Stretchable sheet structure and absorbent disposable product

Abstract

Having a stretchable planar structure that stretches in a stretching direction when a stretching force is applied to it and shrinks when the stretching force is removed: a first flat structure; a second flat structure that is placed over the first flat structure; a first elastic element that is positioned between the first and second planar structures and extends linearly in the direction of stretching; and a second elastic element positioned between the first and second surface structures and extending linearly in the stretching direction, spaced apart from the first elastic element, wherein, while the first and second surface structures are stretched flat in the stretching direction, the first and second surface structures are joined together by a plurality of linear joining units that are aligned in the stretching direction, Each linear joining unit overlaps with the first elastic element and the second elastic element, a joining width of each linear joining unit at a first intersection position of each linear joining unit and the first elastic element, and a joining width of each linear joining unit at a second intersection position of each linear joining unit and the second elastic element, are greater than a joining width of each linear joining unit at any position between the first intersection position and the second intersection position, and While the first elastic element and the second elastic element shrink, the first surface structure or the second surface structure exhibits bulges between the majority of linear joining units to form pleats.

Description

TECHNICAL FIELD

[0001] The present invention relates to a stretchable sheet structure having stretchability and to a disposable absorbent product having the stretchable sheet structure. CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Japanese Patent Application No. JP2022-049269, filed with the Japan Patent Office on March 25, 2022, and No. 2022-071690, filed with the Japan Patent Office on April 25, 2022, the disclosures of which are incorporated herein by reference. TECHNICAL BACKGROUND

[0003] Disposable absorbent products designed to absorb the wearer's body excretions are traditionally provided with gathers that have a stretchable fabric structure at various locations. In the case of a disposable diaper, for example, gathers are provided at parts that come into contact with a groin, around the legs, and at the waist. To prevent leakage, gathers are also provided on an absorbent add-on product located on the inside of the diaper.

[0004] As an example of such gathers, gathers provided with ordered ridges and grooves are known. For example, Japanese Utility Model Application No. H4-71922 (Document 1) discloses a technique for forming gathers with a waist tab by disposing stretchable elastic elements between nonwoven fabrics to which a hot-melt adhesive is applied linearly in fixed-pitch strips so that the stretchable elastic elements overlap with the line of hot-melt adhesive.

[0005] Japanese Patent Application Laid-Open No. 2005-212405 (Document 2) discloses a technique in which, when two sheet materials are intermittently heat-sealed in a stretching direction and a direction orthogonal to the stretching direction, elastic members facing the stretching direction are firmly attached to the sheet materials by welding. International Publication No. 2018 / 070158 (Document 3) discloses a technique in which welding is used to join a pair of sheets together and hold a plurality of elastic members between the pair of sheets.

[0006] As in Document 1, in the case where elastic elements are firmly bonded with a hot-melt adhesive applied linearly in the direction perpendicular to the elastic element, a large amount of hot-melt adhesive is required to correctly bond the elastic elements. This increases the shape-retaining property of the gathers (hereinafter referred to as "rigidity") and deteriorates the feel of the gathers. As in Document 2, in the case where fabrics and elastic elements are bonded with points of the same shape that are intermittently aligned in two dimensions, it is necessary to increase the width of the points in one stretching direction to maintain bonding strength. This reduces the area of ​​the fabric surfaces that can be used as ridges and grooves.According to Document 3, the elastic elements are held in place at the fixing positions during welding, which, however, may reduce the strength of the fabrics at the fixing points of the elastic elements.

[0007] According to documents 1 to 3, however, the ridges and grooves of the gathers are formed perpendicular to the direction of extension of the gathers. This increases the stiffness of the gathers, which attempt to maintain their shape in the direction of extension of the ridges and grooves. This can lead to the gathers coming into excessive contact with the groin or the gathers around the waist becoming too caught on the skin surface when the diaper is worn. PRESENTATION OF THE INVENTION

[0008] It is an object of the present invention to provide a stretchable sheet structure having appropriate stiffness while forming gathers with ordered ridges and grooves, and to provide a disposable absorbent product having the stretchable sheet structure.

[0009] A first aspect of the present invention relates to a stretchable sheet structure that stretches in a stretching direction with a stretching force applied thereto and shrinks when the stretching force is released. The stretchable sheet structure comprises a first sheet, a second sheet superimposed over the first sheet, a first elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction, and a second elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction while being spaced apart from the first elastic member.While the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet are joined together by a plurality of linear joining units aligned in the stretching direction. Each linear joining unit overlaps with the first elastic element and the second elastic element. A joining width of the linear joining unit at a first intersection position of the linear joining unit and the first elastic element and a joining width of the linear joining unit at a second intersection position of the linear joining unit and the second elastic element are larger than a joining width of the linear joining unit at any position between the first intersection position and the second intersection position.As the first elastic element and the second elastic element shrink, the first sheet or the second sheet has bulges between the plurality of linear joining units to form gathers.

[0010] According to the present invention, it is possible to provide the stretchable sheet structure with a suitable rigidity and to form gathers with ordered webs and grooves.

[0011] A second aspect of the present invention relates to a stretchable sheet structure that stretches in a stretching direction with a stretching force applied thereto and shrinks when the stretching force is released. The stretchable sheet structure comprises a first sheet, a second sheet superimposed over the first sheet, a first elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction, and a second elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction while being spaced apart from the first elastic member.While the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet are joined to each other by a plurality of linear joining units aligned in the stretching direction. Each of the plurality of linear joining units is present in an intersecting direction, which intersects with the stretching direction, between the first elastic member and the second elastic member, the intersecting direction being inclined with respect to a direction perpendicular to the stretching direction. Each linear joining unit intersects with the first elastic member and the second elastic member. While the first elastic member and the second elastic member shrink, the first sheet or the second sheet has bulges between the plurality of linear joining units to form gathers.

[0012] A third aspect of the present invention relates to the stretchable sheet structure according to the second aspect, wherein a joining width of the linear joining unit at a first intersection position of the linear joining unit and the first elastic member and a joining width of the linear joining unit at a second intersection position of the linear joining unit and the second elastic member are larger than a joining width of the linear joining unit at any position between the first intersection position and the second intersection position.

[0013] A fourth aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to third aspects), wherein each of the plurality of linear joining units is continuously provided in an intersecting direction intersecting with the stretching direction between the first elastic member and the second elastic member.

[0014] A fifth aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to fourth aspects), wherein the first sheet and the second sheet are joined to each other at each linear joining unit by welding.

[0015] A sixth aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to fifth aspects), wherein the first sheet and the second sheet are a single sheet folded along a fold line, the first sheet and the second sheet being stretched flat in the stretching direction, the first elastic element being positioned in close proximity to and parallel to the fold line, and each linear joining unit not overlapping the fold line.

[0016] A seventh aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to sixth aspects), further comprising a third elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the second elastic member on a side of the second elastic member opposite to the first elastic member. Each of the plurality of linear joining units is present between the second elastic member and the third elastic member in an intersecting direction intersecting the stretching direction. Each linear joining unit overlaps with the third elastic member. The gathers are formed while the first elastic member, the second elastic member, and the third elastic member shrink.Each linear joining unit is linear, while the first sheet and the second sheet are stretched flat in the stretching direction.

[0017] An eighth aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to sixth aspects), further comprising a third elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the second elastic member on a side of the second elastic member opposite to the first elastic member. Each of the plurality of linear joining units is present between the second elastic member and the third elastic member in an intersecting direction that intersects with the stretching direction. Each linear joining unit overlaps with the third elastic member. The gathers are formed while the first elastic member, the second elastic member, and the third elastic member shrink.While the first sheet and the second sheet are stretched flat in the stretching direction, the linear joining unit is bent at a position of the second elastic element.

[0018] A ninth aspect of the present invention relates to the stretchable sheet structure according to the eighth aspect, wherein an angular direction in which each linear joining unit is inclined with respect to the direction perpendicular to the stretching direction between the first elastic member and the second elastic member is opposite to an angular direction in which each linear joining unit is inclined with respect to the direction perpendicular to the stretching direction between the second elastic member and the third elastic member.

[0019] A tenth aspect of the present invention relates to the stretchable sheet structure according to the seventh aspect, wherein, while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet have a margin provided along and in close proximity to the first elastic member on a side of the first elastic member opposite to the second elastic member, and a distance between the first elastic member and the second elastic member is greater than a distance between the second elastic member and the third elastic member.

[0020] An eleventh aspect of the present invention relates to the stretchable sheet structure according to the eighth aspect (or according to the eighth or ninth aspect), wherein, while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet have a margin provided along and in close proximity to the first elastic member on a side of the first elastic member opposite to the second elastic member, and a distance between the first elastic member and the second elastic member is greater than a distance between the second elastic member and the third elastic member.

[0021] A twelfth aspect of the present invention relates to the stretchable sheet structure according to the first or second aspect (or according to any one of the first to eleventh aspects), wherein, while the first sheet and the second sheet are stretched flat in the stretching direction, a region of existence of each linear joining unit in the stretching direction partially overlaps with a region of existence of another linear joining unit in the stretching direction, the other linear joining unit being adjacent to the linear joining unit.

[0022] A thirteenth aspect of the present invention relates to a disposable absorbent product that absorbs a body exudate of a wearer and comprises the stretchable sheet structure according to the first or second aspect (or according to any of the first to twelfth aspects).

[0023] A fourteenth aspect of the present invention relates to the disposable absorbent product according to the thirteenth aspect, wherein the gathers come into contact with a groin of the wearer.

