CN114828797B

CN114828797B - Absorbent article

Info

Publication number: CN114828797B
Application number: CN202080087056.9A
Authority: CN
Inventors: 野本贵志; 七海久孝; 木村明宽; 出谷耕; 卫藤友美
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2019-12-26
Filing date: 2020-10-14
Publication date: 2023-05-02
Anticipated expiration: 2040-10-14
Also published as: WO2021131250A1; KR20220121798A; JP7254690B2; JP2021104201A; CN114828797A

Abstract

An absorbent article having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, the absorbent article comprising: an absorber; a surface sheet provided on the skin side in the thickness direction of the absorber; and a back sheet provided on the non-skin side in the thickness direction of the absorbent body, wherein the back sheet has a woven or knitted fabric in which a plurality of yarns cross each other when viewed in the thickness direction, the plurality of yarns each have a cross portion that crosses each other and a non-cross portion that does not cross each other, and the non-cross portion of the plurality of yarns is provided at an edge in the longitudinal direction of the absorbent article.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article.

Background

In an absorbent article such as a sanitary napkin, after each sheet is laminated and cut into a product shape, the laminated state of each sheet at the front and rear end portions of the product is fixed by sealing the outer edge portions. For example, patent document 1 discloses an absorbent article in which a front sheet and a back sheet are heat sealed to each other at portions extending from longitudinal ends of an absorber, and a pair of seal portions are formed at the longitudinal ends of the absorbent article, respectively. Further, as the surface sheet of patent document 1, a nonwoven fabric sheet composed of thermoplastic synthetic fibers is preferably used.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2001-129019

Disclosure of Invention

Problems to be solved by the invention

According to the absorbent article of patent document 1, the leakage preventing sheet 23 can be interposed between the front sheet and the back sheet, and the sheets can be firmly fixed to each other, thereby preventing the sheets from being peeled off from each other. However, the seal portion is easily hardened by heat welding, and when the seal portion is attached to the boundary, the seal portion is bent and the hard seal portion is brought into contact with the skin of the user, which may give the user a sense of discomfort.

The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an absorbent article which is hardly stiffened at the end edge in the longitudinal direction and is easily perceived as soft by the user.

Means for solving the problems

The main invention for achieving the above object is an absorbent article having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, the absorbent article comprising: an absorber; a surface sheet provided on the skin side in the thickness direction of the absorber; and a back sheet provided on the non-skin side of the absorber in the thickness direction, wherein the back sheet has a woven or knitted fabric in which a plurality of yarns cross each other when viewed in the thickness direction, the plurality of yarns each have a cross portion that crosses each other and a non-cross portion that does not cross each other, and the non-cross portion of the plurality of yarns is provided at an edge of the absorbent article in the longitudinal direction.

Other features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an absorbent article having a hard end edge in the longitudinal direction and flexibility which is easily perceived by a user can be provided.

Drawings

Fig. 1 is a plan view of the sanitary napkin 1 as seen from the skin side.

Fig. 2 is a plan view of the sanitary napkin 1 viewed from the non-skin side.

Fig. 3 is a cross-sectional view taken along line X-X of fig. 1.

Fig. 4 is a partial enlarged view of the surface sheet 3.

Fig. 5 is a diagram showing a state in which the surface sheet 3 is separated into the woven fabric 40 and the fiber assembly 50.

Fig. 6 is an enlarged partial top view of the woven fabric 40 of the face sheet 3.

Fig. 7 is a sectional view taken along the line Y-Y of fig. 4.

Detailed Description

At least the following matters will be clarified from the description of the present specification and drawings.

An absorbent article having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, the absorbent article comprising: an absorber; a surface sheet provided on the skin side in the thickness direction of the absorber; and a back sheet provided on the non-skin side of the absorber in the thickness direction, wherein the back sheet has a woven or knitted fabric in which a plurality of yarns cross each other when viewed in the thickness direction, the plurality of yarns each have a cross portion that crosses each other and a non-cross portion that does not cross each other, and the non-cross portion of the plurality of yarns is provided at an edge of the absorbent article in the longitudinal direction.

According to such an absorbent article, the non-intersecting portion where the yarns do not intersect with each other is a portion constituted by one yarn. The longitudinal end edges are hard to harden by having non-intersecting portions formed of one such yarn, and the user easily feels softness up to the end of the absorbent article.

In the absorbent article, it is preferable that the woven fabric has a plurality of warp yarns and a plurality of weft yarns intersecting with the warp yarns when viewed in the thickness direction, the warp yarns and the weft yarns have the intersecting portions and the non-intersecting portions, respectively, and the longitudinal end edges of the absorbent article have the non-intersecting portions of the warp yarns or the weft yarns.

According to such an absorbent article, the non-intersecting portion where the warp yarn and the weft yarn of the woven fabric do not intersect is a portion constituted by one warp yarn or one weft yarn, and the end edge is hard to harden by having such a non-intersecting portion, so that the user easily feels softness up to the end of the absorbent article.

In the absorbent article, it is preferable that the top sheet further has a nonwoven fiber aggregate, and the fiber aggregate is integrated with the non-skin side surface of the woven fabric or the knitted fabric by interlacing, and a part of the constituent fibers extend toward the skin side in the thickness direction from the skin side surface of the woven fabric or the knitted fabric.

According to such an absorbent article, the strength of the front sheet can be maintained by the interweaving, and the stacked state can be ensured without firmly adhering the woven fabric or knitted fabric to the fiber aggregate. This makes it difficult to increase the rigidity of the longitudinal end portions. Further, since positional displacement of the weft and warp of the woven fabric or positional displacement of the yarns of the knitted fabric is not easily caused by the interweaving, the distance between yarns is easily and uniformly maintained, and the appearance can be maintained. In addition, the excreted liquid is easily transferred to the lower absorber along the fibers extending toward the skin side.

