CN107735063B

CN107735063B - Absorbent article

Info

Publication number: CN107735063B
Application number: CN201680038589.1A
Authority: CN
Inventors: 中嶋海阳; 藤本和也
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2015-06-29
Filing date: 2016-02-24
Publication date: 2020-10-23
Anticipated expiration: 2036-02-24
Also published as: JP2017012281A; WO2017002392A1; TW201705925A; CN107735063A; KR20180021819A; TWI703968B; JP6558979B2

Abstract

An absorbent article having a longitudinal direction, a transverse direction, and a front-to-back direction, and further having: an absorbent main body along a longitudinal direction; and a sheet member including a belt portion in the transverse direction and a pair of leg gather portions in the longitudinal direction. The absorbent article is provided with a waist opening and a pair of leg openings. The first overlap region and the second overlap region are respectively provided on one side and the other side in the front-rear direction, and the first overlap region and the second overlap region are inclined laterally outward from the waistline opening portion side toward the leg opening portion in the longitudinal direction. In the first overlapping region, at least the absorbent main body and the sheet member are joined at a first joining portion. In the second overlap region, at least the absorbent main body and the sheet member are joined at a second joining portion. The end of the first engaging portion is formed at the same position as the end of the first overlapping area.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article.

Background

As a conventional pants-type disposable diaper, patent document 1 discloses a diaper including an absorbent main body formed through a stomach-side opening portion, a crotch portion, and a back-side opening portion, and a pair of belt portions joined to the absorbent main body at joined portions.

Such a pants-type disposable diaper is required to look like underwear. At this time, if the joint portion between the absorbent main body and the belt portion is joined using an adhesive or the like, the rigidity of the joint portion increases, which becomes a cause of discomfort to the wearer. Therefore, a region called dry edge (dry edge) to which no adhesive or the like is applied is provided in front of the end of each joined portion to reduce the uncomfortable feeling felt by the wearer.

Documents of the prior art

Patent document

Patent document 1: japanese Kohyo publication Hei No. 8-507699

Disclosure of Invention

Problems to be solved by the invention

However, in such a pants-type disposable diaper, a pair of joint portions are formed at the noticeable portions of both the abdomen-side front face and the back-side rear face, and therefore, the number of joint portions is increased as compared with a general diaper in which joint portions are formed at two positions on both sides. When the dry edge is provided for the joint portion, the joint portion becomes large, and therefore, this results in weakening of the appearance of the underwear, for example, even when the garment is worn, the joint portion can be recognized by the appearance of the joint portion.

The present invention has been made in view of the above circumstances and has an object to provide an absorbent article that looks more like underwear.

Means for solving the problems

The main aspect of the present invention to achieve the above advantages is an absorbent article having a longitudinal direction, a lateral direction and a front-rear direction, the absorbent article comprising: an absorbent body along the longitudinal direction; and a sheet member including a belt portion in the transverse direction and a pair of leg gather portions in the longitudinal direction, formed with a waistline opening portion and a pair of leg opening portions, provided with a first overlapping region and a second overlapping region on one side and the other side in the front-rear direction, respectively, the first overlapping region and the second overlapping region each being inclined in the longitudinal direction from the waistline opening portion side toward the leg opening portion to the laterally outer side, at least the absorbent main body and the sheet member being overlapped in the first overlapping region and the second overlapping region, in the first overlapping region, at least the absorbent main body and the sheet member are joined at a first joining portion, in the second overlapping area, at least the absorbent main body and the sheet member are joined at a second joining portion, an end of the first joint portion is formed at the same position as an end of the first overlapping area.

Other features of the present invention will become apparent from the present specification which refers to the accompanying drawings.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, by forming the distal end of each first joint portion at the same position as the distal end of each first overlapping region, each joint portion can be made smaller, and therefore, the weakening of the underwear-like impression of the absorbent article can be reduced.

Drawings

Fig. 1 is a schematic perspective view showing the appearance of a diaper 1.

Fig. 2A is a plan view showing the diaper 1 in a state of being elongated in the longitudinal direction. Fig. 2B is a schematic cross-sectional view taken along line a-a of fig. 2A.

Fig. 3A is an unfolded plan view showing the unfolded state of the diaper 1 in a state of being elongated in the longitudinal direction in the middle of the manufacturing process. Fig. 3B is a schematic cross-sectional view taken along line B-B of fig. 3A.

Fig. 4 is a diagram illustrating an example of a manufacturing process of the diaper 1.

Fig. 5 is a diagram illustrating a portion b in fig. 2.

Fig. 6 is a diagram illustrating a portion a in fig. 1.

Fig. 7 is a diagram illustrating the first joint WL1 of the diaper 1 in a state where the belt portion 30 is extended in the lateral direction.

Fig. 8A is a schematic sectional view taken along line C-C of fig. 7. Fig. 8B is a schematic cross-sectional portion taken along line D-D of fig. 7. Fig. 8C is a schematic sectional view taken along line E-E of fig. 7. Fig. 8D is a schematic sectional view taken along line F-F of fig. 7.

Detailed Description

At least the following matters will become clear from the description of the present specification and the accompanying drawings.

Disclosed is an absorbent article having a longitudinal direction, a transverse direction, and a front-to-back direction, the absorbent article comprising: an absorbent body along the longitudinal direction; and a sheet member including a belt portion in the transverse direction and a pair of leg gather portions in the longitudinal direction, formed with a waistline opening portion and a pair of leg opening portions, provided with a first overlapping region and a second overlapping region on one side and the other side in the front-rear direction, respectively, the first overlapping region and the second overlapping region each being inclined in the longitudinal direction from the waistline opening portion side toward the leg opening portion to the laterally outer side, at least the absorbent main body and the sheet member being overlapped in the first overlapping region and the second overlapping region, in the first overlapping region, at least the absorbent main body and the sheet member are joined at a first joining portion, in the second overlapping area, at least the absorbent main body and the sheet member are joined at a second joining portion, an end of the first joint portion is formed at the same position as an end of the first overlapping area.

