etc; wood pulp fibers are one example of cellulose fibers; man-made fibers derived from cellulose, such as regenerated cellulose (rayon), or partially or fully acetylated cellulose derivatives (e.g. cellulose acetate or triacetate) are also considered as cellulose fibers.
"Cluster" or the like as used herein refers to an agglomeration of particles and/or fibers.
"Chemically stiffened fibers", chemically modified fibers", "chemically cross-linked fibers", "curly fibers" and the like as used herein are used interchangeably and refer to any fibers which have been stiffened by chemical means to increase stiffness of the fibers under both dry and aqueous conditions, for example by way of addition of chemical stiffening agents (e.g. by coating, impregnating, etc), altering the chemical structure of the fibers themselves (e.g. by cross-linking polymer chains, etc) and the like.
"Cohesion" as used herein refers to the resistance of similar materials to be separated from each other.
"Compartment" as used herein refers to chambers, cavities, pockets and the like.
"Comprise," "comprising," and "comprises" and "comprised of" as used herein are synonymous with "include", "including", "includes" or "contain", "containing", "contains" and are inclusive or open- ended terms that specify the presence of what follows e.g. a component and do not exclude or preclude the presence of additional, non-recited components, features, elements, members, steps, known in the art or disclosed therein.
"Coverstock" as used herein refers to a lightweight non-woven material used to contain and conceal an underlying absorbent core material; examples are the facing layer or materials that cover the absorbent cores of feminine hygiene garment s, baby diapers and pants and adult incontinence garments. "Crotch region" of an absorbent article as used herein refers to about 50% of the absorbent article's total length (i.e., in the y-dimension), where the crotch point is located in the longitudinal center of the crotch region. That is, the crotch region is determined by first locating the crotch point of the absorbent article, and then measuring forward and backward a distance of 25% of the absorbent article's total length.
"Cross direction (CD)", "lateral" or "transverse" and the like as used herein are used interchangeably and refer to a direction which is orthogonal to the longitudinal direction and includes directions within ±45° of the transversal direction.
"Curing" as used herein refers to a process by which resins, binders or plastics are set into or onto fabrics, usually by heating, to cause them to stay in place; the setting may occur by removing solvent or by cross-linking so as to make them in soluble.
"Diaper", "conventional diaper", "diaper-like", "diaper-like garment" and the like as used herein are used interchangeably and refer to disposable absorbent articles, which typically include a front waist portion and a back waist portion which may be releasable connected about the hips of the wearer during use by conventional fasteners such as adhesive tape fasteners or hook and loop type fasteners. In use, the article is positioned between the legs of the wearer and the fasteners are releasable attached to secure the back waist portion to the front waist portion of the diaper, thereby securing the diaper about the waist of the wearer. The front waist portion and a back waist portion are connected by relatively non-stretchable or stretchable members (the term "stretchable" as used herein refers to materials that are extensible when forces are applied to the material, and offer some resistance to extension). Hence, such articles are generally not configured to be pulled up or down over the hips of the wearer when the fasteners are attached.
"Dispersion layer", "dispersion region", "dispersion surface" or "dispersion material" and the like as used herein refer to the layer overlying the absorbent core having a faster liquid uptake and dispersion capability.
"Disposable" is used herein to describe articles that are generally not intended to be laundered or otherwise restored or reused (i.e., they are intended to be discarded after a single use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
"Drylaying" as used herein refers to a process for making a nonwoven web from dry fiber; these terms apply to the formation of carded webs, as well as to the air laying formation of random webs; a web of fibers produced by drylaying is herein referred to as a "drylaid"; a drylaid web bonded by one or more techniques to provide fabric integrity is herein referred to a "drylaid nonwoven".
"Dry strength" as used herein refers to the strength of ajoint determined in dry state conditions, immediately after drying under specified conditions or after a period of conditioning in the standard laboratory atmosphere.
"Essentially cellulose free", “substantially fluffless” or "little to no cellulose fibers" as used herein refers to an absorbent article, structure, core component and/or element containing less than 20% by weight cellulosic fibers, less than 10% cellulosic fibers, less than 5% cellulosic fibers, no cellulosic fibers, or no more than an immaterial amount of cellulosic fibers which do not materially affect the thinness, flexibility or absorbency thereof.
