CN112334110B

CN112334110B - Liquid-permeable sheet for absorbent article

Info

Publication number: CN112334110B
Application number: CN201980043913.2A
Authority: CN
Inventors: 野本贵志; 七海久孝; 木村明宽; 出谷耕
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2018-06-29
Filing date: 2019-06-28
Publication date: 2022-07-08
Anticipated expiration: 2039-06-28
Also published as: CN112334110A; TW202017543A; KR102606001B1; KR20210024440A; WO2020004648A1; TWI778276B

Abstract

The invention provides a liquid-permeable sheet for an absorbent article, which has excellent liquid permeability, required sheet strength and can inhibit rewet. A liquid-permeable sheet (11) for an absorbent article (10) is provided with: a woven fabric (40) having a 1 st surface (40a) and a 2 nd surface (40b) which are opposed to each other in a thickness direction (Z); and a fiber web (50) that is integrated with the 1 st surface (40a) of the woven fabric (40) by being woven, wherein the constituent yarn (41) of the woven fabric (40) is formed from a cellulose fiber, and the constituent fiber (51) of the fiber web (50) is substantially flush with the 2 nd surface (40b) of the woven fabric (40) or extends to a position outside the 2 nd surface (40b) in the thickness direction.

Description

Liquid-permeable sheet for absorbent article

Technical Field

The present invention relates to a liquid-permeable sheet for an absorbent article, and more particularly to a liquid-permeable sheet for an absorbent article such as a light incontinence pad, a panty liner, a sanitary napkin, a textile absorbent pad, a urine absorbent pad, and a disposable diaper for adults and children.

Background

Conventionally, a liquid-permeable sheet for an absorbent article has been known. For example, patent document 1 discloses an absorbent article including a topsheet positioned on the side opposite to the absorbent body.

The front sheet has a plurality of openings penetrating in the thickness direction.

Documents of the prior art

Patent literature

Patent document 1: japanese laid-open patent publication No. 8-246321

In the absorbent article disclosed in patent document 1, the top sheet has a plurality of openings, so that body fluid can be quickly transferred from the skin-facing surface of the absorbent article to the absorbent body.

Disclosure of Invention

Problems to be solved by the invention

< problem of the invention 1 >

However, since the surface sheet is formed with a plurality of openings, the sheet is low in strength and may be wrinkled or partially broken during wearing. Further, the body fluid absorbed by the absorber may flow back (rewet back) to the front surface side of the topsheet through the opening.

The problem addressed by the invention of claim 1 is to improve the conventional invention and provide a liquid-permeable sheet for an absorbent article, which has excellent liquid permeability and a required sheet strength and can suppress rewetting.

< problem of invention 2 >

Since the top sheet of patent document 1 has a plurality of openings, the sheet has a relatively low strength and may be wrinkled or partially broken during wearing. Further, since the hydrophilic fiber is formed, it can be said that the hydrophilic fiber absorbs menstrual blood and swells, thereby further weakening the sheet strength. Therefore, menstrual blood adhering to the skin cannot be scraped off by the opening of the topsheet. On the other hand, in the case where the surface sheet is formed of hydrophobic fibers in order to prevent such disadvantages, body fluid cannot be sufficiently absorbed.

Further, since the sheet strength of the top sheet is relatively low, the sanitary napkin is easily bent in a habitual manner when taken out from a separate packaging bag in which the sanitary napkin is stored in a folded state, and when the sanitary napkin is attached to underwear, the sanitary napkin may partially lift from the underwear, causing side leakage of menstrual blood and deterioration of wearing comfort.

The problem addressed by the invention of claim 2 is to improve the conventional invention and provide a liquid-permeable sheet for an absorbent article which has excellent liquid permeability, has a required sheet strength, and can suppress rewetting.

Means for solving the problems

The present invention relates to a liquid-permeable sheet for an absorbent article, comprising: a textile fabric having a 1 st side and a 2 nd side opposed to each other in a thickness direction; and a fiber web integrated with the 1 st surface of the woven fabric by being woven, wherein the constituent yarn of the woven fabric is formed of a cellulose fiber, and the constituent fiber of the fiber web is substantially the same as the 2 nd surface of the woven fabric or extends to the outside in the thickness direction from the 2 nd surface.

