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WO2025249356A1 - Dispositif de fabrication de feuille étirable et procédé de fabrication de feuille étirable - Google Patents

Dispositif de fabrication de feuille étirable et procédé de fabrication de feuille étirable

Info

Publication number
WO2025249356A1
WO2025249356A1 PCT/JP2025/018890 JP2025018890W WO2025249356A1 WO 2025249356 A1 WO2025249356 A1 WO 2025249356A1 JP 2025018890 W JP2025018890 W JP 2025018890W WO 2025249356 A1 WO2025249356 A1 WO 2025249356A1
Authority
WO
WIPO (PCT)
Prior art keywords
sheet
rubber thread
section
manufacturing apparatus
anvil roll
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/JP2025/018890
Other languages
English (en)
Japanese (ja)
Inventor
巧 横山
涼 馬場
文人 河津
真二 野間
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.)
Unicharm Corp
Original Assignee
Unicharm Corp
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 Unicharm Corp filed Critical Unicharm Corp
Publication of WO2025249356A1 publication Critical patent/WO2025249356A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS 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
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS 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
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/51—Absorbent 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 outer layers of the pads

Definitions

  • the present invention relates to a stretchable sheet manufacturing apparatus and a stretchable sheet manufacturing method.
  • Patent Document 1 discloses a technique for attaching a wire-like element (corresponding to rubber thread) to a tubular sleeve 1 without welding it by sandwiching the wire-like element in a isthmus 8 formed between connecting portions 6a and 6b.
  • the present invention was made in consideration of the above-mentioned problems, and aims to efficiently manufacture a stretchable sheet in which rubber thread is attached between two sheet members by multiple welds.
  • the main invention for achieving the above object is a manufacturing device for a stretchable sheet in which a first sheet and a second sheet are laminated together with a rubber thread therebetween, the device comprising: an anvil roll; and an ultrasonic horn disposed opposite the outer peripheral surface of the anvil roll, the welded portion forming portion forming portion that sandwiches the laminated first sheet and the second sheet together to form a plurality of welded portions and regulates the position of the rubber thread between the first sheet and the second sheet by the formed welded portions; and a welding portion forming portion disposed upstream of the ultrasonic horn and the anvil roll in a conveying direction in which the rubber thread is conveyed, the welding portion forming portion forming portion being spaced apart from the ultrasonic horn and the anvil roll.
  • This type of stretch sheet manufacturing device can efficiently produce stretch sheets in which rubber thread is attached between two sheet members using multiple welds.
  • FIG. 1 is a plan view of a stretchable sheet 10 manufactured by a manufacturing apparatus (manufacturing method) according to a first embodiment.
  • 2 is a schematic cross-sectional view of the stretchable sheet 10 of FIG. 1.
  • Fig. 3A is a schematic perspective view of a pants-type disposable diaper 1 using a stretchable sheet 10.
  • Fig. 3B is a schematic plan view of the pants-type disposable diaper 1 in an unfolded and stretched state, as viewed from the skin side.
  • 1 is a schematic cross-sectional view showing a stretchable sheet manufacturing apparatus 100 according to a first embodiment.
  • Fig. 5A is a diagram illustrating the surface configurations of the anvil roll 131 and the ultrasonic horn 132.
  • 5B is a schematic enlarged view of the closest portions of the anvil roll 131 and the ultrasonic horn 132.
  • 6A and 6B are explanatory diagrams of a method for attaching the rubber thread 14 by the welded portion 50 (joint j).
  • 10A to 10C are diagrams illustrating modified examples of the surface configuration of the anvil roll 131 and the ultrasonic horn 132.
  • 8A and 8B are diagrams illustrating a case where the position of the rubber thread 14 in the width direction is shifted when forming the welded portion 50.
  • FIG. 9A to 9D are diagrams illustrating the mechanism by which the rubber thread 14 is automatically restored when it is broken during the manufacturing process of the stretch sheet 10 using the stretch sheet manufacturing apparatus 100.
  • FIG. 10A and 10B are diagrams illustrating how the rubber thread 14 is wound around the welded portion forming portion 130.
  • FIG. 10A and 10B are diagrams illustrating how the rubber thread 14 is wound around the welded portion forming portion 130.
  • FIG. 12A and 12B are schematic cross-sectional views of the stretchable sheet manufacturing apparatus 100 when the joining position of the second sheet 12 is changed.
  • FIG. 10 is a schematic cross-sectional view showing a stretchable sheet manufacturing apparatus 100 according to a second embodiment.
  • 10 is a schematic cross-sectional view illustrating a case where the second sheet 12 joins with the rubber thread 14 at the welded portion forming portion 130.
  • FIG. FIG. 10 is a schematic cross-sectional view showing a modified example of the stretchable sheet manufacturing apparatus 100 according to the second embodiment.
  • a weld portion forming section that sandwiches the laminated first sheet and the laminated second sheet with a rubber thread interposed therebetween, the weld portion forming section comprising: an anvil roll; and an ultrasonic horn disposed opposite the outer peripheral surface of the anvil roll.
  • the weld portion forming section sandwiches the laminated first sheet and the laminated second sheet between them to form a plurality of welds, and the formed welds regulate the position of the rubber thread between the first sheet and the second sheet; and a feed-out section that is disposed upstream of the ultrasonic horn and the anvil roll in a conveying direction in which the rubber thread is conveyed and that feeds out at least one of the first sheet and the second sheet together with the rubber thread to the weld portion forming section, wherein tension of a predetermined magnitude or more is applied to the rubber thread upstream of the feed-out section in the conveying direction, and the feed-out section holds at least one of the first sheet and the second sheet and the rubber thread so that even if the rubber thread is cut in the weld portion forming section, the cut rubber thread will not slip off upstream of the feed-out section in the conveying direction.
  • the rubber thread is held in the feed-out section while being pressed against the material sheet (at least one of the first sheet and the second sheet). This prevents the rubber thread from slipping out upstream of the feed-out section, even if it is cut in the welding section and shrinks toward the upstream side. Furthermore, tension of a predetermined magnitude or greater is applied to the rubber thread between the tension adjustment section and the feed-out section, so that the rubber thread continues to be fed out together with the material sheet from the feed-out section toward the feed-out section. When the rubber thread and material sheet reach the feed-out section, the rubber thread is reattached to the material sheet via the welding section. Therefore, even if the rubber thread is cut, it automatically recovers. This allows for efficient production of stretch sheets.
  • the stretch sheet manufacturing apparatus of aspect 2 compared to the reverse case, the length over which the rubber thread wraps around and adheres to the outer surface of the anvil roll is short, making it less likely for frictional force to become excessively large. Also, because the distance the rubber thread travels from the delivery section to the anvil roll is long, the rubber thread is more likely to shift in the cross direction (CD). This makes it easier for the rubber thread to slip into the grooves formed on the outer surface of the anvil roll, making it easier to prevent the rubber thread from being cut when it is pinched between the anvil roll and the ultrasonic horn during the formation of the welded section.
