Pants-type absorbent article

Abstract

Provided is a pants-type absorbent article which can reduce the risk of excessive hardening of the joining regions of the side end sections of the waist section and which can be easily torn along the joining sections after use. In a pants-type absorbent article (1) in which a pair of waist-encircling sections are joined at both side ends in the left-right direction by a pair of joining regions (SS) having a plurality of joining sections (70) in the vertical direction, one sheet (21) and / or the other sheet (22) of the waist-encircling section (20) has a plurality of heat-welded sections (EB) in which heat-welded fibers are joined to each other, and in the stretched state, the heat-welded sections (EB) are joined to each other by the heat-welded fibers. A heat-welded section row (R) along the vertical direction is formed by heat-welded section groups that are adjacent to each other in the vertical direction and have the smallest center distance in the left-right direction, the heat-welded sections (EB) do not join the one sheet (21) and the other sheet (22), and the distance between the joining sections (70) in the vertical direction is wider than the length of the joining sections in the vertical direction. The interval between the joining sections in the vertical direction is narrower than the interval between the first heat-welded section (EB1) and the second heat-welded section (EB2) in the heat-welded section row (R).

Description

Technical Field

[0001] The present invention relates to a pant-type absorbent article. Background Art

[0002] In the past, there is a well-known shorts-type absorbent article in which a waist opening and a pair of leg openings are formed by connecting a ventral (front) waist portion and a dorsal (rear) waist portion using side joints provided at both ends in the left-right direction. For example, Patent Document 1 discloses a shorts-type disposable diaper having a front waist region (front sheet), a rear waist region (rear sheet), and a crotch region, which are formed by, for example, joining the side edges of the front sheet and the side edges of the rear sheet using a semicircular joint point.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-96192 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When removing the pants-type absorbent article from the wearer's body after wearing it (taking off the pants-type absorbent article in the worn state), the waist region is generally torn at the side joints to open the waist opening. When the waist opening is to be opened using the side joints of a disposable diaper such as Patent Document 1, the portion of the waist region on one side (e.g., the front waist region) joined by the side joints may remain joined to the waist region on the other side (e.g., the back waist region) unchanged, and after tearing, the waist region on one side is in a state where the side joints are cut (see Patent Document 1). Figure 7B That is, when the side seams are used to tear and open the waist opening, the waist region on one side is torn off along the contour of the side seams, so it may be necessary to pull the waist region on one side strongly, or the waist region on one side may be torn in an unexpected part. On the other hand, if the side seams are continuously provided over the entire area in the vertical direction of the two side edges of the waist region, the concern that the waist region on one side may be torn in an unexpected part can be reduced, but since the two side edges of the waist region become hard, it may cause discomfort to the wearer.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a pants-type absorbent article which can reduce the concern that the joint region at the side end portions of the waistline portion becomes excessively hard and can be easily torn along the joint portion after use.

[0009] Means for solving problems

[0010] The main technical solution for achieving the above-mentioned purpose is a pants-type absorbent article, which has an upper and lower direction, a left and right direction, and a front and back direction that intersect each other, and the pants-type absorbent article has a pair of waist parts and a liquid-absorbing absorbent body, and the pair of waist parts are joined to each other at both side ends in the left and right directions by a pair of joining areas, characterized in that the joining area has a plurality of joining parts along the upper and lower directions, the waist part has a side sheet and the other side sheet, at least one of the side sheet and the other side sheet has a plurality of heat-welded parts where heat-welded fibers are joined to each other, and in a stretched state, a heat-welded part row along the upper and lower directions is formed by a heat-welded part group that is adjacent to each other in the upper and lower directions and has the smallest center distance in the left and right directions, the heat-welded parts do not join the one side sheet to the other side sheet, and the heat-welded part row has a first heat-welded part and a second heat-welded part at a position that is closer to the inside of the joining part in the left and right directions, and the interval between the joining parts in the upper and lower directions is wider than the length of the joining part in the upper and lower directions, and the interval between the joining parts in the upper and lower directions is narrower than the interval between the first heat-welded part and the second heat-welded part.

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

[0012] Effects of the Invention

[0013] According to the present invention, compared with the case where the vertical interval between the joints is not wider than the vertical length of the joints and the vertical interval between the joints is not narrower than the interval between the first heat weld part and the second heat weld part, the concern about excessive hardening of the joint area can be reduced, and the inner end portion along the left-right direction of the joint is easily torn after use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic perspective view of the diaper 1.

[0015] Figure 2 This is a schematic plan view of the diaper 1 in the unfolded and stretched state as viewed from the skin side of the wearer.

[0016] Figure 3 yes Figure 2 AA section view in.

[0017] Figure 4 It is an explanatory diagram of the welded portion row R provided in the abdominal waistline portion 20 .

[0018] Figure 5A and Figure 5B It is an explanatory diagram of the mounting function of the elastic member 23.

[0019] Figure 6 yes Figure 4 Schematic enlarged view of the Y part in FIG.

[0020] Fig. 7A 2 is a diagram for explaining the structure of a conventional shorts-type absorbent article 2. Figure 7B This is a diagram for explaining a state in which a conventional pants-type absorbent article 2 is torn.

[0021] Figure 8 Yes Figure 6 A diagram for explanation of the schematic enlarged view of FIG.

[0022] Fig. 9 This is a diagram for explaining a state in which the diaper 1 is torn.

[0023] Fig. 10A 2 is a diagram for explaining welded portion arrays Ra and Rb according to a modified example. Fig. 10B It is an explanatory diagram of the hollow welded portion pair 51a.

[0024] Fig.11A 51a is an explanatory diagram of the hollow welded portion pair 51a in the extended state. Fig. 11B and Fig. 11C It is an explanatory diagram of the hollow welded portion pair 51a in a contracted state.

[0025] Fig.12 It is a diagram showing a modified example of the heat welding portion EB.

[0026] Fig.13 This is a schematic plan view partially showing in perspective how the diaper 1 is manufactured using the production line 100 .

[0027] Fig.14 It is an explanatory diagram of the processing performed at the fourth processing position PK4. DETAILED DESCRIPTION

[0028] At least the following matters will become clear from the description of this specification and the accompanying drawings.

[0029] Form 1 is a pants-type absorbent article having mutually intersecting up-down directions, left-right directions, and front-back directions, the pants-type absorbent article having a pair of waist portions and a liquid-absorbing absorbent body, the pair of waist portions being joined to each other at both side ends in the left-right directions by a pair of joining regions, characterized in that the joining region has a plurality of joining portions along the up-down direction, the waist portion having a side sheet and the other side sheet, at least one of the one side sheet and the other side sheet having a plurality of heat-welded portions where heat-welded fibers are joined to each other, in a stretched state, a heat-welded portion row along the up-down direction is formed by a heat-welded portion group that is adjacent to each other in the up-down direction and has the smallest center distance in the left-right direction, the heat-welded portion does not join the one side sheet to the other side sheet, the heat-welded portion row has a first heat-welded portion and a second heat-welded portion at a position closer to the inside in the left-right direction than the joining portion, the spacing between the joining portions in the up-down direction is wider than the length of the joining portion in the up-down direction, and the spacing between the joining portions in the up-down direction is narrower than the spacing between the first heat-welded portion and the second heat-welded portion.

[0030] According to form 1, compared to the case where the vertical interval between the joints is not wider than the vertical length of the joints and the vertical interval between the joints is not narrower than the interval between the first heat weld part and the second heat weld part, the concern about excessive hardening of the joint area can be reduced, and the inner end portion along the left-right direction of the joint is easily torn after use.

[0031] According to aspect 2, in the pants-type absorbent article according to aspect 1, a length of the joining portion in the up-down direction is shorter than a length of the first thermally welded portion in the up-down direction.

[0032] According to the second aspect, compared with the case where the vertical length of the joining portion is longer than the vertical length of the first heat weld portion, the concern that the joining region becomes excessively hard can be reduced.

[0033] According to aspect 3, in the pants-type absorbent article according to aspect 1 or 2, a length of the joining portion in the left-right direction is longer than a length in the up-down direction.

[0034] According to form 3, compared with the case where the length of the joint in the vertical direction is shorter than the length in the horizontal direction, the joint strength of the joint can be easily increased, and the inner end of the joint in the horizontal direction can be easily torn after use.

[0035] In form 4, based on the shorts-type absorbent article recorded in any one of forms 1 to 3, a plurality of elastic components that can be stretched and retracted in the left-right direction are arranged between the one side piece and the other side piece at intervals in the up-down direction, and the length of the joint in the up-down direction is shorter than the thickness of the elastic component in a natural state.

[0036] According to aspect 4, the possibility that the joining portion cuts the elastic member can be reduced.

[0037] In form 5, based on the shorts-type absorbent article recorded in any one of forms 1 to 4, a plurality of elastic components that can be stretched and retracted in the left-right direction are arranged between the one side piece and the other side piece at intervals in the up-down direction, and the length of the joint in the up-down direction is shorter than the thickness of the elastic component in the stretched state.

[0038] According to aspect 5, the possibility that the joining portion cuts the elastic member can be further reduced.

[0039] In form 6, based on the shorts-type absorbent article described in any one of forms 1 to 5, on at least one side of the waistline portion, a plurality of elastic members that can stretch and contract in the left-right direction are arranged at intervals in the up-down direction between the one side piece and the other side piece joined by a plurality of welded parts, and the plurality of welded parts have a plurality of welded part pairs located on both sides of the elastic members in the up-down direction, and each of the elastic members is sandwiched between the welded part pairs in a state of contraction in the left-right direction, thereby limiting the position in the up-down direction relative to the one side piece and the other side piece, and the length of the joining part in the left-right direction is longer than the length of the welded part in the left-right direction.

[0040] According to the sixth aspect, the strength of the joining region can be easily increased compared to a case where the length of the joining portion in the left-right direction is shorter than the length of the welded portion in the left-right direction.