The present invention 2 relates to a liquid-permeable sheet for an absorbent article, including: a textile having a 1 st side and a 2 nd side opposite in a thickness direction; and a fiber web integrated with the 1 st surface of the woven fabric by being interwoven, wherein the constituent yarn of the woven fabric is formed of a continuous twisted yarn including cellulose-based fibers, and the fiber web contains hydrophilic fibers and hydrophobic fibers.

ADVANTAGEOUS EFFECTS OF INVENTION

The liquid-permeable sheet for an absorbent article according to claim 1 has a skin-like texture such as a cloth, and can achieve a good absorption rate of body fluid and suppression of rewetting phenomenon.

The liquid-permeable sheet for an absorbent article according to claim 2 has a skin-touch feeling like a cloth, has excellent scratch resistance to excrement, is less likely to be bent habitually, and can suppress the side leakage of body fluid and the reduction in wearing feeling.

Drawings

The drawings show specific embodiments of the invention 1 and the invention 2, and include not only indispensable structures of the invention but also optional and preferred embodiments.

Fig. 1 is a plan view of a sanitary napkin as an example of the absorbent article of the invention 1, as viewed from the front side.

Fig. 2 is a plan view of the sanitary napkin as viewed from the back side.

Fig. 3 is a sectional view taken along the line III-III of fig. 1.

Fig. 4 is a partially enlarged view of the liquid-permeable sheet (topsheet).

Fig. 5 is a view showing a state in which the liquid-permeable sheet is separated into a fiber web and a woven fabric.

Fig. 6 is a sectional view taken along line VI-VI of fig. 4.

Fig. 7 is an enlarged view of a hydrophilic fiber as an example of the hydrophilic fiber.

Fig. 8 is a plan view of a sanitary napkin as an example of the absorbent article of the invention 2, as viewed from the front side.

Fig. 9 is a plan view of the sanitary napkin as viewed from the back side.

Fig. 10 is a sectional view taken along line X-X of fig. 8.

Fig. 11 is a partially enlarged view of the liquid-permeable sheet (topsheet).

Fig. 12 is a view showing a state in which a liquid-permeable sheet is separated into a fiber web and a woven fabric.

Fig. 13 is a sectional view taken along line XIII-XIII of fig. 11.

Fig. 14 is an enlarged view of a hydrophilic fiber as an example of the hydrophilic fiber.

Detailed Description

< invention 1 >)

The following embodiments relate to the absorbent article shown in the drawings, and include not only the indispensable structure of the invention but also alternative and preferable structures. Hereinafter, an embodiment of a sanitary napkin 10 as an example of an absorbent article of the present invention will be described with reference to the drawings. The sanitary napkin 10 has a longitudinal direction Y, a transverse direction X, and a thickness direction Z.

Referring to fig. 1 to 3, the sanitary napkin 10 has a longitudinal center line P bisecting the dimension in the width direction thereof and a transverse center line Q bisecting the dimension in the longitudinal direction thereof, and includes a skin-facing surface (inner surface) side and a non-skin-facing surface (outer surface) side opposite to the skin-facing surface side, a convex first end edge 10a and a convex second end edge 10b, a convex first side edge 10c and a convex second side edge 10d at the center of the transverse center line Q, a liquid-permeable front sheet 11 positioned on the skin-facing surface side, a liquid-impermeable back sheet 12 positioned on the non-skin-facing surface side, and a liquid-absorbent body 20 positioned between these two

sheets

11, 12. The topsheet 11 and the absorbent body 20 are joined to each other by a known joining means such as a hot melt adhesive to form the liquid absorbent layer 13.

Further, although not shown, an intermediate sheet made of a comparatively bulky fiber nonwoven fabric may be disposed between the topsheet (liquid-permeable sheet) 11 and the absorbent member 20 in order to improve the flexibility of the sanitary napkin 10. In order to suppress leakage of body fluid, a leakage-preventing sheet, preferably having air permeability and formed of a liquid-impermeable fibrous nonwoven fabric or plastic film, may be disposed between the absorbent body 20 and the back sheet 12.