[0024] These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view showing a configuration of an absorbent product; Fig. 2 is a perspective view showing a free state of the absorbent product; Fig. 3 is a sectional view of the absorbent product; Fig. 4 is a sectional view of the absorbent product; Fig. 5 is a sectional view showing the vicinity of a gathered sheet in enlarged dimensions; Fig. 6 is a diagram showing the proximity of a boundary between a middle joining region and a final joining region in enlarged dimensions; Fig. 7 is a plan view showing a part of a gathered sheet; Fig. Figure 8 is a plan view of a portion of the absorbent product; Fig. 9 is a diagram showing linear joining units in enlarged dimensions; Fig. 10 is a perspective view showing the bulges of the inner and outer sheets; Fig. 11 is a diagram showing another example of the linear joining units; Fig. 12 is a diagram showing another example of the linear joining units; Fig. 13 is a diagram showing another example of the linear joining units; Fig. 14 is a diagram showing another example of the linear joining units; Fig. 15 is a sectional view showing another example of a standing gather sheet; Fig. 16 is a sectional view showing another example of a standing gather sheet. DESCRIPTION OF EMBODIMENTS

[0025] Fig. 1 is a plan view showing a configuration of a disposable absorbent product 1 (hereinafter also simply referred to as “absorbent product 1”) according to an embodiment of the present invention. Fig. Figure 1 shows a state in which the absorbent product 1 is opened in a flat state. The absorbent product 1 is an additional absorbent pad arranged on the inside (i.e., the wearer side) of an outer product worn by a wearer to absorb the wearer's body excretions. Examples of the outer product are a disposable diaper, a non-disposable diaper, and a diaper-shaped cover. The absorbent product 1 can be used, for example, for a person receiving care in a hospital or nursing facility. Fig. 1, the surface of the absorbent product 1 is shown on the side that comes into contact with the wearer, facing forward. In the following description, the direction is from top to bottom in Fig. 1 is referred to as the "longitudinal direction", and the direction from right to left, which is perpendicular to the longitudinal direction, is referred to as the "width direction". The absorbent product 1 is bilaterally symmetrical, and the center line, which is Fig. 1 runs in the longitudinal direction, is provided with the reference number 11.

[0026] Fig. Fig. 2 is a perspective view showing a free state of the absorbent product 1. As described later, the absorbent product 1 has elastic elements and is curved as a whole due to shrinkage of the elastic elements.

[0027] Fig. Figure 3 is a sectional view of the absorbent product 1, taken along a plane perpendicular to the longitudinal direction at a position III-III in Fig. 1. Since the gathered fabrics described later have gathers which are formed due to a shrinkage force of the elastic elements, as in Fig. 2 shown, erect, shows Fig. 3 a state in which the gathers are standing. Fig. Figure 4 is a sectional view of the absorbent product 1, taken in a plane perpendicular to the longitudinal direction at a position IV-IV in Fig. 1.

[0028] As in the Fig. 1 to 4, absorbent product 1 comprises a top sheet 21, an absorbent core 22, and a back sheet 23. The absorbent core 22 is positioned between the top sheet 21 and the back sheet 23. The top sheet 21 comprises a middle sheet 31 and a pair of gather sheets 32. The pair of gather sheets 32 are fixedly attached to both side portions of the middle sheet 31 (i.e., at spaced-apart positions on both sides in the width direction) and extend in the longitudinal direction. Each gather sheet 32 ​​is present over the entire length of the middle sheet 31. In other words, the longitudinal length of each gathering sheet 32 ​​is substantially the same as the longitudinal length of the absorbent product 1. The inner portions of the two gathering sheets 32 in the width direction, iethe gathers 34, stand up towards the wearer when the absorbent product 1 is worn.

[0029] In Fig. 1, an upper portion and a lower portion of the absorbent product 1 correspond, respectively, to a front part that comes into contact with the skin on the abdominal side of the wearer, and a rear part that comes into contact with the skin on the back side of the wearer. A portion of the absorbent product 1 that is positioned between and continuous with the front and rear portions is a middle portion that faces the groin of the wearer. It is not necessary to precisely determine the boundaries between the front and middle portions, and between the rear and middle portions. The front, middle, and rear portions of the absorbent product 1 are arranged in this order in the longitudinal direction. In the Fig. 1, the absorbent product 1 has an approximately rectangular shape in plan view, and the front, middle, and rear parts have substantially the same width in the width direction (ie, the width in the right-left direction when the absorbent product 1 is worn; hereinafter also referred to simply as the "width"). In other words, the absorbent product 1 has an approximately constant width over its entire length. The above-described Fig. 3 and Fig. 4 are sectional views of the middle part and the front part of the absorbent product 1, respectively. A section through the rear part of the absorbent product 1 is essentially similar to that in Fig. 4. The width of the absorbent product 1 does not necessarily have to be constant, and the width of the rear part may, for example, be greater than the width of the front part.

[0030] As in the Fig. 1, Fig. 3 and Fig. 4, the absorbent core 22 is sandwiched between the upper sheet 21 and the back sheet 23. The upper sheet 21 and the back sheet 23 are bonded together around the absorbent core 22 with an adhesive. Fig. 1, the contour of the absorbent core 22 is shown by a thin dashed line. To facilitate understanding of the drawings, Fig. 3 and Fig. 4 the absorbent product 1 in the thickness direction (ie in the up-down direction in the Fig. 3 and Fig. 4) larger than the actual dimension, and the components of the absorbent product 1 which are in contact with each other or are actually joined together are shown with appropriate distances in the thickness direction.

[0031] The middle sheet 31 of the upper sheet 21 quickly captures the moisture from the body exudates absorbed by the wearer and transfers the moisture to the absorbent core 22. The absorbent core 22 absorbs the moisture transferred through the middle sheet 31 and quickly immobilizes the moisture. The back sheet 23 prevents the moisture or the like in the body exudates, which are largely transferred through the middle sheet 31 and the absorbent core 22 to the back sheet 23, from escaping to the outside of the absorbent product 1. In the Fig. In the example shown in Figure 3, the absorbent core 22 is in contact with the central sheet 31 and the rear sheet 23, but an interlining (for example, tissue paper) may be disposed between the absorbent core 22 and the central sheet 31 or between the absorbent core 22 and the rear sheet 23. The absorbent core 22 may be enclosed by any other sheet or may be formed by superimposing multiple absorbent cores. This means that the absorbent core 22 and its peripheral structure may take any of various known structures.

[0032] The longitudinal lengths of the upper sheet 21 and the back sheet 23 are greater than the length of the absorbent core 22. The widths of the upper sheet 21 and the back sheet 23 in the width direction are greater than the width of the absorbent core 22. Both side portions of the upper sheet 21 (ie, the portions on both sides in the width direction) are joined to both side portions of the back sheet 23 either directly or indirectly via an inclusion along the entire length. The width of the middle sheet 31 may be smaller than the width of the back sheet 23. In this case, the outermost end portions of the gather sheet 32 ​​in the width direction may be joined to the back sheet 23.At the longitudinal end portions of the absorbent product 1, the longitudinal end portions of the upper sheet 21 are connected either directly or indirectly to the longitudinal end portions of the back sheet 23. The upper sheet 21 and the back sheet 23 are joined together along the entire circumference of the absorbent core 22, so that the absorbent core 22 is entirely surrounded by the upper sheet 21 and the back sheet 23. The upper sheet 21 and the back sheet 23 can be joined, for example, with a hot-melt adhesive. The upper sheet 21 and the back sheet 23 can also be joined together in ways other than hot-melt adhesive.

[0033] For example, a liquid-permeable nonwoven fabric (e.g., a point-bonded nonwoven fabric, an air-permeable nonwoven fabric, or a spunbonded nonwoven fabric) formed from hydrophobic fibers (e.g., polypropylene, polyethylene, polyester, polyamide, or nylon) whose surface has been hydrophilically treated with a surfactant can be used as the middle sheet 31. Note that the middle sheet 31 may also be a nonwoven fabric (e.g., a spunbonded nonwoven fabric) made of hydrophilic fibers such as cellulose, rayon, or cotton.

[0034] The backing sheet 23 may preferably have a layered structure in which multiple sheets are superimposed. For example, the backing sheet 23 may have a structure in which a nonwoven fabric is superimposed over a plastic film or a water-repellent or liquid-impermeable nonwoven fabric. When the backing sheet 23 includes a plastic film, the plastic film is arranged to face the absorbent core 22. The plastic film may preferably be moisture-permeable (air-permeable). This improves the water resistance of the backing sheet 23 and also increases wearing comfort while preventing stuffiness inside the absorbent product 1. Examples of the nonwoven fabric superimposed over the plastic film include water-repellent nonwoven fabrics or liquid-impermeable nonwoven fabrics.This improves the haptics of the backing fabric 23, for example, its feel and texture. The nonwoven fabric can be, for example, a spunbonded nonwoven or a meltblown nonwoven made of hydrophobic fibers, or an SSS nonwoven (spunbonded nonwoven, meltblown nonwoven, and spunbonded nonwoven) that can be subjected to a water-repellent treatment if necessary.

[0035] The absorbent core 22 is an approximately sheet-like element whose thickness is less than its length and width. The absorbent core 22 is arranged across the front, middle, and rear parts of the absorbent product 1. This means that the absorbent core 22 is positioned on the abdominal side, the crotch length, and the back of the wearer. The shape of the absorbent core 22 in plan view can be modified in various ways. For example, the width of the rear part of the absorbent core 22 can be greater than the width of the front part. Alternatively, the width of the middle part of the absorbent core 22 can be smaller than the width of the front and rear parts.

[0036] The absorbent core 22 may be configured, for example, by dispersing a highly absorbent material into a sheet fiber assembly. The fiber assembly may be, for example, an assembly of wood pulp fibers and / or synthetic fibers. The highly absorbent material may be, for example, a particulate SAP (superabsorbent polymer) or a fibrous SAF (superabsorbent fiber). The absorbent core 22 may also be composed of a nonwoven fabric that does not contain a highly absorbent material. As a further alternative, the absorbent core 22 may be a substance that contains substantially no fibers, such as wood pulp fibers, and that contains a highly absorbent material secured between two liquid-permeable sheet members (e.g., nonwoven fabrics) with a hot-melt adhesive or the like.