[0041] In form 7, based on the shorts-type absorbent article described in any one of forms 1 to 6, a plurality of elastic members that can stretch in the left-right direction are arranged at intervals in the up-down direction between the one side sheet and the other side sheet joined by a plurality of welded portions on at least one side of the waist portion, the plurality of welded portions have a plurality of welded portion pairs located on both sides of the elastic members in the up-down direction, each of the elastic members is sandwiched between the welded portion pairs in a state of being contracted in the left-right direction, thereby limiting the position in the up-down direction relative to the one side sheet and the other side sheet, the plurality of welded portion pairs have a first welded portion pair and a second welded portion pair, The second welded portion pair is located next to one side of the first welded portion pair in the left-right direction, the first welded portion pair and the second welded portion pair together sandwich the first elastic member, the first welded portion pair has a first welded portion and a second welded portion, the first welded portion and the second welded portion are located at positions separated by a first interval along the left-right direction on the same side of the up-down direction based on the first elastic member, and in the extended state, the length in the left-right direction from the end of the first welded portion pair on the one side in the left-right direction to the end of the second welded portion pair on the other side in the left-right direction, i.e., the first length, is longer than the length in the left-right direction of the first interval.

[0042] According to the seventh aspect, the concern that the elastic member will fall off from between the welded portion pair can be reduced, and a decrease in the elasticity of the elastic member can be suppressed.

[0043] In form 8, based on the shorts-type absorbent article described in any one of forms 1 to 7, the interval between the first heat-sealed part and the second heat-sealed part is wider than twice the sum of the vertical length of the joining part and the vertical interval between the joining parts.

[0044] According to form 8, compared with the case where the interval between the first heat weld part and the second heat weld part is narrower than twice the sum of the length of the joint in the vertical direction and the interval between the joints in the vertical direction, the inner end portion along the left and right direction of the joint is easily torn after use.

[0045] According to a ninth aspect, in the pants-type absorbent article according to any one of the first to eighth aspects, a distance between the joining portions in the up-down direction is narrower than a length of the joining portions in the left-right direction.

[0046] According to form 9, compared with the case where the vertical interval between the joints is wider than the horizontal length of the joint, it is easy to increase the joint strength and to tear along the inner end of the joint in the horizontal direction after use.

[0047] According to a tenth aspect, in the pants-type absorbent article according to any one of aspects 1 to 9, a length of the joining portion in the left-right direction is longer than a length of the first thermally welded portion in the left-right direction.

[0048] According to the tenth aspect, the strength of the joining region can be improved compared to a case where the length of the joining portion in the left-right direction is shorter than the length of the first heat weld portion in the left-right direction.

[0049] According to an eleventh aspect, in the pants-type absorbent article according to any one of the first to tenth aspects, the area of ​​the joining portion is equal to or smaller than the area of ​​the first thermally welded portion.

[0050] According to the eleventh aspect, compared with the case where the area of ​​the joining portion is larger than the area of ​​the first heat welded portion, the concern that the joining region becomes excessively hard can be reduced.

[0051] According to a twelfth aspect, in the pants-type absorbent article according to any one of aspects 1 to 10, an area of ​​the joining portion is larger than an area of ​​the first thermally welded portion.

[0052] According to aspect 12, compared with a case where the area of ​​the joining portion is smaller than the area of ​​the first heat welded portion, the joining region can be joined more firmly and the inner end portion of the joining portion in the left-right direction can be easily torn after use.

[0053] In form 13, on the basis of the shorts-type absorbent article described in any one of forms 1 to 12, on at least one side of the waistline portion, a plurality of elastic members that can stretch and contract in the left-right direction are arranged at intervals in the up-down direction between the one side piece and the other side piece joined by a plurality of welded parts, and the plurality of welded parts have a plurality of welded part pairs located on both sides of the elastic members in the up-down direction, and each of the elastic members is sandwiched between the welded part pairs in a state of being contracted in the left-right direction, thereby limiting the position in the up-down direction relative to the one side piece and the other side piece, and the area of ​​the joining portion is less than the area of ​​the welded part.

[0054] According to the thirteenth aspect, compared with the case where the area of ​​the joining portion is larger than the area of ​​the welded portion, the concern that the joining region becomes excessively hard can be reduced.

[0055] In form 14, on the basis of the shorts-type absorbent article recorded in any one of forms 1 to 12, on at least one side of the waistline portion, a plurality of elastic members that can stretch and contract in the left-right direction are arranged at intervals in the up-down direction between the one side piece and the other side piece joined by a plurality of welded parts, the plurality of welded parts have a plurality of welded part pairs located on both sides of the elastic members in the up-down direction, each of the elastic members is sandwiched between the welded part pairs in a state of being contracted in the left-right direction, thereby limiting the position in the up-down direction relative to the one side piece and the other side piece, and the area of ​​the joining part is larger than the area of ​​the welded part.

[0056] According to aspect 14, compared with a case where the area of ​​the joint portion is smaller than the area of ​​the welded portion, the joint in the joint region can be firmly joined and the inner end portion of the joint portion in the left-right direction can be easily torn after use.

[0057] ===Present Implementation Method===

[0058] <<Basic structure of shorts-type disposable diapers>>

[0059] As an example of the pants-type absorbent article of this embodiment, a pants-type disposable diaper 1 (hereinafter also referred to as "diaper 1") is described. However, the pants-type absorbent article of the present invention also includes a pants-type sanitary napkin. In addition, the wearer of the pants-type absorbent article is not limited to adults, and may also be a living creature such as an infant or an animal.

[0060] Figure 1 It is a schematic perspective view of the diaper 1. Figure 2 This is a schematic plan view of the diaper 1 in the unfolded and stretched state as viewed from the skin side of the wearer. Figure 3 yes Figure 2 AA section view in. Figure 2 The CC line in the figure is the center line of the diaper 1 in the left-right direction (also referred to as the "center CC in the left-right direction"), and the CL line is the center line in the long-side direction (also referred to as the "center CL in the long-side direction").

[0061] The "expanded state" of the diaper 1 refers to a state in which Figure 1The side joints SS (described later) of the diaper 1 in the pants-type state on both sides in the left-right direction are released, so that the ventral waistline portion 20 (described later) and the dorsal waistline portion 30 (described later) are separated, and the diaper 1 is unfolded on a plane by opening the diaper 1 in the up-down direction. In addition, the "stretched state" of the diaper 1 refers to a state in which the product (diaper 1) is stretched without wrinkles, specifically, it refers to a state in which the size of each component (such as the absorbent body 10, the ventral waistline portion 20, etc.) constituting the diaper 1 is consistent with or close to the size of the component alone. On the other hand, the "natural state" refers to the state when the diaper 1 and the ventral waistline portion 20 are left for a predetermined time. For example, the ventral waistline portion 20 and the dorsal waistline portion 30 of the diaper 1 are pulled to both outer sides in the left-right direction, so that the waistlines 20 and 30 are in the "stretched state", and after the stretched state is continued for 15 seconds, the pulling of the diaper 1 is released and it is placed on a flat surface such as a table. Then, the state after 5 minutes of being placed flat on such a flat surface is regarded as a natural state.

[0062] The diaper 1 in the pants-type state ( Figure 1 ) has mutually intersecting up-down direction, left-right direction and front-back direction, and has a waist opening BH and a pair of leg openings LH. In the up-down direction, the waist opening BH side is set as the upper side, and the side that will become the wearer's crotch side is set as the lower side. In the front-back direction, the side that will become the wearer's abdomen side is set as the front side, and the side that will become the back side is set as the back side. In addition, as Figure 3 As shown, the diaper 1 has a thickness direction in which the materials are stacked, and in the thickness direction, the side in contact with the wearer is defined as the skin side, and the opposite side is defined as the non-skin side.

[0063] The diaper 1 includes an absorbent body 10 and a pair of waist portions 20, 30. The pair of waist portions 20, 30 are joined to the non-skin side of the absorbent body 10 by adhesive or the like. The front portion of the pair of waist portions 20 is also referred to as the ventral waist portion 20, and the rear portion is also referred to as the dorsal waist portion 30. The ventral waist portion 20 and the dorsal waist portion 30 are joined at both end portions in the left-right direction by a pair of joining regions SS.

[0064] like Figure 3As shown, the absorbent body 10 has: an absorbent core 11; a liquid-permeable top sheet 12, which is arranged on the skin side of the absorbent core 11; a liquid-impermeable back sheet 13, which is arranged on the non-skin side of the absorbent core 11; and an outer sheet 14. The absorbent core 11 can be any absorbent core that absorbs and retains excrement, and for example, it can be an absorbent core formed into a prescribed shape by liquid-absorbent materials such as pulp fibers and superabsorbent polymers. In addition, the absorbent core 11 can also be covered by a liquid-permeable sheet such as a tissue or a nonwoven fabric. In addition, the absorbent body 10 appropriately includes leg elastic members, a leak-proof wall portion including a leak-proof wall elastic member, etc., but in Figure 2 It is omitted in the illustration.

[0065] In the present embodiment, the portion overlapping with the joining area SS in the vertical direction is set as the waist circumference portion 20, 30, and the ventral waist circumference portion 20 and the dorsal waist circumference portion 30 are rectangular portions when viewed from above. A roughly trapezoidal extension portion 30E is provided on the lower crotch side of the dorsal waist circumference portion 30. The extension portion 30E can be used to cover the buttocks of the wearer. In the following description, the dorsal waist circumference portion 30 and the extension portion 30E are also collectively referred to as the dorsal outerwear portion 30, 30E. However, it is not limited to the above case, for example, it can be a structure without the extension portion 30E on the dorsal side, or it can be a structure with a portion extending from the ventral waist circumference portion 20 to the lower crotch side.

