WO2024111557A1 - Pants-type absorbent article, and method for manufacturing pants-type absorbent article - Google Patents

Abstract

A pants-type absorbent article (1) comprises an absorbent body (10), a waist member (20) and an engaging member (30), and a front waist portion (20f) and a back waist portion (20B) are joined to one another by means of a pair of side joint portions (40), wherein: the waist member (20) includes a first sheet comprising a non-woven fabric having a fiber orientation in a first direction, and includes perforations (25) for separating the waist member (20) to the front and back; the perforations are arranged in a second direction intersecting the first direction; high-density portions (70, 71), which are parts of the first sheet having a higher density than the surroundings, are provided between the pair of side joint portions (40, 40) in a left-right direction; and the high-density portions (70) are provided on both sides of the perforations (25) in the first direction.

Description

Pants-type absorbent article and manufacturing method of pants-type absorbent article

The present invention relates to a pants-type absorbent article and a method for manufacturing a pants-type absorbent article.

　Conventionally, there are known absorbent articles such as disposable diapers that can be used as tape-type (unfolded type) diapers by cutting off a part of the waistband member formed as a pants-type (shorts-type) diaper. For example, Patent Document 1 discloses a pants-type diaper that has a pair of break guide lines (perforations) on the ventral side of the exterior body, and can be opened like a double door by cutting the exterior body along the break guide lines. This pants-type diaper is a dual-use disposable diaper that can also be used as a tape-type diaper by using a fastening tape that is pulled out after opening.

JP 2010-131197 A

In pants-type and tape-type (dual-use) disposable diapers with breakage-inducing lines (perforations) as in Patent Document 1, if the fiber arrangement direction (fiber orientation, e.g., left-right direction) of the nonwoven fabric constituting the waistband member intersects with the direction of the perforations (e.g., up-down direction), the fibers are difficult to cut, and the waistband member may tear along the fiber orientation (left-right direction) rather than along the perforations (up-down direction). Furthermore, wrinkles formed on the surface of the waistband member may make the perforations difficult to see. In this case, it may be difficult to tear the perforations to separate the waistband member into front and back parts.

The present invention was made in consideration of the above problems, and its purpose is to make it easier to tear the perforations in a pants-type absorbent article that has perforations for separating the waistband member into front and rear parts and can also be used as a tape-type absorbent article.

The main invention for achieving the above-mentioned object is a pants-type absorbent article having an absorbent main body, a waistline member having a front waistline portion and a rear waistline portion, and an engaging member having one end fixed to the waistline member and the other end removably engaging with the non-skin side of the waistline member, the front waistline portion and the rear waistline portion being joined to each other by a pair of side joints, and having a waistline opening and a pair of leg openings, wherein the waistline member has a first sheet made of a nonwoven fabric having a fiber orientation along a first direction, and has perforations for separating the waistline member into front and rear portions, the perforations being arranged from the waistline opening to the leg openings along a second direction intersecting with the first direction, and a high density portion which is a portion of the first sheet that is denser than the surrounding area between the pair of side joints in the left-right direction, and the high density portion is provided on both sides of the perforation in the first direction.
Other features of the present invention will become apparent from the following detailed description of the present invention and the accompanying drawings.

The present invention makes it possible to easily tear the perforations in a pants-type absorbent article that has perforations for separating the waistband member into front and rear parts and can also be used as a tape-type absorbent article.

FIG. 1 is a schematic perspective view of a napkin 1. FIG. 2 is a plan view of the napkin 1 in an unfolded and extended state, as viewed from the thickness direction. 3 is a schematic cross-sectional view taken along the line AA in FIG. 2. 4A and 4B are diagrams illustrating the operation of separating the waistband member 20 of the napkin 1 into front and rear parts. 1 is a developed plan view of the napkin 1 with the front waistline portion 20f and the rear waistline portion 20b separated. 4 is a plan view illustrating the arrangement of a high density portion 70. FIG. FIG. 7 is an enlarged view of region B in FIG. 6. 8A and 8B are diagrams illustrating, as a comparative example, an operation for breaking the perforation 25 in a case where the waistband member 20 does not have a high density portion 70. FIG. 9A and 9B are diagrams illustrating an operation of tearing the perforations 25 when the waistband member 20 is provided with a high density portion 70 in this embodiment. 2 is a schematic cross-sectional view showing a cross section in the thickness direction of a waistband member 20 in which a first sheet and a second sheet are laminated. FIG. 11A to 11E are diagrams showing modified examples of the arrangement of fused portions 71 that constitute the high density 70. FIG. FIG. 2 is a flow diagram of each step carried out in the manufacture of the napkin 1. 1 is a schematic diagram illustrating a manufacturing apparatus 100 for manufacturing a napkin 1. FIG. FIG. 2 is a plan view of the napkin 2 in an unfolded and extended state, as viewed from the thickness direction.

The following points become clear at least from the description in this specification and the accompanying drawings.

(Aspect 1)
a waistband member having an absorbent main body, a front waistband portion and a rear waistband portion, and an engaging member having one end fixed to the waistband member and the other end removably engaging with a non-skin side of the waistband member, the front waistband portion and the rear waistband portion being joined to each other by a pair of side joints, and the waistband member having a waistband opening and a pair of leg openings, wherein the waistband member has a first sheet made of a nonwoven fabric having a fiber orientation along a first direction, and has perforations for separating the waistband member into front and rear portions, the perforations being arranged from the waistband opening to the leg openings along a second direction intersecting with the first direction, and a high density portion which is a portion of the first sheet that is denser than the surrounding area between the pair of side joints in the left-right direction, the high density portion being provided on both sides of the perforation in the first direction.

In the pants-type absorbent article of aspect 1, the fibers arranged to straddle the perforation in the first direction are constrained by the high-density sections provided on both sides of the perforation, reducing their degree of freedom. Therefore, when the perforation is torn along the second direction, the force for tearing the perforation is more likely to act on the fibers, making them more likely to be cut. In addition, the rigidity of the portion of the waistband member where the high-density sections are formed is increased, making it easier to maintain a flat shape, so wrinkles are less likely to occur around the perforation and the perforation is easier to see. This makes it easier to tear the perforation.

(Aspect 2)
A pants-type absorbent article as described in aspect 1, wherein the waistband member has a second sheet laminated with the first sheet, and the high density portion is composed of a plurality of fused portions that fusedly join the first sheet and the second sheet.

In the pants-type absorbent article of aspect 2, the high density portion is formed by the fused portion that joins the two sheets (the first sheet and the second sheet) together, so that the fibers of the nonwoven fabric that constitutes the first sheet and the second sheet are tightly bound to each other, and the force that tears the perforations acts efficiently on the fibers, making it easier to cut the fibers. This makes it easier to tear the perforations.

(Aspect 3)
A pants-type absorbent article as described in aspect 1 or 2, wherein, in the second direction, the high density portion is provided at least at either the end of the perforation on the waist opening side or the end of the perforation on the leg opening side.

In the pants-type absorbent article of aspect 3, the end (upper end) of the perforation on the waist opening side and the end (lower end) on the leg opening side are the positions that serve as the starting points for tearing the perforation. Therefore, if the fibers arranged across the perforation in the first direction at the starting points for tearing the perforation are restrained by the high-density portion, the fibers can be easily cut, and the operation of tearing the perforation can be performed more smoothly.

(Aspect 4)
A pants-type absorbent article as described in any one of aspects 1 to 3, wherein the perforations alternate between groove portions that penetrate the first sheet in the thickness direction and non-penetrating portions that do not penetrate the first sheet along a second direction, and at least a portion of the high-density portions is provided in portions that overlap with the non-penetrating portions in the second direction.

In the pants-type absorbent article of aspect 4, high density portions are provided on both sides of the non-penetrating portion of the perforation in the first direction, so that the fibers are constrained between the high density portions, reducing the degree of freedom and making the fibers easier to cut. In other words, in the non-penetrating portion, the fibers that are arranged so as to straddle the perforation in the first direction can be cut efficiently. This makes it easier to tear the perforation in the non-penetrating portion.

(Aspect 5)
A pants-type absorbent article according to any one of aspects 1 to 4, wherein a distance between the perforation and the high-density portion in the first direction is smaller than a length of the non-through portion in the second direction.