According to such an absorbent article, by forming the distal end of each first joint portion at the same position as the distal end of each first overlapping area, each first joint portion can be made smaller, and the risk of impairing the impression of the absorbent article like underwear can be reduced.

In the absorbent article, it is preferable that a distal end of the second joint portion is formed at the same position as a distal end of the second overlapping area.

According to such an absorbent article, by forming the distal ends of the second joint portions at the same positions as the distal ends of the second overlapping regions, it is possible to reduce the risk of impairing the impression of the absorbent article like underwear even when the absorbent article is viewed not only from the first joint portion side but also from the second joint portion side.

In the absorbent article, it is preferable that the absorbent main body and the sheet member are joined by a plurality of welded regions in each of the first joining portion and the second joining portion.

According to such an absorbent article, the absorbent main body and the sheet member are each joined by the plurality of welded regions, and therefore the first and second joined portions can be made less noticeable than in the case where the entire surfaces of the first joined portion and the second joined portion are welded. Therefore, the increase in rigidity of the first and second joint portions can be reduced.

In the absorbent article, it is preferable that the plurality of welded regions in the first joint portion are arranged in a row of the welded regions parallel to a distal end of the first overlapping region, and the plurality of welded regions in the second joint portion are arranged in a row of the welded regions parallel to a distal end of the second overlapping region, and that two or more of the rows are provided.

According to such an absorbent article, two or more rows are provided in which a plurality of welded regions are arranged in parallel with the distal ends of the first and second overlapping regions, and even if one row of the welded regions is peeled off in the first and second joint portions, the other row of the welded regions is still joined, so that the risk of the joint of the absorbent article being completely peeled off is reduced.

In the absorbent article, it is preferable that the sheet members each include a first elastic member and a second elastic member, an end portion of the first elastic member includes a portion overlapping the welded region, and an end portion of the second elastic member is located between the welded regions adjacent to each other.

According to such an absorbent article, the end portion of the first elastic member of the sheet member includes a portion overlapping the welded region, and the end portion of the second elastic member is disposed between the welded regions adjacent to each other. This prevents influences such as resistance welding or the like due to the elastic member, and can improve the joining strength of the first and second joining portions.

In the absorbent article, it is preferable that the first elastic member and the second elastic member are elastic threads, and an interval between the welded regions adjacent to each other in the first joint portion and the second joint portion is smaller than an interval between the elastic threads adjacent to each other in the longitudinal direction.

According to such an absorbent article, the interval between the welded regions adjacent to each other in each of the first joint portions and the second joint portions is smaller than the interval between the elastic threads adjacent to each other in the longitudinal direction, thereby further improving the joint strength.

In the absorbent article, it is preferable that a distance from a base end to a tip end of the first joint portion at the waistline opening portion side end portion of the first joint portion becomes shorter as approaching the waistline opening portion side, and a distance from a base end to a tip end of the second joint portion at the waistline opening portion side end portion of the second joint portion becomes shorter as approaching the waistline opening portion side.

According to such an absorbent article, as approaching the waistline opening portion side, the respective distances from the base end to the tip end of the respective first and second joint portions at the ends of the first and second joint portions on the waistline opening portion side become shorter, and therefore the first and second joint portions can be made less noticeable. Further, this can prevent the first and second engaging parts from contacting the skin of the wearer when the diaper is worn and can reduce the uncomfortable feeling felt by the wearer.

In the absorbent article, it is preferable that a lower end of the first joint portion and a lower end of the second joint portion are separated from the leg opening portion by a predetermined distance.

According to such an absorbent article, the lower ends of the first and second joined portions are separated from the leg opening portions by a predetermined distance, which can prevent the lower ends of the first and second joined portions from coming into direct contact with the skin of the wearer and reduce the discomfort felt by the wearer.

In the absorbent article, it is preferable that the upper end portion of the belt portion is formed by folding back the sheet member, and each of the leg gather portions includes an elastic sheet which is stretchable in the longitudinal direction.

According to such an absorbent article, the upper end portions of the belt portions are formed by folding back the sheet member and the leg gather portions each include an elastic sheet. Therefore, the strength of the waist opening and the leg openings can be improved. Further, in an absorbent article using a light-colored material such as nonwoven fabric, the color tone of the first and second joined portions becomes darker than the other portions due to the joining of the plurality of members. However, the upper end portions of the belt portions are formed by folding back the sheet member and the leg gather portions each include an elastic sheet, so that the color tones of the first and second joint portions can be made less noticeable.

In the absorbent article, it is preferable that the first joint portion includes a region where the sheet member is located on the other side with respect to the absorbent main body in a state where the belt portion is elongated in the lateral direction.

According to such an absorbent article, the first engaging parts each include a region in which each sheet member is located on the other side with respect to the absorbent main body, and therefore an absorbent article having less noticeable engaging parts can be provided.

The present embodiment

As an example of the absorbent article according to the first embodiment, a pants-type disposable diaper 1 (hereinafter also referred to as "diaper 1") is explained.

Fig. 1 is a schematic perspective view showing the appearance of a diaper 1. The diaper 1 includes an absorbent main body 10, leg gathers 20, and belt portions 30, and has a pants-type shape when worn as shown in fig. 1. The diaper 1 in the pant-type state of fig. 1 includes "longitudinal", "transverse", and "front-rear direction" that are orthogonal to each other. A waist opening HB is formed at the upper side in the longitudinal direction of the diaper 1, and a pair of leg openings HL is formed at both sides in the lateral direction. Further, when the diaper 1 is worn, the front side of the diaper 1 in the front-rear direction is a portion covering the abdominal side of the wearer, and the rear side of the diaper 1 in the front-rear direction is a portion covering the back side of the wearer.

Fig. 2A is a plan view showing the diaper 1 in a state of being elongated in the longitudinal direction of the absorbent main body 10. Fig. 2B is a schematic cross-sectional view taken along line a-a of fig. 2A. Fig. 3A is an unfolding flatness showing the unfolded state of the diaper 1 when elongated in the longitudinal direction of the absorbent main body 10 in the middle of the manufacturing process. Fig. 3B is a schematic cross-sectional view taken along line B-B of fig. 3A. Note that the line X-X in fig. 1 and 2 is the center line in the lateral direction.

