WO2025048782A1

WO2025048782A1 - An absorbent article with a wrapped absorbent core

Info

Publication number: WO2025048782A1
Application number: PCT/US2023/031340
Authority: WO
Inventors: Joseph R. Riegert; Michael D. Sperl; Bruce E. Rogers; Robert M. MAYVILLE
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Priority date: 2023-08-29
Filing date: 2023-08-29
Publication date: 2025-03-06
Anticipated expiration: 2026-02-28

Abstract

An absorbent article includes a bodyside liner, an outer cover, and an absorbent assembly positioned between the bodyside liner and the outer cover. An absorbent core is disposed within a middle casing of a nonwoven wrap. A front extension extends from a front portion of the middle casing, and a rear extension extends from a rear portion of the middle casing. One or both of the front extension and the rear extension of the nonwoven wrap is folded over itself to assist with sealing the absorbent core within the nonwoven wrap.

Description

AN ABSORBENT ARTICLE WITH A WRAPPED ABSORBENT CORE

BACKGROUND

Personal care absorbent articles, such as diapers and incontinence briefs, frequently include an absorbent core that rapidly absorbs bodily fluids (e.g. , urine) and traps the fluid therein to limit retransmission of the fluids to the wearer. The absorbent core can include wood pulp fluff and superabsorbent material for absorbing the fluids

Characteristics of the absorbent core can affect consumer perception of the personal care absorbent articles. For instance, some consumers prefer the soft feel of lower density, higher loft absorbent cores relative to conventional higher density, lower loft absorbent cores. However, manufacturing personal care absorbent articles with lower density, higher loft absorbent cores poses challenges. For example, fluff and/or superabsorbent material in such absorbent cores can displace and deform the shape of the absorbent layer during manufacture.

An absorbent article with a low density, high loft absorbent core and features for maintaining a shape of the absorbent core during manufacture would be useful.

SUMMARY

In general, the present disclosure is directed to an absorbent assembly with an absorbent core disposed within a nonwoven wrap. Moreover, one or more extensions of the nonwoven wrap may be folded over to assist with sealing the absorbent core within the nonwoven wrap. Such sealing can assist with limiting movement of fluff and/or superabsorbent material of the absorbent material during highspeed manufacturing of an absorbent article. For instance, the folded extension(s) can limit or prevent material in the soft, low density absorbent core from exiting or “squishing out” of the nonwoven wrap due to the impact of a blade folder during highspeed manufacturing of an absorbent article.

In one example embodiment, an absorbent article includes a bodyside liner, an outer cover; and an absorbent assembly positioned between the bodyside liner and the outer cover The absorbent assembly includes a nonwoven wrap and an absorbent core. The nonwoven wrap includes a middle casing, a front extension, and a rear extension. The absorbent core is disposed within the middle casing of the nonwoven wrap. The front extension extends from a front portion of the middle casing, and the rear extension extends from a rear portion of the middle casing. One or both of the front extension and the rear extension of the nonwoven wrap is folded over itself.

In another example embodiment, a method for forming absorbent articles includes: forming a plurality of discrete absorbent cores on a nonwoven wrap web to form a composite web; cutting the composite web between the discrete absorbent cores to form a plurality of absorbent assemblies each comprising a nonwoven wrap and an absorbent core, the absorbent core disposed within a middle casing of the nonwoven wrap in each absorbent assembly; folding over at least one of a front extension or a rear extension of each nonwoven wrap; and joining the plurality of absorbent assemblies between a bodyside liner and an outer cover.

These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 is a top plan view of an absorbent article according to example aspects of the present disclosure, in a stretched and laid flat arrangement;

FIG. 2 is a top plan view of an absorbent assembly of the example absorbent article of FIG. 1 ;

FIG. 3 is a schematic, partial section view of the example absorbent garment of FIG. 1 ;

FIG. 4 is a schematic, partial section view of an absorbent garment according to another example embodiment;

FIG. 5 is a schematic, partial section view of an absorbent garment according to another example embodiment;

FIG. 6 is a schematic, side elevation view of a method and apparatus according to example aspects of the present disclosure;

FIG. 7 is another schematic, side elevation view of the example method and apparatus of FIG 6;

FIG. 8 is a side perspective schematic view of a forming drum according to example aspects of the present disclosure; and

FIG. 9 is an exemplary composite web formed during an intermediate step of a method according to example aspects of the present disclosure, with portions cut away to illustrate underlying features; and

FIG. 10 is another schematic, side elevation view of the example method and apparatus of FIG. 6. Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention. DETAILED DESCRIPTION

The present disclosure is generally directed absorbent articles, in which an absorbent assembly is positioned between a bodyside liner and an outer cover. The absorbent assembly includes a nonwoven wrap and an absorbent core. The absorbent core is disposed within a middle casing of the nonwoven wrap, and a front extension and/or a rear extension of the nonwoven wrap may be folded, e.g , over the middle casing of the nonwoven wrap. Such folding of the nonwoven wrap may assist with maintaining a shape of the absorbent core during manufacture of the absorbent article. Moreover, such folding of the nonwoven wrap may assist with limiting movement of fluff and/or superabsorbent material of the absorbent core during manufacture of the absorbent article, such as during folding of the absorbent article with a blade folder. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present disclosure.

When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles "a'', “an", "the" and "said" are intended to mean that there are one or more of the elements. As used herein, the terms "includes" and "including” are intended to be inclusive in a manner similar to the term "comprising." Similarly, the term "or" is generally intended to be inclusive (i.e., "A or B” is intended to mean “A or B or both”). Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about,” “approximately," and "substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. For example, the approximating language may refer to being within a ten percent (10%) margin

Definitions:

The term “absorbent article” refers herein to an article which may be placed against or in proximity to the body (i.e., contiguous with the body) of the wearer to absorb and contain various liquid, solid, and semi-solid exudates discharged from the body Such absorbent articles, as described herein, are intended to be discarded after a limited period of use instead of being laundered or otherwise restored for reuse. It is to be understood that the present disclosure is applicable to various disposable absorbent articles, including, but not limited to, diapers, diaper pants, training pants, youth pants, swim pants, feminine hygiene products, including, but not limited to, menstrual pads or pants, incontinence products, medical garments, surgical pads and bandages, other personal care or health care garments, and the like without departing from the scope of the present disclosure. The term “bonded” refers herein to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered bonded together when they are joined, adhered, connected, attached, or the like, directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements.

The term “carded web” refers herein to a web containing natural or synthetic staple fibers typically having fiber lengths less than about one hundred millimeters (100 mm). Bales of staple fibers can undergo an opening process to separate the fibers that are then sent to a carding process that separates and combs the fibers to align them in the machine direction after which the fibers are deposited onto a moving wire for further processing Such webs are usually subjected to some type of bonding process, such as thermal bonding using heat and/or pressure. In addition to or in lieu thereof, the fibers can be subject to adhesive processes to bind the fibers together, such as by the use of powder adhesives. The carded web can be subjected to fluid entangling, such as hydroentangling, to further intertwine the fibers and thereby improve the integrity of the carded web. Carded webs, due to the fiber alignment in the machine direction, once bonded, will typically have more machine direction strength than cross machine direction strength.

The term “elastic” and derivatives thereof refers to materials or components that are generally capable of recovering their shape after deformation when the deforming force is removed. Specifically, as used herein, the term elastic or elastomeric is meant to be that property of any material or component which, upon application of a biasing force, permits that material or component to be stretchable to a stretched, biased length, which is at least about 125 percent, that is 1.25 times, its relaxed, unbiased length, and that will cause the material to recover at least 40 percent of its elongation upon release of the stretching, elongating force.

The term “fiber” generally refers to an elongated extrudate formed by passing a polymer through a forming orifice, such as a die. Unless noted otherwise, the term “fiber” includes both discontinuous fibers having a definite length and substantially continuous filaments. Substantially continuous filaments may, for instance, have a length much greater than their diameter, such as a length to diameter ratio (“aspect ratio”) greater than about 15,000 to 1 , and in some cases, greater than about 50,000 to 1. The fiber is “hollow" to such an extent that the fiber contains a hollow cavity extending along at least a portion of the fiber in the longitudinal direction. In some cases, the cavity may extend along the entire length of the fiber.

The term “film” refers herein to a thermoplastic film made using an extrusion and/or forming process, such as a cast film or blown film extrusion process. The term includes apertured films, slit films, and other porous films that constitute liquid transfer films, as well as films that do not transfer fluids, such as, but not limited to, barrier films, filled films, breathable films, and oriented films. The term “gsm” refers herein to grams per square meter.

The term “hydrophilic” refers herein to fibers or the surfaces of fibers which are wetted by aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials or blends of fiber materials can be provided by Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 90 are designated “wettable" or hydrophilic, and fibers having contact angles greater than 90 are designated ‘nonwettable” or hydrophobic.