  • CD cross direction
  • the stretch sheet manufacturing apparatus of aspect 3 by making the length of the stretch sheet wrapped around the outer circumferential surface of the anvil roll as long as possible downstream of the position where the anvil roll and the ultrasonic horn face each other, the stretch sheet can be stably transported without wrinkles or other imperfections on the surface.
  • the rubber thread wrapped around the outer circumferential surface of the anvil roll as short as possible upstream of the position where the anvil roll and the ultrasonic horn face each other, the rubber thread is more likely to shift in the cross direction (CD). This makes it easier for the rubber thread to enter the grooves, making it easier to prevent the rubber thread from being cut when it is pinched between the anvil roll and the ultrasonic horn during the formation of the welded portion.
  • the tension of the rubber thread makes it easier for the rubber thread to be pressed against the outer circumferential surface of the conveying roller. Therefore, if the rubber thread is wrapped around at least one-quarter of the conveying roller, the rubber thread is less likely to slip on the outer circumferential surface compared to when it is wrapped around less than one-quarter, and the holding force can be made stronger. As a result, even if the rubber thread breaks, it is less likely to slip off upstream of the feed section, allowing for efficient production of stretch sheets.
  • the rubber thread is wound around two rollers in an S-shape, which makes it easier to hold the rubber thread than when it is wound around a single roller. Therefore, even if the rubber thread breaks, it is less likely to fall out upstream of the feed section, allowing for efficient stretch sheet production.
  • a stretch sheet manufacturing apparatus according to any one of aspects 1 to 5, wherein the delivery section has a pair of nip rollers that rotate around a rotation axis that is perpendicular to the conveying direction, and at least one of the first sheet and the second sheet and the rubber thread are sandwiched between the nip rollers.
  • the rubber thread is easily held firmly by being sandwiched between the nip rollers. Therefore, even if the rubber thread breaks, the contraction is stopped by the nip rollers, making it less likely to slip off upstream of the feed section, allowing for efficient stretch sheet production.
  • a stretch sheet manufacturing apparatus according to any one of aspects 1 to 6, further comprising a tension adjustment unit located upstream of the feed-out unit in the conveying direction, which feeds out the rubber thread to the feed-out unit, and wherein tension of at least the predetermined magnitude is applied to the rubber thread between the tension adjustment unit and the feed-out unit.
  • the stretchable sheet manufacturing device of aspect 7 has a mechanism that applies a tension of a predetermined magnitude or greater to the rubber thread between the tension adjustment unit and the feed-out unit, and the rubber thread is continuously fed out from the feed-out unit to the welded portion forming unit in a stretched state. Therefore, even if the rubber thread is cut in the welded portion forming unit, the cut part of the rubber thread will not reach the upstream side of the feed-out unit, and the stretched rubber thread can continue to be fed out from the feed-out unit. This makes it easier for cut rubber threads to automatically recover, allowing for the efficient production of stretchable sheets.
  • a stretch sheet manufacturing apparatus according to any one of aspects 1 to 7, wherein the first sheet merges with the rubber thread at the feed-out section, and the second sheet merges with the rubber thread at a position between the feed-out section and the welded portion forming section.
  • one sheet joins the rubber thread at the feed-out section and presses down on the rubber thread, making it easier to hold the rubber thread in the feed-out section, making it less likely to slip off upstream even if the rubber thread is broken. Furthermore, another sheet joins downstream of the feed-out section, sandwiching the rubber thread between the two sheets, further preventing the rubber thread from slipping off. And if the rubber thread is cut in the welded portion forming section and shrinks upstream, it is more likely that the rubber thread will stop shrinking by the time it reaches the point where the second sheet joins.
  • the rubber thread is tightly held between two sheets in the feed-out section, making it more likely that the rubber thread will slip off upstream of the feed-out section even if it is broken. Furthermore, because one of the sheets is interposed between the transport roller and the rubber thread in the feed-out section, direct contact between the rubber thread and the roller is unlikely. This reduces the risk of damage to the rubber thread due to friction between the roller and the thread during the transport process.
  • a stretchable sheet manufacturing apparatus according to aspect 10, wherein either the first sheet or the second sheet has a portion between the delivery section and the welded portion forming section where the first sheet or the second sheet is separated from the rubber thread.
  • the rubber thread after the rubber thread is fed from the feed section, it is transported while separated from the sheet member for at least a portion of the way until it reaches the welded portion forming section. Therefore, resistance is reduced compared to when the rubber thread is transported sandwiched between two sheet members, and the rubber thread is more likely to shift in the cross direction (CD). This makes it easier for the rubber thread to slip into the grooves when it is sandwiched between the anvil roll and the ultrasonic horn in the welded portion forming section, making it less likely to be cut. Therefore, stretch sheets can be produced efficiently.
  • CD cross direction
  • a method for producing a stretchable sheet in which a first sheet and a second sheet are laminated with a rubber thread interposed therebetween includes a welded portion forming step in which the laminated first sheet and the second sheet are sandwiched between an anvil roll and an ultrasonic horn arranged opposite to the outer peripheral surface of the anvil roll to form a plurality of welded portions, and the formed welded portions regulate the position of the rubber thread between the first sheet and the second sheet; and a method for producing a stretchable sheet in which a first sheet and a second sheet are laminated with a rubber thread interposed therebetween, the method including: a welded portion forming step in which the laminated first sheet and the second sheet are sandwiched between an anvil roll and an ultrasonic horn arranged opposite to the outer peripheral surface of the anvil roll to form a plurality of welded portions, and the formed welded portions regulate the position of the rubber thread between the first sheet and the second sheet.
  • a method for manufacturing an elastic sheet has been revealed, which is characterized by having a feeding process in which at least one of the two sheets is fed toward the anvil roll and the ultrasonic horn together with the rubber thread, wherein tension of a predetermined magnitude or more is applied to the rubber thread upstream of the feeding section in the conveying direction, and the feeding section holds at least one of the first sheet and the second sheet and the rubber thread so that even if the rubber thread is cut in the welded portion forming section, the cut rubber thread does not slip through to the upstream side of the feeding section in the conveying direction.
  • the rubber thread is held in the feed-out section while being pressed against the first sheet. This prevents the rubber thread from slipping out upstream of the feed-out section, even if it breaks in the welded section and shrinks upstream. Furthermore, even if the rubber thread breaks, tension is applied to the rubber thread between the tension adjustment section and the feed-out section, so the rubber thread continues to be fed from the feed-out section to the welded section while maintaining its stretched state, making it more likely to automatically recover. This allows for efficient manufacturing of stretch sheets.
  • Fig. 1 is a plan view of a stretchable sheet 10 manufactured by the manufacturing apparatus (manufacturing method) of the first embodiment.
  • Fig. 1 is a view of the stretchable sheet 10 in a stretched state without wrinkles.
  • Fig. 2 is a schematic cross-sectional view of the stretchable sheet 10 of Fig. 1.
  • the stretchable sheet 10 has a stretching direction, a thickness direction, and a width direction that are perpendicular to each other.
  • the stretchable sheet 10 also has a first sheet 11 and a second sheet 12 laminated in the thickness direction, as well as multiple rubber threads 14 and multiple joints j interposed between the first sheet 11 and the second sheet 12.
