Panty-type absorbent article

Abstract

The underwear-type absorbent article (1) has an absorbent body (10) and a waist section (20) that joins the abdominal waist section (31) and the back waist section (41) together by a pair of side joints (70, 70). The waist section (20) has an inner end region (IA) and a central region (CA). The value obtained by dividing the difference between the left-right length (LIA) of the inner end region (IA) in the extended state and the left-right length (IIA) of the inner end region (IA) in the natural state by the left-right length (LIA) of the inner end region (IA) in the extended state is less than the value obtained by dividing the difference between the left-right length (LCA) of the central region (CA) in the extended state and the left-right length (ICA) of the central region (CA) in the natural state by the left-right length (LCA) of the central region (CA) in the extended state.

Description

Technical Field

[0001] This invention relates to absorbent articles in the form of underwear. Background Technology

[0002] Previously, absorbent underwear-type articles were known to connect a stretchable abdominal (front) waistband to a back (rear) waistband using lateral joints at both ends in the left and right directions, forming a waistband opening and a pair of leg openings. For example, Patent Document 1 discloses a disposable underwear-type article in which a waistband elastic member is sandwiched between two sheet members, and the elastic member is fixed to the sheet members using three or more striped joints in a direction intersecting the stretching direction of the elastic member.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: WO2018 / 092559 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] After wearing such absorbent underwear, when removing it from the wearer's body, the usual action is to tear open the side seams to open the waistband. However, because the waistband itself is elastic in the lateral direction, the force used to tear the side seams is either used to stretch the waistband to the left and right or it is difficult to apply force to the side seams. Therefore, the side seams become difficult to tear, resulting in the problem of difficulty in removing the absorbent underwear from the wearer's body.

[0008] The present invention was made in view of the aforementioned problems, and its object is to facilitate the removal of the underwear-type absorbent article from the wearer's body by tearing open the side joint in a way that allows the stretchable abdominal waistband and back waistband to be connected by a side joint.

[0009] Solution for solving the problem

[0010] The main invention for achieving the above-mentioned objective is an absorbent underwear-type article having intersecting vertical and horizontal directions. The article comprises: an absorbent body; and a waistband, wherein the waistband is joined at both ends in the horizontal direction by a pair of lateral joints to connect the abdominal waistband and the back waistband. At least a portion of the waistband between the pair of lateral joints has elasticity along the horizontal direction. The waistband, in its extended state, has an inner end region that is higher than the upper end of the absorbent body in the vertical direction and, in the horizontal direction, extends from the inner end of the lateral joint towards the inside. The range extending 20mm to the side; and the central region, which is higher than the upper end of the absorbent body in the vertical direction and sandwiched between a pair of inner end regions in the horizontal direction, the value obtained by dividing the difference between the horizontal length of the inner end regions in the extended state and the horizontal length of the inner end regions in the natural state by the horizontal length of the inner end regions in the extended state is less than the value obtained by dividing the difference between the horizontal length of the central region in the extended state and the horizontal length of the central region in the natural state by the horizontal length of the central region in the extended state.

[0011] Other features of the invention will become apparent from the description and accompanying drawings.

[0012] The effects of the invention

[0013] According to the present invention, in an absorbent underwear-type garment in which a stretchable abdominal waistband and a back waistband are connected by a side joint, it is possible to easily tear open the side joint and remove it from the wearer's body. Attached Figure Description

[0014] Figure 1 This is a rough 3D diagram of Diaper 1.

[0015] Figure 2 This is a rough top view of the diaper 1 in its unfolded and elongated state, viewed from the side of the wearer's skin.

[0016] Figure 3 yes Figure 2 The A-A cross-section diagram in the diagram, and also the... Figure 2 B-B cross-section view.

[0017] Figure 4 This is a schematic top view of the ventral waist section 31 in an expanded and elongated state, viewed from the non-skin side.

[0018] Figure 5A as well as Figure 5B This is an explanatory diagram illustrating the installation function of the elastic member 35. Figure 4 A rough enlarged view of the X section.

[0019] Figure 6 This is a diagram illustrating the shape and arrangement of the welded section 50. Figure 4 A simplified enlarged view of section C.

[0020] Figure 7 This is a diagram illustrating the structure of the side joint 70.

[0021] Figure 8 This is a partial oblique view showing the process of manufacturing diapers 1 through production line 100.

[0022] Figure 9 This is an explanatory diagram of the processing performed at the first processing position PK1.

[0023] Figure 10 This is a diagram illustrating the elasticity of the abdominal waistband 31 (41) as a comparative example of conventional underwear-type diapers.

[0024] Figure 11 This is a diagram illustrating the elasticity of the abdominal waist section 31 (41) of the diaper 1 according to the first embodiment.

[0025] Figure 12 This is a diagram illustrating the elasticity of the absorbent side region SA of the ventral waist portion 31 (41).

[0026] Figure 13 This is a schematic top view showing a modified example of the back waist section 41.

[0027] Figure 14 This is a diagram illustrating the shape and arrangement of the welding section 50 in the second embodiment. Detailed Implementation

[0028] Based on the description in this specification and the accompanying drawings, at least the following will become clear.

[0029] An absorbent underwear-type garment has intersecting vertical and horizontal directions. The garment comprises an absorbent body and a waistband. The waistband's two ends in the horizontal direction are joined together by a pair of lateral joints, connecting an abdominal waistband and a back waistband. At least a portion of the waistband between the lateral joints is elastic in the horizontal direction. The waistband, in its extended state, has an inner end region that is positioned above the upper end of the absorbent body in the vertical direction and extends 20 mm inward from the inner end of the lateral joint in the horizontal direction. The range; and the central region, which is higher than the upper end of the absorbent body in the vertical direction and sandwiched by a pair of inner end regions in the horizontal direction, the value obtained by dividing the difference between the length of the inner end regions in the horizontal direction in the extended state and the length of the inner end regions in the horizontal direction in the natural state by the length of the inner end regions in the horizontal direction in the extended state is less than the value obtained by dividing the difference between the length of the central region in the horizontal direction in the extended state and the length of the central region in the horizontal direction in the natural state by the length of the central region in the horizontal direction in the extended state.

[0030] In this type of absorbent underwear, because the elasticity of the inner end area is less than that of the central area, when tearing the side seam during putting on and taking off, the waistband is less likely to stretch in the lateral direction in the inner end area near the side seam. Therefore, it is easier to apply force efficiently to the side seam and tear it easily. This allows for easy removal of the absorbent underwear from the wearer's body.

[0031] In this underwear-type absorbent article, it is preferable that the waist portion has an outer end region that is further outward in the left-right direction than the inner end of the lateral joint. The value obtained by dividing the difference between the length of the outer end region in the left-right direction in the extended state and the length of the outer end region in the left-right direction in the natural state by the length of the outer end region in the extended state is less than the value obtained by dividing the difference between the length of the inner end region in the left-right direction in the extended state and the length of the inner end region in the left-right direction in the natural state by the length of the inner end region in the left-right direction in the extended state.

[0032] In this type of absorbent underwear, the outer end area, including the side joint, has less stretch in the lateral direction, making it easier to apply force to tear the side joint. Furthermore, because the outer end area is less stretchable, it is easier to grasp by hand. In addition, it is easier to transmit the force of grasping the outer end area and pulling the abdominal waistband and back waistband to opposite sides, and it is easier to insert fingers into the inner end area, thus making it easier to tear the side joint.

[0033] In this underwear-type absorbent article, it is preferable that the waistband portion has skin-side panels and non-skin-side panels laminated in the thickness direction. Between the skin-side panels and the non-skin-side panels, which are joined by multiple welded portions, a plurality of elastic members that can stretch and contract in the left-right direction are arranged at intervals in the vertical direction. Each of the elastic members, in a contracted state in the left-right direction, is installed on the skin-side panels and the non-skin-side panels by being sandwiched between two adjacent welded portions in the vertical direction. The value obtained by dividing the difference between the left-right length in the extended state and the left-right length in the natural state of the elastic member installed by the welded portion arranged in the inner end region by the length in the extended state is less than the value obtained by dividing the difference between the left-right length in the extended state and the left-right length in the natural state of the elastic member installed by the welded portion arranged in the central region by the length in the extended state.

[0034] In this type of absorbent underwear, the elasticity of the member attached to the waistband via a welded section in the inner end region is lower than that of the elastic member attached to the waistband via a welded section in the central region. Therefore, in the inner end region near the side joints, the waistband is difficult to stretch or contract in the lateral direction. Consequently, it is easy and efficient to apply force to the side joints, making them easy to tear.

[0035] In this underwear-type absorbent article, it is preferable that, in the extended state, the width in the left-right direction of at least one of the welded portions disposed in the inner end region is greater than the minimum value of the width in the left-right direction of the welded portion disposed in the central region.

[0036] In this type of absorbent underwear, the elastic member is clamped by a pair of welded portions (welded portion pairs) over a large area in the lateral direction in the inner end region. Therefore, compared to the central region, the elastic member is less prone to lateral expansion and contraction, thus suppressing excessive elongation in the inner end region. Consequently, force is easily applied to the lateral joints, making it easy to tear them apart.

[0037] In this underwear-type absorbent article, it is preferable that, in the extended state, the value obtained by dividing the total width of the welded portion disposed in the inner end region in the left-right direction by the width of the inner end region in the left-right direction is greater than the value obtained by dividing the total width of the welded portion disposed in the central region in the left-right direction by the width of the central region in the left-right direction.

[0038] This type of absorbent underwear-like garment has reduced elasticity at the inner end areas compared to the central area, thus preventing excessive elongation of the inner end areas. Therefore, it allows for efficient and easy application of force to the lateral joints, making it easy to tear them apart.

[0039] In this underwear-type absorbent article, it is preferable that, in the left-right direction, the length of the weld portion located at the position closest to the inner end of the lateral joint is greater than the length in the left-right direction of any of the weld portions located in the region that is more inner than the weld portion.

[0040] According to such underwear-type absorbent articles, the area closest to the side joint in the inner end region can reduce the stretching of the elastic member, thus making it easier to apply force to the side joint more efficiently and to tear the side joint more easily.

[0041] In this underwear-type absorbent article, it is preferable that the back waistband has a buttock cover at a position lower than the lower end of the side joint, at least a portion of the elastic member is disposed on the buttock cover, and in the left-right direction, the length of the welded portion disposed at the position closest to the outer edge of the buttock cover is greater than the length of any of the welded portions disposed in the left-right direction in the region that is more inner than the welded portion.

[0042] According to this type of absorbent underwear, by widening the width of the welded part in the area near the outer edge of the buttocks cover, the elastic member is difficult to stretch and contract, thereby making it easy to apply force to the lower end of the side joint, and the side joint can be easily torn open from the lower side to the upper side in the vertical direction.

[0043] In this type of absorbent underwear, it is preferable that the back waistband has a buttock cover located below the lower end of the side joint, and that a leg elastic member is provided that extends and retracts along the outer edge of the buttock cover, and that the leg elastic member is attached to the back waistband using an adhesive.