[0037] Each gathering sheet 32 ​​has a lateral sheet 321 and elastic elements 3221 to 3223, as shown in the Fig. 1 to 3. In the Fig. 1 and Fig. 3, the reference numerals 321 and 3221 to 3223 are indicated only for the gathering sheet 32 ​​on the right side. The side sheet 321 is a longitudinally elongated sheet element with a corresponding strip. In the present embodiment, the gathering sheets 32 on the right and left sides are each provided with the three elastic members 3221 to 3223. Each of the elastic members 3221 to 3223 has a linear shape extending in the longitudinal direction and is firmly attached to an inner region of the side sheet 321 in the width direction. While the absorbent product 1 is spread out flat, as shown in Fig. 1, the elastic elements 3221 to 3223 are stretched, and when the elastic elements 3221 to 3223 shrink, the gathering sheets 32 shrink and the absorbent product 1 is curved in an approximate cup shape, as shown in Fig. 2. As a result, the inner sections of the gathered fabrics 32 protrude in the width direction from the central fabric 31, as shown in Fig. 3 shown.

[0038] Fig. Fig. 5 is a diagram showing the surroundings of the gathering surface structure 32 on the right side in Fig. 3 in enlarged dimensions. The gathered fabric 32 on the left side also has the same structure. As in Fig. 5, the side panel 321 has a structure in which an inner panel 331 and an outer panel 332 are superimposed by gathers of a single panel. The fold point is located at an inner edge 333 of the gather panel 32 in the width direction. The three elastic members 3221 to 3223 are arranged between the inner panel 331 and the outer panel 332. Hereinafter, the three elastic members 3221 to 3223 are also referred to as "first elastic member 3221," "second elastic member 3222," and "third elastic member 3223" sequentially from the inside to the outside in the width direction. The first elastic member 3221 is arranged along and near the edge 333 of the gather panel 32. The second and third elastic members 3222 and 3223 are spaced outwardly from the first elastic member 3221 in the width direction.

[0039] A water-repellent or liquid-impermeable nonwoven fabric made of hydrophobic fibers (for example, a spunbonded nonwoven, a meltblown nonwoven, or an SMS nonwoven) can be used as the lateral sheet material 321, which can optionally be subjected to a water-repellent treatment. For example, polyurethane yarn, a polyurethane film strip, or thread- or strip-shaped natural rubber can be used as elastic elements 3221 to 3223.

[0040] The lateral sheet 321 is firmly attached to the central sheet 31. In the Fig. 1, Fig. 3 and Fig. 4, the areas where the center sheet 31 and the side sheets 321 are joined to each other, that is, the areas where the center sheet 31 and the gather sheets 32 are joined to each other, are hatched. In the present embodiment, the center sheet 31 and the pair of gather sheets 32 are joined to each other by pressure welding. Hereinafter, these joining areas are referred to as "pressure joining area 4." The term "compression welding" used here refers to, for example, thermal welding in which the sheets are pressed by heat, or ultrasonic welding in which the sheets are pressed by ultrasonic vibration, and is referred to as "embossing." Since the compression is caused by pressure, "compression welding" may also be referred to as "pressure welding."It is noted that the connections between the middle sheet 31 and the gathering sheet 32 ​​may be made by another joining method, for example, a method using a hot melt adhesive in combination.

[0041] The compression joining region 4 includes middle joining regions 41 positioned in the region of a middle section in the longitudinal direction, and end joining regions 42 positioned in the regions of the two end sections in the longitudinal direction. As shown in Fig. 1, there are two central joining regions 41 and four end joining regions 42 in an absorbent product 1. Each central joining region 41 is spaced outward in the width direction from the three elastic elements 3221 to 3223. Each end joining region 42 does not overlap with the three elastic elements 3221 to 3223. As shown in Fig. As shown in Figure 1, each middle joining region 41 is long and slender in the longitudinal direction. Each end joining region 42 includes three linear regions extending in the longitudinal direction. The three linear regions are hereinafter referred to as the "first linear region 421," the "second linear region 422," and the "third linear region 423," in order from the inside to the outside in the width direction. Fig. 1, reference numerals 421 to 423 are indicated only for the linear regions shown in the upper right part. The second linear region 422 and the third linear region 423 are located outside the second and third elastic members 3222 and 3223 in the width direction. Therefore, these linear regions are collectively referred to as the "outer joining region 432," and the first linear region 421, located inside the second and third elastic members 3222 and 3223 in the width direction, is also referred to as the "inner joining region 431."

[0042] The inner joining region 431 and the outer joining region 432 are spaced apart from each other in the width direction. The positions of the second and third elastic elements 3222 and 3223 in the width direction are located between the inner joining region 431 and the outer joining region 432. The position of the innermost first elastic element 3221 in the width direction is located within the inner joining region 431 in the width direction. This means that the positions of the three elastic elements 3221 to 3223 in the width direction do not overlap with any of the existence regions of the inner joining region 431 and the outer joining region 432 in the width direction.

[0043] In the manufacture of the absorbent product 1, a plurality of absorbent cores 22 are sandwiched between the upper sheet 21 and the back sheet 23, both of which are continuous and correspond to a plurality of absorbent products 1, and thereafter, an individual absorbent product 1 is cut out and obtained from this layered continuum. Since the three elastic elements 3221 to 3223 do not overlap with the end joining regions 42, the end sections of the three elastic elements 3221 to 3223 shrink freely within the gathered sheet structure 32 after cutting. Therefore, the end joining regions 42 do not receive any force from the elastic elements 3221 to 3223 after cutting. This can prevent the end joining regions 42 hardened by the compression joint from shrinking significantly inwards when subjected to force by the elastic elements 3221 to 3223, ietowards the wearer's side, thereby improving the comfort of the absorbent product 1. Although in . Fig. 1 the existence areas of the end joining areas 42 in the longitudinal direction overlap with the existence areas of the elastic elements 3221 to 3223 in the longitudinal direction, these existence areas do not have to overlap.

[0044] The second linear region 422 and the third linear region 423 are joined to each other on the inner side in the longitudinal direction. By dividing the outer joining region 432 into the second linear region 422 and the third linear region 423, it is possible to improve the flexibility of the absorbent product 1 in the regions positioned outside the front and rear parts of the absorbent product 1 in the width direction. As a result, the regions positioned outside the front and rear parts in the width direction can easily come along the inner surface of the diaper (including a diaper-shaped cover; the same applies below) or the wearer's body, and accordingly, wearing comfort is improved. In addition, the air permeability of the end joining regions 42 is also improved.

[0045] Fig. Fig. 6 is a diagram showing the proximity of a boundary between a middle joining region 41 and an end joining region 42 in the upper right part of Fig. 1 in enlarged dimensions. In Fig. 6, a large number of dots 40 each represent a portion of the compression joining area 4, i.e., a dot-shaped embossing, and correspond to a recessed area. The dots 40 are hereinafter referred to as "joining elements 40." Although a large number of joining elements 40 are formed in the compression joining area 4, the distances between the joining elements 40 are small, and therefore, an area containing gaps between the joining elements 40 is considered a compression joining area 4.

[0046] As indicated by a guide line in the upper section in Fig. As indicated in Figure 6, an outer edge of the end joining region 42 in the width direction (at a position 443 in the width direction) is located inward in the width direction from the inner edge of the central joining region 41 in the width direction (at a position 442 in the width direction). In this way, by positioning the end joining region 42 within the central joining region 41 in the width direction, there are no portions hardened by the pressure joints in the regions positioned outside the front and rear parts of the absorbent product 1 in the width direction, and accordingly, flexibility is improved. As a result, the regions positioned outside the front and rear parts in the width direction can easily come along the inner surface of the diaper or the wearer's body, and accordingly, wearing comfort is improved.The central joining region 41, positioned outside the end joining region 42 in the width direction, allows the gathers 34 to largely stand upright and effectively prevents the lateral leakage of body excreta. Preferably, the dimension of the end joining region 42 in the width direction, i.e., the distance between the position 443 of the outer edge of the end joining region 42 and a position 444 of the inner edge of the end joining region 42, is greater than the dimension of the central joining region 41 in the width direction, i.e., the distance between a position 441 of the outer edge of the central joining region 41 and the position 442 of the inner edge thereof.

[0047] The central joining region 41 and the outer joining region 432 are continuous in the longitudinal direction. This prevents the body excreta absorbed by the absorbent product 1 from leaking out of the space between the central joining region 41 and the outer joining region 432. As already described, the spacing of the joining elements 40 is so narrow that leakage of the body excreta can be prevented. Preferably, the pressure joining region 4 can extend over the entire length of the cover surface structure 21. In this case, the ultrasonic vibrations continuously act on the projections of a roller (so-called embossing roller) forming the pressure joining region 4 with the aid of ultrasonic vibrations. As a result, the ultrasonic vibrations have a stable effect on the projections of the embossing roller and reduce fluctuations in the strength of the weld seams.Furthermore, wear on the protrusions of the embossing roller is suppressed, and the service life of the embossing roller is improved. When the compression joint area 4 is also formed by heat welding, it is possible to suppress fluctuations in the linear pressure generated between the pair of rollers clamping the sheet on which the compression joint area 4 is formed, and to reduce fluctuations in the strength of the weld seams. Furthermore, wear on the protrusions of the embossing roller is suppressed, and the service life of the embossing roller is improved.

[0048] Further preferably, a maximum value for the total length of the compression joints in the compression joining region 4 in the width direction is 1.25 times or more and 4 times or less of a minimum value thereof. Assuming a straight line in the width direction, the term "total length of the compression joints" as used herein refers to the total length of the regions where the compression joints are actually formed on the straight line by the joining elements 40 or the like (if there is only one region, the length of that region). Preferably, the maximum value for the total length of the compression joints may be 1.5 times or more and 3 times or less of the minimum value thereof. This allows the ultrasonic vibrations to stably act on the protrusions of the embossing roller, thereby reducing fluctuations in the strength of the welds. In addition, wear of the protrusions of the embossing roller is suppressed, and the service life of the embossing roller is improved.In the case where the compression joint area 4 is also formed by heat welding, it is possible to suppress fluctuations in the linear pressure generated between the pair of rollers clamping the sheet on which the compression joint area 4 is formed, thereby reducing fluctuations in the strength of the weld. Furthermore, wear of the protrusions of the embossing roller is suppressed and the service life of the embossing roller is improved.