[0066] The ventral waistline portion 20 includes a skin side sheet (one side sheet) 21 and a non-skin side sheet (the other side sheet 22). In the present embodiment, the skin side sheet 21 and the non-skin side sheet 22 are both made of spunbond nonwoven fabrics. However, this is not limiting at all, and other types of nonwoven fabrics such as SMS (spunbond / meltblown / spunbond) nonwoven fabrics and meltblown nonwoven fabrics may also be used. In addition, in this example, the structural fiber (thermal fusion fiber) F (see Figure 6 ), single fibers of polypropylene (PP) which is a representative example of thermoplastic resins are used, but the invention is not limited thereto. For example, single fibers of other thermoplastic resins such as polyethylene (PE) may be used, and composite fibers having a sheath-core structure such as PE and PP may also be used. In addition, it is also possible that one of the skin side sheets 21 and the non-skin side sheets 22 (for example, the skin side sheets 21) is formed of a spunbonded nonwoven fabric, and the other sheet (for example, the non-skin side sheets 22) is formed of a soft sheet member other than the spunbonded nonwoven fabric. A plurality of dot-shaped (circular) heat-welding portions EB for fusing heat-welding fibers F respectively composed of thermoplastic resins, etc., to each other are scattered on the skin side sheets 21 and the non-skin side sheets 22 (refer to Figure 6By providing the heat-welding portion EB on the skin side sheet 21 (non-skin side sheet 22), the heat-welding fiber F can be kept in a sheet shape. In addition, the heat-welding portion EB does not join the skin side sheet 21 and the non-skin side sheet 22.

[0067] As with the ventral waistline 20, the dorsal waistline 30 has a skin side sheet (one side sheet) 31 and a non-skin side sheet (the other side sheet 32). In the present embodiment, the skin side sheet 31 and the non-skin side sheet 32 ​​are both made of spunbonded nonwoven fabrics. However, it is not limited thereto, and other types of nonwoven fabrics such as SMS (spunbonded / meltblown / spunbonded) nonwoven fabrics may also be used. In addition, in this example, as the structural fiber of the nonwoven fabric, a single fiber of polypropylene (PP) as a representative example of a thermoplastic resin is used, but it is not limited thereto. For example, a single fiber of other thermoplastic resins such as polyethylene (PE) may be used, and a composite fiber having a sheath-core structure such as PE and PP may also be used. In addition, it may be that the sheet (e.g., the skin side sheet 31) of either side of the skin side sheet 31 and the non-skin side sheet 32 ​​is formed by a spunbonded nonwoven fabric, and the sheet (e.g., the non-skin side sheet 32) of the other side is formed by a soft sheet member other than the spunbonded nonwoven fabric. A plurality of dot-shaped (circular) heat-welding portions EB for welding heat-welding fibers F composed of thermoplastic resins, etc., to each other are provided in the skin side sheet 31 and the non-skin side sheet 32. Heat-welding portions EB are provided in the skin side sheet 31 (non-skin side sheet 32) so that the heat-welding fibers F can be kept in a sheet shape. In addition, the heat-welding portions EB do not join the skin side sheet 31 and the non-skin side sheet 32.

[0068] The basic structure of the diaper 1 is described above, but the structure of the diaper 1 is an example and is not limited thereto. For example, in the diaper 1 of the present embodiment, the ventral waistline portion 20 and the dorsal outer covering portions 30, 30E are composed of different components, and the non-skin side of the absorbent body 10 is exposed at the crotch portion. This is not limited thereto, and for example, the diaper may have an outer covering component composed of three components, the ventral waistline portion 20, the dorsal outer covering portions 30, 30E, and the crotch portion connecting them, or may have an outer covering component composed of one component that is continuous from the ventral waistline portion 20 to the dorsal waistline portion 30.

[0069] <<Waist area>>

[0070] The specific structures of the ventral waistline portion 20 and the dorsal waistline portion 30 are described. As described above, the ventral waistline portion 20 and the dorsal waistline portion 30 of the present embodiment have substantially the same structure. Therefore, in the following description, only the ventral waistline portion 20 is described about the contents common to both the ventral waistline portion 20 and the dorsal waistline portion 30. As for the dorsal waistline portion 30, the reference numerals and the like of the components corresponding to the ventral waistline portion 20 are indicated in parentheses as needed, and the specific description is omitted.

[0071] Figure 4 It is an explanatory diagram of the welded portion row R provided in the abdominal waistline portion 20 . Figure 5A and Figure 5B 23 is an explanatory diagram of the installation function of the waist elastic member 23. Figure 4 2 shows the state in which the abdominal waistline portion 20 in the stretched state is stretched in the left-right direction.

[0072] <<Regarding the position limitation of the waist elastic member>>

[0073] The abdominal waistline portion 20 (30) of the present embodiment has a plurality of welded portion rows R, in which a plurality of welded portions 50, 50, ... are arranged in the vertical direction. The plurality of welded portion rows R are arranged at intervals in the horizontal direction. Figure 4 In FIG. 1 , the welded portion row R is depicted as a strip-shaped region extending in the up-down direction, but the actual welded portion row R is formed by arranging a plurality of welded portions 50 at intervals in the up-down direction.

[0074] like Figure 4 As shown, the ventral waistline 20 (30) is provided with a plurality of waist elastic members (elastic members) 23 (33) that can be stretched in the left and right directions at intervals in the up-down direction between the skin side piece 21 (31) and the non-skin side piece 22 (32) joined by a plurality of welding parts 50 (between a pair of pieces). The skin side piece 21 (31) and the non-skin side piece 22 (32) are intermittently joined by a plurality of welding parts 50 dispersedly arranged in the up-down direction and the left and right directions. Thus, the ventral waistline 20 (30) is given elasticity in the left and right directions. That is, the welding parts 50, 50... not only have the function of joining a pair of facing surfaces of the skin side piece 21 (31) and the non-skin side piece 22 (32) to each other, but also have the function of installing the waist elastic member 23 (33) on the skin side piece 21 (31) and the non-skin side piece 22 (32). As a method for forming the welded portion 50 , well-known welding methods such as ultrasonic welding and heat welding can be exemplified.

[0075] The pair of sheets joined by the welding part 50 may be two different sheets, such as the skin side sheet 21 (31) and the non-skin side sheet 22 (32) of the present embodiment, or may be a sheet formed by folding back a sheet to form two layers. In addition, the welding part 50 is not limited to joining only a pair of sheets sandwiching the waist elastic member 23 (33), but may also be a sheet that is stacked with a pair of sheets and joins three or more layers of sheets.

[0076] like Figure 4 As shown, by arranging a plurality of welded portions 50 at predetermined intervals in the vertical direction and the horizontal direction, the softness of the ventral waistline portion 20 (30) can be maintained, and the deterioration of the skin touch when the diaper 1 is worn can be suppressed. If a welded portion is formed that is connected in a long (continuous) linear manner in the vertical direction or the horizontal direction, the nonwoven fabric will become hard at the portion where the welded portion is formed, and it is easy to prevent the nonwoven fabric from deforming in the direction in which the welded portion is formed into a linear (belt-shaped) shape. In contrast, if Figure 4 The welded portion row R in which the small welded portions 50 are dispersedly arranged as shown can provide a soft sheet member that is less likely to make the user (wearer) of the diaper 1 feel the solidification of the nonwoven fabric and is less likely to inhibit deformation in the vertical direction and the horizontal direction.

[0077] In the ventral waistline portion 20 (30), the waist elastic member 23 (33) is attached to the ventral waistline portion 20 (30) by sandwiching the waist elastic member 23 (33) vertically with two welded portions 50, 50 adjacent in the vertical direction among the plurality of welded portions 50 included in the welded portion row R. That is, a pair of welded portions 50, 50 arranged on both sides of the waist elastic member 23 in the vertical direction form a welded portion pair 51, and the elastic member 23 (33) is attached using the welded portion pair 51. Figure 5A and Figure 5B 23 is an explanatory diagram of the installation function of the waist elastic member 23, and is Figure 4 Schematic enlarged view of the X portion in FIG.

[0078] like Figure 5A As shown, a pair of welded portions 50, 50 forming a welded portion pair 51 are arranged at a gap GH50 in the vertical direction. The size of the gap GH50 is set to be the same as or slightly larger than the outer diameter d1 of the waist elastic member 23 when the ventral waist portion 20 is stretched to the maximum in the left-right direction (GH50 ≥ d1).

[0079] However, the waist elastic member 23 becomes thicker as it contracts in the left-right direction. Figure 5BAs shown, compared with the maximum outer shape d2 of the waist elastic member 23 in the state where the waist elastic member 23 is contracted in the left and right directions (i.e., the natural state of the ventral waist circumference 20), the interval GH50 of the welding portion 51 is reduced (GH50<d2). Thus, the waist elastic member 23 in the state of contraction in the left and right directions is sandwiched between the welding portion 51 (the expansion in the up and down directions is limited). Therefore, the position (action) of the waist elastic member 23 relative to the skin side piece 21 and the non-skin side piece 22 in the left and right directions and the up and down directions is limited.

[0080] Therefore, even if the waist elastic member 23 is fixed to the skin side sheet 21 and the non-skin side sheet 22 without using an adhesive, the positional deviation of the waist elastic member 23 can be suppressed, and the elasticity of the ventral waist portion 20 can be maintained. That is, by utilizing the welded portion 50, the waist elastic member 23 can be installed on the skin side sheet 21 and the non-skin side sheet 22 without using an adhesive or reducing the amount of adhesive used. Therefore, the decrease in the softness of the ventral waist portion 20 (elastic sheet 40) caused by the curing of the adhesive can be suppressed. In addition, the decrease in the elastic properties of the waist elastic member 23 caused by the curing of the adhesive can be suppressed.