[0044] In this type of absorbent underwear, the rigidity of the area along the outer edge of the buttock cover can be increased by using an adhesive part to install an elastic leg band. Therefore, when performing an action of tearing the side joint from bottom to top, the buttock cover is difficult to tear even if it is pulled forcefully, and the side joint can be easily torn apart.

[0045] In this underwear-type absorbent article, preferably, at least one of the skin side panel and the non-skin side panel is a spunbond nonwoven fabric in which heat-melted fibers are joined together by a plurality of distributed heat-melted portions, and when viewed in the thickness direction, either the skin side panel or the non-skin side panel has a portion in the inner end region where the welded portion overlaps with the heat-melted portion.

[0046] In this type of absorbent underwear, the unevenness in the thickness direction deepens at the overlap of the heat-fused and welded parts, making it easier to snag fingers compared to other areas. Therefore, the user can easily grasp the inner end area of ​​the waistband and easily tear open the side seam.

[0047] In this underwear-type absorbent article, it is preferable that the side joint has a plurality of locking welds arranged at intervals in the vertical direction, and the depth of the locking welds in the thickness direction is deeper than the depth of the weld in the thickness direction.

[0048] Based on this type of absorbent underwear, by varying the depth of the snap-fit ​​seam and the welded area, when the user grasps the waistband, they can feel the difference between the side seam and other parts by touch. Therefore, the user can easily and accurately identify the part of the waistband where the side seam is formed, and can easily grasp the inner or outer end area to tear the side seam apart.

[0049] In this underwear-type absorbent article, it is preferable that the maximum length of each of the aforementioned fastening weld portions in the left-right direction is less than the maximum length of the weld portion in the left-right direction provided in the aforementioned inner end region.

[0050] In this type of absorbent underwear, compared to cases where the maximum width of the welded portion in the inner end region is less than the maximum width of the locking welded portion, it is easier to suppress the expansion and contraction of the elastic member in the inner end region. Therefore, during the putting-on and taking-off action, force is easily applied to the side joint, making it easy to tear the side joint.

[0051] In this underwear-type absorbent article, preferably, the waistband has a first elastic member that can stretch along the left-right direction and a second elastic member that is disposed adjacent to the first elastic member in the up-down direction. The sheet member constituting the waistband has a plurality of pleats formed by protruding and deforming in the thickness direction along the up-down direction, and at least a portion of the plurality of pleats is continuous between the first elastic member and the second elastic member in the up-down direction.

[0052] In this type of absorbent underwear, continuous pleats are formed between the first and second elastic members in the vertical direction. When the wearer grasps the waistband and pulls it in the left and right direction, their fingers easily get caught in the pleats, making it difficult for them to slip. This allows for easy and stable tearing of the side seams.

[0053] In this underwear-type absorbent article, preferably, the absorbent body has an absorbent core with liquid-absorbing properties, and the waistband portion, in its extended state, has: an absorbent side region that is lower than the upper end of the absorbent body in the vertical direction and extends 20 mm outward from both ends of the absorbent core in the horizontal direction; and a leg area that is lower than the upper end of the absorbent body in the vertical direction and is sandwiched between the absorbent side region and the lateral joint in the horizontal direction. The value obtained by dividing the difference between the length of the absorbent side region in the horizontal direction in the extended state and the length of the absorbent side region in the horizontal direction in the natural state by the length of the absorbent side region in the horizontal direction in the extended state is less than the value obtained by dividing the difference between the length of the leg area in the horizontal direction in the extended state and the length of the leg area in the horizontal direction in the natural state by the length of the leg area in the horizontal direction in the extended state.

[0054] Because of the small dimensional change rate of the absorbent core's side area in this type of absorbent garment, it is difficult for it to stretch or contract in the lateral direction. Therefore, when wearing the absorbent garment, pulling the side area of ​​the absorbent core upwards will also easily pull the absorbent core upwards in conjunction with it. This improves the fit of the absorbent core in the crotch area.

[0055] Furthermore, an absorbent underwear-type garment is specified, which has intersecting vertical and horizontal directions. The garment comprises: an absorbent body having an absorbent core; and a waistband, wherein the waistband's two ends in the horizontal direction are joined together by a pair of lateral joints to the abdominal and back waistbands. At least a portion of the waistband between the pair of lateral joints has elasticity along the horizontal direction. The waistband, in its extended state, has an absorbent body side region, which is lower than the upper end of the absorbent body in the vertical direction and located outwards from both ends of the absorbent core in the horizontal direction. The range up to 20mm; and the leg circumference area, which is lower than the upper end of the absorbent body in the vertical direction and sandwiched between the absorbent body side region and the lateral joint in the horizontal direction, the value obtained by dividing the difference between the length of the absorbent body side region in the horizontal direction in the extended state and the length of the absorbent body side region in the horizontal direction in the natural state by the length of the absorbent body side region in the horizontal direction in the extended state is less than the value obtained by dividing the difference between the length of the leg circumference area in the horizontal direction in the extended state and the length of the leg circumference area in the horizontal direction in the natural state by the length of the leg circumference area in the horizontal direction in the extended state.

[0056] Because of the small dimensional change rate of the absorbent core's side area in this type of absorbent garment, it is difficult for it to stretch or contract in the lateral direction. Therefore, when wearing the absorbent garment, pulling the side area of ​​the absorbent core upwards will also easily pull the absorbent core upwards in conjunction with it. This improves the fit of the absorbent core in the crotch area.

[0057] ===First Implementation Method===

[0058] <Basic Components of Underwear-Style Disposable Diapers>

[0059] As an example of the underwear-type absorbent article according to the first embodiment, the underwear-type disposable diaper 1 (hereinafter also referred to as "diaper 1") will be described. Figure 1 This is a rough 3D diagram of Diaper 1. Figure 2 This is a rough top view of the diaper 1 in its unfolded and elongated state, viewed from the side of the wearer's skin. Figure 3 yes Figure 2 The A-A cross-section diagram in the diagram, and also the one in question. Figure 2 B-B cross-section view.

[0060] The diaper 1 is as follows Figure 1In its original, unworn state, the underwear has three intersecting directions: up / down, left / right, and front / back. Regarding the up / down direction, the top corresponds to the waist opening and the bottom corresponds to the crotch area. Regarding the front / back direction, the front corresponds to the abdomen and the back.

[0061] exist Figure 1 In its underwear-like configuration, the diaper 1 comprises an absorbent body 10 and a waistband 20. The waistband 20 includes a ventral waistband 31 that is elastic in the left-right direction and a dorsal waistband 41 that is elastic in the left-right direction, located behind the ventral waistband 31, and used to form a waistband opening BH together with the ventral waistband 31 on the upper side in the vertical direction. Furthermore, the absorbent body 10, which serves as a crotch area, is provided between the ventral waistband 31 and the dorsal waistband 41.

[0062] Furthermore, the left and right ends 31e, 31e of the abdominal waist portion 31 and the left and right ends 41e, 41e of the corresponding back waist portion 41 are joined by a side joint 70, which serves as a welding part. Thus, the abdominal waist portion 31 and the back waist portion 41, together with the absorbent body 10, form a leg opening LH, LH on each side in the lower and left and right directions.

[0063] Here, "expanded state" refers to the following state: by... Figure 1 The diaper 1 in its underwear-like state has its lateral joints 70 on both sides in the left and right directions unjoined, separating the abdominal waistband 31 from the back waistband 41, and opening the diaper 1 in the up and down directions, thereby unfolding the diaper 1 into a flat shape. In addition, "stretched state" refers to the state in which the product (diaper 1) is stretched without wrinkles, specifically the following state: stretched until the size of each component constituting the diaper 1 (e.g., absorbent body 10, abdominal waistband 31, etc.) is the same as or close to the size of its individual component.

[0064] In its unfolded state, diaper 1 has three intersecting directions: "length direction", "left-right direction", and "thickness direction". Figure 2The direction of the paper is "through the center". The length direction follows the aforementioned up-down direction. One side of the length direction corresponds to the abdominal side (front), and the other side corresponds to the back side (back). The outer side of the length direction corresponds to the upper side (waist opening side) of the up-down direction, and the inner side of the length direction corresponds to the lower side (crotch side) of the up-down direction. Since the length direction and the up-down direction are similar, for illustrative purposes, the up-down direction will sometimes be used instead of the length direction in this unfolded state. On the other hand, the left-right direction is synonymous with the left-right direction in the aforementioned underwear-type state. Regarding the thickness direction, one side corresponds to the skin side that contacts the wearer's body, and the other side corresponds to the opposite non-skin side.

[0065] exist Figure 2 In its unfolded state, the abdominal waistband 31 is arranged along the left-right direction, and the back waistband 41 is arranged along the left-right direction at a predetermined interval from the abdominal waistband 31 along the length direction. Furthermore, an absorbent body 10 is laid between these abdominal waistbands 31 and back waistbands 41 along the length direction, and each end 10ea, 10eb (i.e., the upper front end 10ea and the upper rear end 10eb in the underwear-type state) of the absorbent body 10 along the length direction is respectively joined and fixed to the nearest waistbands 31, 41, thereby giving it an appearance shape that is roughly H-shaped when viewed from above. Furthermore, if, from this state, the diaper 1 is folded in half at a predetermined position CL1 along the length of the absorbent body 10 (corresponding to the center position of the diaper 1 along the length), and the left and right ends 31e and 41e of the waist portions 31 and 41 facing each other in this folded state are joined together by the aforementioned side joints 70, then these waist portions 31 and 41 are connected to each other in a ring shape, thereby becoming... Figure 1 As shown, the diaper 1 is an underwear-type diaper with a waist opening BH and a pair of leg openings LH and LH.

[0066] (Absorbent Subject 10)

[0067] Absorbent body 10 in Figure 2 When unfolded, it presents a roughly rectangular shape when viewed from above. Furthermore, it is arranged such that the length of the absorbent body 10 is along the length of the diaper 1. Additionally, as... Figure 3 As shown, the absorbent body 10 includes: an absorbent body 11; a liquid-permeable top sheet 13 that covers the absorbent body 11 from the skin side and forms the skin side of the absorbent body 10; and a liquid-impermeable back sheet 15 that covers the absorbent body 11 from the non-skin side and forms the non-skin side of the absorbent body 10.

[0068] The absorbent body 11 has an absorbent core 11c with liquid absorption properties and a core-covering sheet (not shown) covering the outer periphery of the core 11c. The absorbent core 11c is a molded body formed from liquid-absorbing raw materials such as pulp fibers and highly absorbent polymers into a roughly hourglass shape when viewed from above, as an example of a predetermined shape. In addition, the core-covering sheet can be a liquid-permeable sheet such as thin paper or non-woven fabric, but it is also possible to not provide a core-covering sheet. Furthermore, the shape of the absorbent core 11c is not limited to the roughly hourglass shape when viewed from above, and other shapes are also possible.