In the absorbent article, it is preferable that the front sheet and the back sheet are joined by a hot melt adhesive at both end edges in the longitudinal direction of the absorbent article.

According to such an absorbent article, when the sheets are joined and cut into a product shape, the warp yarns and the weft yarns of the woven fabric or the yarns of the knitted fabric are less likely to separate from each other.

In the absorbent article, it is preferable that the woven fabric has a plurality of warp yarns and a plurality of weft yarns intersecting the warp yarns when viewed in the thickness direction, the absorbent article has a pressing portion that presses the surface sheet and the absorber, and an average value of lengths in the width direction of a bottom portion of the pressing portion is longer than an average value of lengths between intersections of the warp yarns and the weft yarns of the woven fabric in the width direction.

According to such an absorbent article, the pressing portion is easily bent by having a certain degree of thickness, and the fit to the body is improved. In addition, since the intersection point (crossing portion) of the warp yarn and the weft yarn exists in the width of the pressing portion, the shape of the pressing portion is easily maintained by the thickness of the intersection point, compared with the portion without the intersection point, at the time of pressing.

In the absorbent article, it is preferable that the woven fabric has an elongation in the longitudinal direction of 3 to 8%, the knitted fabric has an elongation in the longitudinal direction of 80 to 100%, and the depth of the pressing portion is uniform.

According to such an absorbent article, since the elongation in the longitudinal direction of the woven fabric and the knitted fabric is low, the elongation of the entire surface sheet is reduced even if either one of the woven fabric and the knitted fabric is used. For a surface sheet which is difficult to elongate, by pressing with a roller or the like having no irregularities, it is easy to provide a pressing portion having a uniform depth. When the bottom of the pressing portion has irregularities, that is, when the depth is changed, the pressing portion is easily hardened, but the pressing portion can maintain flexibility by the constant depth. In addition, the squeezing portion can easily and uniformly suck the excreted liquid.

In the absorbent article, it is preferable that the constituent yarn of the woven fabric is formed of a twisted yarn composed of a plurality of base yarns, and the fineness of the twisted yarn is 30 cotton count or more and 100 cotton count or less.

According to such an absorbent article, the finer the constituent yarn is, the more flexibility the woven fabric can obtain, and the softness is imparted to the absorbent article itself using the woven fabric.

In the absorbent article, it is preferable that the surface sheet further has a nonwoven fiber aggregate including: a skin-side extension portion located closer to the skin side in the thickness direction than the skin side surface of the woven fabric or the knitted fabric; and a non-skin-side extending portion located on the non-skin side in the thickness direction with respect to the non-skin side surface of the woven fabric or the knitted fabric, wherein a maximum thickness of the non-skin-side extending portion is larger than a maximum thickness of the skin-side extending portion.

According to such an absorbent article, since the thickness of the portion extending toward the non-skin side is large, more liquid is likely to enter the absorbent body disposed on the lower side (non-skin side in the thickness direction) of the fiber aggregate along the fibers of the fiber aggregate.

In the absorbent article, it is preferable that the surface sheet further has a nonwoven fiber aggregate including hydrophilic fibers and hydrophobic fibers.

According to such an absorbent article, the surface sheet has a skin feel like a cloth using hydrophilic fibers, is excellent in the scraping property of excrement, and can suppress the formation of creases due to adhesion of fibers to each other using hydrophobic fibers.

In the absorbent article, the hydrophilic fibers preferably contain rayon fibers.

According to such an absorbent article, the rayon not only improves the liquid intake property, but also is thin and soft in the fiber itself, and thus imparts softness to the fiber aggregate.

In the absorbent article, the fiber aggregate preferably does not contain a hydrophilic oil agent.

In such an absorbent article, a hydrophilic oil is often used to impart hydrophilic properties to hydrophobic fibers, but since hydrophilic fibers such as rayon are contained therein, a fiber aggregate can be formed without using a hydrophilic oil. Therefore, it is less likely to cause skin rash or the like due to contact of the oil with the skin, and is softer to the skin.

In the absorbent article, the weight of the hydrophobic fibers per unit area in the fiber aggregate is preferably larger than the weight of the hydrophilic fibers per unit area.

According to such an absorbent article, the weight of the hydrophobic fibers is large, so that the fiber aggregate is difficult to hold the liquid, and the liquid is guided to the absorber side along the fibers of the fiber aggregate. In addition, even if the liquid is intended to flow backward due to the body pressure during the wearing, it is difficult to suck the liquid to flow backward, and the liquid return is suppressed.

In the absorbent article, it is preferable that the woven fabric has a plurality of warp yarns and a plurality of weft yarns intersecting the warp yarns when viewed in the thickness direction, the warp yarns and the weft yarns each have the intersecting portion and the non-intersecting portion, and a proportion of the non-intersecting portion of the weft yarns in the number of all the non-intersecting portions at both ends in the width direction is larger than a proportion of the non-intersecting portion of the weft yarns in the number of all the non-intersecting portions at the center in the width direction in a region where the surface sheet is present at the end edge in the longitudinal direction of the absorbent article.

According to such an absorbent article, both ends in the width direction are portions that are easily abutted against the groin of the wearer during wearing, and the non-intersecting portions of the weft yarns exist, so that the yarn ends of the weft yarns contact the groin, and the skin feel is improved.

Description of the embodiments

Hereinafter, as an absorbent article of the present invention, an embodiment will be described by taking a sanitary napkin as an example. However, the present invention is not limited to this, and the present invention can be applied to other absorbent articles such as menstrual sheets and urine collecting pads.

