Disposable undergarment and method for manufacturing disposable undergarment

A crotch member of a disposable under garment is joined to central portions of a symmetrical ventral member and a symmetrical dorsal member. A crotch side edge of the ventral member includes a recessed line symmetrically recessed toward a waist side edge between a center line and left and right end portions of the ventral member. The recessed line includes bottom portions each closest to the waist side edge located at a position closer to the left and right end portions than the center line. A crotch side edge of the dorsal member include a protruding line symmetrically protruding away from a waist side edge between a centerline and left and right end portions of the dorsal member. The protruding line includes top portions farthest away from the waist side edge located at a position closer to the centerline than the left and right end portions.

TECHNICAL FIELD

The present invention relates to a disposable undergarment, in particular, a disposable pant-type diaper or an absorbent pad holder, and a method for manufacturing a disposable undergarment.

BACKGROUND ART

A pant-type disposable undergarment includes a waist opening at the top and left and right leg openings at the bottom. A known method for continuously manufacturing such a pant-type disposable undergarment forms the leg openings by cutting out a web, that is, a material of a disposable undergarment, leading to generation of a waste material. Methods for continuously manufacturing a pant-type disposable undergarments with reduced waste of material have been proposed in several Patent Literatures.

In the method for manufacturing a pant-type disposable diaper disclosed in JP 3862510 B2, a pair of parallel leg-surrounding elastic members is joined to a stream of a sheet-like web, in a sine curve shape along the web center line. The web is cut into the sine curve shape between the pair of leg-surrounding elastic members and divided into two half-webs. The two half-webs are spaced apart in a direction orthogonal to a web flow direction. An absorbent pad member is joined to the two half-webs alternately in opposite orientations of the ventral and dorsal orientations in every half cycle in the web flow direction. The pad member is folded to allow the two half-webs to be overlaid with each other and to be joined in every half cycle in the flow direction. Both the half-webs are cut at every neighboring portion of the joint, thereby forming a disposable undergarment. Such a manufacturing method in Japanese patent Publication JP 3862510 B2 continuously manufactures the pant-type disposable undergarment with the ventral and dorsal orientations alternately reversed, and thus, takes time and effort to align the orientation of the disposable undergarment. In addition, the pant-type disposable undergarment in JP 3862510 B2 has same shapes of the entire crotch side edges of both the ventral member and the dorsal member formed by cutting the sheet member into two, making it difficult to realize both the shape appropriate for the ventral member and the shape appropriate for the dorsal member. In particular, in the pant-type disposable undergarment in JP 3862510 B2, the distance between the crotch side edge and the waist side edge of the ventral member decreases from the left and right end portions toward the center, leading to a shape different from the usual pant-type undergarment and unfamiliar with a wearer.

In the manufacturing method of the pant-type disposable undergarment disclosed in Japanese Patent Publication JP 5848502 B2, a pair of parallel leg-surrounding elastic members extending in a meandering manner in the flow direction is arranged on a first sheet along the neighborhood of the center line in a width direction, and a second sheet is overlaid thereon and joined to form a sheet member. The sheet member is cut between the pair of leg-surrounding elastic members extending in a meandering manner along the neighborhood of the center line and divided into a ventral sheet member and a dorsal sheet member. The ventral sheet member and the dorsal sheet member are spaced apart in a direction orthogonal to the flow direction. The absorbent body is joined to the ventral sheet member and the dorsal sheet member in every cycle in the flow direction. The absorbent body is folded, and the ventral sheet member and the dorsal sheet member are overlaid with each other and joined in every cycle in the flow direction and are cut at every neighboring portion of the joint. In such a manufacturing method of JP 5848502 B2, the pant-type disposable undergarment is continuously manufactured in a same orientation. In the ventral sheet member and the dorsal sheet member, however, the cut edge between the absorbent bodies joined to both sides meanders with respect to the flow direction in every cycle and the leg-surrounding elastic member along the cut edge also meanders. Therefore, when overlaying and joining the ventral sheet member and the dorsal sheet member to which the absorbent body is joined, the ventral sheet member and the dorsal sheet member might be joined in a state where positions of end portions on the cut edge side of the joint are shifted by contraction of the elastic member, leading to a problem of generating wrinkles in the joint. In addition, the pant-type disposable undergarment in JP 5848502 B2 has same shapes of the entire crotch side edges of the ventral member and the dorsal member formed by cutting the sheet member into two, making it difficult to realize both the shape appropriate for the ventral member and the shape appropriate for the dorsal member.

The method for manufacturing a pant-type disposable undergarment disclosed in WO 2005/007051 A1 is substantially the same as the method in JP 5848502 B2, except for a difference that a pair of parallel leg-surrounding elastic members extends in a meandering manner along the flow direction of the sheet member at a position deviated to one side from the center line in the width direction of the sheet member. The pant-type disposable undergarment manufactured with the method of WO 2005/007051 A1 has same shapes of the entire crotch side edges of both the ventral member and the dorsal member formed by cutting the sheet member into two, making it difficult to realize both the shape appropriate for the ventral member and the shape appropriate for the dorsal member.

SUMMARY OF INVENTION

A disposable undergarment of this application includes a ventral member, a dorsal member including left and right end portions respectively joined to left and right end portions of the ventral member and a crotch member joined to both central portions of the ventral member and the dorsal member. Each of the ventral member and the dorsal member includes an elastic body that is expandable and shrinkable at least in a left-right direction. A left half of a crotch side edge of the ventral member has a same shape as a shape of a right half of a crotch side edge of the dorsal member. Aright half of the crotch side edge of the ventral member has a same shape as a shape of a left half of the crotch side edge of the dorsal member. The left half and the right half of the crotch side edge of the ventral member are symmetrical about a center line of the ventral member. The left half and the right half of the crotch side edge of the ventral member respectively include a left recessed line and a right recessed line recessed in a direction toward a waist side edge of the ventral member, between the centerline of the ventral member and the left and right end portions. Each of the left recessed line and the right recessed line includes a bottom portion closest to the waist side edge of the ventral member, being located at a position excluding the center line and the left and right end portions, located at a position closer to the left and right end portions than the center line. The left half and the right half of the crotch side edge of the dorsal member are symmetrical about a center line of the dorsal member. The left half and the right half of the crotch side edge of the dorsal member respectively include a left protruding line and a right protruding line protruding in a direction away from a waist side edge of the dorsal member, between the center line of the dorsal member and the left and right end portions. Each of the left protruding line and the right protruding line includes a top portion farthest away from the waist side edge of the dorsal member, being located at a position excluding the center line and the left and right end portions, located at a position closer to the center line than the left and right end portions.