As shown in fig. 2A, the diaper 1 is in a flat state in the final stage of the manufacturing process. The manufacturing process of the diaper 1 will be explained later using fig. 4. The diaper 1 in a flat state includes three directions "longitudinal direction", "lateral direction", and "thickness direction" orthogonal to each other. The longitudinal direction of the diaper 1 in a flat state is a direction along the longitudinal direction of the absorbent main body 10. The longitudinal direction corresponds to the longitudinal direction of the diaper 1 in the pants-type state as shown in fig. 1. However, the longitudinal direction in the pants-type state technically has a slightly different meaning from the longitudinal direction in the flat state, and therefore these two directions are handled differently as needed, such as "longitudinal direction in the pants-type state", "longitudinal direction in the flat state", and the like. In fig. 2A, the state in which the diaper 1 is elongated in the longitudinal direction (i.e., the flat state) refers to a state in which the diaper 1 is elongated to the following extent: when the diaper 1 is elongated in the longitudinal direction against a contraction force due to elastic threads (leg gather elastic members) 23 and belt elastic members (elastic threads) 33, which will be described later, gathers and pleats are substantially invisible in the portion where the elastic members are arranged. In addition, the shape of the diaper 1 when stretched in the longitudinal direction is the same as the shape of the diaper 1 when the diaper 1 is extended flat when no contractive force due to various elastic members such as the elastic threads 23 is generated. Further, when only the shape in which the absorbent main body 10 is brought into a flat state is set as the reference state, the state in which the diaper 1 is elongated in the longitudinal direction may also be referred to as a state in which the diaper 1 is elongated in the longitudinal direction against the contraction force due to the elastic member 33 so that the shape of the absorbent main body 10 coincides with the reference state.

In the following description, when the absorbent main body 10 is elongated in the longitudinal direction, a side contacting the abdomen side of the wearer is referred to as a front side (abdomen side) in the longitudinal direction, and a side contacting the back side of the wearer is referred to as a back side (back side) in the longitudinal direction. The transverse direction of the diaper 1 in the flat state is the same concept as the transverse direction and the thickness direction of the diaper 1 in the pants-type state in fig. 1. The thickness direction of the diaper 1 in a flat state is a direction orthogonal to the longitudinal direction and the lateral direction, and the side in contact with the skin of the wearer is referred to as the "skin side", while the opposite side is referred to as the "non-skin side".

As shown in fig. 2A and 2B, in the diaper 1 in a flat state, the absorbent main body 10 is arranged in the longitudinal direction, and a pair of leg gather portions 20 are arranged on both sides of the absorbent main body 10 in the lateral direction. The pair of belt portions 30 are arranged so as to overlap with a part of the absorbent main body 10 and the leg gather portion 20 on the skin side in the thickness direction. As shown in fig. 3A, in the diaper 1, each leg gather portion 20 and each belt portion 30 are formed by the side sheet 40 as a single sheet member. The side sheet 40 is folded back to the inside in the transverse direction at a fold line FL extending in the longitudinal direction, thereby forming each leg gather portion 20 and the belt portion 30.

The leg gather notch portion 25 provided in each leg gather portion 20 is formed by partially removing the leg gather portion 20 at the outer side end portion 20eo (fold line FL) in the transverse direction. Similarly, the notched portions 35 provided in each belt portion 30 are formed by partially removing the belt portion 30 at the outer end portion 30eo (the fold line FL) in the lateral direction. The leg opening portions HL are formed by the leg gather notch portion 25 and the notched portion 35.

The belt portion 30 is joined to the absorbent main body 10 (strictly speaking, the topsheet 13 arranged on the skin side of the absorbent main body 10) and the leg gather portions 20 by a pair of first joining portions WL1 that are inclined from the front end portion 10ef in the longitudinal direction of the absorbent main body 10 toward each of the leg opening portions HL. Similarly, the belt portion 30 is joined to the absorbent main body 10 and the leg gather portions 20 by a pair of second joining portions WL2 that are inclined from the rear end portion 10er in the longitudinal direction of the absorbent main body 10 toward the respective leg opening portions HL. The first engaging portion and the second engaging portion will be described in detail later.

The diaper 1 in this flat state is put into a wearable state like a pants-type diaper 1 by folding the absorbent body 10 in half near the center position CL in the longitudinal direction while the laterally inner end portions 30ei, 30ei of the pair of

belt portions

30, 30 are opened along the lateral direction. At this time, a waistline opening HB is formed by the front end 10ef and the rear end 10er in the longitudinal direction of the absorbent main body 10 and the inner end 30ei of the pair of belt ends 30 (see fig. 1).

As shown in fig. 2A, the absorbent main body 10 is a sheet-like member formed by: a member having a substantially rectangular shape and extending in the longitudinal direction (refer to fig. 3A) is cut along the first joining portion WL1 and the second joining portion WL2, and each end portion in the longitudinal direction of the member has a tapered shape having a substantially V-shape in plan view. The absorbent main body 10 includes an absorbent body 11, a front sheet 13 (corresponding to a skin side sheet) and a back sheet 15 (corresponding to a non-skin side sheet), wherein the front sheet 13 is disposed so as to cover the absorbent body 11 from the skin side and the back sheet 15 is disposed so as to cover the absorbent body 11 from the non-skin side. These

members

13, 11, and 15 are each joined to a member adjacent in the thickness direction with a hot melt adhesive or the like (see fig. 2B and 3B). Examples of the coating pattern of the adhesive may be an omega-shaped pattern, a spiral pattern, a stripe pattern, and the like. This also applies to other adhesives described later.