  • the multiple rubber threads 14 are arranged at intervals across the width of the stretchable sheet 10, aligned along the stretch direction.
  • the rubber threads 14 are attached to the first sheet 11 and the second sheet 12 in a stretched state. This gives the stretchable sheet 10 stretchability in the direction along which the rubber threads 14 are aligned.
  • the rubber threads 14 can be made of natural rubber threads, as well as various known synthetic rubbers such as styrene-based rubber, urethane-based rubber, ester-based rubber, polyurethane, and polyethylene.
  • the multiple joints j join the first sheet 11 and the second sheet 12 to one another using known welding means such as ultrasonic welding, and are arranged intermittently in the stretch direction and width direction of the stretchable sheet 10.
  • welding means such as ultrasonic welding
  • joints j will also be referred to as "welded portions 50.”
  • the multiple joints j also regulate the position of the rubber thread 14 in the stretch direction and width direction relative to the first sheet 11 and the second sheet 12.
  • the position of the rubber thread 14 is regulated by pairs of joints jP formed on both sides of the rubber thread 14 in the width direction.
  • the planar shape of the joints j shown in Figure 1 is rectangular, but the planar shape of the joints j is not particularly limited and can be any shape, such as an ellipse, a circle, or a parallelogram.
  • stretchable sheet 10 in Figure 2 is composed of two sheets, it may also be possible to fold one sheet, with the folded portion being the first sheet portion and the unfolded portion being the second sheet portion. Furthermore, the stretchable sheet 10 may also be made by layering one or more additional sheets on the first sheet 11 and second sheet 12. In other words, the stretchable sheet 10 may be three or more layers.
  • Fig. 3A is a schematic perspective view of a pants-type disposable diaper 1 using a stretchable sheet 10.
  • Fig. 3B is a schematic plan view of the pants-type disposable diaper 1 in an unfolded and stretched state, as viewed from the skin-facing side.
  • the stretchable sheet 10 manufactured by the manufacturing apparatus (manufacturing method) of this embodiment is used, for example, as a component of an absorbent article such as a disposable diaper.
  • the illustrated pants-type disposable diaper 1 (hereinafter also referred to as "diaper”) has an absorbent main body 2 that absorbs and retains body waste, a ventral waist section 3 that is placed against the wearer's ventral region, and a dorsal waist section 4 that is placed against the wearer's ventral region. As shown in the unfolded state in Figure 3B, the left-right center of the ventral waist section 3 overlaps one longitudinal end of the absorbent main body 2, and the left-right center of the dorsal waist section 4 overlaps the other longitudinal end of the absorbent main body 2.
  • the unfolded diaper 1 is folded in half approximately in the longitudinal center, and both left-right sides of the ventral waist section 3 and both left-right sides of the dorsal waist section 4 are joined by welding or the like, thereby forming the diaper 1 into a pants-type diaper.
  • the ventral waistband portion 3 and the back waistband portion 4 are generally rectangular in plan view, and have multiple elastic threads 5 that stretch in the left-right direction of the diaper 1, arranged vertically and spaced apart. Therefore, the ventral waistband portion 3 and the back waistband portion 4 are stretchable in the left-right direction of the diaper 1, and fit the wearer's waist.
  • a stretchable sheet 10 can be used in the ventral waistband portion 3 and the back waistband portion 4.
  • the stretchable direction of the stretchable sheet 10 corresponds to the left-right direction of the diaper 1, and the width direction of the stretchable sheet 10 corresponds to the up-down direction of the diaper 1.
  • the first sheet 11 and second sheet 12 that make up the stretchable sheet 10 can be made of soft sheet materials.
  • they can be made of nonwoven fabrics such as spunbond nonwoven fabrics or SMS (spunbond/meltblown/spunbond) nonwoven fabrics.
  • at least one of the first sheet 11 and the second sheet 12 can be made of a stretchable sheet (stretchable film or stretchable nonwoven fabric) that can stretch in the stretch direction of the stretchable sheet 10.
  • the stretchable sheet 10 is not limited to being used in the ventral waistband portion 3 and the dorsal waistband portion 4.
  • the stretchable sheet 10 can be used in the leg gathers provided on both sides of the absorbent main body in the left-right direction of the diaper so that the disposable diaper fits around the wearer's legs. Because the leg gathers stretch in the longitudinal direction of the absorbent main body, the longitudinal direction of the absorbent main body corresponds to the stretch direction of the stretchable sheet 10.
  • fastening tape hook members
  • Stretchable sheets 10 can be used for the side panels that attach the fastening tape to the back waistband. Because the side panels stretch in the left-right direction of the diaper, the left-right direction of the diaper corresponds to the stretch direction of the stretchable sheets 10.
  • the stretchable sheet 10 can also be used as a component for absorbent articles such as pad-type disposable diapers, sanitary napkins, and sanitary shorts-type napkins, in addition to pants-type and tape-type disposable diapers. It can also be used for other absorbent articles, such as masks and cleaning sheets.
  • FIG. 4 is a schematic cross-sectional view of a stretchable sheet manufacturing apparatus 100 according to a first embodiment.
  • the stretchable sheet manufacturing apparatus 100 which manufactures a stretchable sheet 10 according to the first embodiment, includes a feed-out unit 120, a welded portion forming unit 130, and a tension adjusting unit 140.
  • the stretchable sheet 10 is manufactured as a continuous body (continuous sheet) extending in the stretch direction.
  • the direction in which the continuous body of material is conveyed i.e., the stretch direction of the stretchable sheet 10) is referred to as the machine direction (MD), and the direction perpendicular to the machine direction (i.e., the width direction of the stretchable sheet 10) is referred to as the cross direction (CD).
  • MD machine direction
  • CD cross direction
  • the continuum of the first sheet 11, the continuum of the second sheet 12, the continuum of the rubber thread 14, and the continuum of the stretchable sheet 10 will also be simply referred to as the first sheet 11, the second sheet 12, the rubber thread 14, and the stretchable sheet 10.
  • the feed-out section 120 is located upstream of the welded portion forming section 130 in the conveying direction (MD) and performs a feed-out process of feeding materials such as rubber thread 14, first sheet 11, and second sheet 12 to the welded portion forming section 130.
  • the feed-out section 120 has five types of rollers, first conveying roller 121 to fifth conveying roller 125, which rotate around their rotation axes along the cross direction (CD).
  • the first conveying roller 121 is rotated at a predetermined speed by a drive unit (not shown), thereby conveying the rubber thread 14 (continuous body) and first sheet 11 (continuous body) from the upstream side to the downstream side in the conveying direction (MD).
  • the second conveying roller 122 and third conveying roller 123 are rollers that convey the rubber thread 14 and first sheet 11, respectively, and are driven to rotate in accordance with the rotation of the first conveying roller 121.
  • the fourth transport roller 124 is located between the first transport roller 121 and the welded portion forming unit 130 in the transport direction, and transports the second sheet 12 (continuous body) from the upstream side to the downstream side in the transport direction (MD) while merging the second sheet 12 with the rubber thread 14 and first sheet 11 being transported in the transport direction.
  • the fifth transport roller 125 is a roller that rotates in response to the rotation of the fourth transport roller 124.