In a method for manufacturing a disposable undergarment according to the present invention, a laminated web is formed by joining an inner web and an outer web with each other with an expandable and shrinkable elastic body to be expanded at least in the web flow direction sandwiched between the webs. By cutting the laminated web along a cutting line continuous in the web flow direction with the crotch side edge of one of the ventral member and the dorsal member of the disposable undergarment as one cycle, the laminated web is divided into a half-web formed of continuous ventral member and a half-web formed of continuous dorsal member. One of the half-web formed of continuous ventral member or the half-web formed of continuous dorsal member is moved in a web width direction while shifted by half cycle in the web flow direction so as to allow the ventral member and the dorsal member to be spaced apart from each other and to face each other in every cycle. Each of the crotch members is joined to the ventral member and the dorsal member in every cycle of both the half-webs. Both the webs are overlaid with each other in a state where each of the crotch members is folded. The ventral member and the dorsal member in each of cycles are joined with each other at each of the left and right end portions. A disposable undergarment is formed by cutting the joined ventral member and the dorsal member in every cycle.

Further details, features, and advantages of the present invention will become apparent from the following description with reference to the drawings of preferred exemplary embodiments.

DESCRIPTION OF EMBODIMENTS

A disposable undergarment of one exemplary embodiment of the present invention will be described with reference to the drawings.FIG. 1is a front view of a disposable undergarment of one embodiment of the present invention.FIG. 2is an exploded view of the disposable undergarment illustrated inFIG. 1. The disposable undergarment illustrated inFIGS. 1 and 2illustrates a state where the elastic body is expanded without being contracted. As illustrated inFIG. 1 or 2, a disposable undergarment1according to the present embodiment is a pant-type disposable diaper. The disposable undergarment1includes a ventral member2positioned on a front side of a wearer's torso, a dorsal member3positioned on a back side of the wearer's torso, and a crotch member4joined to a central portion on an inner surface side of the ventral member2and to a central portion of an inner surface side of the dorsal member3and located at the crotch of the wearer.

The ventral member2and the dorsal member3are formed by overlaying an inner sheet positioned on a skin side of the wearer and an outer sheet positioned on a clothing side of the wearer sandwiching elastic bodies12,13,14, and15between the sheets, and by joining the sheets. The material of the inner sheet and the outer sheet is a nonwoven fabric, but not limited to this, and it is allowable to use a resin film, a tissue, a stretchable sheet, a laminate thereof, or a sheet member formed by appropriately joining these together. Furthermore, the inner sheet and the outer sheet may also be formed by folding one sheet.

The pant-type disposable undergarment1is formed by bending the crotch member4joined to the ventral member2and the dorsal member3so as to allow the ventral member2and the dorsal member3to be overlaid with each other, and joining the left and right end portions of both the members2and3. More specifically, a left joint5ais formed along left end portions2aand3aof the ventral member2and the dorsal member3, respectively, and a right joint5bis formed along right end portions2band3bof the ventral member2and the dorsal member3, respectively. The left and right joints5aand5bmay be formed by an adhesive such as a hot melt adhesive or by various sealing methods such as heat sealing and ultrasonic sealing.

A waist opening6of the disposable undergarment1is formed by being encircled by a waist side edge7at an upper end of the ventral member2and by a waist side edge8at an upper end of the dorsal member3. The left leg opening9ais formed by being encircled by a crotch side edge10at a lower end of the ventral member2, a crotch side edge11at a lower end of the dorsal member3, and a left side edge4aof the crotch member4. The right leg opening9bis formed by being encircled by the crotch side edge10of the ventral member2, the crotch end edge11of the dorsal member3, and a right side edge4bof the crotch member4.

As illustrated inFIG. 1 or 2, in a state where the ventral member2and the dorsal member3are expanded, the waist side edge7of the ventral member2and the waist side edge8of the dorsal member3have linear shapes and an equal length. The left and right end portions2aand2bof the ventral member2have linear shapes perpendicular to the waist side edge7. The left and right end portions3aand3bof the dorsal member3have linear shapes perpendicular to the waist side edge8. The lengths of the left and right end portions2aand2bof the ventral member2are equal to the lengths of the left and right end portions3aand3bof the dorsal member3, respectively. Each of the crotch side edge10of the ventral member2and the crotch side edge11of the dorsal member3has a symmetrical shape about a center line C1having a common left-right widths on the ventral member2and the dorsal member3.

As illustrated inFIG. 2, in a state where the ventral member2and the dorsal member3are separated and expanded, that is, in a state where the disposable undergarment1is developed, a left half and a right half of the crotch side edge10of the ventral member2are symmetrical about the centerline C1. The crotch side edge10includes a left end line10a, a left recessed line10b, an intermediate line10c, a right recessed line10d, and a right end line10e. The left end line10a, the intermediate line10c, and the right end line10ehave linear shapes substantially parallel to the waist side edge7. The intermediate line10cis bisected by the center line C1. The left recessed line10bis connected to the left end line10aand the intermediate line10c. The left recessed line10bhas a shape recessed in a direction toward the waist side edge7. A bottom portion10fof the left recessed line10bis a portion closest to the waist side edge7and is located more toward the left end portion2athan the center line C1of the ventral member2. The right recessed line10dis connected to the right end line10eand the intermediate line10c. The right recessed line10dhas a shape recessed in a direction toward the waist side edge7. A bottom portion10gof the right recessed line10dis a portion closest to the waist side edge7and is located more toward the right end portion2bthan the center line C1of the ventral member2.

As illustrated inFIG. 2, the left half and the right half of the crotch side edge11of the dorsal member3are symmetrical about the center line C1. The crotch side edge11includes a left end line11a, a left protruding line11b, an intermediate line11c, a right protruding line11d, and a right end line11e. The left end line11a, the intermediate line11c, and the right end line11ehave a linear shape substantially parallel to the waist side edge8. The intermediate line11cis bisected by the center line C1. The left protruding line11bis connected to the left end line11aand the intermediate line11c. The left protruding line11bhas a shape protruding in a direction away from the waist side edge8. A top portion11fof the left protruding line11bis a portion farthest away from the waist side edge8and is located more toward the center line C1than the left end portion3aof the dorsal member3. The right protruding line11dis connected to the right end line11eand the intermediate line11c. The right protruding line11dhas a shape protruding in a direction away from the waist side edge8. A top portion11gof the right protruding line11dis a portion farthest away from the waist side edge8and is located more toward the center line C1than the right end portion3bof the dorsal member3.