According to the pants-type absorbent article of aspect 5, the smaller the interval between the high density portions arranged on either side of the perforation in the first direction, the lower the degree of freedom of the fibers, making the fibers easier to cut.
Therefore, the operation of breaking the perforation can be made easier compared to when the distance between the high density portion and the perforation is equal to or greater than the length of the non-penetrating portion.

(Aspect 6)
A pants-type absorbent article as described in any of aspects 1 to 5, wherein the waistband member has a second sheet laminated with the first sheet, the high-density portion is composed of a plurality of fused portions that fuse and join the first sheet and the second sheet, and the pitch of the fused portions in the second direction is smaller than the length of the non-penetrating portions in the second direction.

In the pants-type absorbent article of aspect 6, there is a high possibility that at least a portion of the fused portion will be positioned in a position that overlaps with the non-penetrating portion of the perforation in the second direction. Therefore, the fibers that make up the nonwoven fabric are more likely to be restrained by the fused portion on both sides of the non-penetrating portion in the first direction, making it easier to cut the fibers when tearing the perforation. This makes it easier to tear the perforation.

(Aspect 7)
The pants-type absorbent article according to any one of Aspects 1 to 6, wherein the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions, and an area of each of the fused portions is smaller than an area of each of the embossed portions.

In the pants-type absorbent article of aspect 7, if the area of each fused portion is smaller than the area of each embossed portion, the probability that the fused portion will overlap the embossed portion can be reduced compared to the reverse case. This prevents the rigidity of the waistband member from becoming excessively high, resulting in poor feel against the skin, and prevents the bonding strength between the first sheet and the second sheet from decreasing.

(Aspect 8)
The pants-type absorbent article according to any one of Aspects 1 to 6, wherein the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions, and an area of each of the fused portions is equal to or greater than an area of each of the embossed portions.

In the pants-type absorbent article of aspect 8, each fused portion is formed large, so the proportion of the area occupied by the fused portions that bind the fibers of the nonwoven fabric in the high-density portion is larger than in the opposite case. In other words, the fibers are more likely to be bound around the perforations, and when the perforations are torn, the fibers that are arranged across the non-penetrating portions are more likely to be cut. This makes it easier to tear the perforations.

(Aspect 9)
The pants-type absorbent article according to any one of Aspects 1 to 8, wherein the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions, and has portions where the fused portions and the embossed portions do not overlap when viewed in the thickness direction.

In the pants-type absorbent article of aspect 9, the fused portion is more likely to be arranged between two adjacent embossed portions, so compared to the reverse case, the pitch at which the fused portion restrains the fibers is more likely to be smaller overall, making it easier to reduce the degree of freedom of the fibers. Therefore, when the perforations are torn, the fibers are more likely to be cut, making it easier to perform the operation of tearing the perforations.

(Aspect 10)
A pants-type absorbent article as described in any one of Aspects 1 to 9, wherein each of the first sheet and the second sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions, and the average thickness of the portion of the waistband member where the embossed portions are formed is greater than the average thickness of the portion where the fused portions are formed.

In the pants-type absorbent article of aspect 10, the fused portion is formed deep in the thickness direction in the waistband member, which increases the fusion strength between the laminated first and second sheets. Therefore, in the area where the fused portion is formed, the fibers are strongly constrained and easily cut, making it easier to break the perforations. Furthermore, even if the embossed portion and the fused portion overlap in part of the waistband member, it is easier to ensure the fusion strength between the first and second sheets.

(Aspect 11)
A pants-type absorbent article as described in any one of aspects 1 to 10, wherein an elastic member exhibiting stretchability in the first direction is not provided in the region of the waistband member between the side joint portion and the perforation in the first direction.

In the pants-type absorbent article of aspect 11, when the waistband member is separated into front and back parts along the perforation, the area of the waistband member between the perforation and the side joint is less likely to stretch and wrinkle. Therefore, when the pants-type absorbent article is worn, the area comes into contact with the wearer's skin in a flat manner, making it less likely to cause discomfort to the wearer.

(Aspect 12)
A pants-type absorbent article according to any one of aspects 1 to 11, wherein the high density portion is provided in a region of the waistband member between the side joint portion and the perforation in the first direction.

In the pants-type absorbent article of aspect 12, a high-density portion is provided in the area of the waistband member between the side joint and the perforation, which increases the rigidity of the area, making it more difficult for wrinkles to form and easier to maintain a flat shape. Therefore, when the pants-type absorbent article is worn, the area comes into flat contact with the wearer's skin, making it less likely to cause discomfort to the wearer.

(Aspect 13)
A method for manufacturing pants-type absorbent articles, comprising: a conveying step of continuously conveying a first sheet made of a nonwoven fabric having fiber orientation along a first direction along a conveying direction; a high density portion forming step of forming a high density portion in a predetermined area of the first sheet, which is a portion of the first sheet that is denser than the surrounding area; a perforation forming step of forming perforations in the first sheet along a second direction that intersects the first direction; and an engaging member attaching step of fixing one end of an engaging member that removably engages with the first sheet to the first sheet, wherein the perforation forming step is performed after the high density portion forming step, and the high density portions are provided on both sides of the perforation in the first direction.

According to the method for manufacturing a pants-type absorbent article of aspect 13, the perforation forming step is carried out after the high-density portion is formed in the high-density portion forming step, so that the perforations can be formed in a state where the rigidity of the base sheet (first sheet) is increased. This makes it easier to form the perforations stably and accurately. This makes it possible to provide a pants-type absorbent article in which the operation of tearing the perforations can be performed more smoothly.

(Aspect 14)
A method for manufacturing a pants-type absorbent article as described in aspect 13, comprising an elastic member attachment process for attaching an elastic member stretched along the conveying direction by sandwiching it between a second sheet, which is continuously conveyed in the conveying direction, and the first sheet in the thickness direction, and an elastic member cutting process for cutting the elastic member at a predetermined position in the first direction, wherein the elastic member cutting process is performed prior to the high density portion forming process.

In the manufacturing method of the pants-type absorbent article of aspect 14, since there is no elastic member in the area where the high-density portion is formed, the formation of the fused portion at a position overlapping the elastic member is suppressed. This makes it difficult for poor fusion to occur in the fused portion, and makes it easier to ensure the bonding strength between the first sheet and the second sheet.

First Embodiment
A pants-type napkin 1 (hereinafter, simply referred to as "napkin 1") will be described as an example of a pants-type (shorts-type) absorbent article according to a first embodiment of the present invention. Note that pants-type absorbent articles also include pants-type diapers and pants-type absorbent pads.

<Basic structure of napkin 1>
Fig. 1 is a schematic perspective view of a napkin 1 according to a first embodiment. Fig. 2 is a plan view of the napkin 1 in an unfolded and extended state, as viewed from the thickness direction. Fig. 3 is a schematic cross-sectional view taken along line AA in Fig. 2.

The "stretched state" of the napkin 1 refers to the state in which the entire napkin 1 (whole product) is stretched without wrinkles by stretching each elastic member of the napkin 1 (such as the absorbent body elastic member 50 and waist circumference elastic member 26 described below), specifically, the state in which each member constituting the napkin 1 (such as the non-skin side sheet 21 and skin side sheets 22, 23 described below) is stretched until its dimensions match or are close to the dimensions of the individual member.

As shown in FIG. 1, the napkin 1 has a "vertical direction," a "lateral direction," and a "front-to-back direction" that are perpendicular to one another. Also, as shown in FIG. 3, it has a "thickness direction" in which the various components are layered. In the vertical direction, the side that faces the wearer's waist when the napkin 1 is worn by the wearer is referred to as the "upper side," and the side that faces the wearer's crotch is referred to as the "lower side." In the front-to-back direction, the side that faces the wearer's stomach when worn is referred to as the "front side," and the side that faces the wearer's back is referred to as the "rear side." In the thickness direction, the side that comes into contact with the wearer's skin when the napkin 1 is worn by the wearer is referred to as the "skin side," and the opposite side is referred to as the "non-skin side."

In addition, the napkin 1 has a "vertical direction" and a "horizontal direction" that are perpendicular to each other when in the unfolded state shown in FIG. 2. The "vertical direction" is the direction along the top-to-bottom direction in a pants-type garment, and the "horizontal direction" is the direction along the left-to-right direction in a pants-type garment.

The napkin 1 of this embodiment comprises a liquid-absorbent body 10 that absorbs excretory fluids such as menstrual blood, a waistband member 20 that is placed over the non-skin side of the absorbent body 10 and is placed around the wearer's waist when the napkin 1 is worn, and engaging members 30 provided on both the left and right sides of the waistband member 20.