"Essentially fluffless" or "little to no fluff pulp" as used herein refers to an absorbent article, structure, core, component and/or element containing less than 20% by weight fluff pulp, less than 10% fluff pulp, less than 5% fluff pulp, no fluff pulp, or no more than an immaterial amount of fluff pulp which do not materially affect the thinness, flexibility or absorbency thereof.
"Fabric" as used herein refers to a sheet structure made from fibers, filaments and/or yarns.
"Feminine hygiene garments" as used herein refer to absorbent hygiene articles intended to be worn by woman, for absorbing and containing body exudates.
"Fiber" as used herein refers to the basic threadlike structure from which nonwovens, yarns and textiles are made. It differs from a particle by having a length at least 4 times its width; "Natural fibers" are either of animal (wool, silk), vegetable (cotton, flax, jute) or mineral (asbestos) origin, while "Man-made fibers" may be either polymers synthesized from chemical compounds (polyester, polypropylene, nylon, acrylic etc.) or modified natural polymers (rayon, acetate) or mineral (glass). "Fiber" and "filament" are used interchangeably.
"Fluff pulp" or "Pulp fluff" as used herein refers to wood pulp specially prepared to be drylaid. The fibers can be either natural or synthetic or a combination thereof.
"Front region" as used herein refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the front of a wearer. "Garment facing layer" as used herein refers to elements of the chassis that form the outer surface of the absorbent article, such as the backsheet, the side panels, the waist fasteners, and the like, when such elements are present.
"Heat activated adhesive" as used herein refers to a dry adhesive that is rendered tacky or fluid by application of heat or heat and pressure to the assembly.
"Heat sealing adhesive" as used herein refers to a thermoplastic adhesive which is melted between the adherent surfaces by heat application to one or both of the adjacent adherent surfaces.
"High loft" as used herein refers to general term of low density, thick or bulky fabrics.
"Hot-melt adhesive" as used herein refers to a solid material that melts quickly upon heating, then sets to a firm bond upon cooling; used for almost instantaneous bonding.
"Hydrophilic" as used herein refers to having an affinity for being wetted by water or for absorbing water.
"Hydrophobic" as used herein refers to lacking the affinity for being wetted by water or for absorbing water.
"Immobilization layer" as used herein refers to a layer able to be applied to the absorbent polymer material or absorbent polymer material area with the intent to gather, bond and/or immobilize absorbent material and/or absorbent layer.
"Join", "joined" and "joining" as used herein refers to encompassing configurations wherein an element is directly secured to another element by affixing the element directly to the other element, as well as configurations wherein the element is indirectly secured to the other element by affixing the element to an intermediate member or members which in turn is or are affixed to the other element.
"Knitting" as used herein refers to the technique for interlocking loops of fibers with needles or similar devices. "Layer" refers to identifiable components of the absorbent article, and any part referred to as a "layer" may actually comprise a laminate or combination of several sheets or webs of the requisite type of materials. As used herein, the term "layer" includes the terms "layers" and "layered."
"Upper" refers to the layer of the absorbent article which is nearest to and/ or faces the wearer facing layer; conversely, the term "lower" refers to the layer of the absorbent article which is nearest to and/or faces the garment facing layer. "Layer" is three dimensional structure with a x dimension width, y dimension length, and z-dimensions thickness or caliper, said x-y dimensions being substantially in the plane of the article, however it should be noted that the various members, layers, and structures of absorbent articles according to the present invention may or may not be generally planar in nature, and may be shaped or profiled in any desired configuration.
"Machine direction (MD)", "longitudinal" and the like as used herein are used interchangeably and refer to a direction running parallel to the maximum linear dimension of the structure and includes directions within ±45° of the longitudinal direction.
"Major surface" as used herein refers to a term used to describe the surfaces of greatest extent of a generally planar or sheet-like structural element and to distinguish these surfaces from the minor surfaces of the end edges and the side edges, i.e., in an element having a length, a width, and a thickness, the thickness being the smallest of the three dimensions, the major surfaces are those defined by the length and the width and thus having the greatest extent.