The absorbent body 20 has a 1 st end edge 20a opposite to the 1 st end edge 10a, a 2 nd end edge 20b opposite to the 2 nd end edge 10b, and a 1 st side edge 20c and a 2 nd side edge 20d extending in the longitudinal direction Y between the 1 st end edge 20a and the 2 nd end edge 20 b. The front sheet 11 and the back sheet 12 extend outward from the outer periphery of the absorbent body 20, and a pair of side sheets 14 extending in the longitudinal direction Y so as to face each other in the transverse direction X are arranged on the skin-facing surface side of the front sheet 11. The pair of side sheets 14 are joined to the surface sheet 11 by side joining portions (not shown) formed by a known adhesive means or welding means. Although not shown, in the side sheet 14, in order to form a leakage preventing wall that rises toward the body side in the worn state, an elastic material extending in the longitudinal direction Y may be disposed in the side sheet 14 so as to be contractible in the extended state. The side joining portion for fixing the side sheet 14 may be a seal line extending in the longitudinal direction Y and having design elements such as a pattern and a geometric pattern.

The sanitary napkin 10 has both end portions 16 formed of the front sheet 11, the back sheet 12 and the side sheets 14 and extending in the transverse direction X outside the longitudinal direction Y of the 1 st end edge 20a and the 2 nd end edge 20b of the absorbent body 20, and both side edge portions 17 extending in the longitudinal direction Y outside the transverse direction X of the 1 st side edge 20c and the 2 nd side edge 20d of the absorbent body 20. The flaps 18 formed by the parts of the side edges 17 projecting outward in the transverse direction X are located in the central part in the longitudinal direction Y of the sanitary napkin 10. The

sheets

11, 12, and 14 stacked on each other are joined to each other by an outer peripheral seal portion 19 located along the outer peripheral edge of the sanitary napkin 10.

Referring to fig. 2, a plurality of fastening regions 30 are disposed on the back surface side of the sanitary napkin 10. The plurality of fastening regions 30 are used for fastening the sanitary napkin 10 to clothing such as underwear, and the plurality of fastening regions 30 are formed of an adhesive or a pressure-sensitive adhesive applied in a plurality of lines extending in the longitudinal direction Y. The fastening region 30 has a central region 31 extending in the longitudinal direction Y in a region overlapping with the absorbent body 20 and side regions 32 located at the wing portions 18. The fixing region 30 is covered with a spacer (not shown) made of a plastic film.

The top sheet 11 is liquid-permeable and has a skin-facing surface (upper surface) 11a and a non-skin-facing surface (lower surface) 11b located on the opposite side of the skin-facing surface 11a, and the top sheet 11 is formed of a laminate of a woven fabric 40 and a fibrous web 50. The back sheet 12 can be formed of a liquid-impermeable and moisture-permeable plastic film, a liquid-impermeable fibrous nonwoven fabric, a laminate of the above materials, or the like. As the side sheet 14, a known nonwoven fabric can be used, but in order to effectively prevent the side leakage of body fluid, a sheet having water repellency or water repellency is preferably used.

The outer peripheral seal portion 19 can be formed by bonding with an adhesive, bonding by a known welding means such as ultrasonic welding, thermal welding, laser welding, or high-frequency welding, or bonding by embossing, either alone or in combination. The

sheets

11, 12, and 14 stacked in the thickness direction Z are bonded to each other with an adhesive such as a hot melt adhesive. Examples of the method for applying the hot melt adhesive include various known coating methods such as spiral coating, coater coating, curtain coater coating, and spray coating.

Referring to fig. 3 and 4, the absorbent body 20 includes a liquid-absorbent core 21 formed by mixing superabsorbent polymer particles (SAP) and cellulose fibers such as fluffed wood pulp and rayon fibers and shaping the mixture into a predetermined shape, and a liquid-permeable core wrap sheet 22 wrapping the entire liquid-absorbent core 21 to improve shape retention and liquid diffusion properties of the liquid-absorbent core 21.

The dimension of the core wrap sheet 22 in the longitudinal direction Y is larger than the dimension of the liquid-absorbent core in the longitudinal direction Y, and both

side edge portions

22a, 22b thereof are positioned so as to overlap each other on the bottom surface side of the central portion of the liquid-absorbent core 21 in the transverse direction X so as to wrap the entire liquid-absorbent core 21. By stacking the both

side edge portions

22a, 22b, an overlapping portion 23 is formed in the central portion in the lateral direction X of the absorbent body 20, and the overlapping portion 23 is formed by stacking the both

side edge portions

22a, 22b extending in the longitudinal direction Y.

The core wrap sheet 22 has a 1 st wrap portion 25 that wraps the skin-facing surface side of the liquid-absorbent core 21 and a 2 nd wrap portion 26 that wraps the non-skin-facing surface side of the liquid-absorbent core 21. In the present embodiment, the core wrap sheet 22 is formed of one continuous sheet, but may be formed of a 1 st core wrap sheet forming the 1 st clad 25 and a 2 nd core wrap sheet independent of the 1 st core wrap sheet and forming the 2 nd clad 26.