(Absorbent body 10)
As shown in Fig. 2, the absorbent body 10 has a generally rectangular shape in plan view, with the vertical direction (corresponding to the "longitudinal direction" of the absorbent body 10 in a stretched state) aligned with the top-bottom direction of the napkin 1. As shown in Fig. 3, the absorbent body 10 has an absorbent core 11 aligned with the vertical direction (top-bottom direction), a top sheet 12 arranged closer to the skin than the absorbent core 11, and a back sheet 13 arranged closer to the skin than the absorbent core 11. However, the absorbent body 10 may have other sheet members. For example, a second sheet (not shown) may be provided between the top sheet 12 and the absorbent core 11 in the thickness direction. In addition, an absorbent body elastic member 50, which will be described later, is provided between the absorbent core 11 and the back sheet 13.

The absorbent core 11 is a member that absorbs and retains liquids such as menstrual blood, and is formed from liquid-absorbent fibers such as pulp fibers mixed with superabsorbent polymer (SAP). The outer periphery of the absorbent core 11 may be covered with a liquid-permeable sheet member (core wrap sheet) such as tissue paper or nonwoven fabric.

The top sheet 12 is a liquid-permeable sheet member that can come into contact with the wearer's skin when worn, and is made of, for example, a hydrophilic air-through nonwoven fabric or a spunbond nonwoven fabric.

The back sheet 13 is formed in a two-layer structure with a liquid-impermeable sheet 13a for preventing liquids such as menstrual blood absorbed in the absorbent core 11 from leaking out to the outside, and a hydrophobic sheet 13b arranged on the non-skin side of the liquid-impermeable sheet 13a. For example, a resin film is used as the liquid-impermeable sheet 13a, and for example, a flexible nonwoven fabric is used as the hydrophobic sheet 13b. However, the hydrophobic sheet 13b does not necessarily have to be provided, and the back sheet 13 may be composed of only the liquid-impermeable sheet 13a.

Furthermore, leak-proof wall portions (not shown) may be provided on both the left and right sides of the absorbent body 10. The leak-proof wall portions are equivalent to so-called three-dimensional gathers, and when the napkin 1 is worn, the leak-proof wall portions rise up from both the left and right sides of the absorbent body 10 toward the wearer's skin, thereby preventing excreted liquids such as menstrual blood from leaking out to the outside of the absorbent body 10.

2 and 3, the absorbent body 10 of this embodiment is provided with a plurality of absorbent body elastic members 50 that stretch along the vertical direction (up-down direction). The absorbent body elastic members 50 are made of, for example, rubber thread, and are arranged in a state of stretching in the vertical direction (up-down direction) on the non-skin side of the absorbent core 11 (between the back sheet 13 and the absorbent core 11 in FIG. 3). In the napkin 1 of this embodiment, five absorbent body elastic members 50 are provided at a predetermined interval in the left-right direction (see FIG. 2). The stretch ratio of the absorbent body elastic members 50 is preferably about 1.4 to 3.3 times. The stretch ratio is expressed as the value obtained by dividing the length of the elastic member in the stretched state by the length of the elastic member in the natural state. By setting the stretch ratio of the absorbent body elastic members 50 to a relatively high ratio, the relatively rigid absorbent body 10 can be contracted from the non-skin side in the thickness direction, making it easier for the absorbent body 10 to fit the wearer's body when the napkin 1 is worn. In other words, the absorbent body 10 is lifted up toward the wearer's skin due to the elasticity exhibited by the absorbent body elastic member 50, making it easier for the absorbent body 10 to adhere closely to the wearer's crotch area, and making it less likely for menstrual blood and other excretory fluids to leak.

(Waist Member 20)
The waistband member 20 is an exterior body composed of multiple sheet members, and includes at least a non-skin side sheet 21, skin side sheets 22, 23, and multiple waistband elastic members 26, 26... (see FIG. 3). In the following description, the portion of the waistband member 20 that is in front of the center position CL (ventral side) in the vertical direction is also called the front waistband section 20f, and the portion that is behind the center position CL (dorsal side) is also called the rear waistband section 20b. The front waistband section 20f is a portion that contacts the ventral side of the wearer's body when the napkin 1 is worn, and corresponds to the "front body" of the napkin 1. The rear waistband section 20b is a portion that contacts the dorsal side of the wearer's body when the napkin 1 is worn, and corresponds to the "rear body" of the napkin 1.

The non-skin side sheet 21 is a non-elastic sheet member that is placed on the closest side to the skin of the napkin 1, and is made of, for example, spunbond nonwoven fabric or SMS nonwoven fabric. In this embodiment, the non-skin side sheet 21 has a shape that is narrowed toward the inside in the left-right direction at the vertical center (the part including the center position CL) as shown in the plan view of Figure 2.

The skin side sheet 22 and the skin side sheet 23 are sheet members laminated on the skin side of the non-skin side sheet 21 on the front side (ventral side) in the longitudinal direction, and are formed from the same nonwoven fabric as the non-skin side sheet 21.

Hereinafter, one of the non-skin side sheet 21 and the skin side sheet 22 (23) may be referred to as the "first sheet" and the other sheet may be referred to as the "second sheet." In addition, a sheet member (third sheet) other than the non-skin side sheet 21 and the skin side sheet 22 (23) may be provided as a sheet member constituting the waistband member 20. In addition, as shown in FIG. 3, the non-skin side sheet 21 may be folded back at the top and bottom ends, so that the waistband member 20 may partially have a structure of three or more layers.

The waist elastic members 26 are formed, for example, from rubber thread, and are arranged at a predetermined interval in the vertical direction between the non-skin side sheet 21 and the skin side sheet 22 (23), and are attached in a stretched state in the left-right direction. The elasticity in the left-right direction exhibited by these waist elastic members 26 allows the waist member 20 to fit the waist of the wearer.

The waist elastic member 26 can be attached using an adhesive such as a hot melt adhesive. For example, the waist elastic member 26 can be attached by applying hot melt adhesive to it, stretching it at a predetermined stretch ratio, and sandwiching it between the non-skin side sheet 21 and the skin side sheet 22 (23). That is, the non-skin side sheet 21 and the skin side sheet 22 (23) are joined by the adhesive via the waist elastic member 26. Note that the waist elastic member 26 may also be attached by applying adhesive to the non-skin side sheet 21 and the skin side sheet 22 (23) rather than applying adhesive to the waist elastic member 26 side.

The napkin 1 is folded in half vertically (front-to-back) from the unfolded state shown in FIG. 2, with the center position CL in the vertical direction (shown by a dashed line in FIG. 2) as the folding position, so that the skin side of the front waistline portion 20f (front body) and the skin side of the rear waistline portion 20b (rear body) face each other. In this folded state, both lateral (left-right) ends 40f, 40f of the front waistline portion 20f, which overlap in the front-to-back direction, and both lateral (left-right) ends 40b, 40b of the rear waistline portion 20b are joined using a known joining method such as seal welding to form a side joint 40. As a result, the folded waistline member 20 (20f and 20b) is connected in a ring shape at the front side (ventral side) and the rear side (back side), forming one waistline opening 1a and a pair of leg openings 1b as shown in FIG. 1, and forming a pants-type napkin 1.

(Engagement Member 30)
A pair of engaging members 30 are provided on both left and right sides of the napkin 1. The engaging members 30 each have a base sheet 31 and an engaging portion 32.

The base sheet 31 is a sheet member made of nonwoven fabric or the like, and one side (one end) in the left-right direction is joined to the waistband member 20 by an engaging member joint 35, and is fixed inseparably.
Also, an engaging portion 32 is provided on the other side in the left-right direction of the base sheet 31 (see FIG. 2). In this embodiment, the side joint 40 of the waistband member 20 described above is configured to also serve as the engaging member joint 35. That is, the front waistband portion 20f, the rear waistband portion 20b, and the engaging member 30 are integrally joined and fixed by the side joint 40. However, the engaging member joint 35 may be provided separately from the side joint 40. For example, the engaging member 30 may be joined by the engaging member joint 35 to a predetermined region other than the side joint 40 in the front waistband portion 20f or the rear waistband portion 20b. Also, the engaging member joint 35 may be formed by ultrasonic welding or the like like the side joint 40, or may be formed using an adhesive such as a hot melt adhesive.