< basic Structure of sanitary napkin 1 >

Fig. 1 is a plan view of a sanitary napkin 1 (hereinafter also referred to as "sanitary napkin 1") as seen from the skin side. Fig. 2 is a plan view of the sanitary napkin 1 viewed from the non-skin side. Fig. 3 is a cross-sectional view taken along line X-X of fig. 1.

The sanitary napkin 1 has a longitudinal direction, a width direction and a thickness direction orthogonal to each other. In the longitudinal direction of the sanitary napkin 1, the side that contacts the lower abdomen of the wearer is referred to as the front side, and the side that contacts the buttocks of the wearer is referred to as the rear side. In the thickness direction, the side that contacts the wearer is referred to as the skin side, and the opposite side is referred to as the non-skin side.

As shown in fig. 3, the sanitary napkin 1 includes an absorber 2, a front sheet 3 provided on the skin side in the thickness direction of the absorber 2, a back sheet 4 provided on the non-skin side in the thickness direction of the absorber 2, and a pair of side sheets 5. The topsheet 3 and the absorber 2 are joined to each other by a known joining member such as a hot melt adhesive. The surface sheet 3 and the back sheet 4 have a larger planar dimension than the absorber 2, and cover the entire plane of the absorber 2. The front sheet 3, the back sheet 4, and the side sheet 5 stacked on each other are joined to each other via an outer peripheral seal 8 (see fig. 2) provided along the outer peripheral edge of the sanitary napkin 1.

As shown in fig. 1, a pair of side sheets 5 are provided on both sides of the front sheet 3 in the width direction, and are arranged along the longitudinal direction so as to overlap from the skin side in the thickness direction of the front sheet 3. The pair of side sheets 5 are joined to the front sheet 3 via a joining portion (not shown) formed of a known adhesive member or a welding member.

The sanitary napkin 1 further includes a pair of wing portions 6 extending from a central region in the longitudinal direction of the sanitary napkin 1 to both outer sides in the width direction. The wing portions 6 are formed by side sheets 5 and back sheet 4 extending outward from both side portions in the width direction of the front sheet 3. The sanitary napkin 1 may be configured without the wing portions 6.

In order to enhance the softness of the sanitary napkin 1, an intermediate sheet made of a nonwoven fabric or the like having a relatively high fiber density may be disposed between the topsheet 3 and the absorbent body 2, although not shown. In addition, a leak-proof sheet made of a liquid-impermeable plastic film, nonwoven fabric, or the like having air permeability may be preferably disposed between the absorber 2 and the back sheet 4 in order to suppress leakage of body fluid.

As shown in fig. 2, an adhesive region 11 provided by application of an adhesive or the like is provided on the non-skin side surface (non-skin side surface of the back sheet 4) of the sanitary napkin 1. When the sanitary napkin 1 is used, the adhesive region 11 is adhered to the skin side surface of the undergarment or the like, whereby the sanitary napkin 1 is fixed to the undergarment or the like. In fig. 2, 6 adhesive regions 11 having a rectangular shape with long sides in the longitudinal direction are arranged at intervals in the width direction, but the shape and number of the adhesive regions 11 are not limited thereto.

Similarly, the wing-portion adhesive regions 12 are provided on the non-skin side surfaces (non-skin side surfaces of the back sheet 4) of the wing portions 6. When the sanitary napkin 1 is used, the wing portions are adhered to the non-skin side surface of the undergarment or the like by the adhesive regions 12, whereby the sanitary napkin 1 is fixed to the undergarment or the like. In fig. 2, each wing 6 is provided with one rectangular wing adhesive region 12 having a long side in the longitudinal direction, but the shape and number of the wing adhesive regions 12 are not limited to this. The adhesive region 11 and the wing adhesive region 12 are covered with a spacer (not shown) made of a plastic film.

The sanitary napkin 1 further has a pressing portion (concave portion) 7 formed by pressing the topsheet 3 and the absorber 2. In the present embodiment, the topsheet 3 and the absorber 2 are pressed from the skin side surface of the topsheet 3 in the thickness direction, and the topsheet 3 and the absorber 2 are joined and integrated. The pressing portion 7 prevents the surface sheet 3 from floating, and when menstrual blood or the like flows into the pressing portion 7, penetration into the absorbent body 2 can be promoted, and diffusion can be suppressed.

The topsheet 3 has a liquid-permeable surface (upper surface) 3a and a non-skin-side surface (lower surface) 3b on the opposite side in the thickness direction, and is composed of a woven fabric 40 and a fiber aggregate 50. The back sheet 4 may be formed of a liquid-impermeable and moisture-permeable plastic film, a liquid-impermeable nonwoven fabric, a laminate thereof, or the like. The side sheet 5 may be a known nonwoven fabric, but in order to effectively prevent side leakage of body fluid, a sheet having water repellency or water repellency is preferably used.

The absorbent body 2 is a member that absorbs and retains excrement such as menstrual blood, and includes an absorbent core 10 that absorbs liquid, and a liquid-permeable core wrap sheet 20 that wraps the entire absorbent core 10 in order to improve the shape retention and liquid diffusion properties of the absorbent core 10, as shown in fig. 3.

The absorbent core 10 is a core formed into a predetermined shape by adding a super absorbent polymer (so-called SAP) or the like as liquid absorbent particulate matter to pulp fibers, cellulose absorbent fibers or the like as liquid absorbent fibers. The core wrap sheet 20 is a liquid-permeable sheet, and examples thereof include crepe paper, hydrophilic nonwoven fabric, air-laid nonwoven fabric, and the like.

The core wrap sheet 20 is disposed so as to cover the entire absorbent core 10, and both

side edges

20a and 20b in the longitudinal direction of the core wrap sheet 20 are laminated on each other on the non-skin side of the widthwise central portion of the absorbent core 10 (see fig. 3). In the present embodiment, the core wrap sheet 20 is formed of one continuous sheet, but may be formed separately as a sheet member covering the skin side surface of the absorbent core 10 and a sheet member covering the non-skin side surface.