"Mass flow" as used herein refers to the flow of a liquid from one absorbent element or component to another absorbent element or component by channel flow action.
"Mechanical bonding" as used herein refers to a method of bonding fibers by entangling them. This can be achieved by needling, stitching with fibers or by the use of high-pressure air or water jets and the like.
"Nonwoven" as used herein refers to manufactured sheet, web or batt of directionally or randomly orientated fibers, bonded by friction, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted, tufted, stitch-bonded incorporating binding yarns or filaments, or felted by wet-milling, whether or not additionally needled. The fibers may be of natural or man-made origin and may be staple or continuous filaments or be formed in situ. Commercially available fibers have diameters ranging from less than about 0.001 mm to more than about 0.2 mm and they come in several different forms: short fibers (known as staple, or chopped), continuous single fibers (filaments or monofilaments), untwisted bundles of continuous filaments (tow), and twisted bundles of continuous filaments (yarn). Non wo ven fabrics can be formed by many processes such as melt blowing, spun bonding, solvent spinning, electrospinning, and carding. The basis weight of non wo ven fabrics is usually expressed in grams per square meter (gsm).
"Pant", "training pant", "closed diapers", "prefastened diapers", "pull-on diapers" and "diaper-pants" and the like as used herein are used interchangeably and refer to absorbent articles which are typically applied to the wearer by first leading the feet into the respective leg openings and subsequently pulling the pants from the feet to waist area over the hips and buttocks of the wearer and which are capable of being pulled up or down over the hips of the wearer. Typically, such articles may include a front waist portion and a back waist portion which may be connected about the hips of the wearer by integral or releasable members. A pant may be preformed by any suitable technique including, but not limited to, joining together portions of the article using refastenable and/or nonrefastenable bonds (e.g., seam, weld, adhesive, cohesive bond, fastener, etc.). A pant may be preformed anywhere along the circumference of the article (e.g., side fastened, front waist fastened).
"Polymer" as used herein refers to but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Unless otherwise specifically limited, the term "polymer" includes all possible spatial configurations of the molecule and include, but are not limited to isotactic, syndiotactic and random symmetries.
"Rear" as used herein refers to the portion of an absorbent article or part thereof that is intended to be positioned proximate the back of the wearer.
"Release structure", "release region", "release surface" or "release material" and the like as used herein are used interchangeably and refer to a structure in fluid communication with the absorbent core having a larger relative liquid absorption capacity and/or rate allowing it to quickly take up, temporarily hold and releasing liquids.
"Resin" as used herein refers to a solid or semisolid polymeric material.
"Thermobonding" as used herein refers to a method of bonding fibers by the use of heat and/or high- pressure.
"Thermoplastic" as used herein refers to polymeric materials that have a melting temperature and can flow or be formed into desired shapes on the application of heat at or below the melting point. "Ultrasonic" as used herein refers to the use of high frequency sound to generate localized heat through vibration thereby causing thermoplastic fibers to bond to one another.
"Water-absorbing", "liquid-absorbing", "absorbent", "absorbing" and the like as used herein are used interchangeably and refer to compounds, materials, products that absorb at least water, but typically also other aqueous fluids and typically other parts of bodily exudates such as at least urine or blood.
"Wearer facing layer" as used herein refers to elements of the chassis that form the inner surface of the absorbent article, such as the topsheet, the leg cuffs, and the side panels, etc., when such elements are present.
"Weaving" as used herein refers to the process of interlacing two or more sets of yarns at right angles to form a fabric; a web of fibers produced by weaving is herein referred to as a "woven".