As illustrated inFIG. 2, the shape of a left half of the crotch side edge10bisected at the center line C1of the ventral member2is the same as the shape of the right half of the crotch side edge11bisected at the center line C1of the dorsal member3. The shapes of the left end line10a, the left protruding line10b, the bottom portion10f, and the left half of the intermediate line10cof the crotch side edge10are the same as the shapes of the right half of the intermediate line11c, the right protruding line11d, the top portion11g, and the right end line11eof the crotch side edge11, respectively. In short, when the left half of the crotch side edge10of the ventral member2is moved in the left-right direction and in an approaching direction to abut the right half of the crotch side edge11of the dorsal member3, the shapes of both portions match.

As illustrated inFIG. 2, the shape of a right half of the crotch side edge10bisected at the center line C1of the ventral member2is the same as the shape of the left half of the crotch side edge11bisected at the center line C1of the dorsal member3. The shapes of the right end line10e, the right protruding line10d, the bottom portion10g, and the right half of the intermediate line10cof the crotch side edge10are the same as the shapes of the left half of the intermediate line11c, the left protruding line11b, the top portion11f, and the left end line11aof the crotch side edge11, respectively. In short, when the right half of the crotch side edge10of the ventral member2is moved in the left-right direction and in an approaching direction to abut against the left half of the crotch side edge11of the dorsal member3, the shapes of both portions match.

In the ventral member2of the disposable undergarment1, the left and right bottom portions10fand10ghaving the shortest distance between the waist side edge7and the crotch side edge10are located at positions more toward the left and right end portions2aand2b, respectively, than the center line C1of the ventral member2. This configuration makes it possible to increase the left-right width of a downward protrusion between the left and right bottom portions10fand10gof the ventral member2, leading to an increase in the left-right width of a region to cover the wearer's groin and periphery thereof on the ventral member2. In this manner, the disposable undergarment1can form the ventral member2into an appropriate shape.

Furthermore, in the disposable undergarment1, the distance between the waist side edge7and the crotch side edge10of the ventral member2is longer at a position of the center line C1of the ventral member2than at the position of the left and right end portions2aand2bof the ventral member2. This makes it possible to also increase a top-bottom length of the downward protrusion at the center of the ventral member2. In this manner, the disposable undergarment1can realize an appropriate shape of the ventral member2with the increased left-right width and the top-bottom length of the region to cover the wearer's groin and periphery thereof.

The dorsal member3of the disposable undergarment1is configured such that the left and right protruding lines11band11dcontinuous respectively to the left and right end lines11aand11eprotrude in a direction away from the waist side edge8, making it possible to increase the left-right width of the downward protrusion of the dorsal member3. Moreover, in the dorsal member3, the top portions11fand11ghaving the longest distance between the waist side edge8and the crotch side edge11are respectively located more toward the center line C1than the left and right end portions3aand3bof the dorsal member3. This configuration makes it possible to locate the top portions11fand11gof the downward protrusion of the dorsal member3near the central portion of the dorsal member3to which the crotch member4has been joined. The recessed shape of the intermediate line11cof the dorsal member3would be no problem since the central portion of the dorsal member3is covered with the crotch member4. In this manner, the disposable undergarment1makes it possible to realize an appropriate shape of the dorsal member3with the increased left-right width and the top-bottom length of the portion to cover the buttock of the wearer.

Furthermore, in the disposable undergarment1, the crotch member4overlaps with a portion of the top portions11fand11g, which are portions respectively farthest away from the waist side edge8of the left and right protruding lines11band11dof the crotch side edge11of the dorsal member3. This configuration suppress generation of a recess in a boundary between the crotch member4and the dorsal member3, making it possible to realize an appropriate shape of the dorsal member3, capable of further enhancing prevention of leakage of wastes, or the like.

Furthermore, in the disposable undergarment1forms the depth of the recess from the top portions11fand11gof the crotch side edge11of the dorsal member3to the intermediate line11cto be greatly smaller than a height of the protrusion from the left and right end portions3aand3bof the dorsal member3to the top portions11fand11g. This makes it possible to reduce the size of the recess in the central portion of the dorsal member3and achieve better appearance. Moreover, since the recess in the central portion of the dorsal member3is small, it is relatively easy to bond the crotch member4to the central portion of the dorsal member3.

As illustrated inFIGS. 1 and 2, the ventral member2and the dorsal member3each includes waist-fitting elastic bodies12aand12band body-fitting elastic bodies13aand13bconfigured to stretch and contract in the left-right direction. Moreover, the ventral member2includes a leg-fitting elastic body14and a portion of a leg-fitting elastic body15. The dorsal member3includes a portion of the leg-fitting elastic body15. With the presence of these elastic bodies, the ventral member2and the dorsal member3have regions that stretch and contract.

The waist-fitting elastic body12ais arranged over substantially the entire region from the left end portion2ato the right end portion2bin the waist side edge7and adjacent regions of the ventral member2, and is joined in an expanded state, to the ventral member2. The waist-fitting elastic body12bis arranged over substantially the entire region from the left end portion3ato the right end portion3bin the waist side edge8and adjacent regions of the dorsal member3, and is joined in an expanded state, to the dorsal member3. Although not illustrated, since the waist-fitting elastic bodies12aand12bare contracted in the disposable undergarment1that is placed at rest, waist gathers are formed in a region where the waist-fitting elastic bodies12aand12bof the ventral member2and the dorsal member3are joined. The waist gathers suitably allow the waist opening6of the disposable undergarment1to come in close contact with the wearer to prevent the falling down of the diaper1and the leakage of wastes, or the like, from the waist opening6.

The body-fitting elastic body13ais arranged over substantially the entire area from the left end portion2ato the right end portion2b, in the adjacent region on the crotch side edge10side from the region where the waist-fitting elastic body12aof the ventral member2is joined, and is joined in an expanded state, to the ventral member2. The body-fitting elastic body13bis arranged over substantially the entire area from the left end portion3ato the right end portion3bin the adjacent region on the crotch side edge11side from the region where the waist-fitting elastic body12bof the dorsal member3is joined, and is joined in an expanded state, to the dorsal member3. Although not illustrated, since the body-fitting elastic bodies13aand13bare contracted in the disposable undergarment1that is placed at rest, body-fitting gathers are formed in a region where the body-fitting elastic bodies13aand13bof the ventral member2and the dorsal member3are joined. The body-fitting gathers suitably allow the ventral member2and the dorsal member3of the disposable undergarment1to come into close contact with the wearer, increases the fitness, and prevents leakage of wastes, or the like.