The term “liquid impermeable” refers herein to a layer or multi-layer laminate in which liquid body exudates, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact.

The term “liquid permeable" refers herein to any material that is not liquid impermeable.

The term “meltblown” refers herein to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity heated gas (e.g., air) streams that attenuate the filaments of molten thermoplastic material to reduce their diameter, which can be a microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al., which is incorporated herein by reference. Meltblown fibers are microfibers that can be continuous or discontinuous, are generally smaller than about 0.6 denier, and can be tacky and self-bonding when deposited onto a collecting surface

The term “nonwoven” refers herein to materials and webs of material that are formed without the aid of a textile weaving or knitting process. The materials and webs of materials can have a structure of individual fibers, filaments, or threads (collectively referred to as “fibers”) that can be interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven materials or webs can be formed from many processes, such as, but not limited to, meltblowing processes, spunbonding processes, carded web processes, etc.

The term “pliable” refers herein to materials that are compliant and that will readily conform to the general shape and contours of a body of the wearer.

The term “spunbond” refers herein to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine capillaries of a spinnerette having a circular or other configuration, with the diameter of the extruded filaments then being rapidly reduced by a conventional process such as, for example, eductive drawing, and processes that are described in U.S. Patent No. 4,340,563 to Appel et al., U.S. Patent No. 3,692,618 to Dorschner et al., U.S. Patent No. 3,802,817 to Matsuki et al., U.S. Patent Nos. 3,338,992 and 3,341 ,394 to Kinney, U.S. Patent No. 3,502,763 to Hartmann, U.S. Patent No. 3,502,538 to Peterson, and U.S. Patent No. 3,542,615 to Dobo et al., each of which is incorporated herein in its entirety by reference. Spunbond fibers are generally continuous and often have average deniers larger than about 0 3, and in an embodiment, between about 0.6, 5 and 10 and about 15, 20 and 40. Spunbond fibers are generally not tacky when they are deposited on a collecting surface

The term “superabsorbent'' refers herein to a water-swellable, water-insoluble organic or inorganic material capable, under the most favorable conditions, of absorbing at least about fifteen (15) times its weight and, in an aspect, at least about thirty (30) times its weight, in an aqueous solution containing 0.9 weight percent sodium chloride. The superabsorbent materials can be natural, synthetic, and modified natural polymers and materials. In addition, the superabsorbent materials can be inorganic materials, such as silica gels, or organic compounds, such as cross-linked polymers.

The term “thermoplastic" refers herein to a material which softens and which can be shaped when exposed to heat and which substantially returns to a non-softened condition when cooled.

The term “user” or “caregiver” refers herein to one who fits an absorbent article, such as, but not limited to, a diaper, diaper pant, training pant, youth pant, incontinent product, or other absorbent article about the wearer of one of these absorbent articles. A user and a wearer can be one and the same person.

Absorbent Article:

FIG. 1 representatively illustrates an example embodiment of an absorbent article 20, in a laid flat arrangement The surface of the article 20 which contacts the wearer is facing the viewer in FIG. 1 . The absorbent article 20 may define a front portion 22, a rear portion 24 and a crotch portion 26 connecting the front portion 22 and the rear portion 24. The front portion 22 may define a front waist region 23 and include a front waist edge 41 . The rear portion 24 may define a rear waist region 25 and include a rear waist edge 43. The absorbent article 20 may also define a longitudinal direction 48 and a lateral direction 50, e.g., which are perpendicular to each other. The absorbent article 20 may include a bodyside liner 30, an outer cover 32, and an absorbent assembly 34 located between the bodyside liner 30 and the outer cover 32. In various example embodiments, the bodyside liner 30 may include one or more apertures 31 .

The absorbent assembly 34 may include an absorbent core 80 and at least one nonwoven nonwoven wrap 84. The absorbent core 80 may have a front edge 81 and a rear edge 82. The front edge 81 and the rear edge 82 of the absorbent core 80 may be generally parallel and opposed in the longitudinal direction 48. The absorbent core 80 may also have laterally opposed side edges 83. The nonwoven wrap 84 may have a front edge 85 and a rear edge 86. The front edge 85 and the rear edge 86 of the nonwoven wrap 84 may be generally parallel and opposed in the longitudinal direction 48. The nonwoven wrap 84 may also have laterally opposed side edges 87.

The region between the nonwoven wrap front edge 85 and the absorbent core front edge 81 may define a front extension 90. The region between the absorbent core front edge 81 and the absorbent core rear edge 82 may define a nonwoven wrap region or middle casing 92. The region between the absorbent core rear edge 82 and the nonwoven wrap rear edge 86 may define a rear extension 94 In example embodiments, as shown in FIG. 2, middle casing 92 may extend longitudinally between a front portion 96 and a rear portion 97 along the longitudinal direction 48. The front extension 90 may extend along the longitudinal direction 48 from the front portion 96 of middle casing 92, e.g at the absorbent core front edge 81 , and the rear extension 94 may extend along the longitudinal direction 48 from the rear portion 97 of middle casing 92, e.g., at the absorbent core rear edge 86.

As used herein, reference to a front portion refers to that part of the absorbent article 20 which is generally located on the front of a wearer when in use. Reference to a front waist region refers to that part of the front portion which is located generally near the waist opening. Reference to the rear portion refers to the portion of the absorbent article 20 generally located at the rear of the wearer when in use. Reference to a rear waist region refers to that part of the rear portion which is located generally near the waist opening. Reference to the crotch portion refers to that portion which is generally located between the legs of the wearer when in use.

The crotch portion 26 may have opposite longitudinal side portions 28 which include a pair of elasticized, longitudinally extending leg cuffs 36. The leg cuffs 36 may be generally adapted to fit about the legs of a wearer in use and serve as a mechanical barrier to the lateral flow of body exudates The leg cuffs 36 may be elasticized by leg elastics 38. The absorbent article 20 may further include a front waist elastic 40 and/or a rear waist elastic 42. The rear portion 24 of the absorbent article 20 may further include fasteners 44 configured to hold the absorbent article 20 about the waist of the wearer when in use. The absorbent article 20 may also include a pair of containment flaps which extend longitudinally along the absorbent article 20 and are also adapted to provide a barrier to the flow of body exudates. It should be recognized that individual components of the absorbent article 20, such as the elastic members, may be optional depending upon the intended use of the absorbent article 20.

The bodyside liner 30 of the absorbent article 20 may suitably present a body-facing surface which is intended to be worn adjacent the body of the wearer and is compliant, soft feeling and nonirritating to the wearer's skin. Further, the bodyside liner 30 may be less hydrophilic than the absorbent assembly 34, to present a relatively dry surface to the wearer, and may be sufficiently porous to be liquid permeable, permitting liquid to readily penetrate through a thickness of the bodyside liner 30. A suitable bodyside liner 30 may be manufactured from a wide selection of web materials, such as porous foams, reticulated foams, apertured plastic films, natural fibers (for example, wood or cotton fibers), synthetic fibers (for example, polyester or polypropylene fibers), or a combination of natural and synthetic fibers. The bodyside liner 30 may be suitably employed to help isolate the wearer's skin from fluids held in the absorbent assembly 34.

Various woven and nonwoven fabrics can be used for the bodyside liner 30. For example, the bodyside liner 30 may be composed of a meltblown or spunbonded web of polyolefin fibers. The bodyside liner 30 may also be a bonded-carded web composed of natural and/or synthetic fibers. The bodyside liner 30 may be composed of a substantially hydrophobic material, and the hydrophobic material may, optionally, be treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. The bodyside liner 30 may have one or more apertures 31 extending partially or completely through the thickness of the liner 30. In some example embodiments, the bodyside liner 30 may have a plurality of apertures 31 adapted to receive urine and/or fecal material.

The outer cover 32 of the absorbent article 20 may suitably be composed of a material which is either liquid permeable or liquid impermeable. It is generally preferred that the outer cover 32 be formed from a material which is substantially impermeable to fluids. For example, the outer cover 32 may be manufactured from a thin plastic film or other flexible liquid-impermeable material. For example, the outer cover 32 may be formed from a polyethylene film. If it is desired to present the outer cover 32 with a more clothlike feeling, the outer cover 32 may include a polyethylene film having a nonwoven web laminated to the outer surface thereof, such as a spunbond web of polyolefin fibers.

Further, the outer cover 32 may be formed of a woven or nonwoven fibrous web layer which has been totally or partially constructed or treated to impart a desired level of liquid impermeability to selected regions that are adjacent or proximate the absorbent assembly 34. Still further, the outer cover 32 may optionally be composed of a micro-porous “breathable" material which permits vapors to escape from the composite absorbent assembly 34 while still preventing liquid exudates from passing through the outer cover 32.