  • the configuration of the delivery section 120 shown in Figure 4 is an example, and the configuration and arrangement of each roller and the material delivery method can be changed as appropriate.
  • the first transport roller 121 delivers the first sheet 11 together with the rubber thread 14, and the second sheet 12 joins with them downstream in the delivery direction (MD).
  • the second sheet 12 can also be delivered by the first transport roller 121 together with the rubber thread 14, and then the first sheet 11 can join with them.
  • the fourth transport roller 124 may not be provided, and the first sheet 11, second sheet 12, and rubber thread 14 may be delivered by the first transport roller 121.
  • the weld forming unit 130 is used to carry out the weld forming process, which forms the weld 50 (joint j) that joins the first sheet 11 and the second sheet 12 together, and includes an anvil roll 131 and an ultrasonic horn 132.
  • the anvil roll 131 is a rotating body that rotates around a rotation axis 131c along the cross direction (CD) by a drive source (not shown), and conveys the stretchable sheet 10 in the conveying direction (MD) by rotating with the stretchable sheet 10 wrapped around its outer periphery.
  • the ultrasonic horn 132 is positioned opposite the outer periphery of the anvil roll 131, and amplifies ultrasonic vibrations supplied from a vibrator (not shown) to perform ultrasonic welding at the tip 132t.
  • a vibrator not shown
  • the tip 132t ultrasonically vibrates with the materials (first sheet 11, rubber thread 14, and second sheet 12) sandwiched between them, thereby ultrasonically welding the materials to form a welded portion 50 (joint j).
  • the anvil roll 131 and the ultrasonic horn 132 need only be positioned opposite each other so that they can come into contact at position P1 via at least the materials passing between them.
  • Figure 5A is a diagram explaining the surface configuration of the anvil roll 131 and the ultrasonic horn 132.
  • Figure 5B is a schematic enlarged view of the closest portion of the anvil roll 131 and the ultrasonic horn 132.
  • the outer peripheral surface of the anvil roll 131 is formed with a plurality of convex portions 311 that protrude radially outward. These convex portions 311, together with the tip 132t of the ultrasonic horn 132, ultrasonically weld the material to form the welded portion 50 (joint j).
  • the convex portions 311 are arranged on the outer peripheral surface of the anvil roll 131 in a pattern that corresponds to the arrangement pattern of the welded portions 50 (joint j) in the stretchable sheet 10.
  • a groove portion 312 is formed between two adjacent convex portions 311, 311 in the CD direction.
  • the tip 132t of the ultrasonic horn 132 has a smooth surface with no irregularities, and vibrates in a direction that expands or contracts the gap between it and the outer surface of the anvil roll 131 (i.e., in the thickness direction of the material passing through).
  • the vibration frequency is a predetermined value, for example, between 20 kHz and 40 kHz
  • the amplitude is a predetermined value, for example, between 30 and 50 microns. This causes the tip 132t of the ultrasonic horn 132 to vibrate ultrasonically.
  • Such vibration is generated, for example, by inputting an electrical signal of the above frequency to a piezoelectric element of a converter (not shown) connected to the ultrasonic horn 132.
  • the first sheet 11, second sheet 12, and rubber thread 14 are transported in the transport direction (MD) while wrapped around the anvil roll 131, passing between the anvil roll 131 and the tip 132t of the ultrasonic horn 132 at position P1.
  • the rotational speed of the first transport roller 121, which transports the first sheet 11, etc., is roughly the same as the rotational speed of the anvil roll 131. Therefore, the first sheet 11, etc., are wound around the anvil roll 131 in a taut state without being stretched, but without slack.
  • the rubber thread 14 is transported in a stretched state in the transport direction (MD) between the tension adjustment unit 140 (described below) and the first transport roller 121. In other words, it is transported in the transport direction (MD) with a predetermined amount of tension applied. Therefore, the rubber thread 14 is wound around the anvil roll 131 in a stretched state.
  • the first sheet 11 and the second sheet 12, with the rubber thread 14 interposed therebetween are conveyed in the machine direction (MD) and passed between the anvil roll 131 and the ultrasonic horn 132.
  • the first sheet 11 and the second sheet 12, sandwiched in the thickness direction between the outer peripheral surface of the anvil roll 131 and the tip 132t of the ultrasonic horn 132, are then ultrasonically welded to form multiple welded portions 50 (joints j).
  • the first sheet 11 and the second sheet 12 are melted and joined together by ultrasonic vibrations from the ultrasonic horn 132 at positions corresponding to the convex portions 311 on the outer peripheral surface of the anvil roll 131.
  • the rubber thread 14 is positioned in the groove 312 between two adjacent convex portions 311 in the cross direction (CD) and is not ultrasonically welded.
  • the rubber thread 14 can be prevented from being pinched between the outer circumferential surface of the anvil roll 131 and the tip 132t of the ultrasonic horn 132 and being cut off (see Figure 8B, described below).
  • the welded portion 50 also serves to regulate the position of the rubber thread 14 in the stretching direction and width direction relative to the first sheet 11 and the second sheet 12, i.e., to attach the rubber thread 14 to the first sheet 11 and the second sheet 12.
  • Figures 6A and 6B are explanatory diagrams of the method of attaching the rubber thread 14 using the welded portion 50 (joint j).
  • the distance D50 between the welded portion pair 50P which consists of two welded portions 50, 50 located on both sides of the rubber thread 14 in the width direction (CD)
  • the distance D50 is smaller than the width direction (CD) size of the rubber thread 14 in its natural, unloaded state.
  • the rubber thread 14 in its stretched state is thinner than the thickness of the rubber thread 14 in its natural state by the amount of stretch.
  • the welded portion pair 50P can clamp the rubber thread 14, which is shrinking in the conveying direction and attempting to expand in the width direction (CD), from the width direction (CD), as shown in FIG. 6B. This restricts the position of the rubber thread 14 in the stretch direction (MD) and width direction (CD), and the rubber thread 14 is attached to the first sheet 11 and second sheet 12.
  • FIG. 7 is a diagram explaining modified examples of the surface configuration of the anvil roll 131 and the ultrasonic horn 132.
  • gears 315 extending in the cross direction (CD) are provided at predetermined intervals in the circumferential direction (MD) on the outer peripheral surface of the anvil roll 131.
  • the tip 132t of the ultrasonic horn 132 is provided with a plurality of protrusions 321 that protrude on the side facing the anvil roll 131.
  • the protrusions 321 are provided at predetermined intervals along the cross direction (CD), and when the gear 315 of the anvil roll 131 and the protrusions 321 of the ultrasonic horn 132 face each other, the material is ultrasonically welded to form the welded portion 50 (joint j).
  • welds 50 can be formed in the arrangement shown in FIG. 1 according to the pattern of the protrusions 321 and the circumferential spacing of the gear 315.
  • grooves 322 are formed between two adjacent protrusions 321, 321 in the cross direction (CD) of the ultrasonic horn 132. If rubber thread 14 is placed in the grooves 322 when forming the welds 50 (joints j), cutting of the rubber thread 14 is prevented, and the rubber thread 14 remains attached to the first sheet 11 and the second sheet 12.