[0081] In addition, in the ventral waist portion 20 (30), the waist elastic member 23 (33) is fixed to the skin side sheet 21 (31) and the non-skin side sheet 22 (32) in the joining area SS. When manufacturing the diaper 1, the waist elastic member 23 in the stretched state is sandwiched between the skin side sheet 21 and the non-skin side sheet 22 to form the joining area SS, and the end of the waist elastic member 23 is fixed to the joining area SS. Therefore, even if the ventral waist portion 20 (30) is greatly stretched when the diaper 1 is worn, the waist elastic member 23 (33) can be prevented from falling off between the welded portion pair 51, and the elasticity of the ventral waist portion 20 (30) can be maintained.

[0082] In addition, the relationship between the interval GH50 of the welding part pair 51 and the outer diameters d1 and d2 of the waist elastic member 23 is not limited to the above case. For example, it is also possible to overlap a part of the waist elastic member 23 with the welding part 50 to such an extent that the waist elastic member 23 is not broken. In this case, the waist elastic member 23 can also be sandwiched between the welding part pair 51 in a state of contraction in the left-right direction, and the position of the left-right direction and the up-down direction relative to the skin side sheet 21 and the non-skin side sheet 22 is restricted.

[0083] In addition, it is not limited to sandwiching all the waist elastic members 23 (elastic members) arranged on the ventral waist portion 20 into the welding portion pair 51 and restricting their positions. It is sufficient as long as at least a part of the waist elastic members 23 is restricted in position by the welding portion pair 51, and another part of the waist elastic members 23 may be fixed to the skin side sheet 21 and the non-skin side sheet 22 by an adhesive.

[0084] The pair of waist portions 20 and 30 are joined to each other at both side ends in the left-right direction by a pair of joining areas SS. Figure 4 In the figure, the joining area SS is shown as a strip-shaped area extending in the up-down direction, but the actual joining area SS is as follows: Figure 6 As shown in the figure, the joining area SS of the diaper 1 is formed by arranging a plurality of joining portions 70 at intervals in the vertical direction, and is surrounded by a straight line extending along the vertical direction by connecting the left-right ends of the joining portions 70 adjacent to each other in the vertical direction. The joining area SS of the diaper 1 is continuous from the upper end to the lower end of the overlapping portion of the ventral waistline portion 20 and the dorsal waistline portion 30 when viewed in the front-back direction. Figure 6 yes Figure 4 The joining portion 70 of the present embodiment is substantially rectangular in shape, and examples of joining methods include heat welding, ultrasonic welding, and adhesives.

[0085] <<About cutting the waistline after use>>

[0086] When a pants-type absorbent article is removed from the wearer's body after use, one waist portion is generally torn (cut) at a joining region (joined portion) to open the waist opening. Fig. 7A This is a diagram for explaining the structure of a conventional pants-type absorbent article 2. Figure 7B This is a diagram for explaining a state of tearing a conventional pants-type absorbent article 2. Regarding the conventional pants-type absorbent article 2, the same reference numerals are given to the same parts as those of the diaper 1 of the present embodiment.

[0087] Fig. 7A and Figure 7B The shorts-type absorbent article 2 shown is an example of a conventional shorts-type absorbent article. Fig. 7A As shown, the two side ends of the waist circumference 20, 30 of the shorts-type absorbent article 2 are joined by a plurality of joints 70 (joining area SS). The joints 70 of the shorts-type absorbent article 2 are semicircular welded portions arranged intermittently in the up-down direction. The semicircular joints 70 are firmly joined in a manner that does not cause the waist circumference 20, 30 to separate when worn. In order to remove the shorts-type absorbent article 2 from the wearer's body after use, when the ventral waist circumference 20 (the waist circumference on one side) is pulled off by pulling the ventral waist circumference 20 at the joints 70, as shown in FIG. Figure 7B As shown in FIG. 1 , the portion of the ventral waistline portion 20 that is fixed to the dorsal waistline portion 30 (the other waistline portion) by the joint portion 70 tends to remain fixed to the dorsal waistline portion 30. Therefore, the ventral waistline portion 20 after being torn off may have a shape in which the shape of the joint portion 70 is cut off ( Figure 7B ), or the ventral waistline portion 20 may be torn in an unexpected direction near the joint 70. In addition, the action of tearing off the ventral waistline portion 20 along the outline of the joint 70 requires a force to pull up the ventral waistline portion 20. On the other hand, if the joint 70 is provided continuously from the upper end to the lower end of the ventral waistline portion 20 in order to easily cut the ventral waistline portion 20 using the joint 70, the end portions of the waistline portions 20 and 30 may become hard, which may give the wearer a stiff and uncomfortable feeling.

[0088] On the other hand, the diaper 1 can reduce the concern that the joining region SS becomes excessively hard, and can be easily cut along the inner end portion of the joining portion 70 in the left-right direction. Figure 8 Yes Figure 6 A diagram for explanation of the schematic enlarged view of FIG. Figure 8 Omitted Figure 6 The heat-fused fiber F in the figure is not shown, and the folded portion of the non-skin side sheet 22 in the ventral waistline portion 20 is omitted. Figure 6 , Figure 8 In the above description, the heat-welded portion EB of the skin-side sheet 21 is described, but the heat-welded portion EB of the non-skin-side sheet 22 is also described in the same manner.

[0089] As described above, the diaper 1 is provided with a plurality of joining portions 70 along the vertical direction in the joining region SS, and the ventral waistline portion 20 (30) has a skin side sheet 21 and a non-skin side sheet 22, and the skin side sheet 21 and the non-skin side sheet 22 each have a plurality of heat-welded portions EB where heat-welded fibers F are joined to each other. The heat-welded portions EB do not join the skin side sheet 21 and the non-skin side sheet 22. Among the plurality of heat-welded portions EB, a heat-welded portion row R is formed by a heat-welded portion group that is adjacent to each other in the vertical direction in an extended state and has the smallest center position e in the left-right direction. The plurality of heat-welded portions EB in the present embodiment are arranged in a staggered manner, and among the plurality of heat-welded portions EB, there are heat-welded portions EB whose center e in the left-right direction is at the same position, so the heat-welded portion group with the smallest center distance in the left-right direction is the heat-welded portion EB with the same center e in the left-right direction, which is the heat-welded portion row R. The fusion portion row R has a first heat-welded portion EB1 and a second heat-welded portion EB2 at a position that is closer to the inside of the joining portion 70 in the left-right direction. That is, the center e of the first heat weld portion EB1 in the left-right direction is also the center e of the second heat weld portion EB2 in the left-right direction.

[0090] In the diaper 1, the vertical interval D70 between the joints 70 is wider than the vertical length H70 of the joints 70, and the vertical interval D70 between the joints 70 is narrower than the vertical interval DEB between the first heat-welding portion EB1 and the second heat-welding portion EB2 (H70<D70<DEB). In the diaper 1, the left-right center e of the first heat-welding portion EB1 is the same as the left-right center e of the second heat-welding portion EB2, and the first heat-welding portion EB1 and the second heat-welding portion EB2 are arranged in the vertical direction, so the vertical interval DEB between the first heat-welding portion EB1 and the second heat-welding portion EB2 is also the vertical interval between the first heat-welding portion EB1 and the second heat-welding portion EB2.

[0091] like Figure 8 As shown, a plurality of joining portions 70 of substantially the same size and shape are arranged at equal intervals (D70) in the vertical direction in the joining region SS of the diaper 1. A plurality of heat-sealed portions EB of substantially the same size and shape are arranged at equal intervals in a staggered manner.

[0092] Therefore, compared with the situation where the vertical interval D70 between the joints 70 is not wider than the vertical length H70 of the joints 70 and the vertical interval D70 between the joints 70 is not narrower than the interval DEB between the first heat weld part EB1 and the second heat weld part EB2, the concern about excessive hardening of the joint area SS can be reduced, and the inner end 70e along the left-right direction of the joint 70 is easy to tear after use.

[0093] Generally speaking, the rigidity of the joint 70 is higher than that of a portion not provided with the joint 70. Therefore, since the both side ends of the diaper 1 become harder as the joint 70 is formed wider, in the diaper 1, by setting the vertical distance D70 between the joints 70 to be wider than the vertical length H70 of the joint 70, the concern that the joint area SS becomes too hard can be reduced.

[0094] Furthermore, by making the vertical distance D70 between the joints 70 narrower than the vertical distance DEB between the first heat weld EB1 and the second weld EB2, tearing along the cutting line L at the inner end 70e of the joint 70 in the horizontal direction is facilitated. Fig. 9 This is a diagram for explaining a state in which the diaper 1 is torn.

[0095] like Figure 8As shown in FIG. 1 , in the diaper 1, the cutting line L is an imaginary line connecting the inner end 70e of the joining portion 70 in the left-right direction and the straight line s in the vertical direction. The straight line s connects the upper end 70e and the lower end 70e of the joining portions 70 adjacent to each other in the vertical direction and runs along the vertical direction. The straight line s is the shortest distance between the upper end 70e and the lower end 70e. Figure 6 and Figure 8 In the figure, for convenience, the cutting line L is indicated by a thick double-dashed line. The end 70e on the inner side of the joint 70 in the left-right direction in the cutting line L is a portion where the rigidity difference occurs due to the joint 70, and therefore, it is easy to cut along the inner side end of the joint 70 in the left-right direction. On the other hand, the straight line s portion in the cutting line L is a portion where the rigidity difference is small and it is easy to mistakenly cut in an unexpected direction, but by making the vertical distance D70 between the joints 70 narrower than the vertical distance DEB between the first heat-welded portion EB1 and the second welded portion EB2, it is easy for the force for cutting along the inner side end of the joint 70 in the left-right direction to act directly on the cutting line L, and therefore, it is easy to cut along the cutting line L. Therefore, the cutting line L becomes a cutting line like a perforated line, such as Fig. 9 As shown, the abdominal waistline portion 20 can be efficiently cut along the cutting line L with a small force. In addition, the fear of tearing the abdominal waistline portion 20 in an unexpected direction can also be reduced.