The bodyside liner 30 and outer cover 32 may be generally joined to each other so as to form a pocket in which the absorbent assembly 34 is located. The bodyside liner 30 and outer cover 32 may be joined directly to each other around the outer periphery of the absorbent article 20 by any suitable mechanism, such as, for example, adhesive bonds, sonic bonds, thermal bonds, pressure bonds, and the like, and combinations thereof. For example, a uniform continuous layer of adhesive, a patterned layer of adhesive, a sprayed or meltblown pattern of adhesive, or an array of lines, swirls or spots of adhesive may be used to join the bodyside liner 30 to the outer cover 32. In some example embodiments, the outer cover 32 may include a full web spray of adhesive covering essentially the entire outer cover 32. The full web spray may be adapted to join the outer cover 32 with both the bodyside liner 30 and/or the nonwoven wrap 84 and/or the absorbent core 80.

Such bonding may also be suitable for joining other components of the absorbent assembly 34 and absorbent article 20 of the present invention together. The leg cuffs 36 may be suitably formed by portions of the outer cover 32 and/or bodyside liner 30, which extend beyond the longitudinal sides of the composite absorbent assembly 34 Naturally, the leg cuffs 36 may also be formed from separate materials which are joined with the outer cover 32 and/or bodyside liner 30.

The leg cuffs 36 may include leg elastics 38. Waist elastics 40 and 42 may also be provided. The leg elastics 38 may be arranged to draw and hold the absorbent article 20 against the legs of the wearer. The waist elastics 40 and 42 may also be arranged to draw and hold the absorbent article 20 against the wearer. In some example embodiments, the absorbent article 20 may include a rear waist elastic 42 extending substantially the full width of the article. Example materials for the elastics include strands or ribbons of a polymeric, elastomeric material which are adhered to the absorbent article 20 in a stretched position, or which are attached to the absorbent article while the article is pleated, such that elastic constrictive forces are imparted to the absorbent article 20 In a particular example aspect, the elastics may be composed of individual strands of LYCRA which are available from INVISTA Co., a business having offices in Wichita, Kans., USA.

The leg elastics 38 and waist elastics 40 and 42 may have any configuration which provides the desired performance. For example, the leg elastics 38 and waist elastics 40 and 42 may include a single strand of elastic material, or may include several parallel or non-parallel strands of elastic material The leg elastics 38 may be generally straight or optionally curved to more closely fit the contours of the legs and buttocks of the wearer and better contain bodily exudates. The leg elastics 38 and waist elastics 40 and 42 may be joined with the absorbent article 20 in any of several ways. For example, the elastics may be ultrasonically bonded, thermally bonded, pressure bonded, adhesively bonded, or the like, or combinations thereof to the absorbent article 20.

The fasteners 44 are typically joined to the corners of the rear portion 24 of the absorbent article 20 to provide a mechanism for holding the article 20 on the wearer. Suitable fasteners 44 include tape tab fasteners, hook and loop fasteners, mushroom and loop fasteners, snaps, pins, belts, and the like, and combinations thereof. Typically, the fasteners 44 are configured to be selectively refastenable. It should also be understood that it may be possible to dispense with the fasteners 44 in an absorbent article having a given design configuration. In some example embodiments, the fasteners 44 may be adapted to engage or otherwise join with a fastener landing material 45. In some example embodiments, the fastener landing material 45 includes a loop material joined to the outer cover 32 in the front waist region 23 and adapted to engage hook-type fasteners 44. In other example embodiments, the outer cover 32 may function as the fastener landing material 45 and may be adapted to engage hook-type fasteners 44. In yet other example embodiments, the fastener landing material 45 may be a film adapted to engage with tape tab fasteners 44.

The absorbent assembly 34 may be positioned between the bodyside liner 30 and the outer cover 32 to form the absorbent article 20 The absorbent assembly 34 is generally conformable and capable of absorbing and retaining body exudates. The absorbent assembly 34 may include an absorbent core 80 and at least one nonwoven wrap 84. The absorbent core 80 may be a single, integral piece of material or, alternatively, may include a plurality of individual separate pieces of material which are operably assembled together.

The absorbent core 80 may have any of a number of shapes and sizes. The absorbent core 80 may suitably include various types of wettable, hydrophilic fibrous materials. Examples of suitable materials include naturally occurring organic fibers composed of intrinsically wettable material, such as cellulosic fibers; synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers; inorganic fibers composed of an inherently wettable material, such as glass fibers; synthetic fibers made from inherently wettable thermoplastic polymers, such as particular polyester and polyamide fibers; and synthetic fibers composed of a nonwettable thermoplastic polymer, such as polypropylene fibers, which have been hydrophilized. The absorbent core 80 may also include selected blends of the various types of fibers mentioned above. The absorbent core 80 may include a matrix of hydrophilic fibers, such as a web of cellulosic fibers, mixed with particles of a high-absorbency material such as that commonly known as superabsorbent material.

Organic materials suitable for use as a superabsorbent material in conjunction with the present invention can include natural materials such as agar, pectin, guar gum, and the like; as well as synthetic materials, such as synthetic hydrogel polymers. Such hydrogel polymers include, for example, alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene maleic anhydride copolymers, polyvinyl ethers, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, polyvinylmorpholinone; and polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, polyvinylpyrridine, and the like. Other suitable polymers include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, and isobutylene maleic anhydride polymers and mixtures thereof. The hydrogel polymers are preferably lightly crosslinked to render the materials substantially water insoluble. Crosslinking may, for example, be accomplished by irradiation or by covalent, ionic, van der Waals, or hydrogen bonding. The superabsorbent materials may be in any form suitable for use in absorbent composites including particles, fibers, flakes, spheres, and the like, and combinations thereof. Such superabsorbents are usually available in particle sizes ranging from about twenty (20 pm) to about one thousand microns (1000 pm). The absorbent core 80 can contain from zero percent (0%) to one hundred percent (100%) superabsorbent by weight based upon the total weight of the absorbent core. In various example embodiments, the absorbent core 80 may have at least thirty percent (30%), at least forty percent (40%), at least fifty percent (50%), at least sixty percent (60%), at least seventy percent (70%), at least eighty percent (80%), or at least ninety percent (90%) superabsorbent material based on the total weight of the absorbent core 80.

The nonwoven wraps 84 may be a fibrous nonwoven web made from fine diameter thermoplastic fibers with particular pore sizes and air permeability. While not being limited to the specific method of manufacture, meltblown fibrous nonwoven webs have been found to work particularly well. With respect to polymer selection, polyolefin fibers and especially polypropylene- based polymers have been found to work well. The fibers may be hydrophilic or hydrophobic, though it is desirable that one or more of the resultant nonwoven wraps be hydrophilic. As a result, the fibers may be treated to be hydrophilic as by the use of a surfactant treatment.

The nonwoven wraps 84 may include fibers that are meltblown, spunbond, spunlace, spunbond-meltblown-spunbond, coform, or combinations thereof The nonwoven wraps 84 may have a significant amount of stretchability. For example, the structure of the nonwoven wraps 84 may include an operative amount of elastomeric polymer fibers. Furthermore, the fibers utilized in the nonwoven wraps 84 may be continuous or discontinous. The nonwoven wraps 84 may be in the form of films, nonwoven webs, and laminates of two or more substrates or webs. Additionally, the nonwoven wraps 84 may be textured, apertured, creped, neck-stretched, heat activated, embossed, and micro-strained.

The nonwoven wraps 84 may include a stretchable, durable, hydrophilic, fluid pervious substrate In some example embodiments, the nonwoven wraps 84 may include a coating with a hydrophilicity boosting amount of nanoparticles, wherein such nanoparticles have a particle size of from one nanometer (1 nm) to seven hundred and fifty nanometers (750 nm). Examples of suitable nanoparticles include titanium dioxide, layered clay minerals, alumina oxide, silicates, and combinations thereof. Optionally, a nonionic surfactant can be added to the nonwoven wraps 84 to provide additional or enhanced benefits The nonwoven wraps 84 may additionally or alternatively include materials such as surfactants, ion exchange resin particles, moisturizers, emollients, perfumes, natural fibers, synthetic fibers, fluid modifiers, odor control additives, lotions, viscosity modifiers, antiadherence agent, pH control agents, and the like, and combinations thereof. The absorbent article 10 may also include a surge portion 55 (FIG. 3) to advantageously improve the overall fluid intake rate of the absorbent core 80. The surge portion 55 is typically less hydrophilic than the absorbent core 80 and is configured to collect and temporarily hold fluid surges. This configuration can also help prevent fluid exudates from pooling and collecting on portions of the absorbent core 80

Various woven and nonwoven materials can be used to construct the surge portion 55. For example, the surge portion 55 may be a layer of a spunbonded or meltblown web of polyolefin fibers or a bonded carded web of natural and synthetic fibers. The surge portion 55 may be a substantially hydrophobic material and, optionally, can be treated with a surfactant or otherwise to impart a desired level of wettability and hydrophilicity. The surge portion 55 may also include other wettable fiber materials such as cotton, rayon, wood pulp, inherently wettable synthetic polymers, hydrophilized or surface treated polymers, and the like. The surge portion 55 may be of any desired shape and configuration.