  • the tension adjustment unit 140 is located upstream of the feed-out unit 120 (first transport roller 121) in the transport direction (MD) and is a mechanism that transports the rubber thread 14 downstream in the transport direction (MD).
  • the tension adjustment unit 140 is composed of a pair of nip rollers that rotate while sandwiching the rubber thread 14, for example, as shown in Figure 4.
  • the tension adjustment unit 140 is rotated by a drive unit (not shown) at a slower speed than the first transport roller 121 of the feed-out unit 120 to transport the rubber thread 14.
  • the rubber thread 14 is stretched based on the difference in rotational speed (transport speed) between the tension adjustment unit 140 and the first transport roller 121 in the transport direction (MD), and is sent out downstream of the feed-out unit 120 (feed-out unit 120) in a tensioned state.
  • the tension adjustment unit 140 may be configured other than a nip roller, such as a known tension controller, or a combination of these.
  • the welded portion 50 (joint j) is formed to join the first sheet 11 and the second sheet 12, which are the materials, and the rubber thread 14 is attached to the materials by clamping the rubber thread 14 from both sides in the cross direction (CD) with the pair of welded portions 50P.
  • the rubber thread 14 is placed in the groove portion 312 (322) formed between two convex portions 311 (321) adjacent in the cross direction (CD) (see FIG. 5B ), thereby preventing the rubber thread 14 from being cut.
  • Figures 8A and 8B are diagrams that explain what happens when the position of the rubber thread 14 in the cross direction is misaligned when forming the welded portion 50.
  • Figures 8A and 8B schematically show what happens when the rubber thread 14 is supplied (transported) with its position in the cross direction (CD) misaligned relative to the welded portion forming section 130 (anvil roll 131).
  • FIG. 8A shows two of the multiple rubber threads 14 provided on the stretchable sheet 10, namely, 14a and 14b, wound around the outer peripheral surface of the anvil roll 131. At this time, one rubber thread 14a is positioned overlapping with the groove 312 of the anvil roll 131, while the other rubber thread 14b is positioned offset in the cross direction (CD) from the position of the groove 312 and overlapping with the protrusion 311.
  • one rubber thread 14a is attached between the first sheet 11 and the second sheet 12 by a pair of welds 50P formed based on the protrusion 311.
  • the other rubber thread 14b may be cut when ultrasonic vibrations are applied while it is sandwiched between the protrusion 311 and the ultrasonic horn 132 (tip 132t) as shown in Figure 8B.
  • the rubber thread 14 may be cut if the position of the rubber thread 14 is misaligned in the cross direction (CD) when the weld 50 is formed in the weld forming unit 130, the rubber thread 14 may be cut.
  • the cut rubber thread 14 attempts to contract upstream and downstream in the conveying direction (MD) from the cut position (position P1 in Figure 4).
  • position P1 downstream of position P1, the welded portion pair 50P has already been formed and the rubber thread 14 is clamped in the cross direction (CD), so the rubber thread 14 can remain attached between the first sheet 11 and the second sheet 12.
  • upstream of position P1 the welded portion pair 50P has not yet been formed, so the rubber thread 14 continues to contract upstream in the conveying direction (MD) (towards the feed section 120).
  • the rubber thread 14 must be reset to a state where it can be conveyed, sent again to the welded portion forming section 130, and attached between the first sheet 11 and the second sheet 12. Therefore, with conventional stretch sheet manufacturing equipment, it is necessary to, for example, temporarily stop the conveyance of materials and restore the cut rubber thread so that it can be conveyed normally, which requires time and cost. Furthermore, such work makes it impossible to continuously manufacture stretch sheets. Thus, with conventional stretch sheet manufacturing equipment, there is a risk of a significant drop in production efficiency if the rubber thread is cut when forming the welded portion.
  • the stretchable sheet manufacturing apparatus 100 automatically restores the rubber thread 14 even if it is broken during the manufacturing process of the stretchable sheet 10, making it possible to continuously manufacture the stretchable sheet 10 without stopping the apparatus. Specifically, by implementing the following measures, even if the rubber thread 14 is broken, it is possible to automatically restore the rubber thread 14 without stopping the apparatus. That is, (a) the rubber thread 14 is prevented from slipping out beyond the feed-out section 120 to the upstream side in the machine direction (MD), and (b) the stretched rubber thread 14 is continuously fed from the feed-out section 120.
  • MD machine direction
  • Figures 9A to 9D are diagrams illustrating the mechanism by which the rubber thread 14 automatically recovers when it is cut during the manufacturing process of the stretch sheet 10 using the stretch sheet manufacturing apparatus 100. To simplify the explanation, some components (e.g., the second sheet 12, etc.) are omitted from Figures 9A to 9D.
  • the rubber thread 14 is transported from upstream to downstream in the conveying direction (MD) together with a sheet member (a material sheet such as the first sheet 11), while a weld 50 is formed in the weld forming section 130 and the rubber thread 14 is attached to the sheet member.
  • a sheet member a material sheet such as the first sheet 11
  • the rubber thread 14 is transported in the delivery section 120 of the stretch sheet manufacturing apparatus 100, at least one sheet member is transported in the conveying direction (MD) together with the rubber thread 14 while being wound around the first conveying roller 121.
  • the rubber thread 14 is wound around the first conveying roller 121, and a continuous body of the first sheet 11 is also wound around the first conveying roller 121 on top of the rubber thread 14.
  • the rubber thread 14 is held sandwiched between the outer circumferential surface of the first conveying roller 121 and the first sheet 11. Therefore, even if the rubber thread 14 were to be cut at the welded portion forming portion 130 (position P1) located downstream in the conveying direction (MD) and shrink upstream, the rubber thread 14 would continue to be held by the first conveying roller 121 (feed-out portion 120) while being pressed against the first sheet 11. This prevents the rubber thread 14 from shrinking upstream of the first conveying roller 121 (feed-out portion 120). In other words, (a) the rubber thread 14 is prevented from slipping out upstream of the feed-out portion 120 (so-called "slip-out").
  • the stretched state of the rubber thread 14 is also maintained in the transport direction (MD) between the first transport roller 121 (feed-out section 120) and the tension adjustment section 140.
  • MD transport direction
  • a predetermined tension of zero or more acts on the rubber thread 14 between the first transport roller 121 and the tension adjustment section 140. Therefore, (b) the rubber thread 14 continues to be fed out from the feed-out section 120 to the welded portion forming section 130 downstream in the transport direction (MD) while maintaining its stretched state, and the cut portion of the rubber thread 14 is unlikely to reach any point upstream of the feed-out section 120.
  • the "tension of a predetermined magnitude or greater" applied to the rubber thread 14 between the tension adjustment unit 140 and the payout unit 120 is greater than zero, and preferably 0.2 N or greater.
  • the tension of the rubber thread 14 in the payout unit 120 is 0.2 N or greater, the same magnitude of tension (0.2 N or greater) is acting on the rubber thread 14 between the payout unit 120 and the welded portion forming unit 130. If a tension of 0.2 N or greater is acting on the payout unit 120, the rubber thread 14 is more likely to be continuously supplied from the payout unit 120 to the welded portion forming unit 130, and even if the rubber thread 14 is broken, it can be automatically restored.