[0049] The edge of the end joining area 42 on the middle side in the longitudinal direction (the Fig. 6 with the reference numeral 445; portions corresponding to the edge of the end joining region 42 are indicated by solid lines, and portions other than the edge are indicated by dashed lines) is a discontinuous line interrupted at the positions of the second and third elastic members 3222 and 3223. The edge is inclined toward the center in the longitudinal direction, while approaching the outer side in the width direction. It is noted that the edge is not limited to a straight line, but may also be a curve. An additional joining region 401 is located outside the area in which the edge (in Fig. 6 (denoted by reference numeral 446) in the width direction. This reduces fluctuations in the area of ​​the projections of the embossing roller, which are acted upon by ultrasonic vibrations during rotation of the embossing roller, and thus also reduces fluctuations in the strength of the welds. In addition, wear of the projections of the embossing roller is suppressed and the service life of the embossing roller is improved. In the case where the pressure joining area 4 is also formed by heat welding, it is possible to suppress fluctuations in the linear pressure generated between the pair of rollers and thereby reduce fluctuations in the strength of the welds. In addition, wear of the projections of the embossing roller is suppressed and the service life of the embossing roller is improved.It is noted that the "additional joining region" can be understood, for example, as a deformation of the edge that was originally intended to be linear, or as a joining region that exists around the end joining region 42 regardless of the shape. The additional joining region 401 can be provided within the discontinuous region 446 of the edge in the width direction.

[0050] For the sake of simplicity, the edge of the middle joining region 41 corresponding to the outer position 441 of the outermost joining element 40 in the width direction in the middle joining region 41 is now referred to as “outer edge 441”, the edge of the middle joining region 41 corresponding to the inner position 442 of the innermost joining element 40 in the width direction is referred to as “inner edge 442”, the edge of the end joining region 42 corresponding to the outer position 443 of the outermost joining element 40 in the width direction is referred to as “outer edge 443”, and the edge of the end joining region 42 corresponding to the inner position 444 of the innermost joining element 40 in the width direction is referred to as “inner edge 444”. The ratio of the presence of the joining elements 40 between the outer edge 443 and the inner edge 444 of the end joining region 42 is lower than the ratio of the presence of the joining elements 40 between the outer edge 441 and the inner edge 442 of the middle joining region 41.The term "presence ratio of joining elements 40" used here refers to the ratio of the number of joining elements 40 or the total length of the region where the joining elements 40 are present to the width of the compression joining region 4 when the compression joining region 4 is cut in a straight line extending in the width direction. Note that the "presence ratio of joining elements 40" may be the ratio of the area of ​​the joining elements 40 to the area of ​​a target region as a whole.

[0051] Since the ratio of the presence of the joining elements 40 in the end joining region 42 is lower than the ratio of the presence of the joining elements 40 in the middle joining region 41, the joining elements 40 are not densely scattered in the end joining region 42. This improves the flexibility of the absorbent product in the front and rear parts of the absorbent product 1, and particularly in the parts located outside the front and rear parts in the width direction. This improves the wearing comfort in the front and rear parts. In the middle joining region 41, the gather 32 can be firmly and fixedly attached to the central sheet 31. This prevents lateral leakage of body excretions.

[0052] As in Fig. As shown in Figure 6, the first elastic member 3221, located at the innermost position in the width direction, is positioned inward in the width direction of the inner joining region 431 (first linear region 421). This prevents unnecessary force caused by the first elastic member 3221 from acting on the inside of the first linear region 421 in the width direction while forming ridges and grooves up to the inner edge 333 of the gathered sheet 32.

[0053] A portion of the gathered sheet 32 ​​positioned in the width direction within the pressure bonding region 4 is not firmly connected to the central sheet 31. This portion of the gathered sheet 32 ​​may be spaced above the central sheet 31 (ie, toward the wearer side when the absorbent product 1 is worn). As shown in Fig. As shown in Figure 5, the first elastic member 3221 is attached near the inner edge 333 of each side panel 321 while being stretched and extending in the longitudinal direction. The second and third elastic members 3222 and 3223 are joined to the side panel while being stretched and extending in the longitudinal direction and spaced outward from the first elastic member 3221 in the width direction. The second elastic member 3222 and the third elastic member 3223 are also spaced apart from each other in the width direction. When the absorbent product 1 is worn, the portion of each gathered panel 32 positioned within the central joining region 41 in the width direction is spaced upward from the central panel 31 and stands up toward the wearer side due to the shrinkage of the elastic members 3221 to 3223, as shown in Figure 5. Fig. 3. By shrinking the elastic members 3221 to 3223, the gathers 34 are formed in the part of the gathered sheet 32 ​​positioned within the central joining region 41 in the width direction. Thus, the absorbent product 1 can prevent the leakage of urine or the like from the leg area. Note that, as described later, the side sheet 321 and the elastic members 3221 to 3223 are joined by welding using heat or ultrasonic vibration, but they may also be joined with an adhesive.

[0054] The absorbent product 1 can be modified in various ways. For example, the back sheet 23 is not limited to a single sheet and can be configured by superimposing a plurality of sheets, or can be a sheet obtained by bonding a plurality of sheets in the longitudinal or width direction. The back sheet 23 can have the function of preventing a liquid from leaking from the absorbent core 22 to the outside of the absorbent product 1. Typically, the back sheet 23 can comprise a plastic film having an unlimited number of fine holes and a nonwoven fabric attached to the outer surface of the plastic film. The term "back sheet 23" means a sheet covering the lower surface of the absorbent core 22, that is, the surface on the side opposite the wearer.

[0055] The term "top sheet 21" means a sheet covering the upper surface of the absorbent core 22, that is, the surface facing the wearer. While the top sheet 21 of the disposable absorbent product 1 according to the present embodiment includes the middle sheet 31 and the gather sheets 32, the top sheet 21 may also include sheets other than those described above. The middle sheet 31 is liquid-permeable. However, the middle sheet 31 is not required to be liquid-permeable as a whole. The middle sheet 31 is also not limited to a single sheet and may be configured by superimposing a plurality of sheets, or it may be a sheet obtained by joining a plurality of sheets together in the longitudinal or width direction.

[0056] The gathered fabrics 32 are understood to be fabrics with gathers 34 that extend toward the wearer's groin. The structure and shape of the gathered fabrics 32 are not limited to the examples described above. The gathered fabrics 32 can be joined to the underside of the central fabric 31 by welding accompanied by pressure. In this case, the gathered fabrics 32 can be joined, for example, to the underside of the central fabric 31 in the central joining area 41, and the parts of the gathered fabrics 32 folded upward at the edges of the central fabric 31 can be joined to the top side of the central fabric 31 in the end joining areas 42.

[0057] The lateral sheet 321 of each gathered sheet 32 ​​is not limited to the sheet configured by gathering a single sheet, and may be configured by superimposing a plurality of sheets, or may be a sheet obtained by joining a plurality of sheets in the longitudinal or width direction. The gathered sheets 32 prevent the leakage of body excreta outward in the width direction, and at least the inner sides of the gathered sheets 32 are hydrophobic. Although the gathered sheets 32 in Fig. 3 stand up from outside to inside in the width direction, they can be folded outwards in the width direction in the middle joining area 41 and then stand up in the direction of the bar of the carrier.

[0058] The number of elastic elements included in each gathering sheet 32 ​​may be one, two, four, or more. This means that each gathering sheet 32 ​​is provided with at least one elastic element. Preferably, the elastic element(s) may be linear. The term "linear" includes the meaning of "thin thread-like," "thread-like with a flat cross-section," and "band with a flat cross-section." In any case, it is advantageous that at least one elastic element does not overlap with the end joining regions 42. More specifically, the position of the at least one elastic element in the width direction does not overlap with the area where the end joining regions 42 exist in the width direction. This reduces the possibility that the shrinkage force of the at least one elastic element may act on the end joining regions 42.Preferably, an elastic member may be arranged along and near the inner edge 333 of the lateral sheet 321 in the width direction.

[0059] In the case where the number of elastic elements is one, the outer joint region 432 is a region located outward in the width direction of the elastic element. The inner joint region 431 is a region located inward in the width direction of the elastic element. In the case where the number of elastic elements is two or more, the outer joint region 432 is a region located outward in the width direction of one of the elastic elements. The inner joint region 431 is a region located inward in the width direction of one of the elastic elements.More generally, the outer joint region 432 is a region present in the width direction outside any elastic element of at least one elastic element (where the number of any elastic elements may be one or more), and the inner joint region 431 is a region present in the width direction inward of any elastic element. Since the end joint regions 42 do not overlap with any of the elastic elements, the end joint regions 42 do not receive direct force from the elastic elements. This prevents the end joint regions 42 solidified by the compression joints from significantly expanding inward (i.e., toward the viewer of the drawing in . Fig. 1), i.e., toward the wearer, which accordingly improves the wearing comfort of the absorbent product 1. In other words, it is possible to reduce the lack of wearing comfort when wearing the absorbent product 1 compared to the case where the end joining regions 42 overlap with the elastic elements.