Referring now to FIG. 2, an exemplary absorbent assembly is generally illustrated at 34 with portions cut away to illustrate underlying structure. The absorbent assembly 34 includes an absorbent core 80, a first nonwoven wrap 84 and a second nonwoven wrap 134.

The absorbent core 80 may have a front edge 81 and a rear edge 82. The front edge 81 and the rear edge 82 may be generally parallel and opposed in the longitudinal direction 48 The absorbent core 80 may have two side edges 83. The side edges 83 may be opposed in the lateral direction 50. The side edges 83 and/or the front edge 81 and/or the rear edge 82 may be straight, arcuate, or other shapes, or combinations thereof. For example, in FIG. 2, the rear edge 82 and the front edge 81 are generally straight, whereas the side edges 83 are generally straight in the front portion 22 and in the rear portion 24 and arcuate in the crotch portion 26.

The first nonwoven wrap 84 may have a front edge 85 and a rear edge 86. The front edge 85 and the rear edge 86 may be generally parallel and opposed in the longitudinal direction 48. The first nonwoven wrap 84 may have two side edges 87. The side edges 87 may be opposed in the lateral direction 50 The side edges 87 and/or the front edge 85 and/or the rear edge 86 may be straight, arcuate, or other shape, or combinations thereof. For example, in FIG. 2, the rear edge 86, the front edge 85 and the side edges 87 are generally straight.

The second nonwoven wrap 134 may have a front edge 135 and a rear edge 136. The front edge 135 and the rear edge 136 may be generally parallel and opposed in the longitudinal direction 48. The second nonwoven wrap 134 may have two side edges 137. The side edges 137 may be opposed in the lateral direction 50. The side edges 137 and/or the front edge 135 and/or the rear edge 136 may be straight, arcuate, or other shape, or combinations thereof. The absorbent assembly 34 may have a front extension 90, a middle casing 92, and a rear extension 94. The front extension 90 may have a front extension length 91 as measured in the longitudinal direction 48 from the nonwoven wrap front edge 85 to the absorbent core front edge 81 . In example embodiments including a second nonwoven wrap 134, the front extension 90 is measured using either the front edge 85 of the first nonwoven wrap 84 or the front edge 135 of the second nonwoven wrap 134 depending on which extends the furthest from the core front edge 81 . The middle casing 92 may have a middle casing length 93 as measured in the longitudinal direction 48 from the absorbent core front edge 81 to the absorbent core rear edge 82. The rear extension 94 may have a rear extension length 95 as measured in the longitudinal direction 48 from the absorbent core rear edge 82 to the nonwoven wrap rear edge 86. In example embodiments including a second nonwoven wrap 134, the rear extension 94 may be measured using either the rear edge 86 of the first nonwoven wrap 84 or the rear edge 136 of the second nonwoven wrap 134 depending on which extends the furthest from the absorbent core rear edge 82. The sum of the front extension length 91 , the middle casing length 93 and the rear extension length 95 equals an absorbent assembly length 35.

In various example embodiments, the first nonwoven wrap 84 may be at least partially bonded to itself, to the second nonwoven wrap 134 or both. In various example embodiments, the second nonwoven wrap 134 may be at least partially bonded to itself, to the first nonwoven wrap 84 or both. The first and/or second nonwoven wraps may be bonded in the front extension 90 and/or the middle casing 92 and/or the rear extension 94.

The bonding in the front extension 90 and/or the rear extension 94 and/or the middle casing 92 may be adapted to minimize or eliminate the passage therethrough of absorbent core materials, particularly superabsorbent particles. The bonding in the regions 90, 92 and/or 94 may completely seal the nonwoven wrap or wraps thereby preventing any passage of absorbent materials. Alternatively, or additionally, the bonding in the regions 90, 92 and/or 94 may partially seal the nonwoven wrap or wraps creating a tortuous path that reduces or eliminates the passage of absorbent materials through the regions 90, 92 and/or 94. As discussed in greater detail below, front extension 90 and/or rear extension 94 may be folded to further assist with reducing or eliminating the passage of absorbent core materials.

The first nonwoven wrap 84 and/or the second nonwoven wrap 134 may be bonded to themselves and/or each other by any suitable mechanism and in any suitable pattern. Suitable bonding mechanisms include pressure bonding, thermal bonding, ultrasonic bonding, adhesive bonding, and the like, and combinations thereof.

In various example embodiments, the front extension length 91 may be any suitable length, such as, for example, twenty millimeters (20 mm) to one hundred and fifty millimeters (150 mm), thirty millimeters (30 mm) to one hundred millimeters (100 mm), or forty millimeters (40 mm) to eighty millimeters (80 mm). In various embodiments, the front extension length 91 may be less than two hundred millimeters (200 mm), less than one hundred and twenty millimeters (120 mm), less than seventy-five millimeters (75 mm), or less than sixty millimeters (60) mm. In various example embodiments, the front extension length 91 may be greater than fifteen millimeters (15 mm), greater than twenty-five millimeters (25 mm), greater than forty millimeters (40 mm), greater than fifty millimeters (50 mm), greater than sixty millimeters (60 mm), greater than seventy (70 mm), or greater than one hundred millimeters (100 mm)

In various example embodiments, the front extension length 91 may be at least five percent (5%), at least ten percent (10%), at least fifteen percent (15%), at least twenty percent (20%), or at least twenty-five (25%) percent of the absorbent assembly length 35. In various example embodiments, the ratio of the absorbent assembly length 35 to the front extension length 91 may be less than 50 to 1 , less than 25 to 1 , less than 20 to 1 , or less than 15 to 1 . In various example embodiments, the ratio of the absorbent assembly length 35 to the front extension length 91 may be greater than 3 to 1 , greater than 5 to 1 , greater than 10 to 1, or greater than 15 to 1 .

In various embodiments, the middle casing length 93 may be any suitable length, such as, for example, seventy millimeters (70 mm) to seven hundred millimeters (700 mm), two hundred millimeters (200 mm) to five hundred millimeters (500 mm), or two hundred millimeters (200 mm) to four hundred (400 mm).

In various embodiments, the middle casing length 93 is less than ninety-five percent (95%), less than ninety percent (90%), less than eighty-five percent (85%), less than eighty percent (80%), or less than seventy-five (75%) percent of the absorbent assembly length 35.

In various example embodiments, the rear extension length 95 may be any suitable length, such as, for example, twenty millimeters (20 mm) to one hundred and fifty millimeters (150 mm), thirty millimeters (30 mm) to one hundred millimeters (100 mm), or forty millimeters (40 mm) to eighty millimeters (80 mm). In various embodiments, the rear extension length 95 may be less than two hundred millimeters (200 mm), less than one hundred and twenty millimeters (120 mm), less than seventy-five millimeters (75 mm), or less than sixty millimeters (60) mm. In various example embodiments, the rear extension length 95 may be greater than fifteen millimeters (15 mm), greater than twenty-five millimeters (25 mm), greater than forty millimeters (40 mm), greater than fifty millimeters (50 mm), greater than sixty millimeters (60 mm), greater than seventy (70 mm), or greater than one hundred millimeters (100 mm)

In various example embodiments, the rear extension length 95 may be at least five percent (5%), at least ten percent (10%), at least fifteen percent (15%), at least twenty percent (20%), or at least twenty-five (25%) percent of the absorbent assembly length 35. In various example embodiments, the ratio of the absorbent assembly length 35 to the rear extension length 95 may be less than 50 to 1 , less than 25 to 1 , less than 20 to 1 , or less than 15 to 1 . In various example embodiments, the ratio of the absorbent assembly length 35 to the rear extension length 95 may be greater than 3 to 1 , greater than 5 to 1 , greater than 10 to 1, or greater than 15 to 1

In various example embodiments, the ratio of the rear extension length 95 to the front extension length 91 may be at least 1 to 1 , at least 1 .5 to 1 , at least 2 to 1 , or at least 3 to 1 . When the ratio of the rear extension length 95 to the front extension length 91 is 1 to 1 , the absorbent core 80 is centered within the absorbent assembly 34 When the ratio of the rear extension length 95 to the front extension length 91 is greater than 1 to 1 , the absorbent core 80 is skewed towards the front of the absorbent assembly 34. When the ratio of the rear extension length 95 to the front extension length 91 is less than 1 to 1 , the absorbent core 80 is skewed towards the rear of the absorbent assembly 34. By altering the position of the absorbent core 80 relative to the absorbent assembly 34, the absorbent assembly 34 can remain centered from front to rear in the absorbent article 20 while allowing the absorbent core 80 to be positioned either towards the front portion 22 or towards the rear portion 24 of the absorbent article 20 as desired.