  • Figure 9B shows the case where the rubber thread 14 is cut at position P1 in the welded portion forming section 130.
  • the rubber thread 14 cut at position P1 in the welded portion forming section 130 contracts from position P1 upstream in the machine direction (MD) as shown in Figure 9B.
  • MD machine direction
  • the stretch sheet manufacturing apparatus 100 of this embodiment prevents the cut rubber thread 14 from slipping upstream of the feed-out section 120, and the cut portion 14c of the rubber thread 14 (the end of the cut rubber thread 14) is located between the feed-out section 120 and the welded portion forming section 130.
  • the tension of the rubber thread 14 is essentially zero. Meanwhile, the tension of the rubber thread 14 is maintained at 0.2 N or more between the tension adjustment section 140 and the feed-out section 120.
  • the cut portion 14c of the rubber thread 14 is placed on the first sheet 11 with essentially zero tension (i.e., in an unstretched state).
  • the cut portion 14c is fed toward the welded portion forming section 130 as the first sheet 11 is fed downstream in the conveying direction (MD).
  • the rubber thread 14 is continuously fed downstream in the conveying direction (MD) together with the first sheet 11 from the feed-out section 120.
  • the rubber thread 14 and first sheet 11 continue to be fed at a constant speed from the feed-out section 120 toward the welded portion forming section 130. Note that in FIG.
  • the rubber thread 14 is attached to the sheet member (first sheet 11 and second sheet 12) via the welded portion 50, and is fed downstream in the conveying direction (MD) as a stretchable sheet 10.
  • the tension of the rubber thread 14 increases from zero to a predetermined magnitude of 0.2 N or more.
  • the cut rubber thread 14 naturally returns to its pre-cut state, as shown in FIG. 9A. This allows for efficient production of the stretchable sheet 10.
  • the second sheet 12 joins them somewhere between them and the welded portion forming section 130, so that the rubber thread 14 reaches the welded portion forming section 130 sandwiched between the first sheet 11 and the second sheet 12. Therefore, the position of the rubber thread 14 in the cross direction (CD) reaches the welded portion forming section 130 and is attached to the material sheet without being significantly deviated from the position at the time of feeding out from the feed-out section 120, making it easier for it to recover naturally.
  • the stretch sheet manufacturing apparatus 100 helps prevent the rubber thread 14 from being cut when the welded portion 50 is formed in the welded portion forming section 130 (see Figure 8B).
  • the rubber thread 14b wound around the anvil roll 131 is positioned so as to overlap the convex portion 311 in the cross direction (CD), which creates a problem of it being easily cut when it is sandwiched between the anvil roll 131 and the ultrasonic horn 132.
  • the rubber thread 14b is positioned so as to overlap the groove portion 312 in the cross direction (CD) like the rubber thread 14a, the probability of the rubber thread 14b being cut can be reduced.
  • FIGS. 10 and 11 are diagrams illustrating how the rubber thread 14 is wound around the weld portion forming section 130.
  • Figure 10 shows the rubber thread 14 wound around the outer peripheral surface of the anvil roll 131 upstream in the conveying direction (MD) of position P1, where the anvil roll 131 and the ultrasonic horn 132 face each other.
  • the rubber thread 14 is sent out from the sending section 120 (first conveying roller 121) at an angle ⁇ a toward the anvil roll 131 with respect to the tangent at position P1, where the anvil roll 131 and the ultrasonic horn 132 face each other.
  • the rubber thread 14 begins to wind around the anvil roll 131 at position P2, upstream in the conveying direction (MD) of position P1.
  • the welded portion 50 has not yet been formed, and therefore the position of the rubber thread 14 in the cross direction (CD) is not restricted.
  • the rubber thread 14 is transported in a state in which it can move in the cross direction (CD).
  • tension acts to press the rubber thread 14 toward the radial center (131c) of the anvil roll 131 in the section from position P2 to position P1.
  • the rubber thread 14 may roll in the cross direction (CD) on the outer circumferential surface of the anvil roll 131, or may be pushed aside in the cross direction (CD) upon contact with the tip 132t of the ultrasonic horn 132, potentially entering the groove 312 at position P1 (see FIG. 5B).
  • the length L1 from position P4 where the rubber thread 14 is sent out from the send-out section 120 (first conveying roller 121), to position P2, where the rubber thread 14 begins to wrap around the outer circumferential surface of the anvil roll 131, is longer than the length L2 from position P2 to position P1 (L1 > L2).
  • the length L2 over which the rubber thread 14 is wound around and in close contact with the outer circumferential surface of the anvil roll 131 is shorter than the length L1 over which the rubber thread 14 is transported from the send-out section 120 to the anvil roll 131. Therefore, compared to the reverse case, the rubber thread 14 is more likely to shift (move) in the cross direction (CD) during transport, increasing the probability of it getting caught in the groove 312 of the anvil roll 131. This prevents the rubber thread 14 from being cut when the welded portion forming unit 130 forms the welded portion 50.
  • Figure 11 shows a state in which the rubber thread 14 is wound around the tip 132t of the ultrasonic horn 132 upstream in the conveying direction (MD) of position P1, where the anvil roll 131 and the ultrasonic horn 132 face each other.
  • the rubber thread 14 is sent out from the sending section 120 (first conveying roller 121) at an angle ⁇ b toward the ultrasonic horn 132 with respect to the tangent at position P1, where the anvil roll 131 and the ultrasonic horn 132 face each other, and begins to wind around the ultrasonic horn 132 (tip 132t) at position P2', upstream in the conveying direction (MD) of position P1.
  • the length L1' from position P4 where the rubber thread 14 is sent out from the send-out section 120 (first transport roller 121) to position P2' where it begins to wind around the ultrasonic horn 132 be longer than the length L2' from position P2' to position P1 (L1' > L2').
  • the rubber thread 14 is more likely to shift (move) in the cross direction (CD) during transport compared to the reverse case, increasing the probability of it entering the grooves 322 of the ultrasonic horn 132. This prevents the rubber thread 14 from being cut when the welded portion forming unit 130 forms the welded portion 50.
  • the length L3 (the length along the outer surface of the anvil roll 131 from position P1 to position P3 in Figures 10 and 11) of the rubber thread 14 wound around the circumferential surface of the anvil roll 131 downstream in the conveying direction (MD) from position P1 where the anvil roll 131 and the ultrasonic horn 132 face each other is longer than the length L2 (L2') of the rubber thread 14 wound around the circumferential surface of the anvil roll 131 or the tip 132t of the ultrasonic horn 132 upstream in the conveying direction (MD) from position P1 (L2 ⁇ L3, L2' ⁇ L3).
  • the stretchable stretch sheet 10 Downstream of position P1, where the welded portion 50 is formed by the anvil roll 131 and the ultrasonic horn 132, the rubber thread 14 is attached to the material (the first sheet 11 and the second sheet 12) by the welded portion 50. Therefore, downstream of position P1, the stretchable stretch sheet 10 is transported in a stretched state along the outer circumferential surface of the anvil roll 131. By lengthening the length L3 of the stretchable sheet 10 wrapped around the outer circumferential surface as much as possible, the stretchable sheet 10 can be transported stably downstream in the conveying direction (MD) without wrinkling or other surface defects. Meanwhile, upstream of position P1, the welded portion 50 has not yet been formed, and the position of the rubber thread 14 in the cross direction (CD) is not restricted.