[0060] The presence of the inner joining region 431 and the outer joining region 432 and the presence of one or more (preferably two, as in the embodiment described above) elastic elements arranged in the width direction between the inner joining region 431 and the outer joining region 432 allows the part of each gathered sheet 32 ​​in which the gathers 34 are formed to stand up easily. The presence of at least one elastic element between the inner joining region 431 and the outer joining region 432 stabilizes the overall shape of the gathers 34. In order to allow the ends of the gathers 34 to stand up stably in the gathered sheet 32, it is preferable that the elastic element positioned at the innermost position in the width direction among a plurality of elastic elements can be positioned within the inner joining region 431 in the width direction.In order to position the inner joint portion 431 as far inward as possible, it is also preferable that the elastic member positioned at the second innermost position from the inside in the width direction among the plurality of elastic members be positioned between the inner joint portion 431 and the outer joint portion 432 in the width direction. That is, it is preferable that the number of elastic members positioned within the inner joint portion 431 in the width direction be one.

[0061] At least one elastic element may be provided in various ways on the gathering sheet 32, and in each case, the region(s) of presence of the elastic element(s) in the longitudinal direction may or may not overlap with the region of presence of the end joining region 42 in the longitudinal direction.

[0062] In the above-described embodiment, the compression joint section 4 corresponds to a large number of point joints 40, but it may also be a large number of linear joints or have a mesh joint shape. Of course, the central sheet 31 and each gather sheet 32 ​​may be welded together without a gap across the compression joint section 4. In any case, it is preferable that the maximum value for the total length of the compression joints in the width direction in the compression joint section 4 may be 1.25 times or more and 4 times or less of the minimum value thereof. Further preferably, the above maximum value for the total length may be 1.5 times or more and 3 times or less of the minimum value thereof.

[0063] Preferably, the compression joining region 4 may be continuous from the front joining region 42 to the rear joining region 42. Further preferably, the compression joining region 4 may be present along the entire length of the cover sheet 21 in the longitudinal direction. The term "continuously present" as used here includes the case where the joining elements 40 are spaced apart from each other so far that the body excreta do not leak out. Furthermore, the compression joining region 4 does not always have to be continuous, and the middle sheet 31 and the gathering sheet 32 ​​may be joined to each other with an adhesive at locations where the compression joining region 4 is not present. In the embodiment described above, each end joining region 42 is divided into the inner joining region 431 and the outer joining region 432, but the inner joining region 431 may be omitted.In this case, the outer joining region 432 corresponds to the end joining region 42, and it is preferable that the outer joining region 432 and the middle joining region 41 can be continuous in the longitudinal direction, and accordingly, the pressure joining region 4 as a whole is continuous in the longitudinal direction.

[0064] In the above-described embodiment, the outer edge 443 of each end joining region 42 is positioned widthwise inward from the inner edge 442 of the central joining region 41, but the outer edge 443 of the end joining region 42 may be positioned widthwise inward only from the outer edge 441 of the central joining region 41. In this case, too, it is possible to improve the flexibility of the outer portion(s) of the front and / or rear parts of the absorbent product 1 in the width direction. Since the compression joining region 4 is an array of point-shaped joining elements 40, as described above, the edges 441 to 444 refer to lines in contact with the inner and outer sides of the compression joining region 4.In the case where the edges 441 to 444 are curves, the formulation that one edge is positioned inward in the width direction from another edge basically means that one edge as a whole is positioned inward in the width direction from the other edge as a whole, but also includes the case where an extremely small part of one edge or an extremely small part of the other edge does not satisfy the above definition.

[0065] In the embodiment described above, the outer joint portion 432 includes the second linear portion 422 and the third linear portion 423 extending in the longitudinal direction, but the outer joint portion 432 may be configured by three or more linear portions. These linear portions do not necessarily have to be connected to each other. In this case, the outermost linear portion may be regarded as the outer joint portion 432. Forming the end joint portion 42 as an array of linear portions improves the flexibility of the end joint portion 42 and the air permeability in the end joint portion 42. Preferably, at least a part of the end joint portion 42 on the end side in the longitudinal direction may be an array of a plurality of linear portions extending in the longitudinal direction.

[0066] Preferably, the central sheet 31 and the pair of gathered sheets 32 can be joined together only in the area of ​​the pressure connection 4. This means that they can be joined together only by welding, and no adhesive is applied between them. Of course, an adhesive can be used as an aid when joining the central sheet 31 and the pair of gathered sheets 32.

[0067] The absorbent product 1 described above is merely an example, and the joint formed by welding between the middle sheet 31 and the gather sheets 32 described in the above embodiment can be used as a pants-type disposable diaper, an open-type disposable diaper that is wrapped around the waist with bands, an additional absorbent pad arranged in a diaper or a diaper-shaped cover, a urine pad, or any of other various absorbent products that absorb body excretions of a wearer.

[0068] The structure of each gathered surface structure 32 is described below. Fig. Fig. 7 is a plan view showing a part of the gathering sheet 32 ​​on the right side in the front part of the Fig. 1 shows the absorbent product 1 shown. Fig. 7 also shows the structure of the gathered surface structure 32, which in Fig. 6 is not shown. Fig. 8 shows the structure of Fig. 7 in a part of the absorbent product 1 corresponding to the Fig. 6 is similar to the part shown. Fig. 7 shows a portion of the gathered sheet 32 ​​in which the gathers 34 are formed and a portion of an end portion in which the gathers 34 are not formed. The gathers 34 of the gathered sheet 32 ​​have a stretchable sheet structure that stretches in a stretching direction with a stretching force applied thereto and shrinks when the stretching force is released.

[0069] In Fig. 7, solid lines connecting black filled sections and black filled areas indicate areas in which the inner surface structure 331 and the outer surface structure 332 (cf. Fig. 5) are joined together by welding under pressure. A dashed line 334 indicates the outer edge of the inner sheet 331 in the width direction. The areas connected by welding are so-called embossed areas. The term "compression welding" refers, for example, to heat welding in which the sheets are pressed together by the application of heat, or to ultrasonic welding in which the sheets are pressed together by ultrasonic vibrations, and is referred to as "embossing." Since the sheets are pressed together by pressure, the term "compression welding" can also be referred to as "pressure welding." It is noted that the joints between the inner sheet 331 and the outer sheet 332 can be formed by another joining method, for example, by a method using a hot melt adhesive.

[0070] When the inner sheet 331 and the outer sheet 332 are generally referred to as the “first sheet” and “second sheet,” respectively, the second sheet overlies the first sheet, as shown in Fig. 5. The first elastic member 3221 is an elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction. The second elastic member 3222 is an elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction while being spaced from the first elastic member 3221. The third elastic member 3223 is an elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction while being spaced from the second elastic member 3222 on the side of the second elastic member 3222 opposite the first elastic member 3221.

[0071] In Fig. 7, the upward-downward direction corresponds to the stretching direction of the gathered fabric 32. While the gathered fabric 32 is stretched flat in the stretching direction, ie, while the inner fabric 331 and the outer fabric 332 are stretched flat in the stretching direction, the inner fabric 331 and the outer fabric 332 are joined together in the area of ​​the gathers 34 by a plurality of linear joining units 5 aligned in the stretching direction. This creates the beautiful gathers 34 with orderly webs and grooves.

[0072] In the example in Fig. 7, the inner sheet 331 and the outer sheet 332 are joined together by welding in each linear joining unit 5, indicated as a black solid area. By welding, the gathers 34 can be formed more beautifully than when using adhesive, since it is possible to slightly reduce the joining width of the linear joining units 5, especially the joining width at a point between the intersection positions of a pair of elastic elements. If the connections are made by welding, it is preferable not to use adhesive in combination. This means that it is preferable that the joints be made by welding only.

[0073] Fig. 9 shows three linear joining units 5 in enlarged dimensions. In Fig. 9, one of the linear joining units 5 is enclosed by a double-dashed chain line. As the first elastic element 3221, the second elastic element 3222, and the third elastic element 3223 shrink, the inner sheet 331 or the outer sheet 332 has bulges between the plurality of linear joining units 5, forming the gathers 34. Of course, both the inner sheet 331 and the outer sheet 332 may have bulges between the plurality of linear joining units 5 to form the gathers 34. Fig. Fig. 10 is a perspective view showing a state in which the inner sheet 331 and the outer sheet 332 have bulges. Dotted lines indicate portions of the gathers 34 cut along a plane perpendicular to the width direction. As shown in Fig. As shown in Figure 10, the gathered surface structure 32 has the gathers 34 with ordered webs and grooves.

[0074] As in Fig. As shown in Figure 9, each of the plurality of linear joining units 5 exists continuously in a direction that intersects the stretching direction between the first elastic member 3221 and the second elastic member 3222. Each of the linear joining units 5 also exists continuously in a direction that intersects the stretching direction between the second elastic member 3222 and the third elastic member 3223. The continuous presence of the linear joining units 5 enables the formation of the beautiful gathers 34.

[0075] In the Fig. In the example shown in Fig. 7, the extending direction of the linear joining units 5 between the first elastic member 3221 and the second elastic member 3222 (i.e., the above-mentioned "intersecting direction" between the first elastic member 3221 and the second elastic member 3222) is the same as the extending direction of the linear joining units 5 between the second elastic member 3222 and the third elastic member 3223 (i.e., the above-mentioned "intersecting direction" between the second elastic member 3222 and the third elastic member 3223). This means that each linear joining unit 5 is linear, while the inner sheet 331 and the outer sheet 332 are stretched flat in the stretching direction.The above-mentioned overlap direction, in which the linear joining units 5 exist continuously between the first elastic element 3221 and the third elastic element 3223, is hereinafter referred to as the "linear joining direction." Since the linear joining units 5 are linear, it is possible to linearly design the ridges and grooves extending from the first elastic element 3221 to the third elastic element 3223 and form the beautiful gathers 34.

[0076] The linear joining direction is inclined relative to the direction perpendicular to the stretching direction. All linear joining units 5 have the same linear joining direction. By adjusting the linear joining directions in this way, it is possible to weaken the force exerted on the skin by the gathers 34. In particular, it is possible to weaken the instantaneous force exerted on the skin by the gathers 34 and improve the wearing comfort.