[0069] The top sheet 13 is a soft sheet that is permeable to liquid, such as non-woven fabric. The back sheet 15 is a soft sheet that is impermeable to liquid. Furthermore, as an example of the back sheet 15, a laminated sheet with a two-layer structure can be described, consisting of a leak-proof sheet with impermeable properties such as polyethylene film or polypropylene film and an outer cover sheet made of non-woven fabric adhered to the non-skin side of the leak-proof sheet.

[0070] In addition, such as Figure 2 As shown, at least the back piece 15 is a planar piece that protrudes from the absorbent body 11 in both the longitudinal and lateral directions. Furthermore, leg pleats LG that extend and retract in the longitudinal direction are formed in the portions that protrude in the lateral direction. That is, in these protruding portions, rubber filaments 17 are fixed as elastic members in the longitudinal direction, thereby forming the stretchable leg pleats LG in these portions.

[0071] In addition, such as Figure 2 as well as Figure 3 As shown, the absorbent body 10 has three-dimensional pleats LSG, LSG at each end in the left and right directions as leak-proof walls for the purpose of preventing side leakage. That is, each end of the absorbent body 10 in the left and right directions is provided with the following configuration: rubber filaments 18 along the length direction are installed as elastic members in the sheet-like portion that forms the three-dimensional pleats LSG in a state of elongation in the length direction.

[0072] (Waist circumference 31, 41)

[0073] like Figure 2 As shown, the abdominal waist section 31 is a sheet member that is approximately rectangular in top view when made from the first sheet 32 ​​and the second sheet 33 laminated in the thickness direction. That is, as Figure 3 As shown, the first piece 32 and the second piece 33 are in a state of overlapping each other in the thickness direction, and the pair of opposing surfaces are connected by a method described later. Figure 4 As shown, multiple welded portions 50, 50... are discretely arranged in the vertical and horizontal directions and joined together. Furthermore, as... Figure 2As shown, the abdominal waist portion 31 is arranged to protrude to the left and right sides relative to the absorbent body 10, and overlaps and joins the abdominal end (front upper end) 10ea of ​​the absorbent body 10 from the non-skin side.

[0074] The back waist section 41, like the ventral waist section 31, is a roughly rectangular sheet-like component when viewed from above, made from the first sheet 42 and the second sheet 43 laminated in the thickness direction. That is, as... Figure 3 As shown, the first piece 32 and the second piece 33 are in a state of mutual overlap in the thickness direction, and the pair of opposing surfaces are perpendicular to each other. Figure 4 In the case of the abdominal waist section 31, it is similarly joined by a plurality of welded portions 50, 50… (equivalent to joint portions) discretely arranged in the vertical (length direction) and horizontal directions. Furthermore, as… Figure 2 As shown, the back waist portion 41 is arranged to protrude to the left and right sides relative to the absorbent body 10, and overlaps and joins the back end (rear upper end) 10eb of the absorbent body 10 from the non-skin side.

[0075] Additionally, the back waist section 41 is positioned lower than the portion where the side joint 70 is located in the vertical direction, and has... Figure 2 The buttock cover 41c is roughly trapezoidal as shown. The buttock cover 41c is the part of the buttocks that is covered extensively when the diaper 1 is worn.

[0076] In this example, the first piece 32 (42) and the second piece 33 (43) of the abdominal waist section 31 (41) are made of spunbond nonwoven fabric. However, this is not a limitation; other types of nonwoven fabrics, such as SMS (spunbond / meltblown / spunbond) nonwoven fabric, can also be used. In this example, polypropylene (PP), a representative example of thermoplastic resin, is used as the constituent fiber of the nonwoven fabric, but this is not a limitation. For example, other thermoplastic resin fibers such as polyethylene (PE) can also be used, and composite fibers with a core-sheath structure, such as PE and PP, can also be used.

[0077] <Specific composition of the abdominal waist circumference 31(41)>

[0078] Next, the specific configurations of the abdominal waist portion 31 and the back waist portion 41 will be described. As described above, the abdominal waist portion 31 and the back waist portion 41 of this embodiment have substantially the same configuration. Therefore, in the following description, regarding the common aspects of the abdominal waist portion 31 and the back waist portion 41, only the abdominal waist portion 31 will be described. Regarding the back waist portion 41, reference numerals for components corresponding to the abdominal waist portion 31 will be shown in parentheses as needed, and specific descriptions will be omitted.

[0079] Figure 4 This is a schematic top view of the ventral waist section 31 (elastic piece) in its unfolded and elongated state, viewed from a non-skin-covering side. Additionally, in Figure 4 The diagram shows the abdominal waist portion 31 (41) as a component of diaper 1, and the waist portion 31, 41 can also be used as an elastic sheet for purposes other than diaper 1.

[0080] like Figure 4 As shown, in the abdominal waist portion 31 (41), between the opposing surfaces of the first piece 32 (42) and the second piece 33 (43), multiple elastic waist members 35, 35… (45, 45…) such as rubber threads, which can stretch in the left and right direction, are arranged and inserted at intervals in the vertical direction, and are installed on the pieces 32, 33 (42, 43) based on the aforementioned welding portions 50, 50… . This gives the abdominal waist portion 31 (41) lateral stretchability. That is, the welding portions 50, 50… not only have the function of joining the opposing surfaces of the first piece 32 (42) and the second piece 33 (43) to each other, but also have the function of installing the elastic waist members 35 (45) on the first piece 32 (42) and the second piece 33 (43).

[0081] In the ventral waist portion 31(41) of this embodiment, a plurality of welded portions 50, 50... are arranged adjacently in the vertical direction at predetermined intervals to form a welded portion row 60 along the vertical direction, and a plurality of welded portion rows 60 are provided at intervals in the left-right direction. Figure 4 In the example, each weld row 60 is arranged vertically along the vertical direction, but the weld row 60 can also be formed in a zigzag direction. That is, the plurality of weld portions 50 constituting the weld row 60 can also be arranged in a structure that is staggered in the left and right directions (see below). Figure 14 wait).

[0082] like Figure 4 As shown, by providing multiple welded portions 50 at predetermined intervals in the vertical and horizontal directions, the softness of the abdominal waist portion 31 (41) can be maintained, and the skin feel can be suppressed from deteriorating when wearing the diaper 1. If a linear welded portion is formed that is long and continuous in the vertical or horizontal direction, the nonwoven fabric in the portion where the welded portion is formed will become stiff, and it will also easily hinder the nonwoven fabric from deforming in the linear (ribbon) direction at the welded portion. In contrast, if... Figure 4 The array of welded sections 60, with small welded sections 50 arranged in a dispersed manner as shown, provides a soft sheet component, making it difficult for the user (wearer) of the diaper 1 to feel the nonwoven fabric hardening and to prevent deformation in the vertical and horizontal directions.

[0083] In the abdominal waist section 31 (41), two adjacent welded portions 50, 50 in the vertical direction from among the plurality of welded portions 50 included in the welded portion row 60 are sandwiched between the waist elastic member 35 (hereinafter also referred to as elastic member 35 (45)) and the elastic member 35 is installed in the abdominal waist section 31 (41). That is, a pair of welded portions 50, 50 arranged on both sides of the elastic member 35 in the vertical direction form a welded portion pair 50s, and the elastic member 35 is installed through the welded portion pair 50s. Figure 5A as well as Figure 5B This is an explanatory diagram illustrating the installation function of the elastic member 35. Figure 4 A rough enlarged view of the X section.

[0084] like Figure 5A As shown, the pair of weld portions 50, 50 constituting the weld portion pair 50s are arranged with a vertical spacing GH50. Furthermore, the size of the spacing GH50 is set to be the same as or slightly larger than the outer diameter D35t (D45t) of the elastic member 35 (45) such as a rubber filament, which is stretched to a target elongation ratio in the lateral direction (GH50 ≥ D35t). That is, the stretched elastic member 35 is arranged vertically between the weld portions 50s. With this configuration, in the manufacturing process of the diaper 1 (abdominal waistband 31), after the stretched elastic member 35 is arranged between the first piece 32 and the second piece 33, when the first piece 32 and the second piece 33 are welded, the weld portion 50 can be formed without overlapping with the elastic member 35.

[0085] Furthermore, if the elastic member 35 (45) relaxes from its elongated state, then as Figure 5B As shown, the elastic member 35 (45) contracts in the left-right direction and expands in the up-down direction, with the expanded outer diameter D35t′ being greater than the up-down distance GH50 between the welded portions 50s (D35t′>GH50). Therefore, the up-down expansion of the elastic member 35 (45) is restricted between the welded portions 50s, resulting in a state where the elastic member 35 (45) is substantially clamped between each other in the up-down direction by the welded portions 50, 50. As a result, the elastic member 35 (45) is installed on the abdominal waist portion 31 (41). Furthermore, in Figure 1 In the diaper 1 in the underwear-type state, the elastic member 35 (45) is in a state after being relaxed from the above-mentioned stretched state.

[0086] Incidentally, the elongation ratio mentioned above refers to the value R (=L1 / L0) which represents how many times the full length L1 of the elastic member 35 (45) is stretched to the full length L0 of the unloaded state that constitutes the natural length.

[0087] In addition, in the diaper 1, each area of ​​the abdominal waistband 31 (41) is provided with a welded part 50 of different shapes. Figure 6 This diagram illustrates the shape and arrangement of the welded section 50. Figure 4 A simplified enlarged view of section C.

[0088] like Figure 6 As shown, the welded portion 50 has a generally square first welded portion 51 and a generally rectangular second welded portion 52. For the first welded portion 51 and the second welded portion 52, in the elongated ventral waist portion 31 (41), the length (height) in the vertical direction is equal, while the length (width) in the horizontal direction is different. That is, the horizontal length (width) W52 of the second welded portion 52 is greater than the horizontal length (width) W51 of the first welded portion 51 (W52 > W51). Therefore, as... Figure 5A as well as Figure 5B As explained, when the elastic member 35 (45) is clamped and installed between the welded portions 50s in the vertical direction, the frictional force when clamped by the wider second welded portions 52, 52 is greater than the frictional force when clamped by the narrower first welded portions 51, 51. This makes it easier to prevent the elastic member 35 (45) from detaching from the welded portions 50s (so-called rubber detachment). Furthermore, compared to the portion clamped by the first welded portions 51, 51, the amount of expansion and contraction of the elastic member 35 (45) in the lateral direction is smaller (it is less prone to shrinkage) in the portion clamped by the second welded portions 52, 52. The effect based on the shape difference between the first welded portion 51 and the second welded portion 52 will be explained later.

[0089] In this embodiment, the second weld portion 52, which is wider in the left-right direction, is mainly located in the area adjacent to the inner side of the side joint portion 70 in the left-right direction. That is, within a predetermined range in the abdominal waist portion 31 (41) from the innermost end 70ei in the left-right direction of the side joint portion 70, a row of weld portions 60 composed of the second weld portions 52, 52... is provided (see reference). Figure 4 as well as Figure 6 Specifically, when the abdominal waist portion 31 (41) is set to an elongated state, the area that is higher than the upper end 10et of the absorbent body 10 in the vertical direction and extends from the inner end 70ei of the side joint portion 70 to 20mm inward in the horizontal direction is designated as the inner end region IA, and at least one second weld portion 52 is provided in the inner end region IA.