The engaging portion 32 is a member for removably engaging the engaging member 30 with the waistband member 20, and is provided in a predetermined region of the skin side of the engaging member 30 (the region (other end) opposite the engaging member joint 35 in the left-right direction). The engaging portion 32 in this embodiment is, for example, a hook-and-loop fastener provided with multiple hook members (unillustrated hook-and-loop projections) made of polypropylene or the like on the skin side. By hooking these hook members onto the fibers of the nonwoven fabric constituting the non-skin side sheet 21 provided on the outermost layer of the waistband member 20, the engaging portion 32 (engaging member 30) is removably engaged with the non-skin side of the waistband member 20.

As shown in FIG. 1, in the napkin 1 in the pants-type state, the engaging portion 32 of the engaging member 30 is engaged with the front waist portion 20f in an area laterally inward of the engaging member joint 35 (side joint 40).

<How to put on and take off Sanitary Napkin 1>
Next, a description will be given of the operation of putting on and taking off the napkin 1. In the initial state, the napkin 1 is in a pants-type (shorts-type) form as shown in Fig. 1, and can be worn as a normal pants-type absorbent article. When removing the napkin 1 from the body, the waistline member 20, which is formed in a ring shape along the waistline of the wearer, can be separated into the front waistline portion 20f and the rear waistline portion 20b, and the napkin 1 can be unfolded to remove it.

FIGS. 4A and 4B are diagrams illustrating the operation of separating the waistline member 20 of the napkin 1 into front and rear parts. FIG. 4A is a schematic cross-sectional view showing the napkin 1 in a pants-type state as viewed from the top (the side of the waistline opening 1a) in the vertical direction, and FIG. 4B is a schematic cross-sectional view showing the state in which the waistline member 20 has been separated into front and rear parts.

In the pants-type napkin 1, the front waist portion 20f and the rear waist portion 20b are joined together at side joints 40, 40 provided at both left and right ends to form an annular waist opening 1a as shown in FIG. 4A. A pair of engaging members 30 are provided on both left and right sides of the waist portion 20, and the engaging members 30 engage with the non-skin side of the front waist portion 20f by engaging portions 32.

In addition, in FIG. 4A, a pair of separation sections 25 are provided on both left and right sides of the front waistline section 20f. The separation sections 25 are provided to separate the waistline member 20, which is formed in a ring shape along the waistline of the wearer, into the front waistline section 20f and the rear waistline section 20b, and are provided in the left and right direction anywhere in the area from the side joint section 40 to the section where the engagement section 32 is engaged. In other words, the waistline member 20 can be separated at the separation sections 25 into a section that includes at least the center of the front waistline section 20f and a section that includes at least the center of the rear waistline section 20b.

In this embodiment, the separation section 25 is configured by a number of grooves (groove sections 251, described later) that penetrate the waistline member 20 in the thickness direction and are arranged intermittently in the vertical direction from the waistline opening 1a to the leg openings 1b, so-called perforations (see FIG. 7, etc.). By tearing the waistline member 20 along the perforations, it is possible to easily separate the front waistline section 20f and the rear waistline section 20b. Hereinafter, the separation section 25 is also referred to as the "perforations 25."

The napkin 1 in which the waistline member 20 is separated into the front waistline portion 20f and the rear waistline portion 20b at the separation portion 25 (perforation 25) is in the state shown in FIG. 4B. That is, the separation portion 25 in FIG. 4A is separated into a separation end 25fe on the front waistline portion 20f side and a separation end 25be on the rear waistline portion 20b side, and the front waistline portion 20f and the rear waistline portion 20b are separated from each other in the front and rear directions. In FIG. 4B, a pair of engaging members 30, 30 are joined to the rear waistline portion 20b via engaging member joints 35 (side joints 40) on both the left and right sides, and engaging portions 32, 32 provided on the engaging members 30, 30 are engaged with the front waistline portion 20f, respectively. As a result, the waistline member 20 is formed into a ring shape. When removing the napkin 1 from the wearer's body in this state, the engagement portion 32 is peeled away from the front waistband portion 20f, allowing the napkin 1 to unfold and be easily removed.

FIG. 5 is an expanded plan view of the napkin 1 with the front waistline portion 20f and the rear waistline portion 20b separated. After separation, the napkin 1 can be used as a so-called tape-type napkin, in which an engaging member 30 with an engaging portion 32 is provided on both the left and right sides. In other words, the napkin 1 of this embodiment can be used as both a pants-type and a tape-type.

　Although conventional pants-type napkins have a good fit, they are difficult to put on and take off in restrooms and other places when out and about. For example, when removing a used napkin and putting on a new one while out and about, the wearer needs to put their toes through the leg openings of the pants-type napkin and pull it up to the crotch area, which makes it difficult to put on and take off the napkin in environments where it is difficult for the wearer to take off pants or shoes.

In contrast, with the napkin 1 of this embodiment, the waistband member 20 can be separated at the separation section 25, allowing the napkin 1 to be easily removed. Furthermore, by separating the waistband member 20 of a new napkin 1 at the separation section 25 in advance and leaving it in an unfolded state, it can be used as a tape-type napkin, making it easy to put on and take off even in environments where it is difficult to take off pants or shoes.

<About the operation of tearing perforation 25>
In the napkin 1 of this embodiment, when the operation of tearing the perforation 25 (separation portion 25) to separate the waistline member 20 into front and rear portions is performed, a portion of the waistline member 20 is processed to make it easier to tear the perforation 25. Specifically, high density portions 70 are provided in the waistline member 20, in which the density of portions on both sides in the left-right direction of the perforation 25 is made higher than the surrounding density, making it easier to tear the perforation 25.

6 is a plan view illustrating the arrangement of the high-density portion 70. FIG. 7 is an enlarged view of region B in FIG. 6. The high-density portion 70 is a region in the waistband member 20 where the non-skin-side sheet 21 and the skin-side sheet 22, which are stacked in the thickness direction, are fused together, and is formed by distributing a plurality of fused portions 71, 71... (see FIG. 7) in the shaded region in FIG. 6. This increases the density of the region of the waistband member 20 (front waistband portion 20f) having a predetermined width on both sides of the perforation 25 in the left-right direction. In the high-density portion 70, the fibers constituting the nonwoven fabric of the non-skin-side sheet 21 and the skin-side sheet 22 are restrained by the fused portions 71, so that the degree of freedom of the fibers is lower than in the region where the high-density portion 70 is not formed. In FIG. 7, each fused portion 71 is formed in a rectangular shape arranged at an angle, but the shape and arrangement of the fused portions 71 are not limited to this.

The perforation 25 is formed by alternately arranging groove portions 251 that penetrate the waistband member 20 (first sheet and second sheet) in the thickness direction and non-penetrating portions 252 that do not penetrate along a predetermined direction (in this embodiment, a direction substantially parallel to the vertical direction) (see FIG. 7). Therefore, when tearing the perforation 25, it is necessary to tear the non-penetrating portions 252 along the vertical direction between two groove portions 251, 251 that are adjacent in the vertical direction.

FIGS. 8A and 8B are diagrams illustrating, as a comparative example, the operation of tearing the perforation 25 when the waistband member 20 does not have a high density portion 70. FIGS. 9A and 9B are diagrams illustrating the operation of tearing the perforation 25 when the waistband member 20 has a high density portion 70 in this embodiment. Note that FIGS. 8A and 9A show the action of grabbing one side of the perforation 25 in the left-right direction of the waistband member 20 with one hand, grabbing the other side of the perforation 25 in the left-right direction with the other hand, and pulling outward in both left-right directions while tearing the perforation 25 in the up-down direction.

Figure 8A of the comparative example shows a state in which the perforation 25 was not torn normally. In the process of the user tearing the waistband member 20 along the perforation 25, the tearing direction shifts from the perforation 25, and the waistband member 20 (20f) is torn in the left-right direction. This is due to the fiber orientation of the nonwoven fabric that constitutes the waistband member 20.

Generally, nonwoven fabrics are made up of many intertwined fibers, and often have fiber orientation in a specific direction. In FIG. 8B, the nonwoven fabric that makes up the waistband member 20 has fiber orientation along a "first direction" that is approximately parallel to the left-right direction. Note that the nonwoven fabric that makes up the waistband member 20 of this embodiment contains fibers with an average fiber length of more than 100 mm (so-called long fibers). Also, the first direction and the left-right direction do not need to be completely parallel.