The leg-fitting elastic body14is arranged in a meandering manner so as to extend along the intermediate line10cand the left and right recessed lines10band10dof the crotch side edge10of the ventral member2, rise diagonally away from the crotch side edge10from the front of the bottom portions10fand10g, and extend to the left and right end portions2aand2bof the ventral member2along the upper portion in the region of the body-fitting elastic body13a, and is joined to the ventral member2in an expanded state. The leg-fitting elastic body15includes: a portion15aextending along the left end line11aand the left protruding line11bof the crotch side edge11of the dorsal member3and intersecting the top portion11f; a portion15bextending along the right end line11eand the right protruding line11dof the crotch side edge11of the dorsal member3and intersecting the top portion11g; and left and right portions15cand15dextending being spaced apart in parallel with each other below the leg-fitting elastic body14in the ventral member2. Although not illustrated, since the leg-fitting elastic bodies14and15are contracted in the disposable undergarment1that is placed at rest, leg gathers are formed in the region where the leg-fitting elastic body14is joined around the crotch side edge10of the ventral member2and in the region where the leg-fitting elastic body15is joined around the crotch side edge11of the dorsal member3. The leg gathers suitably allow the left and right leg openings9aand9bof the disposable undergarment1to come into close contact with the wearer, and prevents the leakage of wastes, or the like, from the leg openings9aand9b.

The waist-fitting elastic bodies12aand12b, the body-fitting elastic bodies13aand13b, and the leg-fitting elastic bodies14and15are formed with a group of a plurality of thread-like elastic bodies. Each of the thread-like elastic bodies is formed of a stretchable material such as natural rubber, polyurethane resin, and stretchable hot melt. The elastic bodies12,13,14, and15are not limited to thread-like elastic bodies, but may be band-like elastic bodies or sheet-like elastic bodies. In addition, by forming the ventral member2and/or the dorsal member3as a whole with a material such as a stretchable sheet, the ventral member2and/or the dorsal member3may have stretchable regions. In the case of using a sheet-like elastic body or forming the entire ventral member2or the dorsal member3as a whole of a material such as a stretchable sheet, processing is performed so as to allow a desired tension to act in a direction similar to each of the elastic bodies12,13,14, and15.

InFIG. 2, the elastic bodies12and13, and/or14arranged in a region of the ventral member2and/or the dorsal member3overlaid with the crotch member4may be processed to reduce the tension of the elastic body. This processing results in suppression of deformation or contraction of the crotch member4by the tension of the elastic body. As processing of reducing the tension of the elastic body, for example, it is possible to appropriately select, for example, finely dividing the elastic body with a large number of protrusions, a cutter blade or the like, finely heat sealing the elastic body, or the like.

As illustrated inFIG. 2, the crotch member4has a substantially rectangular shape, and the overlaid portion of the crotch member4and the ventral member2and the overlaid portion of the crotch member4and the dorsal member3are individually joined by an adhesive, or the like. Each of the end edges of the crotch member4in the longitudinal direction is located in the neighborhood of the boundary between the regions of the waist-fitting elastic bodies12aand12bof the ventral member2or the dorsal member3and the regions of the body-fitting elastic bodies13aand13b. Note that the shape of the crotch member4is not limited to a substantially rectangular shape, and may be a band-like shape in which both end edges in the longitudinal direction are curved. The position and the size of the portion overlaid and joined to the ventral member2or the dorsal member3of the crotch member4are not limited to those described above and may be appropriately changed in accordance with the size and shape of the disposable undergarment.

FIG. 3is a schematic cross-sectional view taken along line III-III of the crotch member4illustrated inFIG. 2. As illustrated inFIG. 2 or 3, the crotch member4includes a top sheet21, an absorbent body22, a back sheet23, left and right gathered sheets24and24, a three-dimensional gathered elastic body25, a crotch elastic body26, and a cover sheet27. The top sheet21is formed of a liquid permeable material such as a nonwoven fabric and is positioned on the wearer's skin side and covers the entire top surface of the absorbent body22so as to transmit urine, blood, or the like. The absorbent body22is formed by combining absorbent paper, cotton-like pulp, particulate or fibrous polymeric absorbent, or the like, and absorbs urine, blood, or the like, that have permeated through the top sheet21, so as to be held inside the absorbent body22. The absorbent body22has an hourglass shape, and a dorsal wide portion of the absorbent body22has an area larger than a ventral wide portion. The shape and size of the absorbent body22are not limited to those described above and may be appropriately selected according to the size and shape of the disposable undergarment. The back sheet23is formed of a liquid impermeable material such as a polyethylene film and covers the entire lower surface of the absorbent body22, and prevents wastes, blood, or the like, from leaking to the outside.

The left and right gathered sheets24and24are formed of a nonwoven fabric, a material obtained by bonding a polyethylene film, or the like, onto a nonwoven fabric, and both open end portions of the folded sheet are joined to the left and right sides of the back sheet23. The three-dimensional gathered elastic body25is joined to the inside of the folded back portion of the gathered sheets24and24in a state of being expanded in the longitudinal direction of the crotch member4. This configuration forms three-dimensional gathers on the left and right sides of the crotch member4, leading to prevention of leakage of wastes, or the like, from the crotch member4. While the present embodiment is an exemplary case of providing three three-dimensional gathered elastic bodies25on each of the left and right sides, the number is not limited thereto.

The crotch elastic bodies26and26are joined to the base positions where the left and right gathered sheets24and24stand, in a state of being expanded in the longitudinal direction of the crotch member4. The crotch elastic bodies26and26are arranged in the vicinity of both left and right ends of the absorbent body22. When the weight of the interior of the crotch member4increases due to wastes, the left and right end portions of the crotch member4are pulled up by the tension of the crotch elastic bodies26and26so as to prevent a generation of a gap between the crotch member4and the wearer. Furthermore, since the crotch elastic bodies26and26are localized along the groin of the wearer, the crotch member4can be brought into close contact with the crotch of the wearer, leading to achievement of good fitness and leak-proofness. Note that while the crotch elastic body26according to the present embodiment is arranged one by one linearly along the left and right ends of the crotch member4, it is not limited to this, but a plurality of crotch elastic bodies may be arranged, or may be arranged in a curved line.