[0090] Similarly, the second weld portion 52 is also provided in the region adjacent to the outer side of the absorbent core 11c in the left-right direction. That is, within a predetermined range outward from the outermost end 11ces in the left-right direction of the absorbent core 11c in the abdominal waist portion 31 (41), there is a row of weld portions 60 composed of the second weld portions 52, 52... (see reference). Figure 4 Specifically, when the abdominal waist portion 31 (41) is set to an elongated state, the area that is lower than the upper end 10et of the absorbent body 10 in the vertical direction and extends 20mm outward from the outer end 11ces of the absorbent core 11c in the horizontal direction is designated as the absorbent body side region SA. At this time, at least one second welded portion 52 is provided in the absorbent body side region SA.

[0091] Additionally, the region described below, which is located above the upper end 10et of the absorbent body in the vertical direction and inside the inner end region IA in the horizontal direction, i.e., the region sandwiched between a pair of inner end regions IA, will be designated as the central region CA (see reference). Figure 4 Additionally, the region located above the upper end 10et of the absorbent body in the vertical direction and outside the inner end region IA in the horizontal direction (outer than the inner end 70ei of the side joint 70) is designated as the outer end region OA. Furthermore, the region located below the upper end 10et of the absorbent body in the vertical direction and sandwiched between the absorbent body side region SA and the side joint 70 in the horizontal direction is designated as the leg circumference region EA.

[0092] In addition, Figure 4 as well as Figure 6 In the figure, the side joint 70 is depicted as a strip-shaped area extending in the vertical direction, while the actual side joint 70 is formed by arranging multiple welded portions at intervals in the vertical direction. Figure 7 This diagram illustrates the structure of the side joint 70. In the diaper 1, the side joint 70 has three types of welded portions: a first locking welded portion 71, a second locking welded portion 72, and a third locking welded portion 73, formed using known welding methods such as ultrasonic welding or thermal welding. The first locking welded portion 71 is a generally circular welded portion with a diameter of W71 in the left-right direction. The second locking welded portion 72 is an elongated oval welded portion whose length in the left-right direction is longer than its length in the up-down direction, and has a major diameter of W72 in the left-right direction. The third locking welded portion 73 is a generally semi-circular (semi-elliptical) welded portion in which two welded portions are arranged at predetermined intervals in the left-right direction, and each third locking welded portion 73 has a size of W73 in the left-right direction.

[0093] These three types of fastening and welding parts 71, 72, and 73 are arranged from the upper side to the lower side in a vertical direction, as shown below. Figure 7They are arranged at predetermined intervals to form the side joint 70. Furthermore, for each of the plurality of locking welds 71 ​​to 73 forming the side joint 70, the inner end 70ei of the side joint 70 is indicated by the innermost position among the inner ends in the left-right direction.

[0094] <Regarding the manufacturing method of diaper 1>

[0095] Next, the manufacturing method of diaper 1 will be described. Diaper 1 is manufactured using production line 100. Figure 8 This is a partial oblique view showing the process of manufacturing diapers 1 through production line 100.

[0096] In production line 100, for example, the two nonwoven fabrics 32 and 33 (equivalent to sheet members) involved in the abdominal waist section 31 are conveyed in the form of continuous sheets 32a and 33a (equivalent to a continuous body of sheet members) in the conveying direction. Similarly, the two nonwoven fabrics 42 and 43 (equivalent to sheet members) involved in the back waist section 41 are also conveyed in the form of continuous sheets 42a and 43a (equivalent to a continuous body of sheet members) in the conveying direction. Furthermore, whenever each pair of continuous sheets 32a, 33a, 42a, and 43a passes through multiple processing positions PK1 to PK5 set in the conveying direction, each pair of continuous sheets 32a, 33a, 42a, and 43a undergoes processing corresponding to each processing position PK1, PK2, etc.

[0097] Furthermore, in this case, when the direction orthogonal to both the thickness direction and the transport direction of the continuous sheets 32a, 33a, 42a, and 43a is defined as the "CD direction," in this example, the two continuous sheets 32a, 33a, 42a, and 43a, namely the two continuous sheets 32a and 33a involved in the abdominal waist section 31 and the two continuous sheets 42a and 43a involved in the dorsal waist section 41, are transported side by side in the CD direction. However, this is not a limitation.

[0098] Furthermore, in this example, the aforementioned processing positions are arranged sequentially from upstream to downstream in the conveying direction, with processing positions PK1 to PK5 being the first and fifth processing positions, respectively. Moreover, the processing procedures at each processing position PK1, PK2, etc., are largely the same for the processing of the two continuous sheets 32a and 33a involved in the abdominal waist section 31 and for the processing of the two continuous sheets 42a and 43a involved in the dorsal waist section 41.

[0099] Therefore, the common content will be described in the following description without distinction between the abdominal waist section 31 and the dorsal waist section 41. For example, it will be simply referred to as "belt member 31 (41)" or "two continuous sheets 32a, 33a (42a, 43a)". In addition, in this case, the reference numerals following the terms indicating each member, such as "continuous sheet 32a, 33a (42a, 43a)", "rubber filament 35 (45)", "continuous body of rubber filament 35a (45a)", etc., are reference numerals for the members involved in the abdominal waist section 31, and the reference numerals in parentheses that follow are reference numerals for the members involved in the dorsal waist section 41.

[0100] like Figure 8 As shown, the conveying of the two continuous sheets 32a and 33a (42a, 43a) involved in each belt member 31 (41) is achieved through a so-called transverse flow configuration. That is, the two continuous sheets 32a and 33a (42a, 43a) are conveyed in a direction corresponding to the left-right direction of the diaper 1 in the conveying direction. Therefore, in the two continuous sheets 32a and 33a (42a, 43a), the boundary position PBL between the diapers 1, 1 adjacent in the left-right direction is hypothetically set in the conveying direction according to the product spacing P1. Furthermore, at the fifth processing position PK5 at the end of the production line, the two continuous sheets 32a and 33a (42a, 43a) are cut at the cutting target position PC using this boundary position PBL, thereby generating a single diaper 1.

[0101] In addition, the conveying of the two continuous sheets 32a, 33a (42a, 43a) involved in each belt component 31 (41) is achieved by a suitable conveying device (not shown) such as a belt conveyor or conveying roller.

[0102] Unless otherwise specified, these conveying devices are used to transport two continuous sheets 32a and 33a (42a and 43a) in the conveying direction. As an example of a belt conveyor, one can cite a conventional belt conveyor with a driving rotating annular belt as the conveying surface, or a suction belt conveyor with an adsorption function on the outer circumference of the annular belt.

[0103] When manufacturing diaper 1, as Figure 8 As shown, firstly, the two continuous sheets 32a and 33a (42a and 43a) involved in each belt component 31 (41) are passed through the first processing position PK1.

[0104] Furthermore, during this process, the two continuous sheets 32a and 33a (42a and 43a) overlap each other in the thickness direction. In addition, during the overlap, between the two continuous sheets 32a and 33a (42a and 43a), a pair of opposing surfaces 32ast and 33ast (42ast and 43ast) facing each other are arranged as a continuous elastic member in the conveying direction, and multiple continuous sheets 35a, 35a... (45a, 45a...) with intercalated rubber filaments are arranged in the CD direction in a state of elongation in the conveying direction according to the aforementioned target elongation ratio (corresponding to the arrangement process).

[0105] In addition, simultaneously or immediately following this overlap, the aforementioned welded portions 50, 50... are formed on the two continuous sheets 32a, 33a (42a, 43a) as joints, thereby joining a pair of opposing surfaces 32ast, 33ast (42ast, 43ast) of the two continuous sheets 32a, 33a (42a, 43a) to each other through the welded portions 50, 50... (equivalent to the joint forming process).

[0106] Here, in production line 100, the diaper 1 is oriented left-right along the conveying direction, and the diaper 1 is oriented up-down along the CD direction. Therefore, the welded portion 50 is formed in pairs on both sides of the continuous rubber filament 35a (45a) in the CD direction. That is, a pair of welded portions 50, 50 arranged on both sides of the continuous body 35a (45a) in the CD direction constitutes a welded portion pair 50s. Furthermore, multiple pairs of these welded portion pairs 50s are formed in the conveying direction with gaps between them and adjacent welded portion pairs 50s (see reference). Figure 4 wait).

[0107] The welded portion 50 can be formed, for example, using a heat sealing device or an ultrasonic welding device 160 (joint forming device) (see reference). Figure 9 Additionally, the heat sealing device (not shown) includes, for example, a pair of rollers that rotate and are heated along the conveying direction. One roller is a heat-embossing roller with protrusions on its outer peripheral surface corresponding to each weld portion 50, and the other roller is an anvil roller with a smooth outer peripheral surface that receives the aforementioned protrusions. Further details regarding the ultrasonic welding device 160 will be described later.

[0108] Next, as Figure 8As shown, the two continuous sheets 32a and 33a involved in the abdominal waistband 31 and the two continuous sheets 42a and 43a involved in the back waistband 41 pass through the second processing position PK2. During this process, a single absorbent body 10, generated through other processes (not shown), is laid and fixed between the two continuous sheets 32a and 33a involved in the abdominal waistband 31 and the two continuous sheets 42a and 43a involved in the back waistband 41, thereby forming a continuous, approximately ladder-shaped diaper body 1hs, unfolded into an approximately H-shape. The absorbent body 10 can be fixed, for example, by using a rotating roller device (not shown). The rotating roller device, for example, has a rotating roller that rotates along the conveying direction, and the rotating roller has multiple holding portions on its outer peripheral surface that can detachably hold the absorbent body 10.

[0109] Next, the approximately ladder-shaped diaper continuous 1hs passes through the third processing position PK3. During this passage, the absorbent body 10 is folded in half at a predetermined position CL1 in the CD direction, thereby aligning the two continuous sheets 32a, 33a of the abdominal waistband 31 with the two continuous sheets 42a, 43a of the back waistband 41 in the thickness direction. This folding can be performed, for example, using a bending guide device (not shown). The bending guide device includes, for example, guide plates and guide rollers positioned at predetermined positions in the conveying direction. These guide plates and guide rollers guide the approximately ladder-shaped diaper continuous 1hs in a folded shape as it passes through its positioned position.

[0110] Next, the folded diaper continuous 1hsb passes through the fourth processing position PK4. During this passage, the two continuous sheets 32a and 33a of the overlapping abdominal waistband 31 and the two continuous sheets 42a and 43a of the overlapping back waistband 41 are welded together at each of the cutting positions PC in the transport direction, forming a pair of lateral joints 70, 70. This fixes the diaper continuous 1hsb into a folded state. As a result, a continuous diaper 1s of underwear-type diapers 1, 1... connected in the left-right direction is generated.