The absorbent body 11 includes an absorbent core formed by forming a specific liquid absorbent material into a predetermined shape (for example, a substantially hourglass shape when viewed from above) and a core wrap sheet covering the outer peripheral surface of the absorbent core, so that the absorbent body 11 is a member that absorbs excreted liquid such as urine when the diaper 1 is worn. Examples of such liquid absorbent materials are liquid absorbent fibers (e.g., pulp fibers) and liquid absorbent particulates such as superabsorbent polymers (so-called SAP). For the core wrap sheet, a liquid permeable sheet such as a cotton paper sheet or a nonwoven fabric sheet may be used. It should be noted that the shape of the absorbent body 11 is not limited to the substantially hourglass shape as viewed from above as shown in fig. 3A and may have any other shape.

The front sheet 13 is formed by a liquid-permeable sheet such as a breathable nonwoven fabric, and the planar dimension of the front sheet 13 is such a dimension as to protrude from both sides in the longitudinal direction of the absorbent body 11 and both sides in the transverse direction of the absorbent body 11. However, the front sheet 13 is not limited thereto and may be formed by a soft sheet member having liquid absorbency.

As shown in fig. 3B, the back sheet 15 is formed by overlapping and joining two sheet members, i.e., a leakage-preventing sheet 15f and an exterior sheet 15n, in the thickness direction. The leakage-preventing sheet 15f is a liquid-impermeable sheet member made of a Polyethylene (PE) film, a polypropylene (PP) film, or the like and is arranged on the skin side in the thickness direction of the back sheet 15. The exterior sheet 15n is a sheet member made of nonwoven fabric or the like, is arranged on the non-skin side in the thickness direction of the back sheet, and is a member constituting the exterior of the absorbent main body 10. However, the back sheet 15 is not limited to the above configuration as long as it has a certain leak-proof property. The back sheet 15 is also a sheet having a planar dimension such that the sheet protrudes from both sides in the longitudinal direction of the absorbent body and both sides in the lateral direction of the absorbent body. The front sheet 13 and the back sheet 15 are overlapped and joined together in the thickness direction so that respective ends of the front sheet 13 and the back sheet 15 each having a substantially V-shape in the longitudinal direction are substantially matched, thereby holding the absorbent body between the

sheets

13 and 15.

As shown in fig. 3A and 3B, the leg gather portion 20 is a sheet member which is long in the longitudinal direction and is joined to both sides in the transverse direction of the absorbent main body 10, and the leg gather portion 20 is contracted along the leg opening portion HL when the diaper 1 is made into a pants type to form a gathered leg gather. Each leg gather portion 20 is formed by laying two layers of a first sheet 21 and a second sheet 22 made of nonwoven fabric or the like in the thickness direction. Note that the absorbent main body 10 and the leg gather portions 20 are joined using a hot melt adhesive or the like when the inner end portions in the lateral direction of the leg gather portions 20 are each sandwiched between the topsheet 13 and the backsheet 15 of the absorbent main body 10.

As shown in fig. 3A and 3B, the belt portion 30 is a sheet member that is long in the longitudinal direction and is provided on both sides in the transverse direction of the leg gather portion 20, and the belt portion 30 forms a waist belt when the diaper 1 is made into a pants-type shape (see fig. 1). Each of the belt portions 30 is formed by laying a first sheet 31 and a second sheet 32 made of nonwoven fabric or the like in two layers in the thickness direction.

As described above, in the present embodiment, each leg gather portion 20 and each belt portion 30 are integrally formed by the sheet member 40 which is a single member. In other words, the first sheet 21 of the leg gather portion 20 and the first sheet 31 of the belt portion 30 are configured as the first sheet 41, and the second sheet 22 of the leg gather portion 20 and the second sheet 32 of the belt portion 30 are also configured as the second sheet member 42. In the present embodiment, in the sheet member 40, the portion disposed on the laterally inner side of the fold line FL becomes the leg gather portion 20, and the portion disposed on the laterally outer side of the fold line FL becomes the belt portion 30.

Each leg opening HL is formed to extend across the folding line FL. As described above, the leg opening portion HL is formed by the leg gather notch portion 25 and the notched portion 35, wherein the leg gather notch portion 25 is formed by removing the first sheet 21 and the second sheet 22 of the leg gather portion 20, and the notched portion 35 is formed by removing the first sheet 31 and the second sheet 32 of the belt portion 30.

Further, leg gather elastic members (elastic threads) 23 made of elastic threads or the like are arranged in a state of being elongated in the longitudinal direction between the first sheet 21 and the second sheet 22 of the leg gather portion 20, and are fixed with a hot melt adhesive or the like. In fig. 3A, the two elastic threads 23 are arranged at positions further inward with respect to the laterally inner end of the leg gather notch portion 25 (i.e., the laterally inner end of the leg opening portion HL). By these elastic threads 23, stretchability in the longitudinal direction can be provided to each leg gather portion 20. Therefore, when the diaper 1 is pants-type, the leg gather portion 20 is contracted along the leg opening portion HL and a gathered leg gather is formed, so that the fit around the legs of the wearer can be improved.

Likewise, a band elastic member (elastic thread) 33 made of an elastic thread or the like is disposed between the first sheet 31 and the second sheet 32 of the band portion 30 in a state of being elongated in the longitudinal direction, and is fixed with a hot melt adhesive or the like. In fig. 3A, the plurality of elastic strands 33 are arranged side by side in the lateral direction in a region further outside with respect to the lateral outside end of the notched portion 35 (i.e., the lateral outside end of the leg opening portion HL). The elastic thread 33 provides the band portions 30 with stretchability in the longitudinal direction. Therefore, when the diaper 1 is pants-type, a contraction force along the waist opening HB is generated almost over the entire region of each belt portion 30, and slippage of the waist portion is suppressed when the diaper 1 is worn.