Absorbent Assembly:

Turning now to FIG. 3, the first nonwoven wrap 84 and/or the second nonwoven wrap 134 may at least partially envelope the absorbent core 80. As shown in FIG. 3, the absorbent core 80 may have a liner facing surface 98 and an outer cover facing surface 100. As used herein, the term “fully envelope" means to enclose or enfold completely within one or more coverings. As used herein, the term “at least partially envelope” means to cover at least one of the liner facing surface 98 and the outer cover facing surface 100 of the absorbent cores 80 with one or more coverings. In example embodiments, the first nonwoven wrap 84 and/or the second nonwoven wrap 134 may fully envelope or at least partially envelope the absorbent core 80 in the manner described in U S. Patent Publication No. 2007/0044903, the disclosure of which is hereby incorporated by reference where not contradictory One skilled in the art will appreciate that many different variations are possible. In various example embodiments described herein, the first nonwoven wrap 84 and the second nonwoven wrap 134 may be interchanged.

Absorbent article 20 includes the bodyside liner 30 joined with the outer cover 32 and the absorbent assembly 34 located therebetween. The absorbent assembly 34 includes an absorbent core 80 fully enveloped by a combination of a first nonwoven wrap 84 and a second nonwoven wrap 134. The first nonwoven wrap 84 is folded around the liner facing surface 98 of the absorbent core 80 and partially around the front and rear edges 81 , 82 of the absorbent core 80. The second nonwoven wrap 134 is folded around the outer cover facing surface 100 of the absorbent core 80 and partially around the front and rear edges 81 , 82 of the absorbent core 80. The first and second nonwoven wraps 84 and 134 overlap at the front and rear extensions 90, 94 and form the middle casing 92 with the absorbent core 80 therein.

In various embodiments, the first nonwoven wrap 84 and/or the second nonwoven wrap 134 may be a hydrophobic barrier layer. The hydrophobic barrier layer may include breathable fibrous materials such as a woven or nonwoven fabric, including but not limited to, meltblown webs, fine fiber spunbond webs such as those having fiber deniers of about two (2) or less, bonded and carded webs, hydroentangled fabrics and other fabrics having the similar properties. Suitable polymeric materials for making the barrier layer include those capable of making fibrous webs; examples include but are not limited to polyamides, polyesters and polyolefins, such as polyethylene and/or polypropylenes. In a preferred example aspect, the hydrophobic barrier layer may include a meltblown web of polypropylene fibers having a basis weight from 16 g/m2 to about 64 g/m2 or from 20 g/m2 to 40 g/m2. The fibrous barrier layer may include a single sheet or multiple layered sheets which collectively have the desired characteristics.

As noted above and shown in FIG. 3, the front extension 90 may be folded over itself. In example embodiments, the front extension 90 may be folded over the middle casing 92. For instance, the front extension 90 may be folded over the middle casing 92 such that the front extension 90 is folded onto and contacts the middle casing 92 between the front and rear portions 96, 97 of the middle casing 92. Such folding of front extension 90 may assist with reducing or eliminating the passage of absorbent core materials from middle casing 92 at the front portion 96 of the middle casing 92. For instance, folding the front extension 90 may reinforce the bond between the first nonwoven wrap 84 and the second nonwoven wrap 134 at the front portion 96 of the middle casing 92. Moreover, debonding of the first nonwoven wrap 84 and the second nonwoven wrap 134 at the front portion 96 of the middle casing 92 may be limited or prevented by folding the front extension 90 over the middle casing 92 Thus, fluff and/or superabsorbent material in the absorbent core 80 may be retained within the middle casing 92 during manufacture of the absorbent article 20, such as during high-speed folding of the absorbent article 20 with a blade folder.

It will be understood that the rear extension 94 may also be folded over itself, e.g., in addition or as an alternative to the front extension 90 as shown in FIGS. 4 and 5. In example embodiments, the rear extension 94 may be folded over the middle casing 92 For instance, the rear extension 94 may be folded over the middle casing 92 such that the rear extension 94 is folded onto and contacts the middle casing 92 between the front and rear portions 96, 97 of the middle casing 92. Such folding of rear extension 94 may assist with reducing or eliminating the passage of absorbent core materials from middle casing 92 at the rear portion 97 of the middle casing 92. For instance, folding the rear extension 94 may reinforce the bond between the first nonwoven wrap 84 and the second nonwoven wrap 134 at the rear portion 97 of the middle casing 92. Moreover, debonding of the first nonwoven wrap 84 and the second nonwoven wrap 134 at the rear portion 97 of the middle casing 92 may be limited or prevented by folding the rear extension 94 over the middle casing 92. Thus, fluff and/or superabsorbent material in the absorbent core 80 may be retained within the middle casing 92 during manufacture of the absorbent article 20, such as during high-speed folding of the absorbent article 20 with a blade folder.

As shown In FIG 3, the front extension 90 may be folded over such that the first nonwoven wrap 84 at the front extension 90 is folded over and/or contacts itself. However, it will be understood that the front extension 90 may be folded over such that the second nonwoven wrap 134 at the front extension 90 is folded over and/or contacts itself in alternative example embodiments. Similarly, as shown in FIGS. 4 and 5, the rear extension 94 may be folded over such that the first nonwoven wrap 84 at the rear extension 94 is folded over and/or contacts itself. However, it will be understood that the rear extension 94 may be folded over such that the second nonwoven wrap 134 at the rear extension 94 is folded over and/or contacts itself in alternative example embodiments.

As shown in FIGS. 3 through 5, the front extension 90 and/or the rear extension 94 may be folded over the middle casing 92 such that the end of the front extension 90 and/or the end of the rear extension 94 is positioned between the bodyside liner 30 and the absorbent core 80, e.g., along a thickness of the absorbent article 20 that is perpendicular to the longitudinal and lateral directions 48, 50. In other example embodiments, the front extension 90 and/or the rear extension 94 may be folded over the middle casing 92 such that the end of the front extension 90 and/or the end of the rear extension 94 is positioned between the outer cover 32 and the absorbent core 80, e.g., along the thickness of the absorbent article 20. In example embodiments with surge portion 55, the front extension 90 and/or the rear extension 94 may be folded over the middle casing 92 such that the end of the front extension 90 and/or the end of the rear extension 94 is positioned between the surge portion 55 and the absorbent core 80, e.g., along the thickness of the absorbent article 20. It will be understood that in example embodiments, the front extension 90 and/or the rear extension 94 may be also folded without extending back over the middle casing 92.

Forming Apparatus and Method:

A method for making absorbent articles, including those described herein, generally includes forming discrete absorbent cores on a nonwoven wrap web to create a composite web, at least partially bonding the composite web between the absorbent cores, cutting the composite web between the absorbent cores into discrete absorbent assemblies, folding over at least one of a front extension or a rear extension of each absorbent assemblies wrap, and joining the plurality of absorbent assemblies between a bodyside liner and an outer cover. Other absorbent article components, such as, for example, flaps, elastics, fasteners, and the like, and combinations thereof, may be added as described herein.

As used herein, the term “forming discrete absorbent cores” refers to the process of creating a series of single, unattached absorbent cores wherein a first absorbent core is formed and is not directly connected with a subsequent absorbent core. Forming discrete absorbent cores is in contrast to a process wherein a web of interconnected absorbent cores are formed and then cut apart to obtain separate cores. The folding, bonding and cutting may be performed in any suitable order and may occur substantially simultaneously and/or may be accomplished with multiple units or with a single unit adapted to perform multiple functions.

The method and apparatus described herein may be particularly useful when forming fragile or unstable absorbent cores. For example, the absorbent cores formed by the methods and apparatus described herein may be composed of a selected mixture of absorbent hydrophilic fibers and superabsorbent particles. In particular example aspects, the absorbent cores may be constructed to contain at least about thirty percent (30%) by weight of superabsorbent material. In some example embodiments, the method and apparatus may be used to form absorbent cores containing at least thirty-eight percent (38%), at least forty-three percent (43%), at least fifty percent (50%), at least fifty- five percent (55%), at least sixty percent (60%), at least sixty-five percent (65%), at least seventy percent (70%), or at least seventy-five percent (75%) superabsorbent particles by weight. In some example embodiments, the method and apparatus may be used to form absorbent cores having more than seventy-five percent (75%) superabsorbent material by weight.