"Web material" as used herein refers to an essentially endless material in one direction, i.e. the longitudinal extension or the length, or the x- direction in Cartesian coordinates relative to the web material. Included in this term is an essentially unlimited sequence of pieces cut or otherwise separated from an essentially endless material. Often, though not necessarily, the web materials will have a thickness dimension (i.e. the z-direction) which is significantly smaller than the longitudinal extension (i.e. in x-direction). Typically, the width of web materials (they-direction) will be significantly larger than the thickness, but less than the length. Often, though not necessarily, the thickness and the width of such materials is essentially constant along the length of the web. Without intending any limitation, such web materials may be cellulosic fiber materials, tissues, woven or nonwoven materials and the like. Typically, though not necessarily, web materials are supplied in roll form, or on spools, or in a folded state in boxes. The individual deliveries may then be spliced together to form the essentially endless structure. A web material may be composed of several web materials, such as multilayer non-woven, coated tissues, nonwoven/film laminates. Web materials may comprise other materials, such as added binding material, particles, hydrophilizing agents and the like.
"Wet burst strength" is a measure of a layer's ability to absorb energy, when wet and subjected to deformation normal to the plane of the web. "Wet strength" as used herein refers to the strength of a joint determined immediately after removal from a liquid in which it has been immersed under specified conditions of time, temperature and pressure. The term is commonly used in the art to designate strength after immersion in water.
"Wetlaying" as used herein refers to the forming a web from an aqueous dispersion of fibers by applying modified paper making techniques; a web of fibers produced by wetlaying is herein referred to as a "wetlaid".
"Wood pulp" as used herein refers to cellulosic fibers used to make viscose rayon, paper and the absorbent cores of products such as feminine hygiene garments, baby diapers and pants and adult incontinence garments.
"X-y dimension" as used herein refers to the plane orthogonal to the thickness of the article, structure or element. The x- and y-dimensions correspond generally to the width and length, respectively, of the article, structure or element.
"Z-dimension" as used herein refers to the dimension orthogonal to the length and width of the article, structure or element. The z-dimension corresponds generally to the thickness of the article, structure or element.

Claims

1. An absorbent article comprising a liquid pervious topsheet (300), a liquid impervious backsheet (200), an absorbent core (100) positioned between the liquid pervious topsheet and the liquid impervious backsheet, said absorbent core comprising a bottom core wrap sheet (120), a top core wrap sheet (110) and absorbent material (130) between the bottom core wrap sheet and the top core wrap sheet, wherein the absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp, wherein the absorbent material is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel, wherein said at least one channel comprises a first channel portion (140) extending in a longitudinal direction of the absorbent core and a second channel portion (180) extending at an angle with respect to the first channel portion, said first channel portion (140) having a first channel width (wcl) seen in a transverse direction of the absorbent core, said first channel portion comprising a first attachment zone (145) where the top core wrap sheet is attached to the bottom core wrap sheet, said first attachment zone having a first attachment width (wbl) seen in the transverse direction, and said second channel portion (180) having a second channel width (wc2) seen in a direction perpendicular on a centre line of the second channel portion, said second channel portion comprising a second attachment zone (185) where the top core wrap sheet is attached to the bottom core wrap sheet, said second attachment zone having a second attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion, wherein a first ratio (wbl/wcl) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.
2. The absorbent article of claim 1, wherein the first ration is at least 5% larger than the second ratio (wbl/wcl >= 1.05*wb2/wc2), preferably at least 10% larger, more preferably at least 20% larger.
3. The absorbent article of any previous claim, wherein, in the first and the second attachment zone, the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy.
4. The absorbent article of any previous claim, wherein the first and second channel width are substantially the same, wherein preferably the second channel width is less than 10% smaller or larger than the first channel width (wc2 = wcl +/- 10%).
5. The absorbent article of any previous claim, wherein the first channel portion (140) and the second channel portion (180) are interconnected.
6. The absorbent article of any previous claim, wherein the at least one channel comprises a further channel portion (160) extending in a longitudinal direction of the absorbent core, said further channel portion having a further channel width (wcf) seen in a transverse direction of the absorbent core and comprising a further attachment zone (165) where the top core wrap sheet is attached to the bottom core wrap sheet, said further attachment zone having a further attachment width (wbf) seen in the transverse direction, wherein the first channel portion (140) is connected to a first end of the second channel portion (180) and the further channel portion (160) is connected to a second opposite end of the second channel portion (180).