< woven fabric 40 and fiber Assembly 50 of surface sheet 3 >

Fig. 4 is an enlarged view of a part of the topsheet 3 when viewed from the skin side, and fig. 5 is a view showing a state in which the topsheet 3 is separated into the woven fabric 40 and the fiber aggregate 50. As shown in fig. 3, 4 and 5, the topsheet 3 has a woven fabric 40 on the skin side and a fiber aggregate 50 on the non-skin side. As shown in fig. 3 and 5, the woven fabric 40 has a lower surface 40a facing the fiber aggregate 50 and an upper surface 40b serving as a surface for contact with the skin opposite thereto. The woven fabric 40 and the fiber aggregate 50 are integrated by intertwining (interlacing). The method of interlacing woven fabric 40 with fibrous assembly 50 will be described later.

As shown in fig. 4, the woven fabric 40 is composed of constituent yarns 41 woven in a lattice shape. The constituent yarn 41 has a plurality of warp yarns 42 and a plurality of weft yarns 43 intersecting the warp yarns 42 when viewed in the thickness direction, and a plurality of woven eyes 45 are formed by the intersection. The constituent yarn 41 of the woven fabric 40 is a twisted yarn formed by twisting a raw yarn composed of cotton yarn (cotton fiber). In addition to cotton fibers, cellulose fibers such as natural cellulose fibers such as hemp and pulp fibers, regenerated cellulose fibers such as rayon and semisynthetic cellulose fibers such as acetate fibers are preferably used as the raw yarn material. The cotton yarn used as the base yarn is preferably 30 to 100 cotton counts. The finer the constituent yarn 41 is, the more flexible the woven fabric 40 can be.

The woven fabric 40 mainly composed of cotton material or the like is located on the skin side of the surface sheet 3, so that a comfortable skin touch can be obtained for the user, and a skin problem is not easily caused. The knitting method of the woven fabric 40 is not limited to the plain weave knitted in a lattice form as described above, and a known knitting method such as twill knitting, satin knitting, and winding knitting can be appropriately used.

The surface sheet 3 of the present embodiment has the woven fabric 40, but the woven fabric 40 may be a knitted fabric. The knitted fabric is constituted by knitting and bundling yarns in which a plurality of fibers are twisted, but the plurality of yarns cross each other when viewed in the thickness direction, similar to the woven fabric. The knitted fabric may be any one of warp knitting and weft knitting, and examples thereof include a tabasheer, a tricot, a rib fabric, a deer pattern, a honeycomb mesh fabric, a double knit fabric, and a terry fabric.

The fiber aggregate 50 is a fiber aggregate formed by a known method such as a spunbonding method using long fibers, a dry method in which short fibers are carded in a certain direction by a carding machine and finished to form a web, and is formed into a nonwoven fabric at a stage before forming. The fiber aggregate 50 is formed of constituent fibers 51 containing hydrophilic fibers. As the hydrophilic fiber of the present embodiment, rayon fiber is used. Not only is the liquid intake properties improved by the rayon fibers improved, but the rayon fibers are soft due to the finer fibers themselves, and thus softness is imparted to the fiber assembly 50. The hydrophilic fibers are not limited to rayon fibers, and may be regenerated cellulose fibers such as fibrillated rayon, natural cellulose fibers such as cotton and crushed pulp, semisynthetic cellulose such as acetate fibers, and the like.

As a method of interweaving the woven fabric 40 and the fiber aggregate 50, for example, a known water-jet interweaving method can be used. In the process of producing the liquid-permeable sheet by the water-jet weaving method, a high-pressure water jet is sprayed from a plurality of nozzles arranged at intervals in a direction intersecting with the conveyance direction of the continuous laminate, onto a continuous laminate in which a continuous fiber aggregate, which is a material of the fiber aggregate 50, is laminated on the upper surface of a continuous lattice-like woven fabric, which is a material of the woven fabric 40. This makes it possible to wind and integrate the constituent fibers 51 of the fiber aggregate 50 and the constituent yarns 41 of the woven fabric 40. In addition, the integrated sheet can be provided with a pattern by the pressure of water. In addition, in the case where the woven fabric 40 is a knitted fabric, the knitted fabric and the fiber aggregate 50 can be interwoven and integrated by the same method.

The surface sheet 3 of the present embodiment, which is formed by interlacing the woven fabric 40 on the skin side with the fiber aggregate 50 on the lower surface (non-skin side surface) 40a of the woven fabric 40, has higher strength than the surface sheet 3 formed of only nonwoven fabric. Further, since the fiber aggregate 50 is integrated with the woven fabric 40 without an adhesive or the like, the fiber aggregate is excellent in flexibility as compared with the case of being bonded to each other with an adhesive or the like. Therefore, the sanitary napkin 1 using such a topsheet 3 is easy to maintain softness up to the longitudinal end 1 ep. Further, since the warp yarn 42 and the weft yarn 43 of the woven fabric 40 are not easily displaced (in the case of the knitted fabric, the displacement of the yarns is not easily caused) by the interweaving, the distance between the yarns can be easily and uniformly maintained, and the beauty of the surface sheet 3 can be maintained.