[0077] In the Fig. In the example shown in Figure 9, there are two independent joining regions 501 and 502 on the side of the third elastic member 3223 opposite the first elastic member 3221. These joining regions 501 and 502 may not be included in the linear joining units 5, or they may be included in the linear joining units 5. In the case where the joining regions 501 and 502 are included in the linear joining units 5, the linear joining units 5 exist discontinuously on the side of the third elastic member 3223 opposite the first elastic member 3221.

[0078] As in Fig. 5, the inner sheet 331 and the outer sheet 332 are a single sheet folded back at the edge 333. Since the edge 333 is the fold line of the single sheet, the edge 333 is also referred to as "fold line 333" hereinafter. While the inner sheet 331 and the outer sheet 332, as shown in Fig. 7, are stretched flat in the stretching direction, the first elastic element 3221 is positioned in the immediate vicinity of and parallel to the fold line 333. At the same time, each linear joining unit 5 does not overlap with the fold line 333. This means that each linear joining unit 5 is located just before reaching the fold line (edge) 333. In other words, each linear joining unit 5 is spaced apart from the fold line 333. This prevents the gathered sheet 32 ​​from hardening by welding at the fold line (edge) 333 and improves the feel of the gathers 34. In particular, it is possible to improve the feel when the ends of the gathers 34 come into contact with the fold. The distance between the fold line 333 and the first elastic element 3221 can preferably be less than or equal to 5 mm and more preferably less than or equal to 3 mm.

[0079] Each linear joining unit 5 intersects with the first elastic element 3221, the second elastic element 3222 and the third elastic element 3223. Referring to Fig. 9, the position of the intersection between each linear joining unit 5 and the first elastic element 3221 is referred to as the "first intersection position 511," the position of the intersection between each linear joining unit 5 and the second elastic element 3222 is referred to as the "second intersection position 512," and the position of the intersection between each linear joining unit 5 and the third elastic element 3223 is referred to as the "third intersection position 513." The joint width of each linear joining unit 5 at the first intersection position 511 is larger than the joint width of the linear joining unit 5 at any position between the first intersection position 511 and the second intersection position 512.The joining width of each linear joining unit 5 at the second intersection position 512 is larger than the joining width of the linear joining unit 5 at any position between the first intersection position 511 and the second intersection position 512, and is also larger than the joining width of the linear joining unit 5 at any position between the second intersection position 512 and the third intersection position 513. The joining width of each linear joining unit 5 at the third intersection position 513 is larger than the joining width of the linear joining unit 5 at any position between the second intersection position 512 and the third intersection position 513.

[0080] The term "joining width" can be defined in various ways as long as the width of each linear joining unit 5 is approximately determined. For example, the joining width can be defined as the width (length) of the linear joining unit 5 cut along a straight line parallel to the stretching direction. The joining width can also be defined as the width (length) of the linear joining unit 5 cut along a straight line perpendicular to the linear joining direction. The joining width at a position between two adjacent intersection positions is smaller than the joining widths at the intersection positions. In other words, the joining widths of the linear joining units 5 at the intersection positions are relatively large.

[0081] When the joining widths at positions other than the intersection positions are relatively reduced, the gathers 34 have large ridges and grooves formed at regular intervals (compared with the case where the linear joining unit 5 is thickened as a whole). Meanwhile, the first elastic member 3221, the second elastic member 3222, and the third elastic member 3223 can be firmly and fixedly attached to the inner sheet 331 and the outer sheet 332 at the intersection positions.

[0082] Strictly speaking, the elastic members at the overlapping positions are firmly fixed to the inner sheet 331 and the outer sheet 332 without being cut by heat. To achieve such fixing, the inner sheet 331 and the outer sheet 332 are welded together on both sides of the elastic members in the width direction, with the inner sheet 331 and the elastic members only slightly welded together, and the outer sheet 332 and the elastic members also only slightly welded together. To achieve such welding, grooves are formed in the protrusions of the embossing roller used in the welding to bypass the elastic members.Accordingly, for example, the inner sheet 331 and the elastic members are lightly welded together, and the outer sheet 332 and the elastic member on both sides of the elastic members are lightly welded together in the width direction. Alternatively, while the elastic members are sandwiched between the inner sheet 331 and the outer sheet 332 under slight pressure, heat may be applied to weld the elastic members to the inner sheet 331 and / or the outer sheet 332.

[0083] In the gathers 34, each linear joining unit 5 is inclined relative to the direction perpendicular to the stretching direction between the first elastic element 3221 and the second elastic element 3222, as well as between the second elastic element 3222 and the third elastic element 3223. This allows the gathers 34 to deform slightly when they come into contact with the skin. In this way, the wearing comfort of the absorbent product 1 can be improved.

[0084] In the Fig. 7, while the inner sheet 331 and the outer sheet 332 are stretched flat in the stretching direction, the edge 333 of the inner sheet 331 and the outer sheet 332 is located along and in close proximity to the first elastic member 3221 on the side of the first elastic member 3221 opposite to the second elastic member 3222. That is, the edge 333 of the gather sheet 32, the first elastic member 3221, the second elastic member 3222 and the third elastic member 3223 are positioned outward in the width direction in this order. The distance between the first elastic element 3221 and the second elastic element 3222 is greater than the distance between the second elastic element 3222 and the third elastic element 3223. This allows the gathers 34 to be arranged at the end side of the gathers 34, ieon the side of the first elastic element 3221, slightly deform, and wearing comfort is improved. This also allows for increased rigidity of the gather 34 on the root side of the gather 34, i.e., on the side of the third elastic element 3223, and thus a stable stand of the gather 34 (the same also applies to the . Fig. 11 to 14 and other variants described later).

[0085] As indicated by reference numerals 52 in Fig. 9, an existence area 52 of each linear joining unit 5 in the stretching direction partially overlaps with an existence area 52 of a linear joining unit 5 which is adjacent to the above linear joining unit 5 in the stretching direction, while the inner sheet 331 and the outer sheet 332 are stretched flat in the stretching direction (the same also applies to the Fig. 11 to 14 and other variants described later). Even in the case where the linear joining units 5 are assumed only between the first elastic member 3221 and the third elastic member 3223, the above-mentioned existence ranges of adjacent linear joining units 5 overlap each other. This suppresses fluctuations in the line pressure caused in the embossing roller during welding with the embossing roller, and accordingly reduces fluctuations in the strength of the welds and the occurrence of perforation during welding. Furthermore, wear of the protrusions of the embossing roller is suppressed, and the service life of the embossing roller is improved.

[0086] Fig. 11 is a diagram showing another example of the linear joining units 5 and three linear joining units 5 as in Fig. 9 shows. The linear joining units 5 in Fig. 11 are discontinuous between the first elastic element 3221 and the second elastic element 3222, and are also discontinuous between the second elastic element 3222 and the third elastic element 3223. Thus, the linear joining units 5 do not necessarily have to be continuous between the elastic elements. The other structure of the linear joining units 5 in Fig. 11 is similar to Fig. 9. This means that the joining width of each linear joining unit 5 at the first intersection position 511 is greater than the joining width of the linear joining unit 5 at any position between the first intersection position 511 and the second intersection position 512. The joining width of each linear joining unit 5 at the second intersection position 512 is greater than the joining width of the linear joining unit 5 at any position between the first intersection position 511 and the second intersection position 511, and is also greater than the joining width of the linear joining unit 5 at any position between the second intersection position 512 and the third intersection position 513.The joining width of each linear joining unit 5 at the third intersection position 513 is larger than the joining width of the linear joining unit 5 at any position between the second intersection position 512 and the third intersection position 513. The same also applies to those described below. Fig. 13 and Fig. 14.

[0087] The linear joining units 5 are linear. In the gathers 34, each linear joining unit 5 is inclined relative to the direction perpendicular to the stretching direction between the first elastic element 3221 and the second elastic element 3222 and between the second elastic element 3222 and the third elastic element 3223. The description of the linear joining units 5 in Fig. 9 is also on the Fig. 11 is applicable, except that the linear joining units 5 are continuous between the first elastic element 3221 and the third elastic element 3223.

[0088] Fig. 12 is a diagram showing another example of the linear joining units 5 and showing three linear joining units 5 as shown in Fig. 9. The linear joining units 5 in Fig. 12 have a constant joining width between the first elastic element 3221 and the third elastic element 3223. This means that the joining widths at the first intersection position 511, the second intersection position 512, and the third intersection position 513 are the same as the joining width at any position between the first intersection position 511 and the second intersection position 512, and are also the same as the joining width at any position between the third intersection position 513 and the second intersection position 512. The linear joining units 5 can have a constant joining width as long as the distances between the linear joining units 5 are large enough to form sufficiently large ridges and grooves. The description of the linear joining units 5 in Fig. 9 also applies to the Fig. 12, with the exception that the linear joining units 5 have a constant joining width.

[0089] Fig. 13 is a diagram showing another example of the linear joining units 5 and showing three linear joining units 5 as shown in Fig. 9 shows. While the inner sheet 331 and the outer sheet 332 are stretched flat in the stretching direction, each linear joining unit 5 is in Fig. 13 at the position of the second elastic element 3222, ie at the second overlap position 512. The remaining structure of the linear joining units 5 in Fig. 13 is similar to that of Fig. 9 shown linear joining units 5, and the description of the linear joining units 5 in Fig. 9 also refers to the example in Fig. 13 is applicable, except that the linear joining units 5 are bent.

[0090] Each of the linear joining units 5 in Fig. 13 exists in a first intersecting direction that intersects the stretching direction between the first elastic member 3221 and the second elastic member 3222, and exists in a second intersecting direction that intersects the stretching direction between the second elastic member 3222 and the third elastic member 3223. Since the first intersecting direction and the second intersecting direction are different directions, the linear joining units 5 are bent. Each linear joining unit 5 intersects with the first elastic member 3221, the second elastic member 3222, and the third elastic member 3223 at the first intersecting position 511, the second intersecting position 512, and the third intersecting position 513, respectively.In the gathers 34, upon shrinkage of the first elastic element 3221, the second elastic element 3222, and the third elastic element 3223, ridges and grooves are formed, which are bent between each pair of adjacent linear joining units 5. The gathers 34 are composed of these ridges and grooves.