As the weight percentage of superabsorbent increases, the amount of absorbent core integrity resulting from fiber intertwining generally is reduced, thereby resulting in an absorbent core that is more difficult to process and is inherently more fragile. Additionally, low fiber integrity and high superabsorbent concentrations result in more “free” superabsorbent particles capable of moving within and without the absorbent core

In example embodiments, the fibers of the absorbent core may also be arranged to provide a high loft, low density absorbent core. For example, the absorbent core may have an average basis weight from about three hundred (300) gsm to about one thousand, two hundred (1200) gsm, such as from about four hundred (400) gsm to about one thousand (1000) gsm, such as from about five hundred (500) gsm to about nine hundred (900) gsm, such as from about six hundred (600) gsm to about eight hundred (800) gsm As another example, the absorbent core may have an average density from about one-tenth (0.1) grams per cubic centimeter to about three-tenths (0.3) grams per cubic centimeter, such as from about eighteen hundredths (0.18) grams per cubic centimeter to about twenty-five hundredths (0.25) grams per cubic centimeter, such as from about two-tenths (0.2) grams per cubic centimeter to about twenty-two hundredths (0.22) grams per cubic centimeter. As the average basis weight and/or density of the absorbent core decreases, the amount of absorbent core integrity resulting from fiber intertwining generally is reduced, thereby resulting in an absorbent core that is more difficult to process and is inherently more fragile.

With reference to FIGS. 6 and 7, an example method and apparatus for forming discrete absorbent cores 80 interposed between a first nonwoven wrap web 184 and a second nonwoven wrap web 234 is illustrated. FIGS. 7 and 10 representatively illustrate continuations of the method and apparatus illustrated in FIG. 6. The method and apparatus includes a first web supply, such as a first supply roll 148, for providing a first nonwoven wrap web 184. A depositor, such as forming drum 152, deposits a series of discrete absorbent cores 80 onto the first nonwoven wrap web 184. A second web supply, such as a second supply roll 154, provides a second nonwoven wrap web 234 to sandwich the discrete absorbent cores 80 between the first nonwoven wrap web 184 and the second nonwoven wrap web 234 resulting in a composite web 147. The various webs move in a machine direction as indicated by arrows 188.

In alternative example embodiments, the method and apparatus may exclude a second nonwoven wrap web and may include only a first nonwoven wrap web. In yet other example alternative embodiments, three or more nonwoven wrap webs may be included in the method and apparatus. In yet other example embodiments, a first nonwoven wrap and a second nonwoven wrap may be interchanged such that the series of discrete absorbent cores are deposed onto the second nonwoven wrap web then joined with the first nonwoven wrap web.

A folding apparatus 178 is adapted to fold the first nonwoven wrap web 184 and/or the second nonwoven wrap web 234 to at least partially envelope the series of discrete absorbent cores 80.

The composite web 147 is transported to a bonder 158 which at least partially bonds the composite web 147 in attachment regions 60 between the absorbent cores 80 (FIG. 9). The bonding within the attachment regions 60 is adapted to reduce or prevent movement of superabsorbent material from the absorbent cores 80 through the attachment region 60. In general, the greater the percentage of bonding in the attachment region 60, the greater the reduction in superabsorbent movement though the attachment region 60.

A separator, such as a cutter 127 (FIG. 7) separates the composite web 147 along dividing lines 130 in the attachment regions 60 into discrete absorbent assemblies 34 (FIG. 9).

The shown example embodiment airlays fibrous absorbent material directly onto the first nonwoven wrap web 184, and includes a hammermill fiberizer 166 and a rotatable forming drum 152. Fiberizer 166 disintegrates sheets of wood pulp fiber 66 or other suitable fibers and introduces the individual fibers into forming chamber 168. In addition, a superabsorbent supply, such as provided by supply conduit 170 and nozzle 172, selectively introduces particles of superabsorbent material into forming chamber 168.

Quantities of superabsorbent material may be continuously introduced into the forming chamber or individual quantities of superabsorbent material may be intermittently introduced into the forming chamber with a pulsing mechanism. The chosen technique will depend upon the desired distribution of superabsorbent across the area and through the thickness of the absorbent cores. Suitable techniques for introducing particles of superabsorbent material into a forming chamber are described in U.S. Pat. No. 6,416,697 and U.S. Pat. No. 5,028,224, the disclosures of which are hereby incorporated by reference where not contradictory.

Referring now to FIG. 8, an example forming drum 152 is illustrated. The forming chamber 168, the first nonwoven wrap web 184 and the absorbent cores 80 are not shown to better illustrate the underlying apparatus. The forming drum 152 has a peripheral outer surface 190 and includes a mechanism for forming a vacuum therein to draw the wood pulp fibers and superabsorbent particles onto a nonwoven wrap web. The nonwoven wrap web is carried by the peripheral outer surface 190 of rotatable forming drum 152, which moves the nonwoven wrap web through the forming chamber generally in the direction indicated by arrow 189 The peripheral surface 190 of the forming drum 152 includes an air permeable forming screen 153. As air is drawn though the forming screen 153 by the vacuum within the forming drum 152, wood pulp fibers and superabsorbent particles are drawn onto the first nonwoven wrap web to generate a series of discrete airlaid absorbent cores which are substantially regularly spaced along the machine direction length of nonwoven wrap web. Suitable techniques of vacuum forming are described in U.S. Pat. No. 6,630,096 and U S. Pat. No. 6,630,088, the disclosures of which are incorporated herein by reference where not contradictory.

The forming drum 152 includes a plurality of contour rings 191 joined to the peripheral outer surface 190. The contour rings 191 are located about both sides of the forming drum 152 and extend around the circumference of the forming drum 152 The contour rings 191 partially block the forming screens 153 and generally direct the superabsorbent and/or fibers to the unblocked portions of the forming screen 153 thereby forming the absorbent cores 80 and defining the side edges 83 (e.g., FIG. 2).

The forming drum 152 also includes a plurality of cross plates 192 joined to the peripheral outer surface 190, the contour rings 191 or both. The cross plates 192 extend generally perpendicularly between the contour rings 191. The cross plates 192 partially block the forming screen 153 and generally direct the superabsorbent and/or fibers to the unblocked portions of the forming screen 153 thereby forming the absorbent cores 80 and defining the absorbent core front edge 81 and the absorbent core rear edge 82 (FIG. 2).

The plurality of cross plates 192 defines a first edge 194 and a second edge 195. The distance, as measured about the circumference of the forming drum 152, from the first edge 194 of a first cross plate 198 to the first edge 194 of a second sequential cross plate 199, defines a forming pitch 196 The forming pitch 196 equates to the absorbent assembly length 35 (FIG. 2)

The distance, as measured about the circumference of the forming drum 152, from the first edge 194 of a first cross plate 198 to the second edge 195 of the first cross plate 198, defines the spacing between absorbent cores 80 The spacing between absorbent cores 80 equates to the length of the attachment region 60 which in turn equates to the sum of the front extension length 91 and the rear extension length 95.

The first nonwoven wrap web 134 overlays at least a portion of the peripheral outer surface 190 of the forming drum 152. Both the forming drum 152 and the first nonwoven wrap web 134 move in the direction 189. Vacuum is drawn through the forming screen 153 and first nonwoven wrap 134 in the direction indicated by arrows 156 which in turn draws the superabsorbent material and/or fibrous material onto the nonwoven wrap web 184. The contour rings 191 and the cross plates 192 substantially block the vacuum in select areas of the forming screens 153 thereby substantially preventing the accumulation of absorbent material on the nonwoven wrap web 184 in areas wherein the nonwoven wrap web 184 overlies the contour rings 191 and/or cross plates 192. Guiding absorbent material in this way results in discrete cores 80 being formed on the nonwoven wrap web 134 in the unblocked portions of the forming screen 153.

Referring again to FIG. 6, a scarfing mechanism may be located at an exit end of forming chamber 168. The shown scarfing mechanism includes a scarfing drum 174 which is rotatably driven to operably remove excess absorbent material from the individual absorbent cores 80. The removed material may optionally be recycled back into forming chamber 168. Suitable scarfing methods and apparatus are discussed in U.S. Pat. No. 6,627,130, the disclosure of which is incorporated herein by reference where not contradictory.

Upon leaving the position of scarfing drum 174, the nonwoven wrap web 184 and the series of absorbent cores 80 formed thereon may be removed from the forming drum 152 and placed upon a second nonwoven wrap web 234. At a transfer screen 114, a second nonwoven wrap web 234 may be mated with the series of absorbent cores 80 and the associated first nonwoven wrap web 184 coming off from the surface of the forming drum 152 to form the composite web 147. A transfer conveyor 116 may move the composite web 147 from its position near the forming drum 152 into the nip between a pair of debulker rolls 118. The debulker rolls 118 are set and resiliently held at a selected gap, and operably compress together the nonwoven wrap web 184, absorbent cores 80 and the second nonwoven wrap web 234. This compression densifies the absorbent cores 80 and may at least partially bond the first nonwoven wrap web 184 to the second nonwoven wrap web 234 in some example embodiments.