[0096] In addition, regarding the cutting line L, by continuously setting the inner end 70e and the straight line s of the joining portion 70 adjacent to each other in the vertical direction in the left-right direction, the cutting line L can be made into a continuous shape, so that it is easy to efficiently cut the ventral waistline 20 along the cutting line L. Moreover, in the cutting line L, it is more preferred that the inner end 70e and the straight line s of the joining portion 70 in the left-right direction are a straight line without bending. Thus, since the cutting line L can be made into a straight line, it is easy to efficiently cut the ventral waistline 20 with a lighter force. In addition, the cutting line L of the diaper 1 of the present embodiment is along the vertical direction (parallel to the vertical direction), but it is not limited thereto. The cutting line L can have an inclination relative to the vertical direction, or it can be a sawtooth shape or a wave shape accompanied by bending or curvature. The shape of the cutting line L can be changed according to the shape and configuration of the joining portion 70. By changing the shape and arrangement of the joint 70 and changing the shape of the cutting line L, the joint strength of the joint 70 can be adjusted, or the feel on the wearer's skin caused by the rigidity of the joint 70 can be adjusted.

[0097] Regarding the joint portion 70 in the joint area SS, it is preferable that the length W70 of the joint portion 70 in the left-right direction is longer than the length H70 of the joint portion 70 in the upper-lower direction (H70<W70). Thus, compared with the case where the length H70 of the joint portion 70 in the upper-lower direction is shorter than the length W70 in the left-right direction, it is easy to increase the joint strength of the joint portion 70, and it is easy to tear the abdominal waistline portion 20 along the inner end 70e of the joint portion 70 after use.

[0098] In the joint portion 70, it is preferred that the interval D70 between the joint portions 70 in the vertical direction is narrower than the length W70 in the horizontal direction of the joint portion 70 (D70<W70). Thus, compared with the case where the interval D70 between the joint portions 70 in the vertical direction is wider than the length W70 in the horizontal direction of the joint portion 70, it is easy to increase the joint strength of the joint portion 70, and it is easy to tear the abdominal waistline portion 20 along the inner end portion 70e in the horizontal direction of the joint portion 70 after use.

[0099] In addition, it is preferable that the length H70 of the joint 70 in the vertical direction is shorter than the length HEB of the first heat weld EB1 (heat weld EB) in the vertical direction (H70<HEB). Since the longer the length H70 of the joint 70 in the vertical direction is, the higher the rigidity of the joint area SS becomes, therefore, by making the length H70 of the joint 70 in the vertical direction shorter than the length HEB of the first heat weld EB1 in the vertical direction, the concern that the joint area SS becomes excessively hard can be reduced compared to the case where the length H70 of the joint 70 in the vertical direction is longer than the length HEB of the first heat weld EB1 in the vertical direction.

[0100] In the ventral waist portion 20 of the diaper 1, a plurality of waist elastic members 23 that can be stretched in the left-right direction are arranged at intervals in the vertical direction between the skin side sheet 21 and the non-skin side sheet 22. In the diaper 1, it is preferred that the vertical length H70 of the joint 70 is greater than the thickness d2 of the elastic member in the natural state (refer to Figure 5B In addition, it is more preferable that the length H70 of the joining portion 70 in the vertical direction is shorter than the thickness d1 of the elastic member in the stretched state.

[0101] When manufacturing the diaper 1, the joint 70 (joining area SS) is formed in a state where the waist elastic member 23 in the stretched state is sandwiched between the skin side sheet 21 and the non-skin side sheet 22. At this time, although the end of the waist elastic member 23 is fixed to the joining area SS, if the joint 70 based on the welding is formed at a position overlapping with the waist elastic member 23 when the diaper 1 is observed in the thickness direction, the waist elastic member 23 may be cut. In contrast, by making the length H70 of the joint 70 in the vertical direction shorter than the thickness d2 of the elastic member in the natural state, and more preferably, by making the length H70 of the joint 70 in the vertical direction shorter than the thickness d1 of the elastic member in the stretched state, the concern that the waist elastic member 23 is cut by the joint 70 can be reduced. If the length H70 of the joint 70 in the up-down direction is made shorter than the thickness d2, d1 of the elastic member, it can be made difficult for the waist elastic member 23 and the joint 70 to overlap when the joint 70 is formed, or, even if the waist elastic member 23 and the joint 70 overlap, only a part of the waist elastic member 23 is missing, which can reduce the concern of completely breaking the waist elastic member 23.

[0102] In particular, when the waist elastic member 23 is attached to the skin side sheet 21 and the non-skin side sheet 22 without using an adhesive or with a reduced amount of adhesive in the fixing of the waist elastic member 23 as in the diaper 1, it is important to fix the waist elastic member 23 using the joining area SS. In such a case, in order to reduce the concern of cutting of the waist elastic member 23, it is preferred that the length H70 of the joining portion 70 in the vertical direction is shorter than the thickness d2 and d1 of the elastic member.

[0103] In the ventral waistline portion 20, it is preferred that the plurality of waist elastic members 23 are arranged away from each other in the vertical direction. This can reduce the concern that the waist elastic members 23 excessively tighten the wearer's body when worn, and reduce the concern that the plurality of waist elastic members 23 hinder the cutting of the ventral waistline portion 20 when the ventral waistline portion 20 is cut after use.

[0104] In addition, as described above, each waist elastic member 23 is sandwiched between the welding portion pair 51 (a pair of welding portions 50, 50) under the state of contraction in the left-right direction, thereby limiting the position of the upper and lower directions relative to the skin side sheet 21 and the non-skin side sheet 22. In this case, it is preferred that the length W70 of the left-right direction of the junction 70 is longer than the length W50 of the left-right direction of the welding portion 50 (W70>W50). In order to maintain the shorts-type state, it is required to more firmly join the joining area SS of the diaper 1. Therefore, by making the length W70 of the left-right direction of the junction 70 longer than the length W50 of the left-right direction of the welding portion 50, the joining strength of the joining area SS can be improved compared with the case where the length W70 of the left-right direction of the junction 70 is shorter than the length W50 of the left-right direction of the welding portion 50.

[0105] Regarding the welded portion 50, it is preferable that the area S70 of the joint portion 70 is larger than the area S50 of the welded portion 50 (S70>S50). By making the area 70 of one joint portion 70 in the bonding area SS larger than the area S50 of one welded portion 50, the joint of the joint area SS can be made stronger and the inner end 70e of the joint portion 70 in the left-right direction can be easily torn after use, compared with the case where the area S70 of the joint portion 70 is smaller than the area S50 of the welded portion 50.

[0106] The area S70 of the joint 70 may be less than or equal to the area S50 of the welded portion 50 (S70 ≤ S50). This can reduce the possibility of excessive hardening of the joint region SS compared to the case where the area S70 of the joint 70 is larger than the area S50 of the welded portion 50.

[0107] In addition, it is preferable that the interval DEB between the first heat-welded portion EB1 and the second heat-welded portion EB2 is wider than twice the sum of the length H70 of the joining portion 70 in the vertical direction and the interval D70 between the joining portions 70 in the vertical direction (DEB>(H70+D70)×2). Thus, compared with the case where the interval DEB between the first heat-welded portion EB1 and the second heat-welded portion EB2 is narrower than twice the sum of the length H70 of the joining portion 70 in the vertical direction and the interval D70 between the joining portions 70 in the vertical direction, it is easier to tear the ventral waistline portion 20 along the inner end portion 70e in the left-right direction of the joining portion 70 after use.

[0108] Preferably, the left-right length W70 of the joint 70 is longer than the left-right length WEB of the first heat weld EB1 (W70>WEB). Thus, the joint strength of the joint area SS can be improved compared to the case where the left-right length W70 of the joint 70 is shorter than the left-right length WEB of the first heat weld EB1.

[0109] In addition, it is preferable that the area S70 of one of the joint portions 70 in the joint region SS is larger than the area SEB of the first heat-welded portion EB1 (S70>SEB). Thus, compared with the case where the area S70 of the joint portion 70 is smaller than the area SEB of the first heat-welded portion EB1, the joint of the joint region SS can be made firmer, and the abdominal waistline portion 20 can be easily torn along the inner end 70e of the joint portion 70 in the left-right direction after use.

[0110] The area S70 of the joint 70 may be smaller than the area SEB of the first heat weld EB1 (S70 ≤ SEB). This can reduce the concern that the joint region SS becomes excessively hard compared to when the area S70 of the joint 70 is larger than the area SEB of the first heat weld EB1.

[0111] In this embodiment ( Figure 4 In the embodiment of the present invention, each welded portion row R is arranged straightly in the vertical direction, but the welded portion row R can also be bent in the left-right direction. The plurality of welded portions 50 constituting the welded portion row R can also be arranged offset in the left-right direction ( Fig. 10A ). In addition, in the present embodiment, the plurality of welded portion rows R are arranged at substantially equal intervals in the left-right direction, but the left-right intervals of the plurality of welded portion rows R can be arbitrarily changed. For example, in the abdominal waistline portion 20, the left-right intervals of the plurality of welded portion rows R at the left-right end portions are shortened, and the left-right intervals of the plurality of welded portion rows R at the left-right center portions are lengthened.

[0112] like Fig. 10A As shown, the ventral waistline portion 20 (30) may also have two types of welded portion arrays, namely, "hollow welded portion array Ra" and "normal welded portion array Rb". The following describes a modified example of the welded portion array R. In addition, regarding the shorts-type absorbent article of the modified example, the same reference numerals are given to the parts having the same structure as the above-mentioned diaper 1, and the description thereof is omitted. Fig. 10A 2 is a diagram for explaining welded portion arrays Ra and Rb according to a modified example. Fig. 10B It is an explanatory diagram of the hollow welded portion pair 51a. Fig.11A 51a is an explanatory diagram of the hollow welded portion pair 51a in the extended state. Fig. 11B and Fig. 11C It is an explanatory diagram of the hollow welded portion pair 51a in a contracted state.