[0111] like Figure 7As explained, the side joint 70 has multiple welded portions 71, 72, 73, etc. arranged in the CD direction (vertical direction). Each welded portion 71, 72, 73 is configured to weld the continuous piece 33a of the abdominal waist portion 31 to the continuous piece 43a of the back waist portion 41, and is also configured to weld a pair of opposing surfaces 32ast, 33ast of the continuous pieces 32a, 33a of the abdominal waist portion 31 to each other, and is also configured to weld a pair of opposing surfaces 42ast, 43ast of the continuous pieces 42a, 43a of the back waist portion 41 to each other.

[0112] The formation of the side joint 70 can be performed, for example, using a heat-sealing device (not shown). The heat-sealing device, for example, has a pair of rollers that rotate and are heated along the conveying direction. One roller is a heat-embossing roller with protrusions on its outer peripheral surface corresponding to the shapes of the welded portions 71, 72, 73 of the side joint 70; the other roller is an anvil roller with a smooth outer peripheral surface that receives these protrusions. Alternatively, depending on the situation, it can also be performed using a device described later... Figure 9 The ultrasonic welding device 160 is substantially the same as the welding device used to form the aforementioned lateral joint 70.

[0113] Next, as Figure 8 As shown, the continuous body 1s of the underwear-type diaper passes through the fifth processing position PK5. And, during this passage, the continuous body 1s is cut at the aforementioned cutting target position PC located between the pair of side joints 70, 70, thereby manufacturing the diaper 1.

[0114] Furthermore, during this cutting, the two continuous sheets 32a, 33a (42a, 43a) involved in the abdominal waist section 31 and the dorsal waist section 41, as well as the continuous rubber filaments 35a, 35a… (45a, 45a…), are cut at the aforementioned cutting target position PC. Moreover, due to the easing of the elongation state of the rubber filaments 35 (45) caused by this, the rubber filaments 35 (45) are installed onto each belt member 31, 41 by the clamping of a pair of welded portions 50, 50 at the welded portion 50s. Regarding this… Figure 4 As explained.

[0115] The cutting can be performed, for example, using a cutting device not shown. The cutting device, for example, has a pair of rollers rotating along the conveying direction. One roller is a cutting roller with a cutting edge on its outer circumferential surface, and the other roller is an anvil roller whose outer circumferential surface receives the cutting edge.

[0116] Furthermore, as mentioned above, the processing of the components 32a, 33a, and 35a involved in the abdominal waist portion 31 and the processing of the components 42a, 43a, and 45a involved in the back waist portion 41 are largely the same. Additionally, hereafter, one of the continuous pieces 32a and 33a of the abdominal waist portion 31 will be referred to as "first continuous piece 32a" and "second continuous piece 33a," respectively.

[0117] Figure 9 This is an explanatory diagram of the processing performed at the first processing position PK1. That is, it is a schematic side view of the ultrasonic welding device 160, the main device constituting this processing, viewed from the CD direction.

[0118] like Figure 9 As shown, at the first processing position PK1, upstream of the ultrasonic welding device 160 in the conveying direction, a conveying mechanism 151 for conveying the first continuous sheet 32a, a conveying mechanism 152 for conveying the second continuous sheet 33a, and a conveying mechanism 153 for conveying the continuous body 35a of rubber filaments are respectively provided. Furthermore, each of the conveying mechanisms 151, 152, and 153 has conveying rollers 151R, 152R, and 153R that rotate about a rotation axis along the CD direction, and a servo motor (not shown) that drives the rotation of each corresponding conveying roller 151R, 152R, and 153R as a drive source. Furthermore, the conveying roller 151R is driven to rotate along the conveying direction to send the first continuous sheet 32a to the ultrasonic welding device 160. In addition, the conveying roller 152R is also driven to rotate along the conveying direction to send the second continuous sheet 33a to the ultrasonic welding device 160. Furthermore, the conveying roller 153R is also driven to rotate along the conveying direction to send the continuous rubber filament 35a to the ultrasonic welding device 160.

[0119] On the other hand, the ultrasonic welding apparatus 160 has an anvil roller 161a (equivalent to a roller) that rotates along the conveying direction, and a welding head 161h disposed at a predetermined position P161h in the rotation direction Dc161a of the anvil roller 161a.

[0120] The welding head 161h is supported by a suitable support member 161s and is positioned substantially immovably at the aforementioned predetermined position P161h. Furthermore, the welding head 161h has a flat vibrating surface 161hs disposed facing the outer peripheral surface 161as of the anvil roller 161a. This surface 161hs vibrates in a direction that widens or narrows the gap between itself and the outer peripheral surface 161as. The vibration frequency is, for example, a predetermined value of 20kHz to 35kHz, and the amplitude is, for example, a predetermined value of 1 micrometer to 30 micrometers. Therefore, the vibrating surface 161hs undergoes ultrasonic vibration, thereby ultrasonically welding the two pieces 32a and 33a passing between the surface 161hs and the outer peripheral surface 161as. That is, the aforementioned welded portion 50 is formed on the two pieces 32a and 33a. Incidentally, this vibration is generated by inputting an electrical signal of the aforementioned frequency to a piezoelectric element of a transducer (not shown) connected to the welding head 161h.

[0121] The anvil roller 161a is supported by a suitable support member (not shown) such as a bearing, enabling it to rotate about a rotation axis along the CD direction. Furthermore, the roller 161a is driven to rotate by a servo motor (not shown) acting as a drive source. On the roller 161a, the first continuous sheet 32a conveyed from the transfer roller 151R, the second continuous sheet 33a conveyed from the transfer roller 152R, and the continuous body 35a of rubber filaments conveyed from the transfer roller 153R are wound with substantially no relative sliding relative to the outer peripheral surface 161as of the roller 161a. Therefore, by driving the rotation of the anvil roller 161a, the first continuous sheet 32a, the second continuous sheet 33a, and the continuous body 35a of rubber filaments are conveyed along the outer peripheral surface 161as of the roller 161a at a conveying speed value equal to the circumferential speed value of the anvil roller 161a. That is, the two continuous sheets 32a and 33a and the continuous body of rubber filament 35a are transported by a transport path that bends along the outer peripheral surface 161as.

[0122] Here, the circumferential speed (mpm) of the conveyor roller 151R of the first continuous sheet 32a and the circumferential speed (mpm) of the conveyor roller 152R of the second continuous sheet 33a are approximately the same as the circumferential speed (mpm) of the anvil roller 161a. Therefore, the first continuous sheet 32a and the second continuous sheet 33a are wound onto the anvil roller 161a in a state that is neither significantly elongated nor slack. On the other hand, the circumferential speed (mpm) of the conveyor roller 153R of the continuous rubber filament 35a is approximately one-elongation ratio (1 / elongation ratio) of the circumferential speed (mpm) of the anvil roller 161a. Therefore, the continuous rubber filament 35a is elongated to the aforementioned elongation ratio during its passage between the conveyor roller 153R and the anvil roller 161a, and is wound onto the anvil roller 161a in this elongated state.

[0123] Furthermore, in this example, the winding sequence onto the anvil roller 161a is as follows: first, the first continuous sheet 32a is wound, then the continuous body 35a of rubber filaments is wound, and finally, the second continuous sheet 33a is wound. Thus, these three elements form a state where the continuous body 35a of rubber filaments is interposed between the first continuous sheet 32a and the second continuous sheet 33a on the outer peripheral surface 61as of the anvil roller 161a.

[0124] Furthermore, such as Figure 9 As shown, on the outer peripheral surface 161as of the anvil roller 161a, a plurality of protrusions 161at, 161at... are formed corresponding to the aforementioned welding portions 50, 50... Furthermore, when the first and second continuous pieces 32a and 33a of the continuous body 35a containing the inserted rubber filaments pass the configuration position P161h of the welding head 161h based on the rotation of the anvil roller 161a, ultrasonic vibration energy is transmitted from the vibration surface 161hs of the welding head 161h to the two pieces 32a and 33a. Consequently, a pair of opposing surfaces 32ast and 33ast of the two pieces 32a and 33a locally heat up and melt at the position corresponding to the protrusions 161at. As a result, the pair of opposing surfaces 32ast and 33ast of the two pieces 32a and 33a are joined together according to the discontinuously dispersed joining pattern of the plurality of welding portions 50, 50... as described above. Furthermore, the first continuous sheet 32a and the second continuous sheet 33a, joined by the welding section 50, are conveyed towards the aforementioned second processing position PK2, which is downstream in the conveying direction, in a continuous body 35a with rubber filaments sandwiched between them.

[0125] Alternatively, the circumference (length in the circumferential direction) of the outer peripheral surface 161as of the anvil roller 161a can be set as the length of one or more pieces (multiples of one piece) in the conveying direction of the underwear-type diaper 1. For example, along the rotation direction of the outer peripheral surface 161as of the anvil roller 161a, Figure 4 The pattern of the joint 50 shown has n quantities (n = 1, 2, 3...). In the conveying direction (left-right direction of the diaper 1), the welded portions 50 are formed synchronously in such a way that the positions of the first welded portion 51 and the second welded portion 52 are formed without offset. This allows for the precise arrangement of each welded portion 50 (welded portion row 60) without timing deviation. Furthermore, even in the event of timing deviation, it is easy to visually identify situations such as the second welded portion 52 overlapping with the side joint 70, thus enabling accurate judgment of the product's quality.

[0126] On the other hand, the circumference (length in the circumferential direction) of the outer peripheral surface 161as of the anvil roller 161a can be set to one piece or a shorter length in the conveying direction of the underwear-type diaper 1. For example, multiple patterns forming the second weld portion 52 disposed in the inner end region IA are provided around the anvil roller 161a. Furthermore, the pattern forming the second weld portion 52 must be disposed in the inner end region IA, and at least one set of the same pattern is disposed in the central region CA. By rotating the anvil roller 161a multiple times, one piece of weld portion 50 (weld portion row 60) of the diaper 1 is formed.

[0127] This reduces the diameter of the anvil roller 161a. Furthermore, since the second weld portion 52 can be formed in the central region CA with the same pattern as the inner end region IA, the expansion and contraction of the elastic member 35 (45) can be suppressed by the absorber side region SA, etc. The effect of suppressing the expansion and contraction of the absorber side region SA will be explained later. Figure 12 To explain.

[0128] <Regarding the elasticity of the waist circumference 20>

[0129] The waist section 20 (abdominal waist section 31 and back waist section 41) of the diaper 1 formed in this way has different elasticity than conventional diapers by adjusting the shape and arrangement of the welded portion 50 where the waist elastic member 35 (45) is installed on the waist section 20. Furthermore, by making the elasticity different, the ease of putting on and taking off can be improved compared to conventional diapers.