Further, an elastic sheet 43 formed of a nonwoven fabric or the like having stretchability is preferably provided between the first sheet 41(21, 31) and the second sheet member 42(22, 32). As shown by the hatching in fig. 3A, each elastic piece 43 is a belt-like elastic piece member having a width wider than the width of the leg opening portion HL in the lateral direction. Each elastic sheet 43 further includes an opening having the same shape as the leg opening portion HL, and is fixed to the sheet 41 and the sheet 42 with a hot melt adhesive or the like while being elongated in the longitudinal direction. Therefore, the peripheral edge portions of the leg opening portions HL are reinforced by the elastic sheet 43 over the entire periphery (the sand pattern portion in fig. 1). In addition, due to the contraction force generated by the flat elastic sheet 43, the adhesiveness of the peripheral edge portion of the leg opening HL is further improved. If the elastic sheet 43 is not provided in the peripheral portion of the leg opening portion HL, but only elastic threads such as the elastic threads 23 are provided, wrinkles are easily formed between the elastic threads, the leg opening portion may become loose when the diaper 1 is worn, and marks of the elastic threads may be easily left on the skin of the wearer. In contrast, when the flat elastic thread 43 is arranged at the peripheral edge portion of the leg opening portion HL, the fit can be improved. Since the diaper 1 generally uses a light-colored material such as nonwoven fabric, the color of the first joint portion WL1 to which a plurality of members are joined becomes darker. However, when the elastic sheet 43 is arranged, the number of members increases and the color of the first joint WL1 may be less noticeable.

A nonwoven fabric containing elastomer fibers exhibiting substantial elasticity such as a polyurethane-based elastomer and thermoplastic resin fibers exhibiting substantial inelasticity such as a polyolefin-based resin, which is subjected to a so-called gear-stretch process to produce stretchability, may be taken as an example of such an elastic sheet 43. However, the present invention is not limited thereto at all.

As shown in fig. 3B, the folded portion FLb is preferably provided in the outer end region in the lateral direction of the belt portion 30 by folding the belt portion 30 inward twice in the lateral direction at the first belt end folding line FLb1 and the second belt end folding line FLb2 and fixing the folded portion FLb in this folded state with a hot melt adhesive or the like (fig. 1). Each second belt end folding line FLb2 is a portion that becomes the laterally inner end 30ei of each belt portion 30 in fig. 2A and a portion that becomes the hip opening HB. By configuring the waistline opening portion HB in such an end-folded structure, the pressure acting on the waist of the wearer can be reduced when the diaper 1 is worn. Further, like the elastic pieces 43 of the leg opening portions HL, the waistline opening portion HB can allow the color of the first joining portion WL1 to become less noticeable by the folded-back portion FLB on which a plurality of members are superimposed, and also can reduce the risk of damage of impression like underwear. However, the end region in the lateral direction does not necessarily have the above-described folded-back structure.

< production of diaper 1 >

Next, a method of manufacturing the diaper 1 will be briefly explained. Fig. 4 is a diagram showing one example of a manufacturing process of the diaper 1.

In this example, the diaper 1 is manufactured in such a manner that a substrate sheet used as a material is subjected to predetermined processing (S101 to S105) while being conveyed in a conveying direction. Hereinafter, the conveying direction of the sheet member is referred to as "MD direction", and the direction orthogonal to the MD direction is referred to as "CD direction". The MD direction is a direction along the length direction (longitudinal direction) in fig. 2A, and the CD direction is a direction along the transverse direction in fig. 2A.

The sheet member serving as the base sheet of the diaper 1 in the present embodiment is composed of the absorbent-main-body continuous sheet 10A and the side continuous sheet 40A. The absorbent-main-body continuous sheet 10A is a sheet member in which a plurality of absorbent main bodies 10 are continuously aligned in the longitudinal direction (longitudinal direction). That is, the absorbent-main-body continuous sheet 10A is a sheet member having the following states: the plurality of absorbent bodies 11 are sandwiched in the thickness direction between the continuous piece of the front sheet 13 and the continuous piece of the back sheet 15 extending in the MD direction. Likewise, the side continuous sheet 40A is a sheet member in which the sheet members 40 forming the leg gather portion 20 and the belt portion 30 are continuously aligned in the longitudinal direction (longitudinal direction).

First, as shown in fig. 4, the substrate sheet is continuously conveyed in the MD direction (S101) in a state where the side continuous sheet 40A is joined to both sides in the CD direction (transverse direction) of the absorbent-main-body continuous sheet 10A.

Next, with respect to the substrate sheet being conveyed, the notched portions 35 and the leg gather notched portions 25 constituting the leg opening portions HL are formed at respective positions extending across the fold line FL on both sides of the absorbent body 11 in the CD direction (lateral direction) (S102). The notch portion is formed using a cutting roller (not shown) or the like. The state shown by the S102 process in fig. 4 is a state corresponding to the diaper 1 in the developed state in fig. 3A.

Next, the portion of the side continuous sheet 40A corresponding to the belt portion 30 is folded back inward in the CD direction (lateral direction) at each fold line FL, so that a state is formed in which a portion of the absorbent main body 10, the leg gather portion, and the belt portion 30 overlap in the thickness direction (S103).

Next, the first joining portion WL1 and the second joining portion WL2 are formed by ultrasonic welding to join the belt portion 30, the absorbent main body 10, and the leg gather portion 20 (S104).

Next, cutting of the substrate sheet is performed (S105). Specifically, each diaper 1 is separated from the substrate sheet continuous in the MD direction, and the four corners of the rectangle are cut off along the first joint portion WL1 and the second joint portion WL 2. At this time, it is desirable to form the end WLp1 of the first joint and the end WLp2 of the second joint by cutting the substrate sheet at the weld area WU (described later). By cutting the substrate sheet at the weld area WU, the risk of peeling from the end WLp1 of the first joint and from the end WLp2 of the second joint can be reduced.

Thus, the diaper 1 in the flat state shown in fig. 2A is formed.

< first junction WL1 and second junction WL2>

Hereinafter, the first joint WL1 and the second joint WL2 will be explained in more detail.

A pair of first engaging portions WL1 are provided symmetrically with respect to the center line X-X on the front side in the front-rear direction, and a pair of second engaging portions WL2 are provided symmetrically with respect to the center line X-X on the rear side in the front-rear direction. Since the first joint WL1 and the second joint WL2 have the same configuration in the front-rear direction, one first joint WL1 will be described below.