[0091] The webs and grooves that are curved can reduce the rigidity of the gathers 34. This means that the gathers 34 can be easily deformed at the second overlap position 512 when the gather sheets 32 contract to form the edge 333 (see Fig. 5) against the body. This allows the gathers 34 to rest gently against the body, thus improving the comfort of the absorbent product 1. Furthermore, the curvature of the gathers 34 ensures a large interior space within the gathers 34. Therefore, it is possible to absorb a large amount of body excretions at once.

[0092] Preferably, the first intersecting direction and the second intersecting direction described above may be opposite directions with respect to the direction perpendicular to the stretching direction. In other words, an angular direction in which each linear joining unit 5 is inclined with respect to the direction perpendicular to the stretching direction between the first elastic member 3221 and the second elastic member 3222 is opposite to an angular direction in which each linear joining unit 5 is inclined with respect to the direction perpendicular to the stretching direction between the second elastic member 3222 and the third elastic member 3223. In other words, each linear joining unit 5 has an approximately V-shape. This allows each ridge and groove to be bent like a spring, thus improving the grip of the gathers 34.

[0093] In order to allow the gathers 34 to stand up better, the extension direction of the linear joining units 5, ie the second overlap direction, can run perpendicular to the extension direction between the second elastic element 3222 and the third elastic element 3223.

[0094] Fig. 14 is a diagram showing another example of the linear joining unit 5 and three linear joining units 5 as shown in Fig. 13 shows. While the inner sheet 331 and the outer sheet 332 are stretched flat in the stretching direction, each linear joining unit 5 is in Fig. 14 at the position of the second elastic element 3222, ie at the second overlap position 512. The linear joining units 5 in Fig. 14 are discontinuous between the first elastic element 3221 and the second elastic element 3222 and also discontinuous between the second elastic element 3222 and the third elastic element 3223. The remaining structure of the linear joining units 5 in Fig. 14 is similar to Fig. 13. The description of the linear joining units 5 in Fig. 13 and the description of the linear joining units 5 in Fig. 9, which on Fig. 13 are also applicable to the Fig. 14 is applicable, except that the linear joining units 5 are discontinuous between the first elastic element 3221 and the third elastic element 3223.

[0095] Fig. Fig. 15 is a diagram showing a section through the standing gathering sheet structures 32 as another example as in Fig. 3 shows. In Fig. 15 are the elements that are related to those in Fig. 3 are identical, are provided with the same reference numerals. Each gathered surface structure 32 in Fig. 15 extends from the inner side of the central joining region 41 in the width direction to the outer side in the width direction and then to the inner side in the width direction via the third elastic member 3223 and the second elastic member 3222. The first elastic member 3221 is arranged near the inner end of the gathered sheet 32 ​​in the width direction. In this way, the gathers 34 can be erected in the width direction, first toward the outer side and then toward the inner side. This increases the interior space of the gathers 34.

[0096] Fig. Fig. 16 is a diagram showing a section through the standing gathering sheet structures 32 as another example as in Fig. 3 shows. In Fig. 16 are the elements that are related to those in Fig. 3 are identical, are provided with the same reference numerals. Each gathered surface structure 32 in Fig. 16 is erected from the inside of the central joining region 41 in the width direction to the inside in the width direction and stands up via the third elastic element 3223 and the second elastic element 3222 in the width direction to the outside and then to the inside. The first elastic element 3221 is arranged near the inner end of the gathered sheet 32 ​​in the width direction. In this way, the gathers 34 can be erected in the width direction once to the inside and then to the outside and then to the inside. This increases the interior space of the gathers 34. Since the Fig. 15 and Fig. 16 shown gathers 32 have the gathers 34 which are curved in section, it is advantageous to use the linear joining units 5 which are arranged as in Fig. 13 or Fig. 14 are bent.

[0097] The structure and application of the gathered sheets 32 can be modified in various ways. The stretchable sheet structure of the gathered sheets 32 can be used at various locations other than the gathers 34 of the absorbent product 1 that come into contact with a person's groin. In the above description, the stretchable sheet structure is a structure formed by the inner sheet 331, the outer sheet 332, the elastic members, and the linear joining units 5, and is a structure that stretches in a stretching direction with a stretching force applied thereto and shrinks when the stretching force is released. The gathers 34 can be regarded as the stretchable sheet structure itself or considered as included in the stretchable sheet structure.An object containing the stretchable sheet structure may be referred to as a "stretchable sheet object." The gathers 34 and the gathered sheets 32 in the above description also serve as stretchable sheet objects.

[0098] The absorbent product having the above-described stretchable sheet structure is not limited to an additional absorbent pad and can be a pants-type disposable diaper, an open-type disposable diaper that is wrapped around the waist with ties, an additional absorbent pad disposed within a diaper or diaper-shaped cover, a urine pad, or any other absorbent product that absorbs the wearer's body excreta. For example, the stretchable sheet structure can be used as a structure that forms gathers around the waist of a disposable diaper or as a structure that forms gathers around the legs of the disposable diaper.In this way, the above-described inner sheet 331 and outer sheet 332, which include the elastic elements, can serve as sheets for use in other applications. These sheets, which include the elastic elements in the stretchable sheet structure, can be generally referred to as "first sheet" and "second sheet." The number of elastic elements is also not limited to three, but is at least two, but may be four or more.That is, the stretchable sheet structure comprises at least the first sheet, the second sheet overlying the first sheet, the first elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction, and the second elastic member positioned between the first sheet and the second sheet and extending linearly in the stretching direction while being spaced apart from the first elastic member.

[0099] The first sheet and the second sheet do not necessarily have to be made by gathering a single sheet; they can also be separate sheets. The first sheet and the second sheet can be made of the same material or different materials. The first sheet and the second sheet are not limited to nonwovens. They can also be plastic films or sheets made of other materials that may have an affinity for water or hydrophobic properties.

[0100] While the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet are joined together by a plurality of linear joining units that are aligned in the stretching direction. Like the linear joining units 5, which are shown, for example, in the Fig. 9 and 11 to 14, the shape of the linear joining units can be linear or curved. Each linear joining unit can be bent or curved at two or more points. For example, each linear joining unit can have an approximately horizontally oriented C-shape or an approximately horizontally oriented S-shape. The linear joining units do not necessarily have to have exactly the same shape. For example, the shapes of the linear joining units can gradually change in the stretching direction. In this way, although each of the linear joining units exists in the direction that intersects with the stretching direction between the first elastic member and the second elastic member, the intersection direction does not necessarily have to be constant as long as it does not become parallel to the stretching direction.

[0101] As described in the Fig. 9 and 11 to 14, the direction of intersection is inclined with respect to the direction perpendicular to the stretching direction. Accordingly, it is possible to provide a stretchable sheet structure that has adequate rigidity and at the same time forms gathers with ordered ridges and grooves. The direction of cooperation, ie, the direction of extension of the linear joining units, may preferably be inclined at an angle of greater than or equal to 3 degrees and less than or equal to 25 degrees with respect to the width direction, and further preferably at an angle of greater than or equal to 5 degrees and less than or equal to 20 degrees. When the direction of intersection changes in the width direction, the direction of extension of the linear joining units may include a portion that is parallel to the width direction. In the case where the linear joining units are as shown in the Fig. 13 and Fig. 14 are bent, it is preferable that the inclination angle of the extension direction of each linear joining unit with respect to the width direction between the first elastic member on the end side and the second elastic member is larger than the inclination angle of the extension direction of the linear joining unit with respect to the width direction between the second elastic member and the third elastic member (which are not on the end side) so that the linear joining units on the end side of the gathers can be easily bent.In this case, the inclination angle of the extension direction of each linear joining unit with respect to the width direction between the first elastic member and the second elastic member may be on the same side as the inclination angle of the extension direction of the linear joining unit with respect to the width direction between the second elastic member and the third elastic member or on a side different therefrom.

[0102] The phrase "while the first sheet and the second sheet are stretched flat in the stretch direction" refers to a state in which the stretchable sheet structure is stretched until the ridges and grooves of the gathers disappear. In this state, each elastic element is in a stretched state.

[0103] As previously described, the number of elastic elements contained in the stretchable sheet structure is at least two. Therefore, if two elastic elements are at the center and are generally referred to as “first elastic element” and “second elastic element” respectively (of course, these elastic elements are not limited to the Fig. 3), the first sheet or the second sheet has bulges between the linear joining units to form the gathers as the first elastic member and the second elastic member contract. The term "bulges" as used herein refers to the case where the sheets are bent outward to form the ridges and grooves, and may refer, for example, to the case where a part of the first sheet or a part of the second sheet is spaced from the surface including the linear joining units. It is noted that both the first sheet and the second sheet may have bulges between the linear joining units.At least one of the first and second sheet structures between the linear joining units does not necessarily have to have “perfect” bulges between the linear joining units, but may also have significant bulges between the linear joining units.

[0104] With respect to the first elastic member and the second elastic member, as described above, it is preferable that the joining width of each linear joining unit at the first intersection position between the linear joining unit and the first elastic member and the joining width of the linear joining unit at the second intersection position between the linear joining unit and the second elastic member be larger than the joining width of the linear joining unit at any position between the first intersection position and the second intersection position. As described above, the term "joining width" can be defined variously as long as the width of the linear joining units is appropriately determined.By increasing the joining width at the overlapping positions, the flexibility of the gathers can be ensured while maintaining the stability of the connections between the first and second fabrics and the first and second elastic elements. By increasing the joining width only at the overlapping positions, it is possible to achieve cushioning properties of the gathers without excessively increasing the stiffness of the gathers, thereby creating gathers that are comfortable to the touch. This makes it possible to create a stretchable fabric structure that has appropriate stiffness while forming gathers with orderly ridges and grooves.