[0113] In the ventral waistline portion 20 of the modified example, a plurality of welded portion rows Ra and Rb are arranged at a predetermined interval D1 in the left-right direction. As the interval D1 in the left-right direction of the welded portion rows Ra and Rb, a length of about 4 to 14 times the length La of the welded portion 50 in the left-right direction can be exemplified, and the plurality of welded portion rows Ra and Rb are arranged at a relatively wide interval. Hereinafter, the welded portion pair 51 sandwiching the waist elastic member 23 in the welded portion 50 belonging to the hollow welded portion row Ra is referred to as a "hollow welded portion pair 51a", and the welded portion pair 51 sandwiching the waist elastic member 23 in the welded portion 50 belonging to the normal welded portion row Rb is referred to as a "normal welded portion pair 51b".

[0114] like Fig. 10A As shown, in the normal welded portion row Rb, the welded portions 50 are arranged in a row in the vertical direction. Therefore, the normal welded portion pair 51b is composed of two welded portions 50 disposed one each on both sides of the waist elastic member 23 in the vertical direction.

[0115] On the other hand, in the hollow welded portion row Ra, a group of two welded portions 50 adjacent to each other at a narrow interval in the left-right direction is arranged in the up-down direction, and is composed of two rows of welded portion rows. Fig. 10B As shown, the hollow welded portion pair 51 a is composed of four welded portions 50 , two of which are disposed on both sides of the waist elastic member 23 in the up-down direction.

[0116] exist Fig. 10B In the embodiment, the hollow welded portion pair 51a arranged near the joining area SS is referred to as the "first hollow welded portion pair 51a1 (first welded portion pair)". The hollow welded portion pair 51a located next to one side in the left-right direction is referred to as the "second hollow welded portion pair 51a2 (second welded portion pair)". The first hollow welded portion pair 51a1 and the second hollow welded portion pair 51a2 together sandwich the same waist elastic member 23 (first elastic member).

[0117] The first hollow welded portion pair 51 a 1 includes a first welded portion 501 and a second welded portion 502 , which are located at the same side (here, the lower side) in the up-down direction with respect to the waist elastic member 23 and are separated by a first interval S1 in the left-right direction.

[0118] Furthermore, when the abdominal waistline portion 20 is stretched in the left-right direction, the left-right length D1 (first length) from the end of one side of the first hollow welded portion pair 51a1 in the left-right direction to the end of the other side of the second hollow welded portion pair 51a2 in the left-right direction is longer than the left-right length Lb of the first interval S1 (D1>Lb).

[0119] In the following description, the length D1 is also referred to as the "welded portion pair interval D1". In addition, the left-right length Lb of the first interval S1 refers to the length from the end of the other side of the first welded portion 501 in the left-right direction (the second welded portion 502 side) to the end of the one side of the second welded portion 502 in the left-right direction (the first welded portion 501 side).

[0120] As described above, in the hollow welded portion pair 51a, a portion of the welded portion 50 is hollow on one side of the waist elastic member 23 in the vertical direction, and a non-welded portion 52 is formed between the welded portions (501 and 502) arranged in the left-right direction. The non-welded portion 52 is a region having a length substantially equal to the left-right length Lb of the first interval S1 and is narrower than the welded portion pair interval D1. Therefore, when the waist elastic member 23 contracts ( Fig. 11B ), the two welded parts (501 and 502) on both outer sides of the non-welded part 52 are close to each other, and the skin side sheet 21 and the non-skin side sheet 22 (hereinafter also referred to as "sheets 21, 22") located in the non-welded part 52 are sandwiched by the two welded parts (501 and 502). As a result, in the non-welded part 52, the density of the fibers constituting the sheets 21, 22 is increased.

[0121] By providing the non-welded portion 52 with a spacing Lb narrower than the spacing D1 of the welded portion pair as in the hollow welded portion pair 51a, when the waist elastic member 23 contracts, the sheets 21 and 22 of the non-welded portion 52 can be sandwiched by the welded portions (501 and 502), and the fiber density of the sheets 21 and 22 can be increased in the non-welded portion 52. Specifically, Lb is preferably 2.54 mm or less, and more preferably about 0.5 mm. As a result, in the non-welded portion 52, dense fibers are easily wound around the waist elastic member 23, and the movement of the waist elastic member 23 can be restricted. Therefore, it is possible to suppress the waist elastic member 23 from falling off from the hollow welded portion pair 51a.

[0122] In particular, in the pants-type diaper 1, in the process of forming the side joint SS when manufacturing the diaper 1, the sheets 21 and 22 are relatively strongly welded, so the waist elastic member 23 may be broken. In addition, when the diaper 1 is worn, when the adhesive region SS is held and the diaper 1 is pulled up, a strong pulling force acts on the adhesive region SS, and the waist elastic member 23 may be broken. Even if the waist elastic member 23 is separated from the adhesive region SS, the waist elastic member 23 contracted from the adhesive region SS is restrained by the hollow welded portion pair 51a, and the waist elastic member 23 can be prevented from falling off from the hollow welded portion pair 51a. Therefore, the reduction in the elasticity of the ventral waist portion 20 can be suppressed.

[0123] In addition, in the hollow welded portion pair 51a, the non-welded portion 52 is provided in a part in the left-right direction. Therefore, compared with the case where the normal welded portion pair 51b having the same length Lc as the hollow welded portion pair 51a is provided, the area ratio of the welded portion 50 in the left-right direction can be suppressed, and the flexibility of the abdominal waistline portion 20 can be ensured. In addition, the non-welded portion 52 easily becomes the bending base point of the abdominal waistline portion 20 in the left-right direction. Therefore, the abdominal waistline portion 20 is easy to bend in the left-right direction and is easy to fit the waistline of the wearer.

[0124] As described above, by providing the hollow welded portion pair 51a in the ventral waistline portion 20, it is possible to suppress the waist elastic member 23 from falling off, suppress the decrease in elasticity, and ensure the softness of the ventral waistline portion 20. That is, the position of the waist elastic member 23 relative to the sheets 21 and 22 can be restricted by the welded portion pair 51, and the softness of the ventral waistline portion 20 can be ensured by suppressing the amount of adhesive used.

[0125] In addition, in the ventral waistline portion 20 illustrated in FIG. 10 , a hollow welded portion row Ra (a hollow welded portion pair 51a) having a shape that is bent in the left-right direction is arranged near the bonding area SS and near the side of the absorbent body 10. However, the shape, number, and arrangement position of the hollow welded portion row Ra are not particularly limited, and the ventral waistline portion 20 only needs to have at least one hollow welded portion pair 51a. In addition, in FIG. 10 , the shape of the welded portion 50 is a parallelogram, but the shape of the welded portion 50 is not particularly limited. In addition, the shapes of the multiple welded portions 50 of each welded portion row Ra, Rb may be the same or different.

[0126] In addition, all the welded portion rows provided in the ventral waist circumference portion 20 may be hollow welded portion rows Ra, but it is preferred that a normal welded portion row Rb consisting of one row and a hollow welded portion row Ra are mixed. Thus, the waist elastic member 23 can be prevented from falling off from the welded portion pair 51, and the softness of the ventral waist circumference portion 20 can be ensured.

[0127] In the present embodiment, the welding part 50 and the joining part 70 are respectively rectangular in shape and arranged in the up-down direction and the left-right direction, the heat-welding part EB is circular in shape and a plurality of heat-welding parts EB are arranged in a staggered manner, but the present invention is not limited thereto. The welding part 50, the joining part 70 and the heat-welding part EB can be respectively arbitrarily shaped and arranged in an arbitrary manner.

[0128] The joint portion 70 is not limited to a rectangular shape, and may be any shape such as a circular shape, an elliptical shape, a semicircular shape, etc. However, it is preferred that the inner end 70e of the joint portion 70 in the left-right direction is along the up-down direction. By making the inner end 70e of the joint portion 70 in the left-right direction along the up-down direction, it is easy to cut the abdominal waistline portion 20 along the cutting line L after use.

[0129] In addition, the heat-welding portions EB are not limited to circular shapes, and may be rectangular or elliptical shapes or other arbitrary shapes. In addition, the arrangement of the heat-welding portions EB is not limited to a staggered arrangement. They may be arranged in a grid-like manner at equal intervals, or may be arranged in a state not along the up-down direction or the left-right direction, or may be arranged at unequal intervals.

[0130] Fig.12 It is a diagram showing a modified example of the heat welding portion EB. Fig.12 The plurality of heat-welded portions EB of the modified example shown are arranged in a staggered manner in the stretched state, but the plurality of heat-welded portions EB are arranged in a state slightly offset from the vertical direction and the horizontal direction. In this case, the plurality of heat-welded portions EB are arranged in a state slightly offset from the vertical direction and the horizontal direction. Fig.12 The heat-welding portion group surrounded by the double-dashed line in the figure forms a heat-welding portion row E along the up-down direction. The heat-welding portion row E may also include a first heat-welding portion EB1 and a second heat-welding portion EB2. In this case, the interval DEB between the first heat-welding portion EB1 and the second heat-welding portion EB2 is the shortest distance DEB of a straight line connecting the outer end of the first heat-welding portion EB1 and the outer end of the second heat-welding portion EB2.

[0131] <About the manufacturing method of the diaper 1>

[0132] Next, a method for manufacturing the diaper 1 will be described. The diaper 1 is manufactured by a production line 100 . Fig.13 This is a schematic plan view partially showing in perspective how the diaper 1 is manufactured using the production line 100 .