For such a nonwoven fabric having fiber orientation along the first direction, the perforations 25 are formed to extend in the "second direction" (a direction substantially parallel to the vertical direction) that intersects with the first direction. Therefore, if fibers having orientation in the first direction are arranged in the non-penetrating portion 252 between two adjacent grooves 251, 251 of the perforations 25 in the second direction, the force that tears the perforations 25 along the second direction is blocked by the fibers along the first direction. In other words, in order to tear the perforations 25 along the second direction (vertical direction), it is necessary to cut the fibers arranged along the first direction (horizontal direction) in the non-penetrating portion 252 of the perforations 25. In other words, it is necessary to cut the fibers arranged along the first direction across the extension line (non-penetrating portion 252) of the perforations 25 formed along the second direction.

However, in typical nonwoven fabrics, the tangled fibers can move freely to a certain extent, so the fibers may deform or move as shown in FIG. 8B in response to the force applied to tear the perforation 25 along the second direction, making it difficult to cut the fibers. If the fibers are not cut by the force applied to tear the perforation 25 in the second direction, the force may be deflected from the second direction to the first direction, as if the force were to be deflected in the orientation direction of the fibers (first direction). As a result, as shown in FIG. 8A, the waistband member 20 may tear in the first direction (left-right direction) while tearing the perforation 25 in the second direction (up-down direction), making it impossible to wear the napkin 1.

In contrast, in the napkin 1 of this embodiment, fused portions 71, 71 (high density portions 70) are provided on both sides of the perforation 25 in the first direction (left-right direction) between a pair of side joints 40, 40 in the left-right direction of the waistband member 20. The fused portions 71, 71 (high density portions 70) restrain the fibers arranged across the perforation 25 (non-penetrating portion 252), reducing their degree of freedom. In other words, in the first direction, the fibers are more likely to be prevented from moving or deforming between the fused portions 71, 71 arranged on either side of the perforation 25. Therefore, when the perforation 25 is torn along the second direction, the fibers are less likely to escape and the force for tearing the perforation 25 is more likely to act on the fibers, making it easier for the fibers to be cut as shown in FIG. 9B. This prevents the waistband member 20 from tearing along the fiber orientation direction (first direction), making it possible to neatly tear the perforation 25 along the second direction as shown in FIG. 9A.

Furthermore, in the portion of the waistband member 20 of the napkin 1 where the high density portion 70 is formed around the perforation 25, the rigidity of the nonwoven fabric is increased, making it easier for the waistband member 20 to maintain its flat shape. In other words, wrinkles are less likely to form around the perforation 25. This prevents the perforation 25 from being hidden by wrinkles and becoming difficult to see, making it easier to tear the perforation 25.

As mentioned above, the non-skin side sheet 21 and the skin side sheets 22, 23 (first sheet and second sheet) of the waistband member 20 are both made of nonwoven fabric such as spunbond nonwoven fabric. Generally, spunbond nonwoven fabrics are formed into a sheet shape by heat fusing entangled (intertwined) fibers (webs). That is, the surface of each of the nonwoven fabrics making up the non-skin side sheet 21 and the skin side sheet 22 (23) (first sheet and second sheet) is dotted with a number of embossed sections 27, 27... formed by heat fusing (see Figure 2, etc.).

In contrast, in the waistband member 20 of the napkin 1, the high density portion 70 is formed by a fused portion 71 that fuses the non-skin side sheet 21 and the skin side sheets 22, 23 (first sheet and second sheet) that are stacked in the thickness direction. In other words, the fused portion 71 in the napkin 1 is different from the embossed portion 27 that is formed during the manufacture of each nonwoven fabric (first sheet, second sheet), and it joins two nonwoven fabrics (first sheet and second sheet) to each other. And, by providing such a fused portion 71, the fibers of the nonwoven fabrics that constitute the non-skin side sheet 21 and the skin side sheets 22, 23 (first sheet and second sheet) are more likely to be tightly bound to each other. Therefore, the force that breaks the perforation 25 is more likely to act efficiently on the fibers, and the fibers are more likely to be cut. This makes it possible to make the operation of breaking the perforation 25 easier to perform.

Furthermore, it is preferable that the high density portion 70 is provided at least on one of the ends of the perforation 25 on the waist opening 1a side and the end on the leg opening 1b side in the second direction. In other words, it is preferable that the high density portion 70 is provided at least on one of the upper and lower ends of the perforation 25. The upper and lower ends of the perforation 25 are positions that serve as starting points when tearing the perforation 25. For example, when tearing the perforation 25 from the top to the bottom in the vertical direction, the upper end (end on the waist opening 1a side) of the perforation 25 becomes the cut. Therefore, if the fibers straddling the perforation 25 in the first direction (left-right direction) are restrained by the high density portion 70 (fused portion 71) at the upper end (lower end) where the tearing starts, the fibers can be easily cut, and the operation of tearing the perforation 25 can be started more smoothly.

Furthermore, in the second direction (vertical direction), it is preferable that at least a part of the high density portion 70 (fused portion 71) is provided in the portion of the perforation 25 that overlaps with the non-penetrating portion 252 that does not penetrate the first sheet and the second sheet in the thickness direction. As described above, in order to tear the perforation 25 cleanly, it is necessary to efficiently cut the fibers arranged in the non-penetrating portion 252 so as to straddle the perforation 25 in the first direction (left-right direction). At this time, if fused portions 71, 71 are provided on both sides of the non-penetrating portion 252 in the first direction (left-right direction), the fibers are constrained between the fused portions 71, 71, and the degree of freedom is reduced, making it easier to cut the fibers. Therefore, it is possible to make it easier to tear the non-penetrating portion 252 of the perforation 25.

In addition, in FIG. 7, the high density portion 70 (fused portion 71) is provided at a predetermined distance from the perforation 25 in the first direction (left-right direction). Since the perforation 25 and the high density portion 70 do not overlap, the rigidity of the non-penetrating portion 252 of the perforation 25 is prevented from becoming excessively high, making the perforation 25 easier to break. At this time, it is preferable that the distance Wg between the high density portion 70 (fused portion 71) and the perforation 25 in the first direction is smaller than the length l252 of the non-penetrating portion 252 of the perforation 25 in the second direction (up-down direction) (Wg<l252). The smaller the distance (Wg) between the high density portions 70, 70 (fused portions 71, 71) arranged on either side of the perforation 25 in the first direction, the lower the degree of freedom of the fibers, making it easier to cut the fibers. Therefore, compared to when the distance Wg between the high-density portion 70 and the perforation 25 is equal to or greater than the length l252 of the non-penetrating portion 252, the operation of tearing the perforation 25 can be performed more easily. In addition, the smaller the distance Wg, the higher the rigidity of the waistband member 20 in the vicinity of the perforation 25, which prevents the cut surface from curling when the perforation 25 is torn, making it easier to form a clean cut surface.

However, the high density portion 70 (fused portion 71) may be formed so as to overlap with the perforation 25 in the first direction (left-right direction) (see FIG. 11).

Furthermore, it is preferable that the pitch p71 in the second direction (vertical direction) of the multiple fused portions 71, 71... that form the high density portion 70 is smaller than the length l252 in the second direction of the non-penetrating portion 252 of the perforation 25 (p71<l252). With this configuration, it is highly likely that at least a portion of the fused portion 71 will be positioned so as to overlap with the non-penetrating portion 252 in the second direction. Therefore, the fibers that make up the nonwoven fabric are more likely to be restrained by the fused portions 71 on both sides of the non-penetrating portion 252 in the first direction (horizontal direction), making it easier to cut the fibers when tearing the perforation 25. This makes it possible to make the perforation 25 easier to tear.

In addition, in the napkin 1, each fused portion 71 is formed so that the area S71 of each of the fused portions 71 joining the non-skin side sheet 21 and the skin side sheets 22, 23 is smaller than the area S27 of each of the embossed portions 27 formed in the manufacturing process of the non-skin side sheet 21 and the skin side sheets 22, 23 (first sheet and second sheet) (S71<S27). Since the embossed portions 27 are formed in a dispersed manner throughout the nonwoven fabric, there is a possibility that a part of the fused portion 71 overlaps with the embossed portion 27 when the high density portion 70 is formed. In the portion where the embossed portion 27 and the fused portion 71 overlap, the rigidity of the waistband member 20 may become excessively high, and the feel of the waistband member 20 may become hard against the skin. Furthermore, the fused portion 71 is formed overlapping the embossed portion 27, which may cause poor fusion and reduce the bonding strength between the first sheet and the second sheet.