7. The absorbent article of any previous claim, wherein the first and further channel width are substantially the same, wherein preferably the further channel width is less than 10% smaller or larger than the first channel width (wcf = wcl +/- 10%).
8. The absorbent article of any previous claim, wherein the second channel portion (180) is a straight portion.
9. The absorbent article of any previous claim, wherein the second channel portion (180) is a curved portion.
10. The absorbent article of any previous claim, wherein the at least one channel comprises a first channel (1000) and a second channel (2000), said first channel including the first and second channel portion (140, 180), said first and second channel being arranged so as to be mirror images relative to a longitudinal central axis (A) of the absorbent core.
11. The absorbent article of the previous claim, wherein the first and second channel (1000, 2000) each have a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length of the absorbent core, preferably at least 30% of the length of the absorbent core (La).
12. The absorbent article of any one of the claims 1-9, wherein the at least one channel comprises, preferably consists of, an interconnected channel (1000’) comprising the first and second channel portion, wherein the first channel portion (140) extends along a longitudinal central axis (A) of the absorbent core and the second channel portion (180) is connected to the first channel portion and diverges away from the longitudinal central axis, wherein the interconnected channel comprises a third channel portion (190) which is arranged to be a mirror image of the second channel portion relative to the longitudinal central axis of the absorbent core, said third channel portion having a third attachment zone.
13. The absorbent article of the previous claim, wherein the interconnected channel (1000’) has a length (Lc) measured in a longitudinal direction of the absorbent core, said length being at least 20% of the length (La) of the absorbent core, preferably at least 30% of the length of the absorbent core.
14. The absorbent article of claims 6 or 7 and 12 or 13, comprising a second further channel portion, wherein the first channel portion (140) is connected to a first end of the third channel portion (190) and the second further channel portion (170) is connected to a second end of the third channel portion (190).
15. The absorbent article of any previous claim, wherein the first and the second attachment zone include the same type of attachment.
16. The absorbent article of any previous claim, wherein each of the first and second attachment zone comprises a plurality of discrete bonding spots and is delimited by a polygon including adjacent peripheral bonding points or edges of the plurality of discrete bonding spots, and straight lines interconnecting said adjacent peripheral bonding points or edges.
17. The absorbent article of any previous claim, wherein the first attachment zone is a permanent attachment zone.
18. The absorbent article of any previous claim, wherein the second attachment zone is a permanent attachment zone.
19. The absorbent article of any previous claim, wherein the first and/or second channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
20. The absorbent article of any previous claim, wherein, seen in a longitudinal direction of the absorbent core, an average length (lb) of the first attachment zone is smaller than an average length (lc) of the first channel portion.
21. The absorbent article of the previous claim, wherein the first attachment width (wbl) is less than 90% of the first channel width (wcl), preferably less than 80%, more preferably less than 70%, and more than 25%.
22. An absorbent article comprising a liquid pervious topsheet (300), a liquid impervious backsheet (200), an absorbent core (100) positioned between the liquid pervious topsheet and the liquid impervious backsheet, said absorbent core comprising a bottom core wrap sheet (120), a top core wrap sheet (110) and absorbent material (130) between the bottom core wrap sheet and the top core wrap sheet, wherein the absorbent material comprises at least one of superabsorbent particles and cellulosic fluff pulp, wherein the absorbent material is arranged such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to an area surrounding the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel, wherein said at least one channel comprises a channel portion (180) extending at an angle with respect to a longitudinal direction of the absorbent core, said channel portion (180) having a channel width (wc2) seen in a direction perpendicular on a centre line of the channel portion, said channel portion comprising an attachment zone (185) where the top core wrap sheet is attached to the bottom core wrap sheet, said attachment zone having an attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion, wherein the attachment width is less than 80% of the channel width (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
23. The absorbent article of the previous claim, wherein, in the attachment zone, the top core wrap sheet is attached to the bottom core wrap sheet by sealing, wherein preferably the sealing is realized by heat and/or pressure and/or ultrasonic energy.
24. The absorbent article of any previous claim, wherein the channel width is at least 5% of the width of the absorbent core, preferably at least 7%, e.g. at least 10%, and less than 30%.