Upon leaving debulker rolls 118, a debulker conveyor 120 transports the debulked composite web 147 to a folder such as, for example, folding system 178 Folding system 178 may be adapted to wrap the first nonwoven wrap web 184 and/or the second nonwoven wrap web 234, if utilized, or both the first nonwoven wrap web 184 and the second nonwoven wrap web 234 to at least partially envelope the series of discrete absorbent cores 80 within the composite web 147. After exiting the folding system 178, the composite web 147 may be directed to a bonding module 158 which at least partially bonds the first nonwoven wrap web 184 and/or the second nonwoven wrap web 234 in an attachment region 60.

The illustrated example embodiments include a first and a second nonwoven wrap web. However, in an alternative example embodiment, the method may include forming discrete absorbent cores on a first nonwoven wrap web to form a composite web, folding the first nonwoven wrap web about the discrete absorbent cores, bonding, debulking and cutting the composite web between the absorbent cores to create discrete absorbent assemblies. In various example embodiments, the folding, bonding and debulking may occur in any order. In various example embodiments, the debulking and bonding may occur in a single module adapted to both debulk the absorbent cores and bond the composite web between the absorbent cores. In various example embodiments, the debulking may be omitted. In various example embodiments, the folding may be omitted. In various example embodiments, the cutting may occur in the same step wherein the absorbent assemblies are cut and separated

Various types of mechanisms may be employed in the bonder 158 to form bonds within the attachment regions 60 For example, the attachment regions 60 may include bonds formed by adhesive bonding, thermal bonding, ultrasonic bonding, pressure bonding, or the like, or combinations thereof. Where adhesive bonding is employed, the adhesive may be applied by patterned extrusion, patterned spraying, patterned printing or the like. The patterns may be configured to substantially avoid placing excessive amounts of adhesive onto the fibrous, hydrophilic material used to construct absorbent cores 80.

The composite web 147 is transported along conveyor 128 to a cutter 127. The cutter 127 may be provided by any suitable apparatus, such as, for example, a rotary knife or other suitable cutting mechanism. The cutter 127 separates the composite web 147 along appointed dividing lines 130 (FIG. 9) to provide individual absorbent assemblies 34. The representatively shown absorbent assemblies 34 include an absorbent core 80 enveloped by a first nonwoven wrap 84 and a second nonwoven wrap 134.

Referring now to FIG. 9, a top plan view of a portion of the composite web 147 is shown after leaving the bonding module 158. Portions of FIG. 9 have been cut away to illustrate underlying structure. The composite web 147 moves in the machine direction 188. The composite web 147 includes a first nonwoven nonwoven wrap web 184 in facing relation with a second nonwoven nonwoven wrap web 234. A series of discrete absorbent cores 80 are disposed between the first nonwoven nonwoven wrap web 184 and the second nonwoven nonwoven wrap web 234 The first nonwoven wrap web 184 and the second nonwoven wrap web 234 are at least partially bonded together in the attachment regions 60. Cutting mechanism 127 divides the composite web 147 at the dividing lines 130 to create absorbent assemblies 34. The dividing lines 130 are registered to cut between the absorbent cores 80 resulting in each absorbent assembly 34 including a front extension 90 and a rear extension 94.

The dividing lines 130 may be located at any position between the absorbent cores 80. For example, the dividing lines 130 may be positioned such that attachment region 60 is divided in half in the machine direction 188. Alternatively, the dividing line 130 may be skewed such that attachment region 60 is divided unequally as illustrated in FIG. 9. In other words, the resultant front extensions 90 and the rear extensions 94 may be of different lengths.

The absorbent assemblies 34 include a first nonwoven wrap 84 and a second nonwoven wrap 134 in facing relation. An absorbent core 80 is disposed between the first nonwoven wrap 84 and the second nonwoven wrap 134. The first nonwoven wrap 84 and the second nonwoven wrap 134 are at least partially bonded together in the front extension 90 and the rear extension 94. The bonding may occur in any suitable pattern or concentration. For example, the bonding may include discrete bond points scattered throughout the front extension 90 and the rear extension 94. In another example, the bonding may include adhesive covering essentially the entire front extension 90 and the entire rear extension 94 One skilled in the art will appreciate that many different patterns, combinations and coverage areas are possible.

Once the absorbent assemblies 34 are divided, the front extension 90 and/or the rear extension 94 may be folded over. For example, the absorbent assemblies 34 may be transported to a folder 140 that folds over one or both of the front extension 90 and the rear extension 94. In example embodiments, folder 140 may fold the front extension 90 and/or the rear extension 94 over the middle casing 92. The folder 140 may include an air nozzle directed towards the front extension 90 and/or the rear extension 94, and airflow from the nozzle may fold over the front extension 90 and/or the rear extension 94. As another example, the cutter 127 and a conveyor 129 may be positioned such that the front extension 90 and/or the rear extension 94 fold over between the cutter 127 and a conveyor 129, e.g., due to the speed of the conveyor 129. Other suitable methods and mechanisms for folding the front extension 90 and/or the rear extension 94 are also within the scope of the present disclosure.

As discussed in greater detail below, folding over the front extension 90 and/or the rear extension 94 may assist with retaining fluff and/or superabsorbent material in the absorbent core 80 within the middle casing 92 during subsequent manufacturing steps. Once folded, the absorbent assemblies 34 may then be transported along the conveyor 129 to a tacker station 124 where the absorbent assemblies 34 are sandwiched and operably attached between a web of bodyside liner 131 and a web of outer cover 132. More particularly, the illustrated embodiment of conveyor 129 is configured in a conventional manner to position a series of absorbent assemblies at predetermined, spaced-apart locations along the longitudinal, length dimension of bodyside liner web 131. The outer cover web 132 can then be directed by a suitable transporting mechanism to a position overlying both bodyside liner web 131 and absorbent assemblies 34. Accordingly, the absorbent assemblies 34 are interposed between the bodyside liner web 131 and the outer cover web 132 to form a series of interconnected absorbent articles 202.

With reference to FIG. 10, a conveyor 200 transports the series of interconnected absorbent articles 202 to a cutter 204, such as a rotary knife, that separates the series of interconnected absorbent articles 202 into individual absorbent articles 20. After cutting, a conveyer 206 transports the articles 20 to a folder 208 that folds the articles 20 for packaging. The folder 208 may be a blade folder that impacts the articles 20 during the folding process. Folding the front extension 90 and/or the rear extension 94 may assist with retaining fluff and/or superabsorbent material in the absorbent core 80 during the folding of the absorbent articles 20 at the folder 208. For instance, the folded front extension 90 and/or rear extension 94 may limit or prevent the soft, low density discrete absorbent core 80 from exiting or “squishing out" of the middle casing 92 due to the impact of the blade folder. Moreover, folding over the front extension 90 and/or the rear extension 94 may form a seal and reinforce bonding between the first nonwoven wrap 84 and the second nonwoven wrap 134 to limit or prevent the material from the absorbent core 80 exiting the middle casing 92 due to the impact of the blade folder.

Folding of the front extension 90 and/or the rear extension 94 may be achieved at high speeds. For instance, a speed of the series of interconnected absorbent articles 202 in the machine direction 188 at the cutter 204 may be no less than five hundred meters per minute (500 m/min), no less than eight hundred meters per minute (800 m/min), no less than one thousand meters per minute (1000 m/min), or no less than one thousand, two hundred meters per minute (1200 m/min). The speed of the series of interconnected absorbent articles 202 in the machine direction 188 at the cutter 204 may be no greater than five thousand meters per minute (5000 m/min) in some example embodiments.

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.

EXAMPLE EMBODIMENTS

First example embodiment: An absorbent article, comprising: a bodyside liner; an outer cover; and an absorbent assembly positioned between the bodyside liner and the outer cover, the absorbent assembly comprising a nonwoven wrap and an absorbent core, wherein the nonwoven wrap comprises a middle casing, a front extension, and a rear extension, the absorbent core disposed within the middle casing of the nonwoven wrap, the front extension extending from a front portion of the middle casing, the rear extension extending from a rear portion of the middle casing, and wherein one or both of the front extension and the rear extension of the nonwoven wrap is folded over itself.

Second example embodiment: The absorbent article of the first example embodiment, wherein the front extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap, and the front extension contacts the middle casing between the front and rear portions of the middle casing.

Third example embodiment: The absorbent article of either the first example embodiment or the second example embodiment, wherein the rear extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap, and the rear extension contacts the middle casing between the front and rear portions of the middle casing.

Fourth example embodiment: The absorbent article of any one of the first through third example embodiments, wherein: the nonwoven wrap comprises a first layer and a second layer bonded together to form the nonwoven wrap; and the front extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap such that the first layer of the nonwoven wrap at the front extension of the nonwoven wrap is folded over the first layer of the nonwoven wrap at the middle casing of the nonwoven wrap.