[0105] Preferably, the joint widths at the first and second intersection positions are 5 times or more and 12 times or less of the joint width at any position between the first intersection position and the second intersection position, and more preferably 7 times or more and 10 times or less of the joint width at any position between the first and second intersection positions. This facilitates the formation of sufficiently large ridges and grooves.

[0106] The techniques for ensuring the flexibility of the gathers, namely the technique of inclining the linear joining units with respect to the direction perpendicular to the stretching direction and the technique of increasing the joining width of the linear joining units at the intersection positions of the linear joining units and the elastic elements, are independent techniques, and there is no need to always apply both techniques to the stretchable sheet structure.

[0107] Each linear joining unit intersects with the first elastic element and the second elastic element at the first intersection position and the second intersection position, respectively. As previously described, the first sheet and the second sheet are not fully connected at the intersection points with the elastic elements due to the engagement of the elastic elements. This means that the "intersection point" of the linear joining units and the elastic elements refers to a conceptual intersection point of the linear joining units and the elastic elements, and not an overlap of the joining areas of the first and second sheets with the elastic elements. As previously described, the linear joining units can be continuous in the aforementioned intersection direction or discontinuous.If the gathers are to be given a certain degree of rigidity, it is preferable for the linear joining units between the elastic elements to be continuous. This prevents, for example, the leakage of bodily excretions such as urine when the gathers come into contact with the groin. The linear joining units refer to the joining areas that contribute to the formation of the ridges and grooves. In the . Fig. In the examples shown in Figures 9 and 11 to 14, the linear joining units primarily refer to the joining regions between the first elastic element 3221 and the third elastic element 3223, as well as to the joining regions between the inner sheet 331 and the outer sheet 332, but may also include the regions 501 and 502. At least the joining regions between adjacent elastic elements are considered linear joining units.

[0108] At the linear joining units, the first sheet and the second sheet are preferably joined by welding. However, an adhesive can also be used to join the sheets together, or welding and an adhesive can be used in combination to join the sheets together. When joined by welding, the first and second sheets are preferably water-repellent or liquid-impermeable hydrophobic fabrics formed from hydrophobic fibers. The first sheet and the second sheet can be formed, for example, from materials of the same type or from different types, selected, for example, from a spunbonded nonwoven, a meltblown nonwoven, or an SMS nonwoven.The use of welding enables reliable formation of the ridges and grooves and stable formation of attractive gathers with evenly aligned ridges and grooves in the stretch direction. Furthermore, the stable formation of the ridges and grooves reduces the possibility of the elastic elements or the linear joining units (i.e., the welded areas) coming into contact with the skin, thus improving the feel of the gathers.

[0109] In the case where the number of elastic elements, as in the Fig. 9 and 11 to 14, is three, and in which these elastic elements are generally referred to as “first elastic element”, “second elastic element” and “third elastic element” (of course, these elastic elements are not limited to the first elastic element 3221, the second elastic element 3222 and the third elastic element 3223 shown in Fig.3), the above description focusing on the first elastic member and the second elastic member is also applicable to the description of the second elastic member and the third elastic member. This means that each of the linear joining units exists in a direction intersecting with the stretching direction between the second elastic member and the third elastic member, and each linear joining unit intersects with the second elastic member and the third elastic member. Then, as the first elastic member, the second elastic member, and the third elastic member shrink, ridges and grooves are formed between adjacent ones of the linear joining units to form the gathers.

[0110] Preferably, the joining width of each linear joining unit at the second intersection position of the linear joining unit and the second elastic element and the joining width of the linear joining unit at the third intersection position of the linear joining unit and the third elastic element are larger than the joining width of the linear joining unit at any position between the second intersection position and the third intersection position. The other descriptions described above, which focus on the first elastic element and the second elastic element, also apply to the descriptions about the second elastic element and the third elastic element.

[0111] The stretchable fabric structure described above can also be used in products other than absorbent products. The stretchable fabric structure can be used in various products where an orderly formation of gathers is desired.

[0112] The configurations of the preferred embodiment and variations described above can be combined as appropriate as long as there are no mutual contradictions.

[0113] While the invention has been particularly shown and described, the foregoing description is in all respects exemplary and not restrictive. It is therefore recognized that numerous modifications and variations may be devised without departing from the scope of the invention. LIST OF REFERENCE SYMBOLS 1 absorbent product 5 linear joining unit 34 gathers 331 Inner surface structure (first surface structure) 332 Outer surface structure (second surface structure) 333 Margin (fold line) 511 First overlap position 512 Second overlap position 3221 First elastic element 3222 Second elastic element 3223 Third elastic element QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-049269

[0002] JP 2022-071690

[0002] JP 4-71922

[0004] JP 2005-212405

[0005] WO 2018 / 070158

[0005]

Claims

[1] A stretchable sheet structure which stretches in a stretching direction with a stretching force applied thereto and which shrinks when the stretching force is released, comprising: a first surface structure; a second sheet superimposed over the first sheet; a first elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction; and a second elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the first elastic element, wherein, while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet are joined to each other by a plurality of linear joining units aligned in the stretching direction, each linear joining unit overlaps with the first elastic element and the second elastic element, a joining width of each linear joining unit at a first intersection position of each linear joining unit and the first elastic element and a joining width of each linear joining unit at a second intersection position of each linear joining unit and the second elastic element are greater than a joining width of each linear joining unit at any position between the first intersection position and the second intersection position, and while the first elastic element and the second elastic element shrink, the first sheet or the second sheet has bulges between the plurality of linear joining units to form gathers. [2] A stretchable sheet structure which stretches in a stretching direction with a stretching force applied thereto and which shrinks when the stretching force is released, comprising: a first surface structure; a second sheet superimposed over the first sheet; a first elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction; and a second elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the first elastic element, wherein, while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet are joined to each other by a plurality of linear joining units aligned in the stretching direction, each of the plurality of linear joining units is provided in an intersecting direction intersecting with the stretching direction between the first elastic member and the second elastic member, the intersecting direction being inclined with respect to a direction perpendicular to the stretching direction, each linear joining unit intersects with the first elastic element and the second elastic element, and while the first elastic element and the second elastic element shrink, the first sheet or the second sheet has bulges between the plurality of linear joining units to form gathers. [3] The stretchable sheet structure according to claim 2, wherein a joining width of each linear joining unit at a first intersection position of each linear joining unit and the first elastic member and a joining width of each linear joining unit at a second intersection position of each linear joining unit and the second elastic member are larger than a joining width of each linear joining unit at any position between the first intersection position and the second intersection position. [4] The stretchable sheet structure according to any one of claims 1 to 3, wherein each of the plurality of linear joining units is continuously provided in an intersecting direction intersecting with the stretching direction between the first elastic member and the second elastic member. [5] A stretchable sheet structure according to any one of claims 1 to 4, wherein the first sheet and the second sheet are joined together at each linear joining unit by welding. [6] Stretchable sheet structure according to one of claims 1 to 5, wherein the first sheet and the second sheet are a single sheet folded along a fold line, wherein the first sheet and the second sheet are stretched flat in the stretching direction, the first elastic element is positioned in close proximity to and parallel to the fold line, and each linear joining unit does not overlap with the fold line. [7] Stretchable sheet structure according to one of claims 1 to 6, further comprising: a third elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the second elastic element on a side of the second elastic element opposite the first elastic element, wherein each of the plurality of linear joining units is provided in an intersecting direction intersecting with the stretching direction between the second elastic member and the third elastic member, each linear joining unit overlaps with the third elastic element, the gathers are formed while the first elastic element, the second elastic element and the third elastic element shrink, and each linear joining unit is linear, while the first sheet and the second sheet are stretched flat in the stretching direction. [8] Stretchable sheet structure according to one of claims 1 to 6, further comprising: a third elastic element positioned between the first sheet and the second sheet and extending linearly in the stretching direction, being spaced from the second elastic element on a side of the second elastic element opposite the first elastic element, wherein each of the plurality of linear joining units is provided in an intersecting direction intersecting with the stretching direction between the second elastic member and the third elastic member, each linear joining unit overlaps with the third elastic element, the gathers are formed while the first elastic element, the second elastic element and the third elastic element shrink, and while the first sheet and the second sheet are stretched flat in the stretching direction, each linear joining unit is bent at a position of the second elastic element. [9] The stretchable sheet structure according to claim 8, wherein an angular direction in which each linear joining unit is inclined with respect to the direction perpendicular to the stretching direction between the first elastic member and the second elastic member is opposite to an angular direction in which each linear joining unit is inclined with respect to the direction perpendicular to the stretching direction between the second elastic member and the third elastic member. [10] Stretchable sheet structure according to claim 7, wherein while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet have an edge which is present along and in the immediate vicinity of the first elastic element on a side of the first elastic element opposite the second elastic element, and a distance between the first elastic element and the second elastic element is greater than a distance between the second elastic element and the third elastic element. [11] Stretchable sheet structure according to claim 8 or 9, wherein while the first sheet and the second sheet are stretched flat in the stretching direction, the first sheet and the second sheet have an edge which is present along and in the immediate vicinity of the first elastic element on a side of the first elastic element opposite the second elastic element, and a distance between the first elastic element and the second elastic element is greater than a distance between the second elastic element and the third elastic element. [12] A stretchable sheet structure according to any one of claims 1 to 11, wherein while the first sheet and the second sheet are stretched flat in the stretching direction, a region of existence of each linear joining unit in the stretching direction partially overlaps with a region of existence of another linear joining unit in the stretching direction, the other linear joining unit being adjacent to the respective linear joining unit. [13] A disposable absorbent product that absorbs a wearer’s body excretion, comprising: the stretchable sheet structure according to any one of claims 1 to 12. [14] The disposable absorbent product of claim 13, wherein the gathers contact a groin of the wearer.

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