Similarly to the elastic bodies12,13,14, and15, the three-dimensional gathered elastic body25and the crotch elastic body26are formed of stretchable thread-like materials such as natural rubber, polyurethane resin, and stretchable hot melt. Moreover, the elastic bodies25and26are not limited to thread-like elastic bodies, but may be band-like elastic bodies or sheet-like elastic bodies. Moreover, the entire gathered sheet24may be formed of a material such as a stretchable sheet. In the case of using a sheet-like elastic body or forming the entire gathered sheet24as a whole of a material such as a stretchable sheet, processing is performed so as to allow a desired tension to act at a position or in a direction which each of the elastic bodies25and26is extending, illustrated inFIGS. 2 and 3.

The cover sheet27is arranged in the outermost layer of the crotch member4and covers a boundary of each of the joint between the back sheet23and each of the left and right gathered sheets24and24. A material such as a nonwoven fabric same as the material of the outer sheet of the ventral member2and the dorsal member3or the gathered sheet24may be used for the outside (clothing side of the wearer) of the cover sheet27. The use of the same nonwoven fabric makes it possible to unify the appearance and texture of the entire disposable undergarment1. Note that the back sheet23may be arranged on the outermost layer of the crotch member4without providing the cover sheet27. Moreover, the cover sheet27and the gathered sheet24may be formed as an integral sheet.

Next, a method for manufacturing the disposable undergarment1according to the present embodiment will be described with reference to the drawings.FIG. 4is a plan view illustrating a portion of the laminated web for manufacturing the disposable undergarment1.FIG. 5is a plan view illustrating a state where two half-webs formed by cutting the laminated web are arranged by being spaced apart in a web width direction and shifted by half cycle in a web flow direction.FIG. 6is a plan view illustrating a state where a crotch member is joined to two half-webs.FIG. 7is a plan view illustrating a state where the crotch member is folded to allow two half-webs to be stacked with each other and joined in every cycle. For convenience of explanation,FIG. 7illustrates an inverted version of a state of a half-web102overlaid on a half-web101illustrated inFIG. 6, that is, a state of the half-web101overlaid on the half-web102. In each of the figures, the longitudinal direction of the web is the web flow direction and the direction orthogonal to the web flow direction is the web width direction. In each of the figures, the web, the ventral member, the dorsal member, and the crotch member are illustrated in expanded states without contraction of the elastic body.

First, as illustrated inFIG. 4, the elastic bodies12,13,14, and15are sandwiched between an inner web100aforming the inner sheet of each of the ventral member2and the dorsal member3, and an outer web100bforming the outer sheet of each of the ventral member2and the dorsal member3, and in this state, the inner web100aand the outer web100bare overlaid and joined with each other, thereby forming a laminated web100. At this time, an adhesive may be applied to the surface of each of the elastic bodies12,13,14, and15, or an adhesive may be applied to one or both of the surfaces of the inner web100aand the outer web100b, to which individual elastic bodies are jointed. Moreover, each of the elastic bodies may be fixed to the inner web100aand/or the outer web100bby heat sealing, or the like. The elastic bodies12and13are joined to the inner web100aor the outer web100bin a state of being expanded with a desired tension in the web flow direction. Each of the elastic bodies14and15is arranged in an appropriate position and shape in relation to a cutting line D1to be described below in a state of being expanded with a desired tension, and then joined to the inner web100aor the outer web100b. While each of the elastic bodies12,13,14, and15is a group of thread-like elastic bodies, it is not limited thereto, and a band-like elastic body or a sheet-like elastic body may be used. Moreover, it is allowable to form a region that expands or contracts on the inner web and/or the outer web in advance by forming the inner web100aand/or the outer web100bwith the stretchable sheet. In the case of using a sheet-like elastic body or forming the inner web100aand/or the outer web100bwith a stretchable sheet, processing is performed so as to allow a desired tension to act in a direction similar to each of the elastic bodies12,13,14, and15.

The cutting line D1is a line formed with cyclic continuation of the crotch side edge10of the ventral member2and is also a line formed with continuation of the crotch side edge11of the dorsal member3shifted by half cycle. By appropriately designing the shape of the cutting line D1, it is possible to reduce overlapping portions and non-functioning portions in the material at the time of manufacturing and to avoid deficient portions, and thus, to achieve appropriate shapes of both the ventral member2and the dorsal member3formed by the cutting on the cutting line D1. As illustrated inFIG. 4, the cutting line D1has a meandering shape with respect to the web flow direction. In detail, the cutting line D1is formed such that intermediate lines11cand10csubstantially parallel to the web flow direction are alternately arranged across the center line (not illustrated) in the web width direction, and a hill portion having a top portion11for11gis arranged between the intermediate lines11cand10cin the flow direction. The top portions11fand11gare located more toward the intermediate line11cthan the intermediate line10c, and are mirror symmetrical about the intermediate line11c. The intermediate line10cor11cis connected to the top portion11for11gvia an inclined portion. The inclined portion is linear, but may be gently curved. It is preferable that the boundary between the intermediate line10cor11cand the inclined portion and the boundary between the top portion11for11gand the inclined portion is gently curved.

As illustrated inFIG. 4, the elastic bodies14and15are arranged in parallel to each other in a meandering shape with respect to the web flow direction. The elastic bodies14and15each includes a portion extending along the intermediate line10cof the cutting line D1across the intermediate line10c, inclined portion extending along the inclined portions on both sides of the intermediate line10cof the cutting line D1and then extending away from the inclined portion to reach a region in which the elastic body13is arranged, and an intermediate portion interconnecting these inclined portions. The above-described individual portions of the elastic bodies14and15are substantially linear but may be gently curved. Moreover, it is preferable that the boundary portion between the individual portions of the elastic bodies14and15is gently curved. The intermediate portions of the elastic bodies14and15have a substantially linear shape parallel to the elastic bodies12and13. This arrangement makes it possible to suppress generation of wrinkles by contraction of the laminated web100in the width direction due to the influence of the elastic bodies14and15. The elastic body15intersects the cutting line D1in the vicinity of the intermediate portion of the inclined portion and is cut along the cutting line D1. The meandering elastic body15is cut along the cutting line D1in the vicinity of the intermediate portion of the inclined portion, making it possible to prevent the edges of the ventral member2and the dorsal member3from being rounded due to the influence of the elastic body. It is also allowable to cut not merely the elastic body15but also the elastic body14along the cutting line D1.