As shown in fig. 1, the first joint portion WL1 has a shape that is inclined from the front end portion 10ef in the longitudinal direction near the center in the lateral direction of the absorbent main body 10 toward the leg opening portion HL. The first joint portion WL1 is a portion that joins the absorbent main body 10 and the belt portion 30 and joins the leg gather portion 20 and the belt portion 30. At this time, the outermost tip WLp1 of the first joint in the lateral direction of the first joint WL1 and the innermost base WLb1 of the first joint in the lateral direction of the first joint WL1 are substantially parallel to each other.

The length of the first joint portion WL1 in the longitudinal direction is the distance from the waistline opening portion HB to the lower end of the first joint portion WL1, and the length of the end portion in the lateral direction of the belt portion 30 is the length from the waistline opening portion HB to the lower end of each belt portion lateral end portion 30es, which is the outer side end portion of the belt portion 30. At this time, the length of the first engaging portion WL1 in the longitudinal direction is longer than the length of the belt portion transverse end portion 30es in the longitudinal direction. That is, in the longitudinal direction, the lower end of the first engaging portion WL1 is formed on the lower side of the lower end of the belt portion lateral end portion 30 es. Therefore, even when the belt portion 30 is elongated in the lateral direction by the elastic threads 33, a portion that is not elongated or contracted in the lateral direction is formed on the lower side of the first joint portion WL1, so that the joint strength of the first joint portion WL1 can be improved.

Further, the lower end of the first engagement portion WL1 is preferably separated from the leg opening portion HL by a predetermined distance. In the present embodiment, the leg gather portion 20 and the belt portion 30 are formed by a single sheet member 40. At this time, when the lower end of the first joining portion WL1 is formed on the upper side so as to be separated from the leg opening portion HL by a predetermined distance (for example, approximately 2mm to 10mm), a portion where the leg gather portion 20 and the band portion 30 are connected is formed. The outer end portion 20eo in the lateral direction in fig. 2 is a portion where the leg gather portion 20 and the belt portion 30 are connected in the pants-type state shown in fig. 1. This can prevent the lower end of the first engagement portion WL1 having relatively high rigidity from directly contacting the skin of the wearer and reduce the sense of discomfort felt by the wearer. In the first joining portion WL1 where the leg gather portion 20 and the belt portion 30 are joined, the joining process is performed on the single sheet member 40, so that the joining strength can be improved and the peeling of the joining portion can be reduced.

Fig. 5 is a diagram illustrating a portion b in fig. 2.

As shown in fig. 5, a plurality of weld regions WU joined by ultrasonic joining are formed in each first joining portion WL 1. In the present embodiment, ultrasonic welding is used for the joining of the first joining portion WL 1; however, the joining may be performed by welding such as thermal welding or using an adhesive such as a hot melt adhesive.

Since the diaper 1 is generally formed of nonwoven fabric or the like, the diaper 1 has a soft characteristic and has a good texture. However, when the weld region WU is formed without a gap in the entire region of each first joint WL1, the first joint WL1 becomes hard. For this reason, in the present embodiment, a plurality of welding regions WU each having a triangular shape are formed, and a bonded portion and an unbonded portion are provided in the region of each first joint WL1, thereby reducing the hardening of the first joint WL 1.

At this time, a plurality of welding regions WU are continuously arranged in parallel with the end WLp1 of the first joint (a first overlap region LA1 to be described later) to form one row of welding regions WU, and it is preferable to arrange a plurality of rows of welding regions WU in parallel with the end WLp1 of the first joint. The column arranged in the direction of the arrow R1 in fig. 5 is a column located on the base end WLb1 side of the first joint, and the column arranged in the direction of the arrow R2 in fig. 5 is a column located on the tip WLp1 side of the first joint. For example, even if an excessive force is applied to the first joint WL1 when the diaper 1 is worn or the like, and the row R1 of the weld region WU located on the base end WLb1 side of the first joint is peeled off, the row R2 of the weld region WU located on the distal end WLp1 side of the first joint is maintained. This can reduce the risk of the first joint WL1 being completely peeled off.

Further, it is preferable that a portion where the weld region WU and the elastic thread 33 overlap and a portion where the weld region WU and the elastic thread 33 do not overlap are formed in the end WLp1 of the first joint. When the elastic thread 33 overlapping the welding region WU is referred to as a first elastic member 33a and the elastic thread 33 not overlapping the welding region WU is referred to as a second elastic member 33b, in the portion of the end WLp1 of the first joint where the first elastic member 33a is provided, not only the absorbent main body 10 and the sheet member 40 but also the first elastic member 33a overlap, and therefore if ultrasonic welding is performed from above the absorbent main body 10, the sheet member 40, and the first elastic member 33a, the joint strength may be reduced by the first elastic member 33 a. However, by providing the second elastic member 33b that does not overlap the welding region WU and providing the second elastic member 33b located between the adjacent welding regions WU in the end WLp1 of the first joint, it is possible to alleviate the decrease in the joint strength of the first joint WL 1.

Further, the interval L33 between adjacent elastic threads is preferably smaller than the interval Lwu between adjacent weld areas WU. At this time, the interval L33 between the adjacent elastic threads 33 is the distance from the center of the elastic thread 33 to the center of the adjacent elastic thread 33 (hereinafter, also referred to as "pitch"), and the interval Lwu between the adjacent weld regions WU is the distance from the center of gravity of the weld region WU to the center of gravity of the adjacent weld region WU. Even if each elastic thread 33 has an elastic force stretching in the transverse direction at the portion where the elastic thread 33 is disposed, since the pitch of the weld regions WU is smaller than the pitch at which the elastic force of the elastic thread 33 acts, the joining strength of the first joining portion WL1 can be further improved.

Fig. 6 is a diagram illustrating a portion a in fig. 1.

When the distance from the base end WLb1 of the first joint to the tip WLp1 of the first joint is defined as L, it is preferable that L becomes shorter as approaching the lumbar opening HB. As shown in fig. 6, L1 < L2 < L3 is defined when L1, L2, and L3 approach the hip opening HB in this order. Each first joint portion WL1 is formed by cutting from the tip WLp1 of the first joint portion located at the upper portion of the first joint portion WL1 on the waistline opening portion HB side toward the base end WLb1 of the first joint portion. Therefore, the first joint portion is less noticeable, and the wearer can also feel less uncomfortable when the diaper 1, the first joint portion WL1, is worn in contact with the wearer's abdomen.