  • MD conveying direction
  • the rubber thread 14 can be more easily moved in the cross direction (CD). This helps prevent the rubber thread 14 from being cut at position P1.
  • the first transport roller 121 that transports the rubber thread 14 has the rubber thread 14 wound around it over an area of at least 1/4 of its circumference.
  • the rubber thread 14 is wound around an area of approximately 1/3 of the circumference of the first transport roller 121.
  • the rubber thread 14 is wound around the first transport roller 121 together with at least one sheet member (first sheet 11 in Figure 10), and is transported while being held by the first transport roller 121. Therefore, the longer the length wound around the first transport roller 121, the stronger the holding force.
  • the rubber thread 14 in a stretched state is wound around the first transport roller 121, so the tension of the rubber thread 14 itself presses the rubber thread 14 against the outer circumferential surface of the transport roller 121. If the rubber thread 14 is wound over a range of at least one-quarter of the circumference of the transport roller 121, the rubber thread 14 is less likely to slip on the outer circumferential surface than if it is wound over less than one-quarter, thereby achieving a stronger holding force. Therefore, even if the rubber thread 14 is cut when forming the welded portion 50, it is easier to prevent the cut rubber thread 14 from slipping off upstream in the transport direction (MD) from the feed section 120 (first transport roller 121). This makes it easier to automatically restore the rubber thread 14 without stopping the stretch sheet manufacturing apparatus 100, allowing for efficient production of stretch sheets 10.
  • MD transport direction
  • the rubber thread 14 is wrapped around the first transport roller 121 over an area of at least 1/4 of the circumference of the first transport roller 121, with the first sheet 11 overlapping the rubber thread 14.
  • the rubber thread 14 is held between the outer surface of the transport roller and the first sheet 11, and the length pressed down by the first sheet 11 is longer, resulting in a stronger holding force. Therefore, even if the rubber thread 14 is cut, it is easier to prevent it from coming loose.
  • the rubber thread 14 is wound in an S-shape around the first transport roller 121 and the second transport roller 122.
  • the rubber thread 14 is more easily held in place than when it is wound around a single roller. Therefore, even if the rubber thread 14 breaks, it is more likely that the broken rubber thread 14 will slip off upstream of the delivery section 120 in the conveying direction (MD).
  • a tension adjustment unit 140 is provided upstream of the feed-out unit 120 in the conveying direction (MD).
  • the tension adjustment unit 140 and the feed-out unit 120 rotate at different peripheral speeds, thereby applying a predetermined amount of tension (at least 0.2 N) to the rubber thread 14.
  • a predetermined amount of tension at least 0.2 N
  • the rubber thread 14 is constantly stretched when it is fed from the feed-out unit 120 to the welded portion forming unit 130. Therefore, even if the rubber thread 14 is cut in the welded portion forming unit 130, the rubber thread 14 can be continuously fed in a stretched state from the feed-out unit 120. This makes it easier for the cut rubber thread 14 to automatically recover, allowing for efficient production of the stretchable sheet 10.
  • the rubber thread 14 and first sheet 11 are fed from the feed-out section 120 (first conveyor roller 121), and then the second sheet 12 joins them at some position in the conveyance direction (MD) before reaching the welded portion forming section 130.
  • first sheet 11 joins the rubber thread 14 at the feed-out section 120 (first conveyor roller 121), and the rubber thread 14 is pressed down, making it easier for the rubber thread 14 to be held by the first conveyor roller 121.
  • the rubber thread 14 is sandwiched between the two sheets, which further reduces the likelihood of the rubber thread 14 slipping out. Furthermore, with the rubber thread 14 sandwiched between the two sheets in this manner, when the rubber thread 14 is cut in the welded portion forming section 130 and shrinks toward the upstream side in the conveying direction (MD), the shrinkage is more likely to stop by the time the second sheet joins.
  • the fourth conveying roller 124 presses the rubber thread 14 and first sheet 11 in the thickness direction to join the second sheet 12, which makes it easier to prevent the cut rubber thread 14 from slipping out upstream in the conveying direction (MD) of the fourth conveying roller 124. This makes it easier to efficiently manufacture the stretchable sheet 10.
  • FIG. 12A and 12B are schematic cross-sectional views illustrating a case where the joining position of the second sheet 12 is changed in the stretch sheet manufacturing apparatus 100.
  • FIG. 12A illustrates a case where the second sheet 12 joins the rubber thread 14 and the first sheet 11 in the welded portion forming section 130.
  • the fourth conveying roller 124 that joins the second sheet 12 with the rubber thread 14 in FIG. 4 is not provided. Instead, the second sheet 12 is supplied directly to the welded portion forming section 130, where it joins the rubber thread 14 and the first sheet 11 at position P1.
  • the rubber thread 14 is conveyed while separated from the second sheet 12 until just before the welded portion forming section 130. Therefore, the resistance on one side in the thickness direction is smaller than when the rubber thread 14 is conveyed sandwiched between two sheets (the first sheet 11 and the second sheet 12) as shown in FIG. 4. Therefore, the rubber thread 14 is likely to shift in the cross direction (CD) while being transported from the delivery section 120 to the welded section forming section 130.
  • the rubber thread 14 is sandwiched between the anvil roll 131 and the ultrasonic horn 132 in the welded section forming section 130 to form the welded section 50, the rubber thread 14 is more likely to enter the grooves 312 (322) and is less likely to be cut. This makes it easier to efficiently manufacture the stretch sheet 10.
  • Figure 12B shows a case where the second sheet 12 merges with the rubber thread 14 and the first sheet 11 at the feed-out section 120 (first transport roller 121). That is, two sheet members merge with the rubber thread 14 at the feed-out section 120.
  • the fourth transport roller 124 is not provided, and the first sheet 11 and second sheet 12 are fed out by the first transport roller 121. That is, in Figure 12B, the rubber thread 14 is sandwiched between the first sheet 11 and the second sheet 12, and is fed out by the first transport roller 121 toward the welded portion forming section 130.
  • the rubber thread 14 is sandwiched between the two sheets at the position of the first transport roller 121, it is easier to prevent the rubber thread 14 from slipping off upstream in the transport direction (MD) of the first transport roller 121 if it is cut. Furthermore, because a sheet (the second sheet 12 in Figure 12B) is interposed between the rubber thread 14 and the first transport roller 121, direct contact between the rubber thread 14 and the roller is unlikely. This reduces the risk of damage to the rubber thread 14 due to friction between the rubber thread 14 and the roller during transport.
  • a stretchable sheet manufacturing apparatus 100 will be described in which the configuration of the delivery unit 120 is different from that of the first embodiment. Note that the configuration and function of each unit other than the delivery unit 120, and the stretchable sheet 10 to be manufactured are the same as in the first embodiment, and therefore a detailed description of each unit will be omitted.