Fig. 4 is a partially enlarged view of the surface sheet 11, and fig. 5 is an exploded perspective view of the surface sheet 11. The topsheet 11 includes a woven fabric 40 on the skin-facing side and a fibrous web 50 on the non-skin-facing side. The textile fabric 40 has a lower surface (No. 1) 40a opposite the fibrous web 50 and an upper surface (No. 2) 40b opposite the lower surface 40 a. The woven fabric 40 and the fiber web 50 are integrated by being interwoven with each other. Depending on the wearing state of the absorbent article, the upper surface 40b of the woven fabric 40 may be positioned below and the lower surface 40a may be positioned above.

The textile fabric 40 is formed of a constituent yarn 41 woven in a mesh shape. The constituent yarn 41 has a plurality of warp yarns 42 and a plurality of weft yarns 43 crossing the warp yarns 42 with each other, and a plurality of cells 45 are formed by crossing the warp yarns 42 and the weft yarns 43 with each other in the thickness direction Z. The constituent yarn 41 of the woven fabric 40 is a twisted yarn formed by twisting a raw yarn made of cotton yarn (cotton fiber). As the material of the base yarn, cellulose-based fibers such as natural cellulose fibers such as pulp fibers, regenerated cellulose fibers such as rayon, and semi-synthetic cellulose fibers such as acetate fibers can be suitably used in addition to cotton fibers. In particular, thermoplastic resin fibers such as polyethylene and polypropylene, cellulose fibers, and mixtures of these fibers can be suitably used as long as the technical effects described later in the present invention can be achieved. The number of yarns (the total of the warp and the weft) constituting the yarn 41 is 60 to 100, and a material having a thickness of 10 to 100 counts can be suitably used as the cotton yarn used as the base yarn.

The fiber web 50 is a fiber aggregate formed by a known production method such as a spunbond method using long fibers or a dry method in which short fibers are aligned in a certain direction by a carding machine to form a web, and is formed in a previous stage of forming (forming) a nonwoven fabric, and is formed of the constituent fibers 51 containing hydrophilic fibers and hydrophobic fibers. As the hydrophobic fiber, various composite fibers such as a sheath-core composite fiber, a side-by-side composite fiber, and a sea-island composite fiber can be used in addition to single fibers such as polyolefin thermoplastic fibers including polypropylene (PP) and Polyethylene (PE) and polyester thermoplastic fibers including polyethylene terephthalate (PET).

Examples of the hydrophilic fiber include natural cellulose fibers such as cotton and ground pulp, regenerated cellulose fibers such as rayon and fibrillated rayon, and semi-synthetic cellulose fibers such as acetate fibers; and hydrophilized thermoplastic resin fibers and composite fibers. In the present embodiment, the constituent fibers 51 of the fiber web 50 have a hydrophobic fiber of 10gsm to 20gsm and a hydrophilic fiber of 5gsm to 10 gsm.

As a method of interlacing and integrating the woven fabric 40 and the fiber web 50, for example, a known fluid interlacing method (hereinafter, fluid interlacing ) can be used. In the step of producing a liquid-permeable sheet by the fluid interlacing method, a continuous laminate in which a continuous fiber web as a material of the fiber web 50 is laminated on the upper surface of a continuous web structure as a material of the woven fabric 40 is subjected to high-pressure jet of a fluid such as air or water from above to the continuous laminate from a plurality of nozzles arranged at intervals in a direction intersecting the conveyance direction of the continuous laminate, and fibers (including long fibers and short fibers) of the continuous fiber web and constituent yarns of the continuous web can be interlaced and integrated.

When a fluid is ejected from a nozzle onto the upper surface of the continuous laminate, the fibers of the continuous fiber web and the yarns constituting the continuous mesh structure are interlaced at the upper surface side, and the fluid that bounces off the conveying member is also interlaced at the lower surface side opposite to the conveying member. Since the top sheet 11 is formed by interlacing the fiber web 50 made of an aggregate of fibers with the woven fabric 40 by the fluid interlacing method, it can be said that the constituent fibers 51 of the fiber web 50 are easily interlaced with the woven fabric 40, and the layered state can be maintained more stably, as compared with the case where a nonwoven fabric sheet is layered and fluid-interlaced. Further, according to the fluid interlacing method, the surface sheet 11 having desired sheet properties in terms of thickness, mass, absorption rate, sheet strength, and the like can be obtained by appropriately changing the structure of the mesh belt of the conveying member.