As shown in fig. 4, a part of the fibers 51 may be wound around the warp yarn 42 and the weft yarn 43 of the woven fabric 40, wound around the warp yarn 42, or further interwoven so as to enter between the base yarns of the warp yarn 42 and the weft yarn 43. Thereby, the fiber aggregate 50 is stably integrated with the woven fabric 40. Further, a part of the constituent fibers 51 extend toward the skin side in the thickness direction (partially enlarged view of fig. 3) from the skin side surface (upper surface) 40b of the woven fabric 40, and the body fluid discharged to the topsheet 3 spreads along the warp yarns 42 and the weft yarns 43 of the woven fabric 40, and the constituent fibers 51 of the fiber aggregate 50 extending toward the skin side are rapidly transferred to the lower absorber 2. The constituent fibers 51 of the fiber aggregate 50 are short fibers having a fiber length of 25 to 64mm, preferably 32 to 58mm, and more preferably 38 to 51 mm.

If the front sheet 3 is made of only the woven fabric 40, there is a possibility that the constituent yarn 41 of the woven fabric 40 will approach the portion of the end edge 1ed (fig. 1) in the longitudinal direction of the sanitary napkin 1 when the product end is cut into the product shape, but the woven fabric 40 and the fiber assembly 50 are interwoven and integrated, so that the woven fabric 40 has the stable woven eye 45, and the constituent yarn 41 is not easily approaching even when the product is cut. Thus, the end of the article (here, 1 ep) can be thoroughly cut.

As described above, the sanitary napkin 1 according to the present embodiment uses the surface sheet 3 formed by interweaving and integrating the woven fabric 40 and the fiber aggregate 50 on the side contacting the skin of the user. On the other hand, in general sanitary napkins, the surface sheet is often formed of only nonwoven fabric, and in some cases, the sheets are bonded to each other and the product end is cut into the product shape, and then the outer edge portion is heat-welded to fix the sheets to each other. The sealed portion is firmly joined by heat welding, but since the joined portion is easily hardened, there is a possibility that the joined portion is bent at the time of attachment at the boundary with the joined portion, and gives a sense of inconveniences when in contact with the skin of the user.

In this regard, in the sanitary napkin 1 of the present embodiment, the woven fabric 40 made of cotton is not heat-welded to the peripheral seal portion 8 of the front sheet 3, and the front sheet 3 and the back sheet 4 are joined, so that the outer edge portion (end portion 1 ep) in the longitudinal direction is not hardened and flexibility is maintained. Further, the woven fabric 40 of the front sheet 3 is present to the end edge 1ed (fig. 1) in the longitudinal direction of the sanitary napkin 1, whereby the following effects can be obtained.

Fig. 6 is an enlarged partial top view of the woven fabric 40 of the face sheet 3. In fig. 6, the fiber aggregate 50 and the side sheet 5 are omitted for convenience in order to explain the states of the warp yarns 42 and the weft yarns 42 of the woven fabric 40. As shown in fig. 6, warp yarn 42 and weft yarn 43 of woven fabric 40 have intersecting portions cx that intersect each other and non-intersecting portions nx that do not intersect each other, respectively. Further, the edge 1ed in the longitudinal direction of the sanitary napkin 1 has a non-intersecting portion nx of a plurality of warp yarns 42 near the widthwise central position CL of the sanitary napkin 1. The end edge 1ed has non-intersecting portions nx of the plurality of weft yarns 43 and non-intersecting portions nx of the warp yarns 42 on the outer side in the width direction.

The non-intersecting portion nx where the warp yarn 42 and the weft yarn 43 of the woven fabric 40 do not intersect is a portion constituted by one warp yarn 42 or weft yarn 43. Since the end edge 1ed in the longitudinal direction has a plurality of non-intersecting portions nx formed by one such yarn, the end edge 1ed is hard to harden. The softness can be easily perceived by the user by maintaining the softness at the end edges 1ed of the sanitary napkin 1.

In the case where the woven fabric 40 is a knitted fabric, the same effect as that in the case where the woven fabric 40 is used is obtained by setting the intersecting portions cx of the plurality of yarns constituting the knitted fabric and the non-intersecting portions nx of the plurality of yarns to be non-intersecting portions nx of the plurality of yarns at the end edge 1ed in the longitudinal direction of the sanitary napkin 1.

In the sanitary napkin 1 of the present embodiment, the front sheet 3 and the back sheet 4 are joined to each other at both end edges (including the end edges 1 ed) in the longitudinal direction by a hot melt adhesive (not shown). Specifically, the hot melt adhesive is provided in a region from one end to the other end in the longitudinal direction of the surface sheet 3, for example, by drawing an Ω pattern, a spiral pattern, or the like. By fixing the front sheet 3 and the back sheet 4 to the end edge 1ed with the hot melt adhesive, the warp yarns 42 and the weft yarns 43 of the woven fabric 40 are hard to spread even when the product end is cut into the product shape after fixing. The end edge 1ed does not cause scattering of the warp yarn 42 and the weft yarn 43, and thus the sanitary napkin 1 can be kept beautiful.

In the present embodiment, the outer peripheral seal 8 is provided, but since the woven fabric 40 and the fiber aggregate 50 are interwoven and integrated to form the front sheet 3, the shape of the product can be maintained even if the outer peripheral seal 8 is not provided, as long as the front sheet 3, the back sheet 4, and the side sheet 5 stacked on each other are joined by the adhesive such as the hot-melt adhesive. Thus, the flexibility of the product end can be ensured.