[0130] For example, when using disposable underwear-type diapers, when removing the worn diaper from the body, the side joint (70) connecting the abdominal waistband (31) and the back waistband (41) is generally torn open to open the waist opening BH and the leg opening LH. In this case, in conventional underwear-type diapers, due to the lateral elasticity of the abdominal waistband (31) and the back waistband (41), it is sometimes difficult to tear open the side joint (70).

[0131] That is, in order to tear open the side joint 70, when the abdominal waist portion (31) and the back waist portion (41) are grasped near the side joint 70 and stretched in opposite directions, the abdominal waist portion (31) and the back waist portion (41) will elongate in the left and right directions, making it difficult to apply force to the side joint 70. In addition, it is difficult to efficiently tear open the side joint (70) because it requires a lot of effort to elongate the abdominal waist portion (31) and the back waist portion (41).

[0132] In contrast, in diaper 1, by reducing the stretchability of the ventral waist portion 31 and the dorsal waist portion 41 in the left and right directions in the area near the side joint portion 70, it is easier to apply force to the side joint portion 70, and the side joint portion 70 can be torn open efficiently with a small force.

[0133] Figure 10 This is a diagram illustrating the elasticity of the abdominal waistband 31 (41) as a comparative example of conventional underwear-type diapers. Figure 11 This is a diagram illustrating the elasticity of the abdominal waist section 31 (41) of the diaper 1 according to the first embodiment. Figure 10 The basic structure of the abdominal waistband 31 (41) of the comparative example shown is largely the same as that of the abdominal waistband 31 (41) of diaper 1, but the shape and arrangement of the welded portion 50 (welded portion row 60) are different from those of diaper 1. That is, in diaper 1, as Figure 4 As explained above, the welded section rows 60 are formed by two types of welded sections 51 and 52. In contrast, in the comparative example, each welded section row 60 is formed by arranging one type of welded section (the welded section corresponding to the first welded section 51 of the diaper 1) at certain intervals in the vertical and horizontal directions. Furthermore, for the abdominal waistband 31 (41) of the comparative example, a [missing information - likely referring to a specific feature or design] is provided. Figure 4 The areas (central area CA′, inner end area IA′, outer end area OA′, etc.) set in the abdominal waist portion 31 (41) of the diaper 1 described in the text are roughly the same.

[0134] In addition, Figure 10 as well as Figure 11 The top view shown in the diagram represents a top view of the abdominal waistband 31 (41) in its natural state, while the bottom view represents a top view of the abdominal waistband 31 (41) in its extended state. "Natural state" refers to the state when the diaper 1 or the abdominal waistband 31 (41) has been placed for a predetermined time. For example, the abdominal waistband 31 and the back waistband 41 of the diaper 1 are pulled outwards to the left and right, setting the waistbands 31 and 41 to an "extended state." After maintaining this extended state for 15 seconds, the stretch of the diaper 1 is released, and it is placed on a flat surface such as a table. Furthermore, the state after being placed flat on such a surface for 5 minutes is defined as the natural state.

[0135] exist Figure 10In the comparative example shown, the left-right length (width) of the central region CA′ in its natural state is ICA′, and the left-right length (width) of the inner end region IA′ is IIA′. Furthermore, when the abdominal waist section 31(41) changes from its natural state to its extended state, the left-right length (width) of the central region CA′ becomes LCA′, and the left-right length (width) of the inner end region IA′ becomes LIA′.

[0136] Furthermore, the length (width) in the left-right direction of the central region CA′ and the inner end region IA′ is set as the average of the length (width) at the upper end position and the length (width) at the lower end position in the up-down direction. When the abdominal waist section 31 (41) stretches, there is a possibility that the closer it is to the highly rigid absorbent body 10 in the up-down direction, the more difficult it is to stretch under the influence of the absorbent body 10. That is, sometimes there will be a difference in the length (width) in the left-right direction between the upper end position and the lower end position in the up-down direction. Therefore, by setting it as the average of the length (width) at the upper end position and the lower end position in the up-down direction, the error that may occur depending on the measurement position can be minimized as much as possible. In this specification, the definition of the length (width) in the left-right direction of each region (IA, CA, OA, SA, EA, etc.) is the same as below.

[0137] Here, the proportion of the change in length in the left-right direction of the central region CA′ of the abdominal waist portion 31 (41) from its natural state to its extended state (hereinafter also referred to as the "size change rate") is represented by the value obtained by dividing the amount of extension (contraction) of the central region CA′ (LCA′-ICA′) by the length LCA′ when it is extended. That is, the size change rate of the central region CA′ is represented by (LCA′-ICA′) / LCA′. Similarly, the proportion of the change in length in the left-right direction of the inner end region IA′ of the abdominal waist portion 31 (41) from its natural state to its extended state (size change rate) is represented by (LIA′-IIA′) / LIA′.

[0138] Furthermore, in the comparative example, the dimensional change rate (LCA′-ICA′) / LCA′ of the central region CA′ is approximately equal to the dimensional change rate (LIA′-IIA′) / LIA′ of the inner end region IA′. This is because the welded portions 50 (welded portion row 60) where the waist elastic member 35 is installed are evenly arranged, thus exhibiting uniform elasticity throughout the entire ventral waist portion 31 (41). Therefore, when the side joint 70 needs to be torn open during the diaper putting on and taking off operation as described above, the ventral waist portion 31 (41) tends to elongate in the lateral direction as a whole, making it difficult to exert force efficiently on the side joint 70. In addition, due to the rigidity of the absorbent body 10, the dimensional change rate of the central region CA′ may sometimes be smaller than that of the inner end region IA′, while in the comparative example, the ventral waist portion 31 (41) does not change in its tendency to elongate in the lateral direction as a whole.

[0139] Next, in Figure 11 In the ventral waist portion 31(41) of this embodiment shown, the left-right length (width) of the central region CA in its natural state is denoted as ICA, and the left-right length (width) of the inner end region IA is denoted as IIA. Furthermore, when the ventral waist portion 31(41) changes from its natural state to its extended state, the left-right length (width) of the central region CA is denoted as LCA, and the left-right length (width) of the inner end region IA is denoted as LIA. The dimensional change rate of the central region CA is represented by (LCA - ICA) / LCA, and the dimensional change rate of the inner end region IA is represented by (LIA - IIA) / LIA.

[0140] In the diaper 1 of the first embodiment, the ventral waist portion 31 (41) differs from the comparative example in that the dimensional change rate (LIA-IIA) / LIA of the inner end region IA is less than the dimensional change rate (LCA-ICA) / LCA of the central region CA. That is, the dimensional change rate (proportion of change in length in the left-right direction) of the elastic member 35 (45) installed in the inner end region IA by the welded portion 50 (welded portion pair 50s) from its natural state to its extended state is less than the dimensional change rate (proportion of change in length in the left-right direction) of the elastic member 35 (45) installed in the central end region CA by the welded portion 50 (welded portion pair 50s) from its natural state to its extended state.

[0141] Based on this configuration, when tearing the side joint 70 during the putting on and taking off of the diaper 1, the abdominal waist portion 31 (41) is less elastic in the lateral direction compared to the central region CA in the inner end region IA near the side joint 70. Therefore, when the abdominal waist portion (31) and the back waist portion (41) are grasped and pulled in opposite directions, the side joint 70 can be applied efficiently, and the side joint 70 can be easily torn open. Thus, the action of tearing the side joint 70 and removing the diaper 1 from the wearer's body can be performed easily.

[0142] In the diaper 1 of this embodiment, a second weld portion 52 with a width larger than the first weld portion 51 is provided in the inner end region IA of the abdominal waistband portion 31 (41). In other words, the width W52 of at least one of the second weld portions 52 disposed in the inner end region IA is larger than the minimum value of the width W51 of the first weld portion 51 disposed in the central region CA (see reference). Figure 6 According to this configuration, the waist elastic member 35, which is installed in the inner end region IA via the second weld 52, is clamped over a large area in the left-right direction by a pair of second welds 52, 52 (weld pair 50s). As a result, compared with the central region CA, the waist elastic member 35 is less likely to stretch or contract in the left-right direction, thus suppressing excessive elongation of the inner end region IA of the abdominal waist portion 31 (41). Therefore, it is easy to apply force to the side joint 70, and the side joint 70 can be easily torn open when the worn diaper 1 is removed from the body.

[0143] However, if the elasticity of the inner end region IA can be reduced compared to the central region CA, the shape and arrangement of the welded portions 50 can be appropriately modified. For example, each welded portion can be arranged such that the width of the welded portion 50 per unit length of the inner end region IA is greater than the width of the welded portion 50 per unit length of the central region CA. That is, if the value obtained by dividing the total width of the welded portions 50 arranged in the left and right directions of the inner end region IA by the width of the inner end region IA in the left and right directions is greater than the value obtained by dividing the total width of the welded portions 50 arranged in the left and right directions of the central region CA by the width of the central region CA in the left and right directions, the elasticity of the inner end region IA can be made smaller than that of the central region CA. Even with such a configuration, it is easy to apply force to the side joint 70 efficiently, and the side joint 70 can be easily torn apart.

[0144] In addition, Figure 6In this design, the weld portion 50 located in the inner end region IA of the abdominal waist portion 31 (41), at the position closest to the inner end 70ei of the side joint 70 in the left-right direction, is designated as the second weld portion 52t. Preferably, the width W52t of the second weld portion 52t in the left-right direction is greater than the width W50 of any of the other weld portions 50 located in the region further inward in the left-right direction than the second weld portion 52t. That is, preferably, the width of the second weld portion 52t is greater than at least one of the other second weld portions 52 and first weld portions 51. In this case, the left-right stretching in the region closest to the side joint 70 in the inner end region IA can be reduced, thus making it easier to apply force to the side joint 70 more efficiently and to tear the side joint 70 more easily. In addition, since the width of the second welded portion 52t near the side joint 70 is large, the frictional force at the second welded portion 52t relative to the waist elastic member 35 in the left and right directions is increased, making it difficult for so-called rubber detachment to occur.

[0145] Additionally, in the case where the length (width) of the outer end region OA in the left-right direction of the diaper 1 at the abdominal waistband 31 (41) is IOA in the natural state and LOA in the extended state (see reference) Figure 11 The dimensional change rate of the outer end region OA is represented by (LOA-IOA) / LOA. Preferably, the dimensional change rate of the outer end region OA (LOA-IOA) / LOA is less than the dimensional change rate of the inner end region IA (LIA-IIA) / LIA. With this configuration, the lateral stretching of the outer end region OA, including the side joint 70, is reduced, making it easier to apply a force to tear the side joint 70. Furthermore, the outer end region OA is less prone to stretching, making it easier to grasp by hand. Additionally, it is easier to transmit the force that stretches the abdominal waist portion 31 and the back waist portion 41 to opposite sides when the outer end region OA is grasped, and it is easier to insert fingers into the inner end region IA. Therefore, it is easier to tear the side joint 70.