[0133] In the production line 100, for example, the two nonwoven fabrics 21 and 22 (equivalent to the skin side sheet 21 and the non-skin side sheet 22) involved in the ventral waistline portion 20 are respectively transported in the form of continuous sheets 21a and 22a (equivalent to the continuum of each sheet) continuous along the conveying direction, and similarly, the two nonwoven fabrics 31 and 32 (equivalent to the skin side sheet 31 and the non-skin side sheet 32) involved in the back waistline portion 30 are also transported in the form of continuous sheets 31a and 32a (equivalent to the continuum of each sheet) continuous along the conveying direction. And, whenever each of the two continuous sheets 21a, 22a, 31a, 32a passes through a plurality of processing positions PK1 to PK5 set along the conveying direction, each of the two continuous sheets 21a, 22a, 31a, 32a is processed corresponding to each processing position PK1, PK2...

[0134] In addition, here, when the direction orthogonal to both the thickness direction and the conveying direction of the continuous sheets 21a, 22a, 31a, 32a is defined as the "CD direction", in this example, the two continuous sheets 21a, 22a, 31a, 32a, i.e., the two continuous sheets 21a, 22a involved in the ventral waistline portion 20 and the two continuous sheets 31a, 32a involved in the dorsal waistline portion 30 are arranged in the CD direction and conveyed. However, the present invention is not limited to this at all.

[0135] In addition, in this example, as the above-mentioned multiple processing positions, the first processing position PK1 to the fifth processing position PK5 are arranged in this order from upstream to downstream in the conveying direction. And, for the processing at each processing position PK1, PK2..., the processing performed on the two continuous sheets 21a, 22a involved in the ventral waistline portion 20 and the processing performed on the two continuous sheets 31a, 32a involved in the dorsal waistline portion 30 are substantially the same.

[0136] Therefore, the following description of the common contents is not distinguished between the ventral waistline portion 20 and the dorsal waistline portion 30. For example, the description is abbreviated as "belt member 20 (30)" or "two continuous sheets 21a, 22a (31a, 32a)". In this case, the reference numerals immediately following the terms representing each member, such as "continuous sheets 21a, 22a (31a, 32a)", "elastic member 23 (33)", "continuous body 23a (33a) of elastic members", etc., are reference numerals of the members involved in the ventral waistline portion 20, and the reference numerals in parentheses following thereafter are reference numerals of the members involved in the dorsal waistline portion 30.

[0137] like Fig.13As shown, the conveyance of the two continuous sheets 21a, 22a (31a, 32a) involved in each belt member 20 (30) is carried out in a so-called cross-flow form. That is, the two continuous sheets 21a, 22a (31a, 32a) are conveyed in a posture with a direction corresponding to the left-right direction of the diaper 1 facing the conveying direction. Therefore, a boundary position PBL between the diapers 1, 1 adjacent to each other in the left-right direction is virtually set at the product pitch P1 along the conveying direction of the two continuous sheets 21a, 22a (31a, 32a). And, at the fifth processing position PK5 located at the terminal end of the production line, the two continuous sheets 21a, 22a (31a, 32a) are cut using the boundary position PBL as the cutting object position PC, thereby generating a single-piece diaper 1.

[0138] In addition, the conveyance of the two continuous sheets 21a, 22a (31a, 32a) involved in each belt member 20 (30) is carried out by using a suitable conveying device (not shown) such as a belt conveyor and a conveying roller. Therefore, unless otherwise specified, it is assumed that the two continuous sheets 21a, 22a (31a, 32a) are conveyed along the conveying direction by using these conveying devices. As an example of a belt conveyor, a conventional belt conveyor having an endless belt driven to rotate as a conveying surface, a suction belt conveyor having an adsorption function on the outer peripheral surface of the endless belt, etc. can be cited.

[0139] When manufacturing the diaper 1, Fig.13 As shown, first, the two continuous sheets 21a, 22a (31a, 32a) involved in each belt member 20 (30) pass through the first processing position PK1. And, when passing through, the two continuous sheets 21a, 22a (31a, 32a) are overlapped with each other in the thickness direction. In addition, when overlapping, the continuous body 23a, 23a... (33a, 33a...) of the elastic member continuous in the conveying direction is stretched in the conveying direction at the above-mentioned target stretching ratio, and is sandwiched between a pair of mutually facing surfaces 21ast, 22ast (31ast, 32ast) of the two continuous sheets 21a, 22a (31a, 32a) in a manner of arranging a plurality of them in the CD direction.

[0140] In addition, at the same time as or immediately after the overlap, the above-mentioned welded portions 50, 50... are formed as joining portions between the two continuous sheets 21a, 22a (31a, 32a), thereby utilizing the welded portions 50, 50... to join a pair of facing surfaces 21ast, 22ast (31ast, 32ast) of the two continuous sheets 21a, 22a (31a, 32a) to each other.

[0141] Here, in the production line 100, the left-right direction of the diaper 1 is along the conveying direction, and the up-down direction of the diaper 1 is along the CD direction. Therefore, the welded portions 50 are formed in pairs on both sides of the continuous body 23a (33a) of the elastic member in the CD direction. That is, a pair of welded portions 50, 50 arranged on both sides of the continuous body 23a (33a) of the elastic member in the CD direction form a welded portion pair 51 with each other. And, the welded portion pair 51 is formed in a plurality of pairs arranged in the conveying direction with intervals between the welded portion pairs 51 adjacent to the welded portion pairs 51 in the conveying direction (refer to Figure 4 wait).

[0142] The formation of the welded portion 50 can be performed using, for example, a heat sealing device or an ultrasonic welding device. In addition, the heat sealing device, for example, has a pair of rollers that are heated while rotating along the conveying direction. One roller is a heat embossing roller having convex portions corresponding to each welded portion 50 on the outer peripheral surface, and the other roller is an anvil roller that receives the convex portions with a smooth outer peripheral surface. In addition, an ultrasonic welding device can also be used.

[0143] Next, if Fig.13 As shown, the two continuous sheets 21a, 22a involved in the ventral waistline portion 20 and the two continuous sheets 31a, 32a involved in the dorsal waistline portion 30 pass through the second processing position PK2. And, when they pass, the single-sheet absorbent body 10 generated in other processes (not shown) is laid and fixed between the two continuous sheets 21a, 22a involved in the ventral waistline portion 20 and the two continuous sheets 31a, 32a involved in the dorsal waistline portion 30, thereby forming a continuous body 1hs of diapers in a roughly ladder shape formed by continuously unfolding diapers 1h, 1h... in a roughly H shape. The fixing of the absorbent body 10 can be performed, for example, using a rotating drum device not shown. The rotating drum device, for example, has a rotating drum that rotates along the conveying direction, and the rotating drum has a plurality of retaining portions on the outer peripheral surface that can retain the absorbent body 10 in a detachable manner.

[0144] Next, the approximately ladder-shaped diaper continuum 1hs passes through the third processing position PK3. And, when it passes through, the main body 10 is folded in half at a predetermined position CL1 in the CD direction in the absorbent main body 10, thereby making the two continuous sheets 21a, 22a involved in the ventral waistline portion 20 and the two continuous sheets 31a, 32a involved in the dorsal waistline portion 30 overlap in the thickness direction. This folding can be performed, for example, using a bending guide device not shown. The bending guide device has, for example, a guide plate and a guide roller arranged at a predetermined position in the conveying direction. And, these guide plates and guide rollers guide the approximately ladder-shaped diaper continuum 1hs passing through their arrangement positions in such a way that the continuum 1hs becomes a folded shape.

[0145] Next, the diaper continuum 1hsb in the folded state passes through the fourth processing position PK4. And, while passing through, the two continuous sheets 21a, 22a of the ventral waistline portion 20 and the two continuous sheets 31a, 32a of the dorsal waistline portion 30 overlapped in the thickness direction are welded and joined by ultrasonic welding devices 200 (described later) at the positions on both sides of the cutting target position PC in the conveying direction, and a pair of joints 70, 70 are formed, thereby fixing the diaper continuum 1hsb in the folded state. And, as a result, a diaper continuum 1s of shorts-type diapers 1, 1... connected in the left-right direction is generated.

[0146] The bonding area SS has a plurality of joints 70, 70, 70... arranged in the CD direction (vertical direction). In addition, each of the joints 70, 70, 70... fuses the continuous sheet 21a of the ventral waistline portion 20 and the continuous sheet 31a of the dorsal waistline portion 30, and also fuses a pair of facing surfaces 21ast, 22ast of the continuous sheets 21a, 22a of the ventral waistline portion 20 to each other, and also fuses a pair of facing surfaces 31ast, 32ast of the continuous sheets 31a, 32a of the dorsal waistline portion 30 to each other.

[0147] Fig.14 This is an explanatory diagram of the processing performed at the fourth processing position PK4. That is, it is a schematic perspective view of the ultrasonic welding device 200 as a main device constituting the processing as viewed from the upper front.

[0148] like Fig.14 As shown, the ultrasonic welding device 200 at the fourth processing position PK4 includes: a rotating drum 300 with a roughly cylindrical shape, which rotates in one direction around a central axis C30 along the CD direction; and a plurality of ultrasonic processing units 600, 600..., which rotate around the above-mentioned central axis C30 together with the rotating drum 300, and the diaper continuum 1hsb conveyed from the previous process is wound up and sent to the next process in a state where there is roughly no relative sliding between the outer peripheral surface 300s of the rotating drum 300 and the diaper continuum 1hsb.

[0149] In addition, each ultrasonic processing unit 600, 600 ... is provided at a predetermined angle (for example, 90 degrees) in the rotation direction Dc30 of the rotating drum 30. Each ultrasonic processing unit 60 includes: a horn 61 which is arranged on the outer peripheral surface 300s of the rotating drum 300 so as not to be relatively movable and performs ultrasonic vibration; and a roller-shaped anvil 71 which is arranged at a position outside the horn 61 in the rotation radius direction Dr300 of the rotating drum 300 in order to sandwich the diaper continuum 1hsb together with the horn 61.