25. The absorbent article of claim 3 or 23, wherein the sealing is done in accordance with a sealing pattern.
26. The absorbent article of the previous claim, wherein the sealing pattern is a regular pattern, such as a line pattern or a pattern of dots; and/or wherein the sealing pattern comprises a large number of distinct sealing areas, such as dots or lines, spread across the first and second attachment zone, wherein the large number is larger than 10; and/or wherein the sealing pattern comprises a plurality of discrete elements, and wherein each element has a first dimension in a first direction and a second dimensions in a direction perpendicular to the first direction, and wherein the first dimension is smaller than 2 mm, preferably smaller than 1.5 mm, more preferably smaller than 1 mm, e.g. between 0.1 and 0.7 mm.
27. The absorbent article of any one of the previous claims, wherein adhesive is arranged between the bottom core wrap sheet and the top core wrap sheet at least in a portion of the at least one channel, within and/or outside of the first and second attachment zone.
28. The absorbent article of the previous claim, wherein the bottom core wrap sheet is a spunbond meltblown spunbond nonwoven comprising a first spunbond layer, a meltblown layer and a second spunbond layer on the other side of the meltblown layer, wherein preferably the second spunbond layer comprises polypropylene fibres.
29. The absorbent article of any previous claim, further comprising a capillary acceleration sheet between the absorbent core and the liquid pervious topsheet (300).
30. The absorbent article of the previous claim, wherein the capillary acceleration sheet is a through- air-bonded non wo ven having a basis weight between 15 and 50 g/m2, preferably between 15 and 30 g/m2.
31. The absorbent article of any previous claim, wherein the bottom core wrap sheet has a basis weight which is larger than the basis weight of the top core wrap sheet.
32. The absorbent article of any one of the previous claims, the top core wrap sheet comprises at least one spunbond and optionally at least one meltblown layer.
33. The absorbent article of any one of the previous claims, wherein the top core wrap sheet has a basis weight between 8 and 30 g/m2.
34. The absorbent article of any one of the previous claims, wherein the bottom core wrap sheet is in contact with the absorbent material and has an average density between 20 and 400 kg/m3, preferably between 20 and 300 kg/m3, more preferably between 20 and 250 kg/m3, even more preferably between 20 and 200 kg/m3, e.g. between 20 and 120 kg/m3.
35. The absorbent article of any one of the previous claims, wherein an amount of cellulosic fluff pulp in the absorbent material is below 250 g/m2, preferably below 200 g/m2, more preferably below 180 g/m2, even more preferably below 160 g/m2, e.g. between 60 g/m2 and 180 g/m2 or between 70 g/m2 and 170 g/m2.
36. The absorbent article of any one of the previous claims, wherein an amount of superabsorbent particles in the absorbent material is above 300 g/m2, preferably above 320 g/m2, more preferably above 340 g/m2, e.g. between 300 g/m2 and 400 g/m2 or between 320 g/m2 and 390 g/m2.
37. The absorbent article of any one of the previous claims, wherein the superabsorbent particles have a permeability SFC which is higher than 10 x 107 cm3.S.g 1 and/or a permeability GBP which is higher than 20 Da, preferably higher than 25 Da.
38. The absorbent article of any one of the previous claims, wherein the absorbent material comprises more than 60 weight%, preferably more than 70 weight% superabsorbent particles.
39. The absorbent article of any one of the previous claims, wherein the bottom core wrap sheet and/or the top core wrap sheet and/or the capillary acceleration sheet comprises more than 50 weight% of synthetic fibres, preferably more than 80 weight% of synthetic fibres, preferably more than 90 weight% of synthetic fibres, even preferably more than 95weight% of synthetic fibres.
40. The absorbent article of any one of the previous claims, wherein the at least one channel comprises one or more elongated channels each having a channel length measured in a longitudinal direction of the absorbent core, said channel length being at least 10% of the length of the absorbent core, preferably at least 15% of the length of the absorbent core, the one or more elongated channels comprising the channel portions.
41. The absorbent article of the previous claim, wherein the one or more elongated channels comprise at least a first and a second elongated channel extending at a distance of each other in a substantially longitudinal direction of the absorbent core.