In contrast, if the area S71 of the fused portion 71 is smaller than the area S27 of the embossed portion 27, the probability that the fused portion 71 will overlap the embossed portion 27 can be reduced compared to the opposite case. This prevents the rigidity of the waistband member 20 from becoming excessively high, resulting in a poor feel against the skin, and prevents the bonding strength between the non-skin side sheet 21 and the skin side sheets 22, 23 (the first sheet and the second sheet) from decreasing.

However, each fused portion 71 may be formed so that the area S71 of each fused portion 71 is equal to or greater than the area S27 of each embossed portion 27 (S71 ≧ S27). In this case, each fused portion 71 can be formed large, and therefore the proportion of the area of the fused portion 71 that restrains the fibers of the nonwoven fabric in the high density portion 70 increases. In other words, since the fibers are more likely to be restrained around the perforation 25 (on both sides in the second direction), when the perforation 25 is torn, the fibers arranged across the non-penetrating portion 252 are more likely to be cut (see FIG. 9B). This makes it easier to tear the perforation 25.

In any of the above cases (S71<S27, S71≧S27), the waistband member 20 of the napkin 1 has a portion where the fused portion 71 and the embossed portion 27 do not overlap when viewed in the thickness direction. In other words, there is a portion where the fused portion 71 is formed between two adjacent embossed portions 27, 27. With this configuration, compared to the opposite case, the pitch at which the fibers are constrained by the fused portion 71 is likely to be smaller overall, making it easier to reduce the degree of freedom of the fibers. Therefore, when the perforation 25 is torn, the fibers are more easily cut, making it easier to perform the operation of tearing the perforation 25.

In addition, in the waistband member 20 of the napkin 1, the average thickness t71 of the portion where the fused portion 71 is formed is smaller than the average thickness t27 of the portion where the embossed portion 27 is formed (t27>t71). Fig. 10 is a schematic cross-sectional view showing a cross section in the thickness direction of the waistband member 20 in which the first sheet and the second sheet are laminated. As shown in Fig. 10, the embossed portion 27 is formed in each nonwoven fabric (the first sheet and the second sheet) so as to compress the nonwoven fabric by a predetermined thickness in order to fix the intertwined fibers to each other.
On the other hand, the fused portion 71 is formed so as to compress the two nonwoven fabrics to a depth greater than the above-mentioned predetermined thickness in order to bond the two laminated nonwoven fabrics (the first sheet and the second sheet) to each other. Therefore, in FIG. 10, the relationship t27>t71 is established.

By adopting such a configuration, the fusion strength between the laminated first sheet and second sheet is increased in the area where the fusion portion 71 is formed, and the fibers are strongly constrained in the area where the fusion portion 71 is formed, making it easier to break the perforations 25. Furthermore, even if the embossed portion 27 and the fusion portion 71 overlap in part of the waistband member 20, it is easier to ensure the fusion strength between the first sheet and second sheet.

The average thickness t27 of the portion of the waistband member 20 where the embossed portion 27 is formed and the average thickness t71 of the portion of the waistband member 20 where the fused portion 71 is formed can be measured as follows. First, a test piece to be measured is cut out from the waistband member 20.
Then, for the cross section in the thickness direction of the cut out test piece (cross section corresponding to FIG. 10), the thicknesses of the portions where the embossed portion 27 and the fused portion 71 are formed are measured at about 10 points each using a microscope or the like, and average values t27 and t71 are calculated. Alternatively, the cross section in the thickness direction of the test piece may be photographed, and the average thickness value may be calculated by image analysis using a computer.

Furthermore, it is preferable that the waistband member 20 does not have an elastic member that exhibits stretchability in the first direction in the region between the side joint 40 and the perforation 25 in the first direction (left-right direction). In the napkin 1, a plurality of waistband elastic members 26, 26... are arranged along the first direction (left-right direction) of the front waistband portion 20f, and the waistband elastic members 26 exhibit stretchability along the first direction. On the other hand, the waistband elastic members 26 are arranged in a region inside the positions 26es, 26es in the first direction (left-right direction), and do not exhibit stretchability in a region outside the position 26es in the first direction (see Figures 2, 5, 6, etc.). That is, in the region between the side joint 40 and the perforation 25 in the first direction (left-right direction), an elastic member that exhibits stretchability in the first direction is not provided.

Therefore, when the waistband member 20 is separated into the front and rear along the perforation 25, the area between the separation end 25be (25fe) of the perforation 25 and the side joint 40 in the rear waistband portion 20b in FIG. 5 is less likely to expand or contract. In other words, the waistband member 20 is more likely to maintain a flat surface, and wrinkles are less likely to form. The area between the separation end 25be (25fe) and the side joint 40 is an area that may be pressed strongly against the skin of the wearer's waist when the napkin 1 is used as a tape-type napkin using the engagement member 30, so if wrinkles (unevenness in the thickness direction) are formed in this area, it may cause discomfort or a sense of incongruity to the wearer. In contrast, in this embodiment, wrinkles are less likely to form in the area between the separation end 25be (25fe) and the side joint 40, and the surface of the area comes into contact with the skin of the wearer when the napkin 1 is worn, making it less likely to cause discomfort to the wearer.

The range in which the elasticity of the waist elastic member 26 in the first direction (left-right direction) is effective is adjusted by cutting the waist elastic member 26 at a predetermined position in the first direction (left-right direction) in the elastic member cutting step (S103) of the manufacturing process of the napkin 1 (see FIG. 12) described later.

Furthermore, it is preferable that a high density portion 70 (plurality of fused portions 71) is provided in the region of the waistband member 20 between the side joint portion 40 and the perforation 25 in the first direction (left-right direction). In the portion where the high density portion 70 is provided, the rigidity of the waistband member 20 is increased, wrinkles are less likely to form, and the flat shape is more likely to be maintained. In the napkin 1 of this embodiment, since the high density portion 70 is provided in the region between the side joint portion 40 and the perforation 25 in the first direction (left-right direction) (see FIG. 6), wrinkles are suppressed from forming in that region, making it less likely to cause discomfort to the wearer.

<Modifications of the high density portion 70>
7 has been described as an example of the arrangement of the multiple fused portions 71, 71 that make up the high density portion 70, but the arrangement of the multiple fused portions 71 may be modified as follows. Figures 11A to 11E are diagrams showing modified examples of the arrangement of the fused portions 71 that make up the high density portion 70. As described above, the fused portions 71 fusion-bond the non-skin side sheet 21 and the skin side sheets 22, 23 (first sheet and second sheet) of the waistband member 20.

11A, the high density portion 70 is formed by vertically elongated fused portions 71, 71... extending in the second direction (up-down direction) being intermittently arranged along the second direction. In FIG. 11B, the high density portion 70 is formed by horizontally elongated fused portions 71, 71... extending in the first direction (left-right direction) being intermittently arranged along the first direction. In FIG. 11C, the high density portion 70 is formed by dispersing dot-shaped fused portions 71, 71.... In FIG. 11D, the high density portion 70 is formed by lattice-shaped fused portions 71, 71.... In FIG. 11E, the high density portion 70 is formed by arranging linear fused portions 71 approximately parallel to the perforation 25 on both sides of the perforation 25 in the first direction. The high density portion 70 may be formed by other types of fused portions 71, or may be formed by combining multiple different types of fused portions 71.

In any of these modified examples, the high density portion 70 is formed on both sides of the perforation 25 in the first direction, and the fibers constituting the nonwoven fabric are easily constrained on both sides of the perforation 25, making it easier to cut the fibers. Furthermore, if the fused portion 71 is arranged in an area that overlaps with the non-penetrating portion 252 of the perforation 25 in the second direction, the degree of freedom of the fibers in that area is reduced, making it easier to cut the fibers when breaking the perforation 25. Therefore, even if the high density portion 70 is deformed as shown in Figures 11A to 11E, the operation of breaking the perforation 25 can be made easier. In Figure 7, the fused portion 71 is arranged so as not to overlap the perforation 25 when viewed in the thickness direction, but as in the modified example shown in Figure 11, a part of the fused portion 71 may be arranged to overlap the perforation 25.