[0150] The horn 61 is extended in the CD direction to form a track shape, and the roller-shaped anvil 71 can roll in the CD direction relative to the track-shaped horn 61, thereby the anvil roller 71 can reciprocate in the CD direction relative to the portion 1ap of the diaper continuum 1hsb mounted on the horn 61. Therefore, during the reciprocating movement, the horn 61 selectively inputs ultrasonic energy to the portion 1ap of the diaper continuum 1hsb sandwiched between the anvil roller 71 and the horn 61, and the joint portion 70 is formed in the above-mentioned portion 1ap of the diaper continuum 1hsb, and the joint area SS is formed.

[0151] Thus, by using the ultrasonic welding device 200, ultrasonic bonding can be performed without the horn 61 and the anvil 71 moving relative to the bonding portion 70. Therefore, even when a plurality of small bonding portions 70 are formed as in the diaper 1, it is easy to reliably form the bonding portion 70 at an accurate position.

[0152] The joining portion 70 may be formed by using, for example, a heat sealing device (not shown).

[0153] The heat sealing device includes, for example, a pair of heated rollers rotating in the conveying direction, one roller being a heat embossing roller having convex portions corresponding to the shape of the bonding portion 70 on its outer circumference, and the other roller being an anvil roller receiving the convex portions with a smooth outer circumference.

[0154] Next, if Fig.13 As shown, the continuous body 1s of the pants-type diaper passes through the fifth processing position PK5. When passing through, the continuous body 1s is cut at the cutting target position PC located between the pair of joining parts 70, 70, thereby manufacturing the diaper 1.

[0155] The cutting can be performed using a cutting device (not shown), for example. The cutting device has, for example, a pair of rollers rotating along the conveying direction. One roller is a cutting roller having a cutting blade on its outer circumference, and the other roller is an anvil roller receiving the cutting blade on its outer circumference.

[0156] ===Other Implementation Methods===

[0157] Above, the embodiments of the present invention have been described, but the above-mentioned embodiments are used to make the understanding of the present invention easy, and are not used to explain the present invention in a limiting manner. In addition, the present invention can certainly be changed and improved without departing from its purpose, and its equivalent is included in the present invention. For example, deformation as shown below can be performed.

[0158] In the above embodiment, the skin side sheet 21 and the non-skin side sheet 22 of the ventral waist circumference portion 20 are both provided with the heat-welding fiber F and the heat-welding portion EB, but the present invention is not limited thereto. Alternatively, the skin side sheet 21 (31) and the non-skin side sheet 22 (32) of the ventral waist circumference portion 20 (30) may be provided with the heat-welding portion EB.

[0159] Furthermore, in the above-mentioned embodiment, the embodiment in which the ventral waistline portion 20 is torn (cut) after use is described, but the dorsal waistline portion 30 may be torn after use.

[0160] Description of Reference Numerals

[0161] 1. Diapers (pants-type absorbent articles, pants-type disposable diapers),

[0162] 10 Absorbent body,

[0163] 11. Absorbent core,

[0164] 12 top sheet, 13 back sheet, 14 outer sheet,

[0165] 20 ventral waist circumference (waist circumference),

[0166] 21 skin side piece (one side piece), 22 non-skin side piece (the other side piece),

[0167] 23 waist elastic member (elastic member),

[0168] 30 back waist (waist), 30E extension,

[0169] 31 skin side piece (one side piece), 32 non-skin side piece (the other side piece),

[0170] 33 waist elastic member (elastic member),

[0171] 50 welding part, 51 welding part pair,

[0172] 70 joint portion, 70e inner end in the left-right direction,

[0173] EB heat welding part, R welding part series,

[0174] SS joint area,

[0175] L cutting line,

[0176] 100 production lines,

[0177] 200 ultrasonic welding device,

[0178] 71 anvil (anvil roller), 61 welding head,

[0179] BH waist opening, LH leg opening.

Claims

1. A shorts-type absorbent article having mutually intersecting up-down directions, left-right directions, and front-back directions, The pants-type absorbent article comprises a pair of waist parts and a liquid-absorbing absorbent body. The pair of waist parts are joined to each other at both side ends in the left-right direction by a pair of joining areas, characterized in that: The joint area has a plurality of joint portions along the up-down direction, The waistline portion has a side panel and another side panel, At least one of the one side sheet and the other side sheet has a plurality of heat-welded portions where heat-welded fibers are bonded to each other. In the extended state, A heat-welding portion row along the up-down direction is formed by a heat-welding portion group adjacent to each other in the up-down direction and having the smallest center distance in the left-right direction, The heat-welded portion does not join the one side sheet to the other side sheet. The heat-welding portion array includes a first heat-welding portion and a second heat-welding portion located on the inner side of the joining portion in the left-right direction. The vertical distance between the bonding portions is wider than the vertical length of the bonding portion, and is narrower than the distance between the first thermal welding portion and the second thermal welding portion.

2. The pants-type absorbent article according to claim 1, characterized in that The length of the joining portion in the up-down direction is shorter than the length of the first heat welding portion in the up-down direction.

3. The pants-type absorbent article according to claim 1 or 2, characterized in that: The length of the joining portion in the left-right direction is longer than the length in the up-down direction.

4. The pants-type absorbent article according to claim 1 or 2, characterized in that: A plurality of elastic members that can stretch in the left-right direction are arranged between the one side sheet and the other side sheet at intervals in the up-down direction. The length of the joining portion in the up-down direction is shorter than the thickness of the elastic member in a natural state.

5. The pants-type absorbent article according to claim 1 or 2, characterized in that: A plurality of elastic members that can stretch in the left-right direction are arranged between the one side sheet and the other side sheet at intervals in the up-down direction. The length of the joining portion in the up-down direction is shorter than the thickness of the elastic member in the extended state.

6. The pants-type absorbent article according to claim 1 or 2, characterized in that: In at least one of the waist portions, a plurality of elastic members that are stretchable in the left-right direction are arranged at intervals in the up-down direction between the one side sheet and the other side sheet joined by the plurality of welded portions. The plurality of welded portions include a plurality of welded portion pairs located on both sides of the elastic member in the up-down direction. Each of the elastic members is sandwiched between the pair of welded portions in a state of being contracted in the left-right direction, thereby restricting the position of the one side sheet and the other side sheet in the up-down direction. The length of the joining portion in the left-right direction is longer than the length of the welded portion in the left-right direction.

7. The pants-type absorbent article according to claim 1 or 2, characterized in that: In at least one of the waist portions, a plurality of elastic members that are stretchable in the left-right direction are arranged at intervals in the up-down direction between the one side sheet and the other side sheet joined by the plurality of welded portions. The plurality of welded portions include a plurality of welded portion pairs located on both sides of the elastic member in the up-down direction. Each of the elastic members is sandwiched between the pair of welded portions in a state of being contracted in the left-right direction, thereby restricting the position of the one side sheet and the other side sheet in the up-down direction. The plurality of welded portion pairs include a first welded portion pair and a second welded portion pair, wherein the second welded portion pair is located next to one side of the first welded portion pair in the left-right direction. The first welded portion pair and the second welded portion pair together sandwich the first elastic member. The first welded portion pair includes a first welded portion and a second welded portion, the first welded portion and the second welded portion being located at a first interval in the left-right direction on the same side in the up-down direction with respect to the first elastic member. In the extended state, A first length in the left-right direction from the one end of the first welded portion pair in the left-right direction to the other end of the second welded portion pair in the left-right direction is longer than a first length in the left-right direction of the first interval.

8. The pants-type absorbent article according to claim 1 or 2, characterized in that: The distance between the first heat-welded portion and the second heat-welded portion is larger than twice the sum of the length of the joining portion in the up-down direction and the distance between the joining portions in the up-down direction.

9. The pants-type absorbent article according to claim 1 or 2, characterized in that: A distance between the joining portions in the up-down direction is narrower than a length of the joining portion in the left-right direction.

10. The pants-type absorbent article according to claim 1 or 2, characterized in that: The length of the joining portion in the left-right direction is longer than the length of the first heat welding portion in the left-right direction.

11. The pants-type absorbent article according to claim 1 or 2, characterized in that: The area of ​​the joining portion is less than or equal to the area of ​​the first heat-welding portion.

12. The pants-type absorbent article according to claim 1 or 2, characterized in that: The area of ​​the joining portion is larger than that of the first heat-welded portion.

13. The pants-type absorbent article according to claim 1 or 2, characterized in that: In at least one of the waist portions, a plurality of elastic members that are stretchable in the left-right direction are arranged at intervals in the up-down direction between the one side sheet and the other side sheet joined by the plurality of welded portions. The plurality of welded portions include a plurality of welded portion pairs located on both sides of the elastic member in the up-down direction. Each of the elastic members is sandwiched between the pair of welded portions in a state of being contracted in the left-right direction, thereby restricting the position of the one side sheet and the other side sheet in the up-down direction. The area of ​​the joining portion is smaller than the area of ​​the welded portion.

14. The pants-type absorbent article according to claim 1 or 2, characterized in that: In at least one of the waist portions, a plurality of elastic members that are stretchable in the left-right direction are arranged at intervals in the up-down direction between the one side sheet and the other side sheet joined by the plurality of welded portions. The plurality of welded portions include a plurality of welded portion pairs located on both sides of the elastic member in the up-down direction. Each of the elastic members is sandwiched between the pair of welded portions in a state of being contracted in the left-right direction, thereby restricting the position of the one side sheet and the other side sheet in the up-down direction. The area of ​​the joining portion is larger than the area of ​​the welded portion.

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