[0146] In this embodiment, such as Figure 8 As explained, when the continuous body of the underwear-type diaper is cut at the cutting target position PC between a pair of side joints 70, 70 during the manufacturing process, the waist elastic member 35 (continuous body 35a) is also cut. At this time, since the waist elastic member 35 contracts in the left and right direction from the cutting target position PC toward the side joints 70, it is difficult to generate elasticity in the outer end region OA. Therefore, in the outer end region OA, the rate of change of size between the natural state and the stretched state becomes extremely small, making it easy to obtain the effect described above.

[0147] Additionally, on the back waistband 41 of diaper 1, an elastic member 45 is also provided on the buttock cover 41c, which is located lower than the lower end of the side joint 70 in the vertical direction (see reference). Figure 2 The elastic member 45 is also related to... Figure 5A and Figure 5B The method described also involves clamping the welded portion 50s in the vertical direction to attach it to the buttock cover 41c. Furthermore, it is preferable that the length (width) in the left-right direction of the welded portion 50 (not shown) located at the outer edge of the buttock cover 41c (i.e., the outline of the leg opening LH) closest to the inner side in the left-right direction is greater than the length (width) in the left-right direction of any of the other welded portions 50 located in a region further inward than this welded portion 50.

[0148] When removing a used diaper 1 from the wearer's body, sometimes the side joint 70 is torn open from the bottom to the top. For example, when a caregiver removes a diaper 1 worn by a bedridden person, it is sometimes easier to tear the side joint 70 from the bottom than from the top. In such cases, if the lower end of the abdominal waistband 31 and the buttock cover 41c of the back waistband 41 are grasped and pulled in opposite directions, it is possible that if the buttock cover 41c is excessively stretched, it may be difficult to apply force to the side joint 70. In contrast, by widening the welded portion 50 in the area close to the outer edge of the buttock cover 41c, the waistband elastic member 45 becomes less elastic, making it easier to apply force to the lower end of the side joint 70 and easily tear the side joint 70 from the bottom.

[0149] Furthermore, the first piece 32 (42) and the second piece 33 (43) constituting the abdominal waistband 31 (41) of diaper 1 as described above can both be made of spunbond nonwoven fabric. On the surface of such spunbond nonwoven fabric, a plurality of dot-shaped hot-melt portions EB (see reference) are generally provided for melting thermoplastic resin or other hot-melt fibers together. Figure 6 Furthermore, in the diaper 1, at least one of the welded portions 50 (second welded portions 52) disposed in the inner end region IA of the diaper 1 has a portion that overlaps with the heat-fused portion EB when viewed in the thickness direction.

[0150] In the area where the heat-fused portion EB overlaps with the welded portion 50, the unevenness in the thickness direction becomes deeper, making it easier to snag fingers compared to other areas. Therefore, the user can easily grasp the inner end region IA of the abdominal waist portion 31 (41) and easily tear open the side joint portion 70.

[0151] In addition, such as Figure 7As explained, the side joint 70 of the abdominal waist portion 31 (41) is formed by a plurality of locking welds 71 ​​to 73. Preferably, the depth d70 in the thickness direction of the locking welds 71 ​​to 73 forming the side joint 70 is deeper than the depth d50 in the thickness direction of the weld 50 for mounting the elastic member 35 (45) (d70 > d50). By making the depths different between the locking welds 71 ​​to 73 and the weld 50, when the user grasps the inner end region IA and the outer end region OA of the abdominal waist portion 31 (41), the difference between the side joint 70 and other parts can be felt by touch.

[0152] That is, by perceiving the thickness and hardness of the ventral waist portion 31 (41), one can accurately identify the portion where the lateral joint 70 is formed. As a result, it is easy to perform the action of grasping the inner end region IA and the outer end region OA and tearing the lateral joint 70 apart.

[0153] Furthermore, preferably, the maximum value of the length (width) in the left-right direction of the plurality of locking weld portions 71 to 73 is less than the maximum value of the length (width) in the left-right direction of the weld portion 50 (second weld portion 52) provided in the inner end region IA. That is, preferably, the maximum value among the width W71 of the first locking weld portion 71, the width W72 of the second locking weld portion 72, and the width W73 of the third locking weld portion 73 is ( Figure 7 The width of the second welded portion 52 (W72) is smaller than the width of the second welded portion 52 (refer to W52). Figure 6 According to this configuration, compared to the case where the width W52 of the second welded portion 52 is less than the maximum value of the width of the locking welded portions 71 to 73, it is easier to suppress the stretching and contraction of the waist elastic member 35 (45) in the inner end region IA. Therefore, during the putting on and taking off of the diaper 1, it is easier to apply force to the side joint 70 and to easily tear the side joint 70.

[0154] Alternatively, a second welded portion 52 may be provided on the abdominal waistband 31 (41) of the diaper 1 in a region other than the inner end region IA. In this embodiment, as Figure 4 As shown, a second welded portion 52 is also provided in the absorbent body side region SA, which is the area extending 20 mm outward from the outer end 11ces of the absorbent core 11c. Furthermore, it is preferable that the dimensional change rate of the absorbent body side region SA in the left-right direction is less than the dimensional change rate of the leg circumference region EA adjacent to the absorbent body side region SA on both sides in the left-right direction.

[0155] Figure 12 This is a diagram illustrating the elasticity of the absorbent side region SA of the ventral waist portion 31 (41). Figure 12In this design, the length of the absorbent body side region SA in its natural state in the left-right direction is defined as ISA, and the length of the leg circumference region EA in its natural state in the left-right direction is defined as IEA. Furthermore, the length of the absorbent body side region SA in its extended state in the left-right direction is defined as LSA, and the length of the leg circumference region EA in its extended state in the left-right direction is defined as LEA. Preferably, the dimensional change rate of the absorbent body side region SA in the left-right direction (LSA - ISA) / LSA is less than the dimensional change rate of the leg circumference region EA in the left-right direction (LEA - IEA) / LEA.

[0156] The absorbent core side region SA is the area that is grasped and pulled by hand when wearing diapers 1 to match the absorbent core 11c with the wearer's crotch. Therefore, when the absorbent core side region SA has a large rate of dimensional change and is prone to stretching and contracting in the lateral direction, it is difficult for the absorbent core 11c to be pulled upwards, and there is a possibility that a good fit cannot be obtained. In contrast, if the absorbent core side region SA has a small rate of dimensional change, when the absorbent core side region SA is pulled upwards, the absorbent core 11c is also easily pulled upwards in conjunction with it, thus improving the fit of the absorbent core 11c in the crotch area.

[0157] Additionally, on the surfaces of the abdominal waistband 31 and the back waistband 41 of the diaper 1 in its natural state, such as Figure 1 As shown, multiple folds extending in the vertical direction are formed. Such folds are formed by the first piece 32 (42) and the second piece 33 (43) constituting the abdominal waist portion 31 (41) bulging and deforming in the thickness direction when the waist elastic member 35 (45) contracts in the left-right direction. Furthermore, it is preferable that at least a portion of such folds are continuous in the vertical direction between two adjacent waist elastic members 35 (45). That is, when two adjacent waist elastic members 35 (45) in the vertical direction among the multiple waist elastic members 35 (45) provided in the abdominal waist portion 31 (41) are designated as the first waist elastic member 35A (45A) and the second waist elastic member 35B (45B) (neither shown), it is preferable that a continuous fold in the vertical direction is formed between the first waist elastic member 35A (45A) and the second waist elastic member 35B (45B).

[0158] By creating continuous pleats along the vertical direction, when the wearer grasps the waist area 31(41) on the abdomen and pulls it to the left and right, their fingers can easily hook onto the pleats, making it difficult for them to slip. As a result, it is easy and stable to perform actions such as tearing open the side joint 70.

[0159] Figure 13 This is a schematic top view showing a modified example of the back waist section 41. Figure 13In the modified example shown, the waist elastic member 45 is not provided on the buttock cover 41c of the back waist portion 41. Instead, a leg elastic member 48 that extends and contracts along the outer edge of the buttock cover 41c (i.e., the outline of the leg opening LH) is provided. This leg elastic member 48 is not attached to the buttock cover 41c using a welded portion 50, but rather using a leg elastic member adhesive portion 81 formed by applying an adhesive such as a hot melt adhesive to a designated area. The leg elastic member adhesive portion 81 is as follows... Figure 13 As shown, multiple members are arranged along the contour of the leg opening LH, thereby giving the leg elastic member 48 the ability to stretch along the leg opening LH and preventing the buttock cover 41c from rolling up after it is fitted to the wearer's buttocks.

[0160] Furthermore, by attaching the leg-circle elastic member 48 to the leg-circle elastic member adhesive portion 81, the rigidity of the area along the outer edge of the buttock cover 41c (the outline of the leg-circle opening LH) increases. Therefore, when removing the diaper 1 from the body, even if the buttock cover 41c is pulled forcefully, the fabric (non-woven fabric) is difficult to tear, and the side joint 70 can be easily torn apart when performing the action of tearing the side joint 70 from the bottom to the top.

[0161] Furthermore, the leg-circle elastic member adhesive portion 81 is configured in a curved manner along the leg-circle opening LH, and in this curved portion, the leg-circle elastic member adhesive portion 81 is installed in a more elongated state compared to other portions. Therefore, the range of extension of the leg-circle elastic member adhesive portion 81 in the region adjacent to the inner side of the side joint portion 70 in the left-right direction (the region overlapping with the inner end region IA in the left-right direction) is smaller than the range of extension of the leg-circle elastic member adhesive portion 81 in the region adjacent to its inner side (the region overlapping with the central region CA in the left-right direction). Therefore, by configuring the leg-circle elastic member adhesive portion 81 in a curved manner along the leg-circle opening LH, the lower end of the side joint portion 70 can be torn open more easily.

[0162] ===Second Implementation Method===

[0163] In the second embodiment, an example will be described where the arrangement of the welded portions 50 provided on the abdominal waist portion 31 and the back waist portion 41 is different from that in the first embodiment. Figure 14 This diagram illustrates the shape and arrangement of the welded portion 50 in the second embodiment, and is different from that in the first embodiment. Figure 6 The corresponding diagram. Furthermore, the basic structure of the disposable diaper in the second embodiment is largely the same as that of the diaper 1 in the first embodiment, except that the arrangement of the welded portion 50 differs from that of the diaper 1.

[0164] The welding portion 50 provided on the abdominal waist portion 31 and the back waist portion 41 in the second embodiment is as follows: Figure 14As shown, a series of welded portions 60 is formed that curves in the left-right direction. That is, in a portion of two adjacent welded portions 50, 50 in the vertical direction, their left-right positions are staggered, resulting in protruding portions on both sides in the left-right direction. However, the shape of the series of welded portions 60 is not limited to this. Figure 14 The configuration of each welded part 50 is not limited to Figure 14 For example, the welded section 60 could be configured such that the welded section 60 has a protruding portion only on one side in the left-right direction.

[0165] By changing the arrangement of the welded sections 60, the wrinkles formed on the surfaces of the ventral waist section 31 and the back waist section 41 can be adjusted. For example, by... Figure 14 That makes the welded section 60 bend in the left and right direction, and the shape and size of the folds formed between two adjacent welded sections 60, 60 in the left and right direction are easy to become irregular, which can make the skin of the abdominal waist circumference 31 (41) softer or show a natural feel.