As shown in the partial enlarged views of fig. 1 and 4, in the region where the topsheet 3 is present at the longitudinal end edge 1ed of the sanitary napkin 1, the warp yarn 42 and the weft yarn 43 of the woven fabric 40 are arranged as follows, with the widthwise center being the center portion 1ch and the widthwise both ends being the end portions 1et, respectively. The central portion 1ch here is a portion extending from the central position CL toward both sides (outside) in the width direction by 10% of the total length of the topsheet 3 in the width direction at the end edge 1ed in the longitudinal direction of the sanitary napkin 1, and the both end portions 1et are also portions extending from the outer end 1ee (fig. 4) in the width direction of the topsheet 3 toward the inside in the width direction by 10% of the total length of the topsheet 3 in the width direction at the end edge 1 ed. In the central portion 1ch of the present embodiment, the total number of the intersecting portions cx and the non-intersecting portions nx disposed at the edge 1ed is 12, and the total number is the non-intersecting portions nx of the warp yarn 42. In the end portion 1et, the total number of intersecting portions cx and non-intersecting portions nx disposed at the edge 1ed is 18, and 15 of them are non-intersecting portions nx and 3 are intersecting portions cx. In addition, the number of non-intersecting portions nx of the weft yarn 43 in the non-intersecting portions nx of the end portion 1et is 7. That is, the proportion of non-intersecting portions nx of the weft yarns 43 in the number (15) of all non-intersecting portions nx in the end portion 1et (i.e., 7/15=about 47%) is larger than the proportion (0/12=0%) of non-intersecting portions nx (0) of the weft yarns 43 in the number (12) of all non-intersecting portions nx in the widthwise central portion 1 ch. The widthwise both ends 1et are portions that are easily abutted against the groin of the wearer during wearing of the sanitary napkin 1. As in the present embodiment, the proportion of the non-intersecting portions nx of the weft yarn 43 in the both end portions 1et is larger than that in the central portion 1ch, so that the yarn ends of the weft yarn 43 are easily brought into contact with the inguinal portions, and the skin touch is improved.

< extrusion part 7>

As described above, the sanitary napkin 1 has the pressing portion 7 formed by pressing the topsheet 3 and the absorbent body 2. The pressing portion 7 of the present embodiment is formed in a linear shape by connecting a plurality of pressing portions along the outer peripheral edge portion of the absorber 2, and thereby has a substantially annular shape that is long in the longitudinal direction as a whole. The shape and arrangement of the pressing portion 7 are not limited to this, and may be formed into a desired shape.

The pressing portion 7 has a bottom portion 7d (see fig. 3), and the average value of the width L (length L in the width direction) of the bottom portion 7d is longer than the average value of the length M (see fig. 4 and 6) between the intersections of the warp yarns 42 and the weft yarns 43 of the woven fabric 40 in the width direction. The average value of each length was determined as follows. First, an enlarged photograph of the surface sheet 3 including the pressing portion 7 and the woven fabric 40 is taken by using a digital microscope VHX-1000 manufactured by KEYENCE, etc. As shown in fig. 4, in the woven fabric 40, in 1 of the fabric eyes 45, the intersection points with the weft yarn 43 of the warp yarns 42 adjacent to one weft yarn 43 are set to C1 and C2. The intersections in the width direction, that is, C1 and C2, are connected by a straight line, and the length of the straight line becomes the length M between the intersections in the width direction. In fig. 4, as another example, intersections with the weft yarn 43 with respect to warp yarns 42 adjacent to another weft yarn 43 are denoted by C3 and C4, and a straight line connecting C3 and C4 is denoted by a length M between the intersections. Based on the enlarged photograph, for example, 10 measurements are randomly performed on the length M, and an average value of the measured values is obtained. In the squeeze portion 7, for example, 10 points of the length L in the width direction of the bottom portion 7d are randomly measured in an enlarged photograph as seen from the skin side of the front sheet 3, and the average value of the measured values is obtained.

The pressing portion 7 is easily bent due to a certain thickness, and the fit of the sanitary napkin 1 to the body is improved. The width L of the bottom 7d of the pressing portion 7 is longer than the length M between the intersections of the warp yarns 42 and the weft yarns 43 in the width direction, and thus, the intersections (intersections cx) of the warp yarns 42 and the weft yarns 43 exist in the width (length in the width direction) of the pressing portion 7. When forming the pressed portion 7, if there is an intersection (intersection cx) at the pressed portion, the shape of the pressed portion 7 is easily maintained by the thickness of the intersection where the yarns overlap.

The pressing portion 7 is formed by pressing the topsheet 3 and the absorber 2 in the thickness direction, and the woven fabric 40 of the topsheet 3 has an elongation in the longitudinal direction of 3 to 8%, more preferably 5 to 6%. The elongation of the woven fabric 40 in the width direction is 15 to 30%, more preferably 19 to 26%. When the woven fabric 40 of the surface sheet 3 is a knitted fabric, the elongation in the longitudinal direction of the knitted fabric is preferably 80 to 100%, more preferably 85 to 95%, and the elongation in the width direction is preferably 150 to 160%.

The "elongation" mentioned above is the elongation (%) of the woven fabric 40 (or knitted fabric) and can be measured according to JIS L1906 "cloth test method of woven fabric and knitted fabric". Specifically, the woven fabric 40 (or knitted fabric) in a state before being interwoven with the fiber aggregate 50 was cut into a size of 25mm in width and 150mm in length, and a test piece was produced, and the test piece was stretched at a predetermined stretching speed (for example, 100 mm/min), and the value of the elongation at break was obtained. As the tensile tester, for example, an Autograph tensile tester (model: AG-I) manufactured by Shimadzu corporation can be used. The measurement was performed 3 times, and the average value thereof was used as the elongation of the woven fabric 40 (or knitted fabric).

In forming the pressing portion 7, since the pressing portion is provided while the sanitary napkin 1 is conveyed in the MD direction (longitudinal direction), the elongation in the longitudinal direction of the woven fabric 40 or knitted fabric is low, and the bottom portion 7d of the pressing portion 7 can be formed without providing irregularities. Specifically, since the woven fabric 40 of the present embodiment has a low elongation in the longitudinal direction, the elongation of the entire surface sheet 3 formed by interlacing the woven fabric 40 with the fiber aggregate 50 is also reduced. When the pressing portion 7 is to be formed by an embossing roll or the like having irregularities on the surface sheet 3 which is difficult to elongate, the surface sheet 3 may not elongate in conformity with the irregularities, and the yarns of the woven fabric 40 may be broken. However, by forming the pressing portion 7 by a roller or the like having a uniform surface without irregularities, the pressing portion 7 of uniform depth can be formed.