<Method of manufacturing napkin 1>
Next, a description will be given of a method for manufacturing the napkin 1. Fig. 12 is a flow diagram of each step carried out in the manufacture of the napkin 1. Fig. 13 is a schematic diagram illustrating a manufacturing apparatus 100 for manufacturing the napkin 1.

The manufacturing apparatus 100 shown in FIG. 13 manufactures the napkin 1 by sequentially carrying out each step (S101 to S109) shown in FIG. 12. The manufacturing apparatus 100 includes a conveying mechanism 110, an elastic member attachment mechanism 120, an elastic member cutting mechanism 130, a high-density portion forming mechanism 140, a perforation forming mechanism 150, an engagement member attachment mechanism 160, an absorbent body attachment mechanism 170, a joining mechanism 180, and a cutting mechanism 190.

First, a conveying step is performed in which base materials such as the non-skin side sheet 21 and the skin side sheets 22 and 23 (first and second sheets) constituting the napkin 1 are conveyed in a predetermined conveying direction (MD direction) (S101). In the manufacturing apparatus 100, the conveying direction (MD direction) is a direction along the left-right direction (first direction) of the napkin 1. In the conveying step, the non-skin side sheet continuous body 21L in which the non-skin side sheet 21 is connected in the conveying direction (left-right direction) and the skin side sheet continuous body 22L (23L) in which the skin side sheet 22 (23) is connected in the conveying direction (left-right direction) are conveyed from the upstream side to the downstream side in the conveying direction at a predetermined conveying speed by the conveying mechanism 110.
While each of these base materials is being transported, each of steps S102 to S109 is carried out, thereby producing the napkin 1.

Next, the non-skin side sheet continuous body 21L and the skin side sheet continuous body 22L (23L) being conveyed in the conveying direction are laminated, and the waist elastic member 26 is sandwiched between them in the thickness direction in an elastic member attachment process (S102). In the elastic member attachment process, the waist elastic member continuous body 26L, which is connected in the conveying direction (left and right direction), is unrolled along the conveying direction while being stretched in the conveying direction at a predetermined stretch ratio by the elastic member attachment mechanism 120. Then, the non-skin side sheet continuous body 21L and the skin side sheet continuous body 22L (23L) are sandwiched between the two sheets and bonded using an adhesive. The adhesive for bonding the waist elastic member continuous body 26L may be applied to the elastic member side (26L) or the sheet side (21L, 22L, 23L). This forms a waist elastic member continuous body 20.

Next, an elastic member cutting process is performed in which the waist elastic member continuum 26L is cut at a predetermined position in the conveying direction (left-right direction) (S103). Specifically, the waist elastic member continuum 26L is cut by the elastic member cutting mechanism 130 so that the range in which the elasticity of the waist elastic member 26 is expressed is between positions 26es, 26es in the left-right direction in FIG. 2. In this embodiment, the waist elastic member continuum 26L is cut at a cutting position near the position where the side joints 40, 40 are formed in the non-skin side sheet continuum 21L in the conveying direction (left-right direction). In the region between the position where the side joint 40 is formed in the conveying direction (left-right direction) and position 26es, the waist elastic member continuum 26L is not joined to the non-skin side sheet continuum 21L and the skin side sheet continuum 22L (e.g., no adhesive is applied). On the other hand, the waist elastic member continuum 26L is joined to the non-skin side sheet continuum 21L and the skin side sheet continuum 22L at positions 26es, 26es. Therefore, the waist elastic member 26 cut near the side joints 40, 40 contracts in the conveying direction (left-right direction) from the side joint 40 toward position 26es, and no longer exhibits stretchability between the side joint 40 and position 26es (see FIG. 2, etc.). This action is also called "cutback" of the elastic member.

When cutting back the waist elastic member 26, it is desirable to cut the waist elastic member 26 at one location near the side joint 40 in the conveying direction (left-right direction). In other words, it is desirable to cut the waist elastic member continuum 26L only at one location between adjacent positions 26es, 26es in the conveying direction (left-right direction). If the waist elastic member continuum 26L is cut (shredded) at multiple locations between adjacent positions 26es, 26es, fragments of the elastic member 26 may remain in the waist member 20 and may fall off to the outside when the napkin 1 is used, or the remaining fragments may get in the way of the operation of tearing the perforations 25.

Next, a high density portion forming process is performed (S104) in which predetermined portions of the non-skin side sheet continuous body 21L and the skin side sheet continuous body 22L (23L) that are being transported in a stacked state are fused together to form a high density portion 70. The high density portion forming process is performed, for example, by forming a plurality of fused portions 71, 71... using a high density portion forming mechanism 140 equipped with an ultrasonic horn and anvil. The shape and arrangement of the fused portions 71 formed in the high density portion forming process are as described in Figures 6 and 8.

In this embodiment, the high density portion forming step (S104) is performed after the elastic member cutting step (S103). Therefore, the waist elastic member 26 is not present in the region where the high density portion 70 is formed (the region between the side joint portion 40 and position 26es in the left-right direction in FIG. 2), and the fused portion 71 is prevented from being formed in a position that overlaps with the waist elastic member 26. This prevents poor fusion of the fused portion 71, making it easier to ensure the bonding strength between the non-skin side sheet continuous body 21L and the skin side sheet continuous body 22L (23L).

Next, a perforation forming step is performed in which the perforations 25 are formed along the CD direction (the vertical direction of the napkin 1) intersecting the conveying direction (the MD direction, the left-right direction of the napkin 1) (S105). The perforations 25 are formed, for example, using a perforation forming mechanism 150 consisting of a cutter roll with blades arranged intermittently along the CD direction. When forming the perforations 25, if the base sheet such as the skin-side sheet continuous body 21L is soft, the blade of the cutter roll may not penetrate the base sheet in the thickness direction, and the perforation portion 252 may not be formed easily. In addition, the perforations 25 may be bent, making it difficult to form accurate perforations 25. In contrast, in this embodiment, the perforation forming step (S105) is performed after the high-density portion 70 is formed in the high-density portion forming step (S104). Therefore, the high-density portion 70 increases the rigidity of the base sheet such as the non-skin-side sheet continuous body 21L, making it easier to maintain the flatness of the base sheet, and the perforations 25 can be formed stably and accurately.

Next, an engaging member attachment step (S106) is performed in which the engaging member 30 is attached to the non-skin side of the waistband member 20. In FIG. 13, the engaging member 30, which is manufactured separately on a line different from the manufacturing apparatus 100, is transferred to the non-skin side of the waistband member 20 by an engaging member attachment mechanism 160 equipped with a transfer drum. Note that, although not shown in FIG. 12 and FIG. 13, before performing the engaging member attachment step (S106), a process is performed in which the portions that will become the pair of leg openings 1b, 1b are cut out of the waistband member 20.

Next, an absorbent body attachment process is performed in which the absorbent body 10 is attached to the skin side of the waistband member 20 (S107). In FIG. 13, the absorbent body 10, which is manufactured separately on a line different from the manufacturing apparatus 100, is transferred to the skin side of the waistband member 20 by an absorbent body attachment mechanism 170 equipped with a transfer drum.

Next, a joining process is performed in which the waistband member 20 and the absorbent body 10 are folded in half at a predetermined position in the CD direction (the center position CL in the vertical direction in Figure 2) using the joining mechanism 180, and the overlapping portions in the thickness direction are joined at a predetermined position in the conveying direction to form the side joints 40 (engagement member joints 35) (S108).

Finally, a cutting step is performed in which the continuous body of the waistline member 20 is cut at predetermined positions in the conveyance direction (both ends in the left-right direction of the napkin 1) using the cutting mechanism 190 (S109).
In this way, individual napkins 1 are formed.

Second Embodiment
In the second embodiment, a pants-type napkin 2 (hereinafter also simply referred to as "napkin 2") in which part of the configuration of the waistband member 20 is different from that of the napkin 1 of the first embodiment will be described.
FIG. 14 is a plan view of the napkin 2 in the opened and extended state as viewed from the thickness direction.

The waistband member 20 of the napkin 2 does not have a waistband elastic member 26, and instead uses elastic sheet members as the skin- side sheets 22, 23, which gives the sheet 20 elasticity in the left-right direction. The skin-side sheets 22 (23) can be, for example, elastic nonwoven fabric. An "elastic nonwoven fabric" is a nonwoven fabric that contains elastic fibers and extensible fibers that have lower shrinkage than the elastic fibers, and that has been subjected to an appropriate stretching process such as gear stretching. The skin-side sheet 22 of this embodiment can use polyurethane elastomer fibers, which are a type of thermoplastic elastomer with elasticity, as the elastic fibers, and polypropylene (PP) fibers, which are a type of polyolefin resin with inelasticity, as the extensible fibers.