[0166] Furthermore, in the second embodiment, similarly to the first embodiment, the width of the welded portion 50 in the inner end region IA, extending 20 mm inward from the inner end 70ei of the side joint 70 in the left-right direction, is greater than the width of the welded portion 50 in the central region CA, which is further inward than the inner end region IA. That is, a second welded portion 52, whose width is greater than the first welded portion 51 in the central region CA, is provided at least in the inner end region IA. Therefore, the dimensional change rate of the inner end region IA in the abdominal waist portion 31 (41) is less than the dimensional change rate of the central region CA. As a result, the inner end region IA is less likely to stretch or contract excessively in the left-right direction, and thus, when the side joint 70 is to be torn open, it is easy to apply force to the side joint 70. Therefore, the side joint 70 can be torn open easily.

[0167] Furthermore, in the second embodiment, a weld row 60 composed of the first weld portion 51 is also provided in the outer end region OA, which is adjacent to the inner end region IA in the left-right direction. This improves the rigidity of the outer end region OA, making it easier to prevent the ventral waist portion 31 (41) from tearing when the lateral joint portion 70 is torn. Additionally, it easily prevents the rubber of the waist elastic member 35 (45) from detaching in the outer end region OA.

[0168] ===Other Implementation Methods===

[0169] The embodiments of the present invention have been described above. However, these embodiments are merely examples to facilitate understanding of the present invention and are not intended to limit the scope of the invention. Furthermore, modifications or improvements can be made to the present invention without departing from its concept, and the present invention naturally includes equivalent configurations. For example, variations as shown below may be possible.

[0170] Explanation of reference numerals in the attached figures

[0171] 1. Diapers (absorbent materials, disposable underwear-style diapers),

[0172] 10 Absorbent Subjects

[0173] 10ea end, 10eb end, 10et upper end,

[0174] 11 absorber, 11c absorbent core, 11ces end.

[0175] 13 top films, 15 back films

[0176] 17 rubber filaments, 18 rubber filaments

[0177] 20 waist area

[0178] 31 Abdominal waist area, 31e End,

[0179] 32, the first piece; 33, the second piece.

[0180] 35 elastic members,

[0181] 41 Back side waist area, 41c Hip area, 41e Ends,

[0182] 42, the first piece; 43, the second piece.

[0183] 45 elastic component, 48 leg circumference elastic component,

[0184] 50 weld joint, 50s weld joint pair,

[0185] 51 First weld joint, 52 Second weld joint,

[0186] 60 welded sections,

[0187] 70 lateral joint, 70ei inner end,

[0188] 71 First locking weld, 72 Second locking weld, 73 Third locking weld

[0189] 81. Adhesive joint of the elastic component of the leg circumference.

[0190] 100 production lines

[0191] 151 conveying mechanism, 151R conveying roller.

[0192] 152 conveying mechanism, 152R conveying roller,

[0193] 153 conveying mechanism, 153R conveying roller.

[0194] 160 ultrasonic welding device,

[0195] 161a anvil roller, 161at convex part, 161h welding head,

[0196] BH waist opening, LH leg opening

[0197] CL1 central position,

[0198] CA central region, IA inner end region, OA outer end region

[0199] SA absorbent side area, EA leg circumference area.

[0200] EB hot melt section.

Claims

1. An absorbent underwear-type garment, the absorbent underwear-type garment having intersecting vertical and horizontal directions, The above-mentioned absorbent underwear-type items have the following characteristics: Absorbent subject; and The waist section, at its two ends in the aforementioned left-right direction, is joined together with the abdominal waist section and the back waist section by a pair of lateral joints. The waist portion, at least a portion of which is located between the pair of lateral joints, possesses elasticity along the left-right direction, characterized in that... The aforementioned waist portion, in its extended state, has: The inner end region, which is located above the upper end of the absorbent body in the vertical direction and extends 20 mm inward from the inner end of the lateral joint in the horizontal direction; and The central region is located above the upper end of the absorbent body in the vertical direction and is sandwiched between a pair of inner end regions in the horizontal direction. The value obtained by dividing the difference between the left-right length of the inner end region in the extended state and the left-right length of the inner end region in the natural state by the left-right length of the inner end region in the extended state is less than the value obtained by dividing the difference between the left-right length of the central region in the extended state and the left-right length of the central region in the natural state by the left-right length of the central region in the extended state.

2. The absorbent underwear-type garment as described in claim 1, characterized in that, The waist portion has an outer end region that is located further outward than the inner end of the lateral joint in the left-right direction. The value obtained by dividing the difference between the left-right length of the outer end region in the extended state and the left-right length of the outer end region in the natural state by the left-right length of the outer end region in the extended state is less than the value obtained by dividing the difference between the left-right length of the inner end region in the extended state and the left-right length of the inner end region in the natural state by the left-right length of the inner end region in the extended state.

3. The absorbent underwear-type garment as described in claim 1 or 2, characterized in that, The aforementioned waist section has skin-lined side panels and non-skin-lined side panels layered in the thickness direction. Between the skin side panel and the non-skin side panel, which are joined by multiple welded joints, a plurality of elastic members capable of stretching and contracting in the left-right direction are arranged at intervals in the vertical direction. Each of the aforementioned elastic members, in a state of contraction along the left-right direction, is installed on the skin side panel and the non-skin side panel by being sandwiched between two adjacent welded portions along the up-down direction. The value obtained by dividing the difference between the length in the left-right direction of the elastic member installed using the weld portion disposed in the inner end region and the length in the left-right direction in the extended state by the length in the left-right direction of the extended state is less than the value obtained by dividing the difference between the length in the left-right direction of the elastic member installed using the weld portion disposed in the central region and the length in the left-right direction in the extended state by the length in the left-right direction of the extended state.

4. The absorbent underwear-type article as described in claim 3, characterized in that, In the extended state described above, the width of at least one of the welded portions disposed in the inner end region in the left-right direction is greater than the minimum value of the width of the welded portion disposed in the central region in the left-right direction.

5. The absorbent underwear-type article as described in claim 3, characterized in that, In the extended state described above, the value obtained by dividing the total width of the weld portion disposed in the inner end region in the left and right directions by the width of the inner end region in the left and right directions is greater than the value obtained by dividing the total width of the weld portion disposed in the central region in the left and right directions by the width of the central region in the left and right directions.

6. The absorbent underwear-type article as described in claim 3, characterized in that, In the aforementioned left-right direction, the length of the weld portion located at the position closest to the inner end of the aforementioned lateral joint in the aforementioned left-right direction is greater than the length of any of the aforementioned weld portions located in the region that is more inner than the aforementioned weld portion in the aforementioned left-right direction.

7. The absorbent underwear-type article as described in claim 3, characterized in that, The aforementioned back waist section has a hip cover located below the lower end of the aforementioned side joint. At least a portion of the aforementioned elastic member is disposed in the aforementioned buttock bra. In the aforementioned left-right direction, the length of the welded portion located closest to the outer edge of the buttock cover in the aforementioned left-right direction is greater than the length of any of the welded portions located in the region that is more inward than this welded portion in the aforementioned left-right direction.

8. The absorbent underwear-type article as described in claim 3, characterized in that, The aforementioned back waist section has a hip cover located below the lower end of the aforementioned side joint. The thigh support is provided with an elastic member that extends and retracts along the outer edge of the aforementioned hip cover. The aforementioned leg circumference elastic member is installed on the aforementioned back waist section using an adhesive.

9. The absorbent underwear-type article as described in claim 3, characterized in that, At least one of the aforementioned skin-side sheet and the aforementioned non-skin-side sheet is a spunbond nonwoven fabric in which heat-melt fibers are joined together by a plurality of dispersed heat-melt portions. When viewed in the thickness direction, either the skin side sheet or the non-skin side sheet has a portion in the inner end region where the welded portion overlaps with the heat-fused portion.

10. The absorbent underwear-type article as described in claim 3, characterized in that, The aforementioned lateral joint has a plurality of locking and welding portions arranged at intervals in the aforementioned vertical direction. The depth in the thickness direction of the aforementioned ferrule is greater than the depth in the thickness direction of the aforementioned ferrule.

11. The absorbent underwear-type article as described in claim 10, characterized in that, The maximum length of each of the aforementioned fastening welded portions in the left-right direction is less than the maximum length of the aforementioned welded portion in the left-right direction located in the aforementioned inner end region.

12. The absorbent underwear-type article as described in claim 1, characterized in that, The waist section has a first elastic member that can extend and retract along the left-right direction and a second elastic member disposed adjacent to the first elastic member in the up-down direction. The sheet member constituting the waist section has multiple folds formed by protruding and deforming along the above-mentioned vertical direction in the thickness direction. At least a portion of the aforementioned plurality of folds are continuous in the aforementioned vertical direction between the aforementioned first elastic member and the aforementioned second elastic member.

13. The absorbent underwear-type article as described in claim 1, characterized in that, The aforementioned absorbent core possesses liquid-absorbing properties. The aforementioned waist portion, in its extended state, has: The absorbent body side region is located below the upper end of the absorbent body in the vertical direction and extends 20 mm outward from both ends of the absorbent core in the horizontal direction; and The leg circumference area is located lower than the upper end of the absorbent body in the vertical direction, and is sandwiched between the absorbent body side area and the side joint in the horizontal direction. The value obtained by dividing the difference between the left-right length of the absorbent side region in the extended state and the left-right length of the absorbent side region in the natural state by the left-right length of the absorbent side region in the extended state is less than the value obtained by dividing the difference between the left-right length of the leg circumference region in the extended state and the left-right length of the leg circumference region in the natural state by the left-right length of the leg circumference region in the extended state.

14. An absorbent article in the form of underwear, the absorbent article having intersecting vertical and horizontal directions. The above-mentioned absorbent underwear-type items have the following characteristics: An absorbent body having an absorbent core with liquid-absorbing properties; and The waist section, at its two ends in the aforementioned left-right direction, is joined together with the abdominal waist section and the back waist section by a pair of lateral joints. The waist portion, at least a portion of which is located between the pair of lateral joints, possesses elasticity along the left-right direction, characterized in that... The aforementioned waist portion, in its extended state, has: The absorbent body side region is located below the upper end of the absorbent body in the vertical direction and extends 20 mm outward from both ends of the absorbent core in the horizontal direction; and The leg circumference area is located lower than the upper end of the absorbent body in the vertical direction, and is sandwiched between the absorbent body side area and the side joint in the horizontal direction. The value obtained by dividing the difference between the left-right length of the absorbent side region in the extended state and the left-right length of the absorbent side region in the natural state by the left-right length of the absorbent side region in the extended state is less than the value obtained by dividing the difference between the left-right length of the leg circumference region in the extended state and the left-right length of the leg circumference region in the natural state by the left-right length of the leg circumference region in the extended state.

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