  • Figure 13 is a schematic cross-sectional view showing a stretchable sheet manufacturing apparatus 100 of a second embodiment.
  • the delivery section 120 has a pair of nip rollers 127 that rotate around a rotation axis in the cross direction (CD) perpendicular to the machine direction (MD).
  • the nip rollers 127 rotate while the first sheet 11, the second sheet 12, and the rubber thread 14 (all of which are continuous bodies) are stacked in the thickness direction, thereby transporting them downstream in the machine direction (MD) at a predetermined transport speed.
  • the rubber thread 14 is held between the first sheet 11 and the second sheet 12 by the nip rollers 127.
  • the stretchable sheet manufacturing apparatus 100 even if the rubber thread 14 is cut when forming the welded portion 50 in the welded portion forming unit 130 and contracts from the cutting position (position P1 in Figure 13) toward the upstream side in the conveying direction (MD), the contraction is stopped by the nip roller 127 (feed-out unit 120), preventing the rubber thread 14 from slipping off upstream. Furthermore, because the rubber thread 14 is transported in a stretched state by the nip roller 127 (feed-out unit 120) and the tension adjustment unit 140 located upstream thereof, even if the rubber thread 14 is cut, the stretched rubber thread 14 can be continuously fed from the nip roller 127. This allows the cut rubber thread 14 to naturally recover, allowing the stretchable sheet 10 to be efficiently manufactured without having to stop the stretchable sheet manufacturing apparatus 100.
  • first sheet 11 and second sheet 12 are joined to the rubber thread 14 at the nip roller 127 (feed-out section 120), but it is sufficient if at least one sheet is joined to the rubber thread 14 at the nip roller 127.
  • first sheet 11 may be joined to the rubber thread 14 at the nip roller 127 (feed-out section 120), and the second sheet 12 may be joined at a predetermined position between the feed-out section 120 and the welded portion forming section 130.
  • FIG. 14 is a schematic cross-sectional view showing the case where the second sheet 12 meets the rubber thread 14 at the welded portion forming section 130.
  • the rubber thread 14 is fed from the feed-out section 120 and transported while separated from the second sheet 12 until just before the welded portion forming section 130. Therefore, compared to when the rubber thread 14 is transported sandwiched between two sheets (the first sheet 11 and the second sheet 12) as shown in FIG. 13, resistance is smaller, and the rubber thread 14 is more likely to shift in the cross direction (CD) while being transported from the feed-out section 120 to the welded portion forming section 130.
  • CD cross direction
  • FIG. 15 is a schematic cross-sectional view showing a modified example of the stretchable sheet manufacturing apparatus 100 of the second embodiment.
  • a spacing roller 128 is provided between the nip roller 127 (feed-out section 120) and the welded section forming section 130 in the transport direction (MD).
  • first sheet 11 and second sheet 12 are joined to the rubber thread 14 by the nip roller 127 and sent downstream in the conveying direction (MD). Then, one of the first sheet 11 and second sheet 12 (second sheet 12 in Figure 15) is separated from the rubber thread 14 in the thickness direction by the separation roller 128. The separated second sheet 12 then rejoins the rubber thread 14 (and first sheet 11) at the welded portion forming section 130.
  • the rubber thread 14 is sandwiched between the two sheet members on both sides in the thickness direction at the nip roller 127, making it easier to hold firmly by the nip roller 127 and less likely to come loose.
  • one sheet (second sheet 12) is separated on one side in the thickness direction, reducing resistance and making it easier for the rubber thread 14 to shift in the cross direction (CD).
  • CD cross direction
  • Pants-type disposable diapers 2 absorbent body, 3 ventral waist portion, 4 dorsal waist portion, 5 elastic thread, 10 Elastic sheet, 11 First sheet, 12 Second sheet, 14 Rubber thread, 50 welded part (joint part), 50P welded part pair, 100 Stretchable sheet manufacturing apparatus, 120 sending section, 121 First conveying roller, 122 Second conveying roller, 123 Third conveying roller, 124 Fourth conveying roller, 125 Fifth conveying roller, 127 nip roller, 128 spacing roller, 130 welding part forming part, 131 anvil roll, 311 convex portion, 312 groove portion, 132 ultrasonic horn, 132t tip, 321 convex portion, 322 groove portion, 140 tension adjustment section, P1 position, MD: conveying direction (stretching direction), CD: width direction, j junction, jP junction pair

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  • Health & Medical Sciences (AREA)
  • Epidemiology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

L'invention concerne un dispositif de fabrication de feuille étirable (100) comprenant : une unité de formation (130) de partie de soudage comprenant un rouleau d'enclume (131) et un émetteur d'ultrasons (132) ; et une unité d'alimentation (120) qui est disposée de façon à être séparée de l'émetteur d'ultrasons (132) et du rouleau d'enclume (131) dans le sens de transport et qui alimente au moins une première feuille (11) et/ou une seconde feuille (12) conjointement avec du caoutchouc en fil (14) vers l'unité de formation (130) de partie de soudage. Une tension supérieure ou égale à une amplitude prescrite est appliquée au caoutchouc en fil (14) sur le côté amont par rapport à l'unité d'alimentation (120) et l'unité d'alimentation (120) maintient le caoutchouc en fil (14) et au moins la première feuille (11) et/ou la seconde feuille (12) de telle sorte que le caoutchouc en fil (14) qui a été coupé par l'unité de formation (130) de partie de soudage ne se détache pas du côté amont par rapport à l'unité d'alimentation (120).
PCT/JP2025/018890 2024-05-28 2025-05-26 Dispositif de fabrication de feuille étirable et procédé de fabrication de feuille étirable Pending WO2025249356A1 (fr)

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JP2024086267A JP2025179493A (ja) 2024-05-28 2024-05-28 伸縮性シート製造装置、及び、伸縮性シート製造方法
JP2024-086267 2024-05-28

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008104853A (ja) * 2006-09-29 2008-05-08 Daio Paper Corp 吸収性物品における伸縮部形成方法及びその形成装置
WO2018167836A1 (fr) * 2017-03-14 2018-09-20 ユニ・チャーム株式会社 Procédé de production et dispositif de production pour élément en feuille utilisé dans des articles absorbants
JP2020500662A (ja) * 2016-12-20 2020-01-16 ザ プロクター アンド ギャンブル カンパニーＴｈｅ Ｐｒｏｃｔｅｒ ＆ Ｇａｍｂｌｅ Ｃｏｍｐａｎｙ 弾性ストランドを有するエラストマー積層体の製造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008104853A (ja) * 2006-09-29 2008-05-08 Daio Paper Corp 吸収性物品における伸縮部形成方法及びその形成装置
JP2020500662A (ja) * 2016-12-20 2020-01-16 ザ プロクター アンド ギャンブル カンパニーＴｈｅ Ｐｒｏｃｔｅｒ ＆ Ｇａｍｂｌｅ Ｃｏｍｐａｎｙ 弾性ストランドを有するエラストマー積層体の製造方法
WO2018167836A1 (fr) * 2017-03-14 2018-09-20 ユニ・チャーム株式会社 Procédé de production et dispositif de production pour élément en feuille utilisé dans des articles absorbants

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