Fifth example embodiment: The absorbent article of any one of the first through fourth example embodiments, wherein: the nonwoven wrap comprises a first layer and a second layer bonded together to form the nonwoven wrap; and the rear extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap such that the first layer of the nonwoven wrap at the rear extension of the nonwoven wrap is folded over the first layer of the nonwoven wrap at the middle casing of the nonwoven wrap.

Sixth example embodiment: The absorbent article of any one of the first through fifth example embodiments, wherein both the front extension and the rear extension of the nonwoven wrap are folded over the middle casing of the nonwoven wrap.

Seventh example embodiment: The absorbent article of any one of the first through sixth example embodiments, wherein: the front and rear portions of the middle casing are spaced apart along a longitudinal direction; a length of the middle casing along the longitudinal direction is no less than three times greater than and no more than fifty times greater than a length of the front extension along the longitudinal direction; and the length of the middle casing is no less than three times greater than and no more than fifty times greater than a length of the rear extension along the longitudinal direction.

Eighth example embodiment: The absorbent article of any one of the first through seventh example embodiments, wherein: the front and rear portions of the middle casing are spaced apart along a longitudinal direction; a length of the front extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters; and a length of the rear extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters.

Nineth example embodiment: The absorbent article of any one of the first through eighth example embodiments, wherein the absorbent assembly is spaced from a front end portion and a rear end portion of the bodyside liner.

Tenth example embodiment: The absorbent article of any one of the first through nineth example embodiments, wherein: the bodyside liner comprises a liquid permeable nonwoven web; the outer cover comprises a liquid impermeable nonwoven web; and the absorbent core comprises one or both of wettable, hydrophilic fibers and superabsorbent material.

Eleventh example embodiment: A method for forming absorbent articles, comprising: forming a plurality of discrete absorbent cores on a nonwoven wrap web to form a composite web; cutting the composite web between the discrete absorbent cores to form a plurality of absorbent assemblies each comprising a nonwoven wrap and an absorbent core, the absorbent core disposed within a middle casing of the nonwoven wrap in each absorbent assembly; folding over at least one of a front extension or a rear extension of each nonwoven wrap; and joining the plurality of absorbent assemblies between a bodyside liner and an outer cover.

Twelfth example embodiment: The method of the eleventh example embodiment, wherein the folding comprises folding the front extension of each nonwoven wrap over the middle casing of the nonwoven wrap such that the front extension contacts the middle casing.

Thirteenth example embodiment: The method of either the eleventh example embodiment or the twelfth example embodiment, wherein the folding comprises folding the rear extension of each nonwoven wrap over the middle casing of the nonwoven wrap such that the rear extension contacts the middle casing.

Fourteenth example embodiment: The method of any one of the eleventh through thirteenth example embodiments, further comprising, prior to cutting the composite web: folding the composite web to enclose the plurality of discrete absorbent cores; and bonding the composite web between the discrete absorbent cores.

Fifteenth example embodiment: The method of any one of the eleventh through fourteenth example embodiments, wherein: a length of the middle casing along a longitudinal direction is no less than three times greater than and no more than fifty times greater than a length of the front extension along the longitudinal direction; and the length of the middle casing is no less than three times greater than and no more than fifty times greater than a length of the rear extension along the longitudinal direction.

Sixteenth example embodiment: The method of one of the eleventh through fifteenth example embodiments, wherein: a length of the front extension along a longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters; and a length of the rear extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters.

Seventeenth example embodiment: The method of one of the eleventh through sixteenth example embodiments, wherein each absorbent assembly is spaced from a front end portion and a rear end portion of the bodyside liner.

Eighteenth example embodiment: The method of one of the eleventh through seventeenth example embodiments, wherein: the bodyside liner comprises a liquid permeable nonwoven web; the outer cover comprises a liquid impermeable nonwoven web; and the absorbent core comprises one or both of wettable, hydrophilic fibers and superabsorbent material.

Nineteenth example embodiment: The method of one of the eleventh through eighteenth example embodiments, wherein folding over at least one of the front extension or the rear extension of each nonwoven wrap comprises directing air from a nozzle towards at least one of the front extension or the rear extension of each nonwoven wrap.

Claims

What Is Claimed:

1. An absorbent article, comprising: a bodyside liner; an outer cover; and an absorbent assembly positioned between the bodyside liner and the outer cover, the absorbent assembly comprising a nonwoven wrap and an absorbent core, wherein the nonwoven wrap comprises a middle casing, a front extension, and a rear extension, the absorbent core disposed within the middle casing of the nonwoven wrap, the front extension extending from a front portion of the middle casing, the rear extension extending from a rear portion of the middle casing, and wherein one or both of the front extension and the rear extension of the nonwoven wrap is folded over itself.

2. The absorbent article of claim 1, wherein the front extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap, and the front extension contacts the middle casing between the front and rear portions of the middle casing.

3. The absorbent article of claim 1, wherein the rear extension of the nonwoven wrap is folded over the middle casing of the nonwoven wrap, and the rear extension contacts the middle casing between the front and rear portions of the middle casing.

4. The absorbent article of claim 1, wherein: the nonwoven wrap comprises a first layer and a second layer bonded together to form the nonwoven wrap; and the front extension of the nonwoven wrap is folded over itself such that the first layer of the nonwoven wrap contacts is folded over itself at the front extension of the nonwoven wrap.

5. The absorbent article of claim 1, wherein: the nonwoven wrap comprises a first layer and a second layer bonded together to form the nonwoven wrap; and the rear extension of the nonwoven wrap is folded over itself such that the first layer of the nonwoven wrap contacts is folded over itself at the rear extension of the nonwoven wrap.

6. The absorbent article of claim 1, wherein both the front extension and the rear extension of the nonwoven wrap are folded over the middle casing of the nonwoven wrap.

7. The absorbent article of claim 1, wherein: the front and rear portions of the middle casing are spaced apart along a longitudinal direction; a length of the middle casing along the longitudinal direction is no less than three times greater than and no more than fifty times greater than a length of the front extension along the longitudinal direction; and the length of the middle casing is no less than three times greater than and no more than fifty times greater than a length of the rear extension along the longitudinal direction.

8. The absorbent article of claim 1, wherein: the front and rear portions of the middle casing are spaced apart along a longitudinal direction; a length of the front extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters; and a length of the rear extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters.

9. The absorbent article of claim 1, wherein the absorbent assembly is spaced from a front end portion and a rear end portion of the bodyside liner.

10. The absorbent article of claim 1, wherein: the bodyside liner comprises a liquid permeable nonwoven web; the outer cover comprises a liquid impermeable nonwoven web; and the absorbent core comprises one or both of wettable, hydrophilic fibers and superabsorbent material

11. A method for forming absorbent articles, comprising: forming a plurality of discrete absorbent cores on a nonwoven wrap web to form a composite web; cutting the composite web between the discrete absorbent cores to form a plurality of absorbent assemblies each comprising a nonwoven wrap and an absorbent core, the absorbent core disposed within a middle casing of the nonwoven wrap in each absorbent assembly; folding over at least one of a front extension or a rear extension of each nonwoven wrap; and joining the plurality of absorbent assemblies between a bodyside liner and an outer cover.

12. The method of claim 11 , wherein the folding comprises folding the front extension of each nonwoven wrap over the middle casing of the nonwoven wrap such that the front extension contacts the middle casing

13. The method of claim 11 , wherein the folding comprises folding the rear extension of each nonwoven wrap over the middle casing of the nonwoven wrap such that the rear extension contacts the middle casing

14. The method of claim 11 , further comprising, prior to cutting the composite web: folding the composite web to enclose the plurality of discrete absorbent cores; and bonding the composite web between the discrete absorbent cores.

15. The method of claim 11 , wherein: a length of the middle casing along a longitudinal direction is no less than three times greater than and no more than fifty times greater than a length of the front extension along the longitudinal direction; and the length of the middle casing is no less than three times greater than and no more than fifty times greater than a length of the rear extension along the longitudinal direction.

16. The method of claim 11 , wherein: a length of the front extension along a longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters; and a length of the rear extension along the longitudinal direction is no less than thirty millimeters and no greater than one hundred millimeters.

17. The method of claim 11 , wherein each absorbent assembly is spaced from a front end portion and a rear end portion of the bodyside liner.

18. The method of claim 11 , wherein: the bodyside liner comprises a liquid permeable nonwoven web; the outer cover comprises a liquid impermeable nonwoven web; and the absorbent core comprises one or both of wettable, hydrophilic fibers and superabsorbent material.

19. The method of claim 11 , wherein folding over at least one of the front extension or the rear extension of each nonwoven wrap comprises directing air from a nozzle towards at least one of the front extension or the rear extension of each nonwoven wrap.