42. A method for manufacturing an absorbent article, comprising the steps of providing a liquid pervious topsheet and a liquid impervious backsheet; arranging an absorbent material comprising at least one of superabsorbent particles and cellulosic fluff pulp, between a bottom core wrap sheet and a top core wrap sheet, such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to areas around the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel; and arranging the liquid pervious topsheet at the side of top core wrap sheet and the liquid impervious backsheet at the side of the bottom core wrap sheet, wherein said at least one channel comprises a first channel portion (140) extending in a longitudinal direction of the absorbent core and a second channel portion (180) extending at an angle with respect to the first channel portion, the method further comprising attaching the top core wrap sheet to the bottom core wrap sheet in a first attachment zone of the first channel portion and in a second attachment zone of the second channel portion; said first channel portion (140) having a first channel width (wcl) seen in a transverse direction of the absorbent core and said first attachment zone having a first attachment width (wbl) seen in the transverse direction, and said second channel portion (180) having a second channel width (wc2) seen in a direction perpendicular on a centre line of the second channel portion and said second attachment zone having a second attachment width (wb2) seen in the direction perpendicular on the centre line of the second channel portion, wherein the attaching is done such that a first ratio (wbl /wcl) of the first attachment width relative to the first channel width is larger than a second ratio (wb2/wc2) of the second attachment width relative to the second channel width.
43. A method for manufacturing an absorbent article, comprising the steps of providing a liquid pervious topsheet and a liquid impervious backsheet; arranging an absorbent material comprising at least one of superabsorbent particles and cellulosic fluff pulp, between a bottom core wrap sheet and a top core wrap sheet, such that at least one channel is formed, wherein less absorbent material per surface area is present in the at least one channel compared to areas around the at least one channel, wherein preferably substantially no absorbent material is present in the at least one channel; and arranging the liquid pervious topsheet at the side of top core wrap sheet and the liquid impervious backsheet at the side of the bottom core wrap sheet, wherein said at least one channel comprises a channel portion (180) extending at an angle with respect to the longitudinal direction of the absorbent core, the method further comprising attaching the top core wrap sheet to the bottom core wrap sheet in an attachment zone of the channel portion; said channel portion (180) having a channel width (wc2) seen in a direction perpendicular on a centre line of the channel portion and said attachment zone having an attachment width (wb2) seen in the direction perpendicular on the centre line of the channel portion, wherein the attaching is done such that the attachment width is less than 80% of the channel width (wb2 < 0.8*wc2), preferably less than 70%, more preferably less than 60%, even more preferably less than 50%.
44. The method of claim 42 or 43, wherein the attaching is done by sealing.
45. The method of the previous claim, wherein the sealing is done in accordance with a sealing pattern comprising a number of discrete sealed elements.
46. The method of any one of the claims 42-45, wherein the method is done such as to result in an absorbent articles of any one of the claims 1-41.
PCT/EP2024/081052 2023-11-03 2024-11-04 Absorbent article with improved attachment zone Pending WO2025093767A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3403631A1 (en) 2017-05-15 2018-11-21 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3453368A1 (en) 2017-09-11 2019-03-13 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3403632B1 (en) 2017-05-15 2019-08-14 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3403630B1 (en) 2017-05-15 2019-08-28 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3711732B1 (en) * 2019-03-21 2021-11-17 Ontex BV Absorbent articles and methods of making
WO2023194456A1 (en) * 2022-04-08 2023-10-12 Drylock Technologies Nv Absorbent insert

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3403631A1 (en) 2017-05-15 2018-11-21 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3403632B1 (en) 2017-05-15 2019-08-14 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3403630B1 (en) 2017-05-15 2019-08-28 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3453368A1 (en) 2017-09-11 2019-03-13 Drylock Technologies NV Absorbent article with channels and method for manufacturing thereof
EP3711732B1 (en) * 2019-03-21 2021-11-17 Ontex BV Absorbent articles and methods of making
WO2023194456A1 (en) * 2022-04-08 2023-10-12 Drylock Technologies Nv Absorbent insert

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