Fig. 7 is a diagram illustrating the first joint WL1 of the diaper 1 in a state where the belt portion 30 is extended in the lateral direction. As shown in fig. 7, the state in which the belt portion 30 of the diaper 1 is extended in the lateral direction refers to a state in which the belt portion 30 is extended in the lateral direction when the diaper 1 is worn by a wearer. In essence, the above state refers to a state in which the respective elastic threads 30 of the belt portion 30 are contracted by 48% to 78% (preferably, a state in which they are contracted by 63%) from a state in which the respective elastic threads 30 of the belt portion 30 are stretched in the transverse direction to such an extent that wrinkles and gathers are not observed.

Fig. 8A is a schematic sectional view taken along line C-C of fig. 7. Fig. 8B is a schematic cross-sectional portion taken along line D-D of fig. 7. Fig. 8C is a schematic sectional view taken along line E-E of fig. 7. Fig. 8D is a schematic sectional view taken along line F-F of fig. 7. Fig. 8A is a sectional view of a portion of the first joint WL1 joining the absorbent main body 10 and the folded portion FLB of the belt portion 30, and shows an upper side of the first belt end fold line FLB 1. Fig. 8B shows a portion of the first joint WL1 where the belt portion 30 located on the lower side of the folded portion FLB is joined to the absorbent main body 10. Fig. 8 and 8D each show a portion where the leg gather portion 20 and the belt portion 30 are joined.

As shown in fig. 8A, 8B, 8C, and 8D, the portion where the sheet member 40(31, 32) constituting the belt portion 30 overlaps the absorbent main body 10 is a first overlapping area LA1, and a weld area WU is formed at this first overlapping area LA1 to form a first join WL 1. At this time, it is preferable that the end WLp1 of the first joint and the end of the first overlap region LA1 are formed at the same position. Specifically, by forming the first joint portion WL1 in the first overlap area LA1 in the above-described manufacturing process S104, and by cutting the portion where the first overlap area LA1 and the first joint portion WL1 overlap in S105, the end WLp1 of the first joint portion and the end of the first overlap area LA1 can be formed at the same position.

In this way, the first joint WLp1 can be made smaller and also damage to the underwear-like impression of the pant diaper 1 provided with joints at the front of the ventral side can be reduced. Note that a state in which the distal end WLp1 of the first joint of the diaper 1 and the distal end of the first overlap region LA1 are formed at the same position when the belt portion 30 is stretched in the lateral direction is also a state in which the distal end WLp1 of the first joint and the distal end of the first overlap region LA1 are formed at the same position in the general pants-type diaper 1 of fig. 1.

Further, as shown in fig. 8A and 8B, in the first joint portion WL1, the portion where the absorbent main body 10 and the belt portion 30 are joined, it is preferable that the absorbent main body 10 is located on one side in the front-rear direction, and the sheet member 40 is located on the other side with respect to the absorbent main body 10. That is, it is preferable that the first joint WL1 be inclined toward the band portion 30 side, and the tip WLp1 of the first joint be located on the band portion 30 side.

Therefore, each first join WL1 having relatively high rigidity can reduce discomfort such as unevenness and the like felt by the wearer, and reduce the possibility that the protruding first join WL1 can be observed through clothing worn on the diaper, thereby enabling the first join WL1 to be less noticeable.

At this time, the absorbent main body 10 does not include an elastic member in the lateral direction, and the belt portion 30 includes a belt elastic member 33 (fig. 7) such as an elastic thread or the like, so that the first joint portion WL1 inclined toward the side of the belt portion 30 can be formed. Since a pulling force in the lateral direction (toward the belt portion 30 side) is applied to each first engagement portion WL1, the first engagement portion WL1 is inclined toward the belt portion side, so that the first engagement portion WL1 can be made less noticeable.

When the angle formed by the first joining portion WL1 and the adjacent sheet member 40(31) is θ, in fig. 8A, the angle θ 1 formed by the first joining portion WL1 in the folded portion FLB and the adjacent sheet member 40 is preferably less than 45 degrees. Likewise, in fig. 8B, the angle θ 2 formed by the first joining portion WL1 where the belt portion 30 and the absorbent main body 10 on the lower side of the folded portion FLB are joined and the adjacent sheet member 40 is preferably less than 45 degrees. Therefore, the first joint WL1 can be allowed to be less noticeable.

In addition, the angle θ 3 formed by the first joint portion WL1 joining the leg gather portion 20 and the belt portion 30 and the adjacent sheet member 40 in fig. 8C, and the angle θ 4 formed by the first joint portion WL1 joining the leg gather portion 20 and the belt portion 30 and the adjacent sheet member in fig. 8D are each preferably larger than θ 1 and θ 2. In particular, it is preferable that θ 3 be 45 degrees or more and θ 4 be 45 degrees or more.

Further, as shown in fig. 8C, θ 3 becomes substantially perpendicular at the portion where the elastic thread 23 of the leg gather portion 20 in the longitudinal direction crosses the elastic thread 33 of the belt portion 30 in the transverse direction in the first joint portion WL 1. In the present embodiment, this is due to the effect of the elastic threads 23 having a longitudinal tension and the elastic threads 33 having a transverse tension.

In addition, in the cross section taken along the line F-F in fig. 7, although the

elastic threads

23, 33 are not provided in the leg gather portion 20 and the belt portion 30 joined by the first joining portion WL1, the elastic threads 23 of the leg gather portion 20 are disposed closer to the cross section taken along the line F-F than the elastic threads 33 of the belt portion 30. Therefore, the first engagement portion WL1 is affected by the tensile force of the elastic wire 23, and θ 4 becomes larger than θ 3.