The depth of the pressing portion 7 refers to a length P (fig. 3) from the bottom surface (bottom) 7d of the pressing portion 7 to the outer peripheral edge in a direction orthogonal to the bottom surface (bottom) 7d of the pressing portion 7. The term "uniform" as used herein refers not to strict uniformity in which the depth of the pressing portion 7 is completely the same at any position, but to a state in which no irregularities are observed in the bottom portion 7d of the pressing portion 7 and no change in the depth to the bottom portion 7d is observed when the topsheet 3 is visually confirmed from the skin side. If a linear pressing portion is formed while pressing a sheet having high elongation so that irregularities are formed at the bottom, the pressing portion is easily hardened by the formed irregularities. On the other hand, as in the pressing portion 7 of the present embodiment, the depth is constant without any irregularities in the bottom portion 7d, so that the surface of the bottom portion 7d becomes smooth, and the pressing portion 7 can maintain flexibility. In addition, by having a uniform depth, the excreted liquid accumulated in the squeezing portion 7 is easily and uniformly sucked.

In general, knitted fabrics tend to be stretched more easily than woven fabrics, but if knitted fabrics are formed by tricot knitting or the like as warp knitting, for example, they have a property of being hard to stretch in the longitudinal direction as described above, and the same effect can be achieved by forming the pressing portion 7 on the surface sheet 3 including such knitted fabrics in the same manner as in the case of the woven fabric 40. In addition, although the knitted fabric formed by weft knitting generally has a high elongation, there is an advantage that the knitted fabric is not easily broken when the pressing portion 7 is formed when such weft knitted fabric is used.

The fiber aggregate 50 includes the hydrophilic fibers as described above, but includes not only the hydrophilic fibers but also the hydrophobic fibers. The hydrophobic fibers are preferably polyester-based thermoplastic resin fibers, but polyolefin-based thermoplastic fibers including polypropylene (PP) and Polyethylene (PE), composite fibers having a core-sheath structure composed of PP and PE, and composite fibers such as side-by-side composite fibers can also be used.

By incorporating the hydrophilic fibers and the hydrophobic fibers in the fiber aggregate 50, the surface sheet 3 has a skin feel like a cloth, is excellent in the scraping property of excrement, and can suppress the formation of creases due to adhesion of fibers to each other by the hydrophobic fibers.

In addition, although hydrophilic performance may be imparted to the hydrophobic fibers by using a hydrophilic finish, the fiber aggregate 50 of the present embodiment does not contain a hydrophilic finish. That is, since the fiber aggregate 50 has hydrophilicity by containing rayon fibers as hydrophilic fibers, a hydrophilic oil agent is not used. Therefore, it is less likely to cause skin rash or the like due to contact of the oil with the skin, and is softer to the skin.

When the fiber aggregate 50 contains hydrophobic fibers, the blending ratio of the hydrophilic fibers to the hydrophobic fibers is preferably larger than the weight of the hydrophobic fibers per unit volume. As an example, the blend is preferably carried out at a ratio of 70 wt% of the hydrophobic fibers and 30 wt% of the hydrophilic fibers. By including the hydrophobic fibers in the fiber aggregate 50, the fiber aggregate 50 itself is difficult to hold the liquid, and the liquid is easily guided to the absorber 2 side along the constituent fibers 51 of the fiber aggregate 50. In addition, even if the liquid is to flow backward under physical pressure during the process of wearing the sanitary napkin 1, the weight of the hydrophobic fibers contained per unit volume is large as the constituent ratio of the fibers of the fiber aggregate 50, and therefore, it is difficult to suck the liquid to flow backward, and the liquid return is suppressed.

Fig. 7 is a cross-sectional view taken along the line Y-Y in fig. 4, and shows the core wrap sheet 20 and the absorbent core 10 positioned on the non-skin side of the topsheet 3 in phantom lines. Referring to fig. 7, in the topsheet 3, the constituent fibers 51 of a part of the fiber aggregate 50 extend to the skin side or the non-skin side in the thickness direction of the woven fabric 40. Specifically, the fiber aggregate 50 includes: the skin-side extending portion 52 located closer to the skin side than the upper surface (skin side surface) 40b of the woven fabric 40 in the thickness direction; and a non-skin-side extension 53 located on the non-skin side in the thickness direction of the lower surface (non-skin side surface) 40a of the woven fabric 40. The non-skin-side extension 53 is a portion that directly jets high-pressure water flow when formed by the water flow interlacing method. On the other hand, the skin-side extending portion 52 is a portion extending toward the belt side as a conveying member between the lattice-like constituent yarn 41 of the woven fabric 40 located below when the high-pressure water flow is injected and the constituent yarn 41.

As shown in fig. 7, if the thickness from the upper surface (skin side surface) 40b of the woven fabric 40 to the point 51a extending to the skin side of the skin-side extending portion 52 is set to be the maximum thickness D1 of the skin-side extending portion 52, and the thickness from the lower surface (non-skin side surface) 40a of the woven fabric 40 to the point 51b extending to the non-skin side of the non-skin-side extending portion 53 is set to be the maximum thickness D2 of the non-skin-side extending portion 53, it is preferable that the maximum thickness D2 of the non-skin-side extending portion 53 is larger than the maximum thickness D1 of the skin-side extending portion 52.