Although not illustrated inFIG. 4, processing for reducing the tension may be performed onto each of the elastic bodies12,13,14, and/or15arranged in a region where the crotch member4of each of the ventral members2and the dorsal member3of the laminated web100is to be overlaid. With this processing, it is possible to prevent generation of wrinkles in the crotch member4overlaid and joined with the ventral member2and the dorsal member3, due to the tension of the elastic body. As processing of reducing the tension of the elastic body, for example, it is possible to appropriately select, for example, finely dividing the elastic body with a large number of protrusions, a cutter blade or the like, heat sealing the elastic body, or the like. Note thatFIG. 5illustrates the continuous half-web101of the ventral member2in which processing of reducing the tension has been performed on the leg-fitting elastic body14arranged in the region along the intermediate line10cof the crotch side edge10of the ventral member2.

Next, the laminated web100is cut along the cutting line D1continuous in the web flow direction by defining one of the crotch side edge10of the ventral member2and the crotch side edge11of the dorsal member3as one cycle. The line formed with cyclic continuation of the crotch side edge10of the ventral member2and the line formed with cyclic continuation of the crotch side edge11of the dorsal member3match with each other when they are overlaid with each other shifted by half cycle in the web flow direction. By cutting the laminated web100along the cutting line D1, the continuous half-web101of the ventral member2and a continuous half-web102of the dorsal member3are formed.

Next, as illustrated inFIG. 5, either the continuous half-web101of the ventral member2or the continuous half-web102of the dorsal member3is moved in the web width direction while being shifted by half cycle in the web flow direction, thereby allowing each of the ventral member2of the half-web101and the dorsal member3of the half-web102to be arranged to face each other and spaced apart from each other in every cycle. The interval between the half-web101and the half-web102is set to an appropriate interval needed for overlaying and joining each of the crotch member4with each of the ventral members2and each of the dorsal members3. Note that shifting the half-web101or the half-web102by half cycle in the web flow direction may be performed after completing moving the half-webs in the web width direction, or shifting the half-webs by half cycle in the web flow direction may be performed while moving them in the web width direction. As a method for shifting the half-web in the web flow direction by half cycle, it is possible to employ various methods such as changing the conveying distance and speed in the web flow direction of the half-web.

Next, as illustrated inFIG. 6, each of the crotch members4is overlaid and joined with the central portion of each of the ventral members2of the half-web101and the central portion of each of the ventral members2of the half-web102. The crotch member4is joined to the ventral member2and the dorsal member3with an adhesive such as a hot melt. Although the left and right end portions of each of the ventral members2of the half-web101protrude toward the half-web102, this would not generate wrinkles due to the tension of the elastic body because this protruding portion contains no elastic body.

Next, as illustrated inFIG. 7, the crotch member4is bent to overlay the half-web101and the half-web102such that the inner sheet of each of the ventral member2and the dorsal member3faces the inner side. No wrinkles are generated because no elastic body is contained in the protruding portions in the left and right end portions of each of the ventral members2of the half-web101. When the half-web101and the half-web102are overlaid, this allows the left and right end portions of the ventral member2and each of the dorsal members3in each of the cycles to be overlaid with stabilized positions in the web width direction and in a state where generation of wrinkles and deviations is suppressed.

Next, the joints5aand5bare formed along the left and right end portions of the ventral member2and the dorsal member3overlaid by each of the cycles. The ventral member2and the dorsal member3are joined with each other by these joints5aand5b. The joints5aand5bare intermittently or continuously formed between the waist side edges7and8of the ventral member2and the dorsal member3, and the crotch side edges10and11. Since the left and right end lines10aand10bof the crotch side edge10of the ventral member2and the left and right end lines11aand11bof the crotch side edge11of the dorsal member3are substantially parallel to the waist side edges7and8, respectively, it is possible to form the joints5aand5bwith sufficient width and across a substantially entire length of the portion between the waist side edges7and8and the crotch side edges10and11. The left and right joints5aand5bmay be formed by an adhesive such as a hot melt adhesive or by various sealing methods such as heat sealing and ultrasonic sealing.

Next, the pant-type disposable undergarment1illustrated inFIG. 1is manufactured in the same orientation continuously in the web flow direction by cutting at a portion between the adjacent joints5aand5bof the ventral member2and the dorsal member3joined in every cycle. With the processing described above according to the present embodiment, it is possible to provide a disposable undergarment that being less wasteful of materials, and having appropriate shapes in both the ventral and dorsal sides. Moreover, it is also possible to provide a method for continuously manufacturing such a disposable undergarment.

Second Embodiment

Next, a disposable undergarment according to another embodiment of the present invention will be described with reference to the drawings.FIG. 8is a front view of a disposable undergarment31according to another embodiment.FIG. 9is an exploded view of the disposable undergarment31illustrated inFIG. 8.FIG. 10is a plan view illustrating a portion of a laminated web300for manufacturing the disposable undergarment31illustrated inFIG. 8. Individual members in these figures are illustrated in a state where the elastic bodies are expanded state without being contracted. Components of the disposable undergarment31, having same structures and functions as those of the disposable undergarment1are denoted by the same names or reference numerals, and description thereof is omitted as appropriate.

As illustrated inFIGS. 8 and 9, the disposable undergarment31is a pant-type disposable diaper. The disposable undergarment31includes a ventral member32positioned on a front side of the wearer's torso, a dorsal member33positioned on a back side of the wearer's torso, and the crotch member4joined to a central portion on an inner surface side of the ventral member32and to a central portion of an inner surface side of the dorsal member33and located at the crotch of the wearer. As the crotch member4, it is allowable to use the one same as the disposable undergarment1. The ventral member32and the dorsal member33are formed by overlaying an inner sheet positioned on a skin side of the wearer and an outer sheet positioned on a clothing side of the wearer and sandwiching waist-fitting elastic bodies42, a body-fitting elastic body43, and leg-fitting elastic bodies44and45, between the sheets, and by joining the sheets in this state. The materials of the inner sheet and the outer sheet of the ventral member32and the dorsal member33may be the same as the materials of the inner sheet and the outer sheet of the ventral member2and the dorsal member3.

The disposable undergarment31is formed into a pant-type diaper by folding the crotch member4joined to the ventral member32and the dorsal member33and then, by joining the left and right end portions in a state where the ventral member32and the dorsal member33are overlaid with each other. A left joint35ais formed along left end portions32aand33aof the ventral member32and the dorsal member33, respectively, and a right joint35bis formed along right end portions32band33bof the ventral member32and the dorsal member33, respectively. The left and right joints35aand35bmay be formed with various sealing methods similar to the case of the left and right joints5aand5bof the disposable undergarment1.