Therefore, by appropriately providing not only the elastic threads 33 of the belt portion 30 but also the elastic threads 23 of the leg gather portion 20, the angle θ formed by the first joint portion WL1 and the adjacent sheet member 40 can be changed. Further, when the compact first joint WL1 feels an underwear-like impression as a whole, the wearer of the diaper 1 can visually recognize the first joint WL1 due to the difference in inclination of the first joint WL1, and thus can reduce concerns such as joint peeling and the like. Further, the boundary between the leg gather portion 20 and the belt portion 30 is easily recognized, and the boundary can be used as a support portion for pulling up the diaper 1 when the diaper 1 is worn.

Other embodiments

Although the embodiments of the present invention have been described above, the above embodiments are for the convenience of understanding the present invention and are not intended to explain the present invention in a limiting manner. Also, it is needless to say that variations and modifications which can be made without departing from the gist of the present invention, and equivalents of the present invention are included in the present invention. For example, variations such as the following are possible.

Although each welding area WU is formed in a triangular shape in the above embodiment, the shape is not limited thereto. For example, each welding region WU may be formed in various shapes such as a circle and a square, and a plurality of rod-shaped welding regions may be provided in parallel with the end WLp1 of the first joint and the end WLp2 of the second joint.

Further, although the first engagement portion WL1 is formed on the front side and the second engagement portion WL2 is formed on the rear side in the above embodiment, it is not necessary to form the second engagement portion WL2 on the rear side. By providing at least the first joint portion WL1 of the front side, which is frequently noticed, it is possible to provide the wearer with an impression of looking like underwear. Also, by providing the second joint portion WL2 on the rear side, the wearer can be given the impression of looking like underwear not only on the front side but also on the rear side.

Description of the reference numerals

1: diapers (absorbent articles, disposable diapers),

10: absorbent main body, 10A: a continuous sheet of the absorbent main body,

10 ef: front end in the longitudinal direction, 10 er: the rear end portion in the length direction,

11: absorber, 13: the front surface of the dough sheet is provided with a dough cover,

15: back sheet, 15 f: leak-proof sheet, 15 n: exterior sheet

20: leg gather portion, 20A: leg gather continuous sheet, 20 eo: an outer end portion in the lateral direction,

21: first sheet, 22: second sheet, 23: leg gather elastic members (elastic threads),

25: a notch part of the leg gather is provided,

30: band portion, 30 es: band transverse end, 30A: the continuous sheet of tape is provided with,

30 ei: laterally inner end, 30 eo: an outer end portion in the lateral direction,

31: first sheet, 32: second sheet, 33: with an elastic member (elastic thread),

33 a: first elastic member, 33 b: a second elastic member which is provided between the first elastic member and the second elastic member,

35: the upper end of the upper cover is provided with a notch part,

40: sheet member, 40A: the side continuous sheet is provided with a side continuous sheet,

41: first sheet, 42: second sheet, 43: an elastic sheet is arranged on the upper surface of the base,

HB: waist opening, HL: an opening part of the leg part is provided,

CL: at the central location of the device, the central location,

FL: fold line, FLB: a turning-back part which is provided with a turning-back part,

FLb 1: first belt end reentry line, FLb 2: a second belt end return line,

lwu: interval, L33: at the interval of the first and second lines,

LA 1: the first region of overlap is such that,

WL 1: first joint, WL 2: a second engaging portion for engaging with the first engaging portion,

WLp 1: end of first joint, WLb 1: the base end of the first engaging portion,

WLp 2: end of second joint, WLb 2: the base end of the second engaging portion,

WU: weld zone

Claims

1. An absorbent article having a longitudinal direction, a transverse direction, and a front-to-back direction, the absorbent article comprising:

an absorbent body along the longitudinal direction; and

a sheet member including a belt portion in the lateral direction and a pair of leg gather portions in the longitudinal direction,

a waist opening part and a pair of leg opening parts are formed,

providing a first overlapping region and a second overlapping region on one side and the other side in the front-rear direction, respectively, each of the first overlapping region and the second overlapping region being inclined in the longitudinal direction from the waist opening portion side toward the leg opening portion to the laterally outer side, at least the absorbent main body and the sheet member overlapping in the first overlapping region and the second overlapping region,

in the first overlapping region, at least the absorbent main body and the sheet member are joined at a first joining portion,

in the second overlapping area, at least the absorbent main body and the sheet member are joined at a second joining portion,

the first joining portion and the second joining portion each have a plurality of welded regions joining the absorbent main body and the sheet member,

ends of the plurality of welded regions in the first joint portion are formed at the same position as an end of the first overlapping region,

the sheet members each include a first elastic member and a second elastic member,

the end portion of the first elastic member includes a portion overlapping the welding region, and

the end of the second elastic member is located between the welding regions adjacent to each other.

2. The absorbent article according to claim 1,

ends of the plurality of welded regions in the second joint portion are formed at the same position as an end of the second overlapped region.

3. The absorbent article according to claim 1 or 2,

the plurality of welded regions in the first joint portion are arranged in a row of the welded regions parallel to an end of the first overlapping region,

the plurality of welded regions in the second joint portion are arranged in a row of the welded regions parallel to an end of the second overlapped region, and

more than two of the columns are provided, respectively.

4. The absorbent article according to claim 1 or 2,

the first elastic member and the second elastic member are elastic threads, and

in the longitudinal direction of the machine,

the interval between the welded regions adjacent to each other in the first joint portion and the second joint portion is smaller than the interval between the elastic threads adjacent to each other.

5. The absorbent article according to claim 1,

lower ends of the plurality of welded regions in the first joint portion and lower ends of the plurality of welded regions in the second joint portion are separated from the leg opening portion by a predetermined distance.

6. The absorbent article according to claim 1,

the upper end portion of the belt portion is formed by folding back the sheet member, and

the leg gathers each include an elastic sheet that is stretchable in the longitudinal direction.

7. The absorbent article according to claim 1,

a distance from a base end to a tip end of the first overlap region at an end of the first overlap region on the waistline opening portion side becomes shorter as approaching the waistline opening portion side, and

a distance from a base end to a tip end of the second overlap region at an end of the second overlap region on the waistline opening portion side becomes shorter as approaching the waistline opening portion side.

8. The absorbent article of claim 7,

9. The absorbent article of claim 7,