The skin-side sheet 22 (23) is joined to the non-skin-side sheet 21 by a plurality of scattered sheet joints (not shown), which gives the waistband member 20 stretchability at least along the left-right direction. In the second embodiment, the sheet joints are formed using known joining means such as ultrasonic welding.

The rest of the configuration of the napkin 2 is basically the same as that of the napkin 1. That is, the configuration of the perforations 25 provided in the waistband member 20, the high density portions 70 (fused portions 71) provided on both sides of the perforations 25 in the left-right direction, etc. are the same as those of the napkin 1. Therefore, the napkin 2 of the second embodiment can also easily tear the perforations 25. When a stretchable nonwoven fabric is used for the skin side sheets 22, 23, it is preferable that the embossed portion and its surrounding area are less stretchable than other areas in order to avoid impairing the texture.

===Other===
The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

In the above embodiment, an example was described in which a pair of engaging portions 32 was provided on both the left and right sides, but multiple pairs of engaging portions 32 may be provided. For example, two engaging portions 32 may be arranged spaced apart in the vertical direction, resulting in a pants-type absorbent article having two pairs of engaging portions 32. In this case, if a stretchable region is provided in the vertical center position of any one pair of engaging portions among the multiple pairs of engaging portions, the waist opening will be more likely to shrink between the engaging portions, thereby achieving a good fit.

In the above embodiment, a pair of perforations 25 (separation portions 25) are provided on both sides of the waistband member 20 in the left-right direction, but the perforations 25 may be provided on only one side. In other words, the waistband member 20 may be configured so that only one side in the left-right direction can be separated into front and rear.

In the above embodiment, the high density portion 70 is formed by distributing a plurality of fused portions 71, 71..., but the high density portion 70 may be formed by different types of fused portions 71. For example, the high density portion 70 may be formed by a two-stage pattern in which an area is formed in which a certain type of fused portion 71a is distributed, and fused portions 71b, which have a higher density per unit area than the fused portions 71a, are arranged to sandwich the area.

1. Napkin (pants-type absorbent article) (first embodiment),
1a waist opening, 1b leg opening,
2. Napkin (pants-type absorbent article) (second embodiment),
10 Absorbent body,
11 absorbent core,
12 top sheet,
13 Back sheet, 13a Liquid impermeable sheet, 13b Hydrophobic sheet,
20 waist member,
20f front waist portion, 20b rear waist portion,
21 non-skin side sheet, 22 skin side sheet, 23 skin side sheet,
25 perforation (separation portion), 25fe separation end, 25be separation end,
251 groove portion, 252 non-penetrating portion,
26 waist elastic member,
27 embossed portion,
28 front leg elastic member, 29 rear leg elastic member,
30 Engagement member,
31 Base material sheet, 32 Engagement portion, 35 Engagement member joint portion,
40 side joint portion, 40f end portion, 40b end portion,
50 absorbent body elastic member,
70 High density part,
71 fusion portion,
100 Manufacturing equipment,
110 conveying mechanism, 120 elastic member attaching mechanism, 130 elastic member cutting mechanism,
140 high density portion forming mechanism, 150 perforation forming mechanism,
160: engagement member attachment mechanism, 170: absorbent body attachment mechanism, 180: joining mechanism, 190: cutting mechanism,
CL Center position

Claims (14)

1. The vertical direction, the horizontal direction, and the front-rear direction intersect with each other,
   An absorbent body;
   A waistband member having a front waistband portion and a rear waistband portion;
   an engaging member having one end fixed to the waistband member and another end removably engaging with the non-skin side of the waistband member;
   having
   The front waistline portion and the rear waistline portion are joined to each other by a pair of side joining portions,
   A pants-type absorbent article having a waist opening and a pair of leg openings,
   The waistband member has a first sheet made of a nonwoven fabric having a fiber orientation along a first direction,
   A perforation is provided for separating the waistband member into front and rear parts,
   The perforations are arranged from the waist opening to the leg openings along a second direction intersecting the first direction,
   a high density portion, which is a portion of the first sheet that is denser than the surrounding area, between the pair of side joint portions in the left-right direction;
   A pants-type absorbent article, characterized in that the high density portion is provided on both sides of the perforation in the first direction.
2. The pants-type absorbent article according to claim 1,
   The waistband member has a second sheet laminated with the first sheet,
   A pants-type absorbent article, characterized in that the high density portion is composed of a plurality of fused portions that fusedly join the first sheet and the second sheet.
3. The pants-type absorbent article according to claim 1 or 2,
   A pants-type absorbent article, characterized in that, in the second direction, the high density portion is provided at at least one of the end of the perforation on the waist opening side and the end of the perforation on the leg opening side.
4. The pants-type absorbent article according to claim 1 or 2,
   The perforations alternate between groove portions penetrating the first sheet in a thickness direction and non-penetrating portions that do not penetrate the first sheet along a second direction,
   A pants-type absorbent article, characterized in that at least a portion of the high density portion is provided in a portion overlapping the non-through portion in the second direction.
5. The pants-type absorbent article according to claim 4,
   A pants-type absorbent article, characterized in that the distance between the perforation and the high-density portion in the first direction is smaller than the length of the non-through portion in the second direction.
6. The pants-type absorbent article according to claim 4,
   The waistband member has a second sheet laminated with the first sheet,
   the high density portion is constituted by a plurality of fused portions that fusedly join the first sheet and the second sheet,
   A pants-type absorbent article, characterized in that the pitch of the fused portions in the second direction is smaller than the length of the non-penetrating portions in the second direction.
7. The pants-type absorbent article according to claim 2,
   the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions;
   A pants-type absorbent article, characterized in that an area of each of the fused portions is smaller than an area of each of the embossed portions.
8. The pants-type absorbent article according to claim 2,
   the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions;
   A pants-type absorbent article, characterized in that the area of each of the fused portions is equal to or greater than the area of each of the embossed portions.
9. The pants-type absorbent article according to claim 2,
   the first sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together through a plurality of scattered embossed portions;
   A pants-type absorbent article, characterized in that, when viewed in the thickness direction, there is a portion where the fused portion and the embossed portion do not overlap.
10. The pants-type absorbent article according to claim 2,
    Each of the first sheet and the second sheet is a nonwoven fabric formed into a sheet shape by thermally fusing entangled fibers together by a plurality of embossed portions scattered therebetween,
    A pants-type absorbent article, characterized in that the average thickness of the portion of the waistband member in which the embossed portion is formed is greater than the average thickness of the portion in which the fused portion is formed.
11. The pants-type absorbent article according to claim 1 or 2,
    A pants-type absorbent article, characterized in that the area of the waistband member between the side joint and the perforation in the first direction does not have an elastic member that exhibits stretchability in the first direction.
12. The pants-type absorbent article according to claim 1 or 2,
    A pants-type absorbent article, characterized in that the high density portion is provided in the region of the waistband member between the side joint portion and the perforation in the first direction.
13. A conveying step of continuously conveying a first sheet made of a nonwoven fabric having fiber orientation along a first direction along a conveying direction;
    a high density portion forming step of forming a high density portion in a predetermined region of the first sheet, the high density portion being a portion of the first sheet that is denser than the surrounding area;
    A perforation forming process of forming perforations in the first sheet along a second direction intersecting the first direction;
    an engagement member attachment step of fixing one end of an engagement member that removably engages with the first sheet to the first sheet;
    A method for producing a pants-type absorbent article comprising the steps of:
    The perforation forming step is carried out after the high density portion forming step,
    A method for manufacturing pants-type absorbent articles, characterized in that the high density portions are provided on both sides of the perforation in the first direction.
14. A method for manufacturing a pants-type absorbent article according to claim 13,
    an elastic member attachment process for attaching an elastic member stretched along the conveyance direction between a second sheet that is continuously conveyed in the conveyance direction and the first sheet in a thickness direction thereof so as to sandwich the elastic member;
    an elastic member cutting step of cutting the elastic member at a predetermined position in the first direction;
    having
    A method for producing a pants-type absorbent article, characterized in that the elastic member cutting step is carried out prior to the high density portion forming step.

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