A waist opening36of the disposable undergarment1is formed by being encircled by a waist side edge37at an upper end of the ventral member32and by a waist side edge38at an upper end of the dorsal member33. The left leg opening39ais formed by being encircled by a crotch side edge40at a lower end of the ventral member32, a crotch side edge41at a lower end of the dorsal member33, and the left side edge4aof the crotch member4. The right leg opening39bis formed by being encircled by the crotch side edge40of the ventral member32, the crotch end edge41of the dorsal member33, and the right side edge4bof the crotch member4.

As illustrated inFIG. 8 or 9, in a state where the ventral member32and the dorsal member33are expanded, the waist side edge37of the ventral member32and the waist side edge38of the dorsal member33have linear shapes and an equal length. The left and right end portions32aand32bof the ventral member32have linear shapes perpendicular to the waist side edge37. The left and right end portions33aand33bof the dorsal member33have linear shapes perpendicular to the waist side edge38. The lengths of the left and right end portions32aand32bof the ventral member32are equal to the lengths of the left and right end portions33aand33bof the dorsal member33, respectively. Each of the crotch side edge40of the ventral member32and the crotch side edge41of the dorsal member33has a symmetrical shape about a center line C2having a common left-right widths on the ventral member32and the dorsal member33.

As illustrated inFIG. 9, in a state where the ventral member32and the dorsal member33are separated and expanded, that is, in a state where the disposable undergarment31is developed, a left half and a right half of the crotch side edge40of the ventral member32are symmetrical about the center line C2. The crotch side edge40includes a left end line40a, a left recessed line40b, an intermediate line40c, a right recessed line40d, and a right end line40e. The left end line40a, the intermediate line40c, and the right end line40ehave linear shapes substantially parallel to the waist side edge7. The intermediate line40cis bisected by the center line C2. The left recessed line40bis connected to the left end line40aand the intermediate line40c. The left recessed line40bhas a shape recessed in a direction toward the waist side edge37. A bottom portion40fof the left recessed line40bis a portion closest to the waist side edge37and is located more toward the left end portion32athan the center line C2of the ventral member32. The right recessed line40dis connected to the right end line40eand the intermediate line40c. The right recessed line40dhas a shape recessed in a direction toward the waist side edge37. A bottom portion40gof the right recessed line40dis a portion closest to the waist side edge37and is located more toward the right end portion32bthan the center line C2of the ventral member32.

As illustrated inFIG. 9, the left half and the right half of the crotch side edge41of the dorsal member33are symmetrical about the center line C2. The crotch side edge41includes a left end line41a, a left protruding line41b, an intermediate line41c, a right protruding line41d, and a right end line41e. The left end line41a, the intermediate line41c, and the right end line41ehave a linear shape substantially parallel to the waist side edge38. The intermediate line41cis bisected by the center line C2. The left protruding line41bis connected to the left end line41aand the intermediate line41c. The left protruding line41bhas a shape protruding in a direction away from the waist side edge38. A top portion41fof the left protruding line41bis a portion farthest away from the waist side edge38and is located more toward the center line C2than the left end portion33aof the dorsal member33. The right protruding line41dis connected to the right end line41eand the intermediate line41c. The right protruding line41dhas a shape protruding in a direction away from the waist side edge38. A top portion41gof the right protruding line41dis the portion farthest away from the waist side edge38and is located more toward to the center line C2than the right end portion33bof the dorsal member33.

As illustrated inFIG. 9, the shape of a left half of the crotch side edge40bisected at the center line C2of the ventral member32is the same as the shape of the right half of the crotch side edge41bisected at the center line C2of the dorsal member33. The shapes of the left end line40a, the left protruding line40b, the bottom portion40f, and the left half of the intermediate line40cof the crotch side edge40are the same as the shapes of the right half of the intermediate line41c, the right protruding line41d, the top portion41g, and the right end line41eof the crotch side edge41, respectively. In short, when the left half of the crotch side edge40of the ventral member32is moved in the left-right direction and in an approaching direction to abut against the right half of the crotch side edge41of the dorsal member33, the shapes of both portions match.

As illustrated inFIG. 9, the shape of a right half of the crotch side edge40bisected at the center line C2of the ventral member32is the same as the shape of the left half of the crotch side edge41bisected at the center line C2of the dorsal member33. The shapes of the right end line40e, the right protruding line40d, the bottom portion40g, and the right half of the intermediate line40cof the crotch side edge40are the same as the shapes of the left half of the intermediate line41c, the left protruding line41b, the top portion41f, and the left end line41aof the crotch side edge41, respectively. In short, when the right half of the crotch side edge40of the ventral member32is moved in the left-right direction and in an approaching direction to abut against the left half of the crotch side edge41of the dorsal member33, the shapes of both portions match.

In the disposable undergarment1, the distance between the waist side edge7and the crotch side edge8of the ventral member2is longer at a position of the center line C1of the ventral member2than at the position of the left and right end portions2aand2bof the ventral member2. In contrast, in the disposable undergarment31, the distance between the waist side edge37and the crotch side edge38of the ventral member32is equal at positions of the left and right end portions32aand32bof the ventral member32and at a position of the center line C2of the ventral member32.

In the ventral member32of the disposable undergarment31, the left and right bottom portions40fand40ghaving the shortest distance between the waist side edge37and the crotch side edge40are located at positions more toward the left and right end portions32aand32b, respectively, than the center line C2of the ventral member32. This configuration makes it possible to increase the left-right width of a downward protrusion between the left and right bottom portions40fand40gof the ventral member32, leading to an increase in the left-right width of a region to cover the wearer's groin and periphery thereof on the ventral member32. In this manner, the disposable undergarment31can form the ventral member32into an appropriate shape.

The dorsal member33of the disposable undergarment31is configured such that the left and right protruding lines41band41dcontinuous respectively to the left and right end lines41aand41eprotrude in a direction away from the waist side edge38, making it possible to increase the left-right width of the downward protrusion of the dorsal member33. Moreover, in the dorsal member33, the top portions41fand41ghaving the longest distance between the waist side edge38and the crotch side edge41are respectively located more toward the center line C2than the left and right end portions33aand33bof the dorsal member33. This configuration makes it possible to locate the top portions41fand41gof the downward protrusion of the dorsal member33near the central portion of the dorsal member33to which the crotch member4has been joined. The recessed shape of the intermediate line41cof the dorsal member33would be no problem since the central portion of the dorsal member33is covered with the crotch member4. In this manner, in the disposable undergarment31, it is possible to realize an appropriate shape of the dorsal member33with the sufficiently increased left-right width and the top-bottom length of the portion to cover the buttock of the wearer.

Furthermore, in the disposable undergarment31, the distance between the waist side edge37and the crotch side edge40become longest at the left and right end portions32a,32b,33a, and33b. This makes it possible to realize a shape like a trunks type with longer joints.