As shown in fig. 7, the surface sheet 3 is preferably cut along the thickness direction of the fiber aggregate 50, and an enlarged photograph of the cut surface is preferably taken using a digital microscope VHX-1000 or the like manufactured by KEYENCE, for example. Based on the enlarged photograph, the separation dimension (D1) from the upper surface 40b of the woven fabric 40 to the point 51a extending to the skin-side most side of the skin-side extending portion 52 is measured, and the separation dimension (D2) from the lower surface 40a of the woven fabric 40 to the point 51b extending to the non-skin-side most side of the non-skin-side extending portion 53 is measured.

In this way, since the maximum thickness D2 of the non-skin-side extension 53 of the fiber aggregate 50 is large, more liquid can be sucked to the non-skin side along the fibers 51 of the fiber aggregate 50, and the liquid can be quickly transferred to the absorbent body 2 disposed on the non-skin side of the fiber aggregate 50.

Other embodiments

The embodiments of the present invention have been described above, but the above embodiments are for easy understanding of the present invention and are not intended to limit the explanation of the present invention. The present invention is capable of modification and improvement without departing from the spirit thereof, and the invention includes equivalents thereof.

Description of the reference numerals

1 sanitary napkins for physiology (absorbent article)

1ch width direction central portion, 1ed end edge

1ee outer end, 1ep end

1et width direction end

2 absorber

3 surface sheet

3a skin side (upper surface)

3b non-skin side (lower surface)

4 back sheet

5 side sheet

6 wing part

7 extrusion part

7d bottom (bottom surface)

8 peripheral seal portion

10 absorbent core

11 adhesion area

12-wing adhesive region

20-core clad sheet

20a, 20b

40 woven fabric

40a lower surface (non-skin side)

40b upper surface (skin side)

41 construction yarn

42 warp yarn

43 weft yarn

45-woven eye

50 fiber aggregate

51 constituent fibers

52 skin side extension

53 non-skin side extensions

60 hydrophilic fibers

C1-C4 intersection point

Claims

1. An absorbent article comprising a plurality of absorbent articles,

the absorbent article has a longitudinal direction, a width direction and a thickness direction which are orthogonal to each other,

the absorbent article comprises:

an absorber;

a surface sheet provided on the skin side in the thickness direction of the absorber; and

a back sheet provided on the non-skin side of the absorber in the thickness direction,

it is characterized in that the method comprises the steps of,

the surface sheet has a woven or knitted fabric having a plurality of yarns intersecting each other as viewed in the thickness direction,

the plurality of yarns each have intersecting portions that intersect each other and non-intersecting portions that do not intersect each other,

the longitudinal end edges of the absorbent article have the non-intersecting portions of the plurality of yarns,

the front sheet and the back sheet are joined by a hot melt adhesive at both end edges in the longitudinal direction of the absorbent article,

the woven fabric has a plurality of warp yarns and a plurality of weft yarns intersecting the warp yarns when viewed in the thickness direction,

the absorbent article has a pressing portion formed by pressing the surface sheet and the absorber,

the average value of the lengths in the width direction of the bottom of the pressing portion is longer than the average value of the lengths between the intersections of the warp yarns and the weft yarns of the woven fabric in the width direction.

2. The absorbent article of claim 1, wherein the absorbent article comprises,

the warp yarns and the weft yarns have the crossing portions and the non-crossing portions respectively,

the longitudinal end edges of the absorbent article have the non-intersecting portions of the warp yarns or the weft yarns.

3. The absorbent article as claimed in claim 1 or 2, characterized in that,

the topsheet also has a nonwoven fibrous assembly,

the fiber aggregate is integrated with the non-skin side surface of the woven fabric or the knitted fabric by interlacing, and a part of the constituent fibers of the fiber aggregate extend toward the skin side in the thickness direction from the skin side surface of the woven fabric or the knitted fabric.

4. The absorbent article of claim 1, wherein the absorbent article comprises,

the elongation in the longitudinal direction of the woven fabric is 3 to 8%, the elongation in the longitudinal direction of the knitted fabric is 80 to 100%, and the depth of the pressing portion is uniform.

5. The absorbent article of claim 1, wherein the absorbent article comprises,

the constituent yarn of the woven fabric is constituted by a twisted yarn constituted by a plurality of base yarns, and the fineness of the twisted yarn is 30 cotton count or more and 100 cotton count or less.

6. The absorbent article of claim 1, wherein the absorbent article comprises,

the topsheet also has a nonwoven fibrous assembly,

the fiber aggregate includes: a skin-side extension portion located closer to the skin side in the thickness direction than the skin side surface of the woven fabric or the knitted fabric; and a non-skin-side extending portion located on the non-skin side in the thickness direction with respect to the non-skin side surface of the woven fabric or the knitted fabric, wherein a maximum thickness of the non-skin-side extending portion is larger than a maximum thickness of the skin-side extending portion.

7. The absorbent article of claim 1, wherein the absorbent article comprises,

the topsheet also has a nonwoven fibrous assembly,

the fiber aggregate includes hydrophilic fibers and hydrophobic fibers.

8. The absorbent article as set forth in claim 7 wherein,

the hydrophilic fibers comprise rayon fibers.

9. The absorbent article as claimed in claim 7 or 8, characterized in that,

the fiber aggregate does not contain a hydrophilic finish.

10. The absorbent article as set forth in claim 7 wherein,

in the fiber aggregate, the weight of the hydrophobic fibers per unit area is larger than the weight of the hydrophilic fibers per unit area.

11. The absorbent article of claim 1, wherein the absorbent article comprises,

in the region where the surface sheet is present in the end edge in the longitudinal direction of the absorbent article,

the proportion of the non-intersecting portions of the weft yarn in the number of all the non-intersecting portions at both ends in the width direction is larger than the proportion of the non-intersecting portions of the weft yarn in the number of all the non-intersecting portions at the center in the width direction.