As illustrated inFIGS. 8 and 9, the ventral member32and the dorsal member33include waist-fitting elastic bodies42aand42bthat stretch and contract in the left-right direction, and body-fitting elastic bodies43aand43b, respectively. Moreover, the ventral member32includes a leg-fitting elastic body44and a portion of a leg-fitting elastic body45. The dorsal member33includes a portion of the leg-fitting elastic body45.

The waist-fitting elastic body42ais arranged over substantially the entire region from the left end portion32ato the right end portion32bin the waist side edge37and adjacent regions of the ventral member32, and is joined in an expanded state, to the ventral member32. The waist-fitting elastic body42bis arranged over substantially the entire region from the left end portion33ato the right end portion33bin the waist side edge38and adjacent regions of the dorsal member33, and is joined in an expanded state, to the dorsal member33. Although not illustrated, waist gathers are formed in a region of the ventral member32and the dorsal member33where the waist-fitting elastic bodies42aand42bare joined.

The body-fitting elastic body43ais arranged over substantially the entire area from the left end portion32ato the right end portion32bin the adjacent region on the crotch side edge40side from the region where the waist-fitting elastic body42aof the ventral member32is joined, and is joined in an expanded state, to the ventral member32. The body-fitting elastic body13aof the disposable undergarment1is arranged above the crotch side edge10of the ventral member2and does not intersect the crotch side edge10. In contrast, the body-fitting elastic body43aof the disposable undergarment31is arranged between the left recessed line40band the right recessed line40d, between the left recessed line40band the left end portion32aof the ventral member32, and between the right recessed line40dand the right end portion32bof the ventral member32. The body-fitting elastic body43ais not arranged in the neighborhood of the left end line40a, the intermediate line40c, or the right end line40eof the crotch side edge40of the ventral member32.

The body-fitting elastic body43bis arranged over substantially the entire area from the left end portion33ato the right end portion33bin the adjacent region on the crotch side edge41side from the region where the waist-fitting elastic body42bof the dorsal member33is joined, and is joined in an expanded state, to the dorsal member33. Although not illustrated, body-fitting gathers are formed in a region of the ventral member32and the dorsal member33where the body-fitting elastic bodies43aand43bare joined.

The leg-fitting elastic body44is arranged in a meandering manner so as to extend along the intermediate line40cand the left and right recessed lines40band40dof the crotch side edge40of the ventral member32, rise diagonally away from the crotch side edge40from the neighborhood of the bottom portions40fand40g, and extend to the left and right end portions32aand32bof the ventral member32along the upper portion in the region of the body-fitting elastic body43a, and is joined in an expanded state, to the ventral member32. The leg-fitting elastic body45includes: a portion45aextending along the left end line41aand the left protruding line41bof the crotch side edge41of the dorsal member33and intersecting the top portion41f; a portion45bextending along the right end line41eand the right protruding line41dof the crotch side edge41of the dorsal member33and intersecting the top portion41g; and left and right portions45cand45dextending being spaced apart in parallel with each other below the leg-fitting elastic body44in the ventral member32.

Although not illustrated, leg gathers are formed in a region where the leg-fitting elastic bodies44or45are joined around the crotch side edge40of the ventral member32and around the crotch side edge41of the dorsal member33.

Each of the waist-fitting elastic body42, the body-fitting elastic body43, and the leg-fitting elastic bodies44and45is formed with a group of a plurality of thread-like elastic bodies. Each of the thread-like elastic bodies is formed of a stretchable material such as natural rubber, polyurethane resin, and stretchable hot melt. The elastic bodies42,43,44, and45are not limited to thread-like elastic bodies, but may be band-like elastic bodies or sheet-like elastic bodies. Furthermore, the entire ventral member32and/or the dorsal member33may be formed of a material such as a stretchable sheet. In the case of using a sheet-like elastic body or forming the entire ventral member32and/or the dorsal member33as a whole of a material such as a stretchable sheet, processing is performed so as to allow a desired tension to act in a direction similar to each of the elastic bodies42,43,44, and45.

InFIG. 9, each of the elastic bodies42,43,44, and/or45arranged in a region of the ventral member32and the dorsal member33overlaid with the crotch member4may be processed to reduce the tension of the elastic body. This processing results in suppression of deformation or contraction of the crotch member4by the tension of the elastic body. As processing of reducing the tension of the elastic body, for example, it is possible to appropriately select, for example, finely dividing the elastic body with a large number of protrusions, a cutter blade or the like, finely heat sealing the elastic body, or the like.

As illustrated inFIG. 9, as the crotch member4, it is allowable to use the one same as the crotch member4of the disposable undergarment1. The shape of the crotch member4and the position and the size of the portion where the crotch member4is overlaid with and joined to the ventral member32or the dorsal member33are not limited to those described above and may be appropriately changed in accordance with the size and shape of the disposable diaper31.

The disposable diaper31can be manufactured by a similar manufacturing method as the method for the disposable diaper1using a laminated web300. First, as illustrated inFIG. 10, the elastic bodies42,43,44, and45are sandwiched between an inner web300aforming the inner sheet of each of the ventral member32and the dorsal member33, and an outer web300bforming the outer sheet of each of the ventral member32and the dorsal member33, and in this state, the inner web300aand the outer web300bare overlaid and joined with each other, thereby forming the laminated web300. Each of the elastic bodies42,43,44, and45is arranged in an appropriate position and shape in relation to a cutting line D2in a state of being expanded with a desired tension, and then joined to the inner web300aor the outer web300b. The elastic bodies42,43,44, and45are not limited to thread-like elastic bodies, but may be band-like elastic bodies or sheet-like elastic bodies. The inner web300aand/or the outer web300bmay be formed with a stretchable sheet. In the case of using a sheet-like elastic body or forming the inner web300aand/or the outer web300bwith a stretchable sheet, processing is performed so as to allow a desired tension to act in a direction similar to each of the elastic bodies42,43,44, and45. As illustrated inFIG. 10, while in the present embodiment, the elastic bodies44and45are arranged in a meandering shape with respect to the web flow direction, there are few linear portions parallel to the web flow direction in comparison with the elastic bodies14and15of the previous embodiment, leading to an entire arrangement with gently curved shapes.

The present invention is not limited to the above-described embodiments and modified examples. For example, the disposable undergarment according to the present invention may be a pad holder that does not include an absorbent body inside the crotch member and configured to be used by attaching an absorbent pad including an absorbent body.