Since the top sheet 11 is formed by integrating the woven fabric 40 on the skin-facing surface side and the fiber web 50 on the non-skin-facing surface side by interlacing, the strength is higher than the case where the top sheet 11 is formed of only a nonwoven fabric, and a stiff and smooth texture (japanese patent No. シャリ) like a cloth can be provided. Further, since the woven fabric 40 has a mesh structure, the contact area with the skin is reduced, and a soft (japanese: さらり) touch can be given.

The menstrual blood excreted in the top sheet 11 spreads along the warp yarns 42 and the weft yarns 43 of the woven fabric 40, and is transferred to the absorbent body 20 below along the constituent fibers 51 of the fiber web 50 extending downward from the mesh 45 of the woven fabric 40. Further, compared with the case where the top sheet 11 is formed of a liquid-permeable fibrous nonwoven fabric, the sheet stiffness is higher even if the sheet has the same mass, because the mesh-like woven fabric 40 formed of the constituent yarn 41 having a larger fineness than the constituent fiber 51 of the fiber web 50 is provided. This can effectively prevent the top sheet 11 from collapsing or lifting from the absorbent body 20.

When the top sheet is formed of only a nonwoven fabric containing hydrophilic fibers, the absorption rate and liquid diffusibility are excellent, and therefore even if the amount of menstrual blood excreted is small, the menstrual blood rapidly diffuses over a wide range, and stains the skin, causing skin problems, and the like. In the present embodiment, the top sheet 11 is formed of a laminate sheet of the woven fabric 40 and the fiber web 50, and menstrual blood is less likely to spread along the constituent yarns of the woven fabric 40 and is absorbed in a dotted manner when the excretion amount is small, so that it is possible to suppress the skin from being contaminated in a wide range and causing skin problems.

Fig. 6 is a cross-sectional view taken along line VI-VI of fig. 4, showing the absorbent body 20 positioned below the topsheet 11 by an imaginary line. Referring to fig. 6, in the top sheet 11, the constituent fibers 51 of the fiber web 50 extend outward in the thickness direction Z from the woven fabric 40. Specifically, the fibrous web 50 has a lower projecting portion 52 extending downward from the lower surface (1 st surface) 40a of the woven fabric 40 and an upper projecting portion (2 nd surface projecting portion) 53 extending upward from the upper surface (2 nd surface) 40b of the woven fabric 40.

That is, the part of the fibrous web 50 is positioned on the same plane as the upper surface 40b of the woven fabric 40 or above the upper surface 40 b. When the top sheet 11 is formed by the fluid-interlacing method, the lower projecting portion 52 of the fiber web 50 is a continuous fiber web to which a fluid is sprayed at a high pressure, and the upper projecting portion 53 is a portion in which a part of the constituent fibers of the continuous fiber web penetrates a continuous web body as a raw material of the woven fabric 40 positioned below and extends toward the mesh belt side as a conveying member.

The body fluid discharged on the surface sheet 11 is absorbed and diffused by the hydrophilic fiber contained in the upper extension 53 of the fibrous web 50, and is spread in the longitudinal direction Y and the transverse direction X by the warp yarn 42 and the weft yarn 43 of the woven fabric 40, and is rapidly transferred to the absorbent body 20. At this time, the part of the fiber web 50 is positioned on the substantially same plane as the upper surface 40b of the woven fabric 40 or above the upper surface 40b, so that the area for absorbing menstrual blood can be increased while being close to the skin, and more menstrual blood can be absorbed. Further, by locally positioning the fiber web 50 containing the hydrophobic fibers above the upper surface 40b of the woven fabric 40, it is possible to suppress the occurrence of a so-called rewet phenomenon (rewet) in which the body fluid absorbed and held by the woven fabric 40 and the absorbent body 20 flows back by the action of body pressure or the like.

Since the woven fabric 40 is composed of the plurality of warp yarns 42 extending continuously and the plurality of weft yarns 43 extending continuously so as to cross the warp yarns 42 in the thickness direction Z, it can be said that the strength is not easily lowered even if the fabric is in direct contact with the skin and receives a body pressure during wearing or is in contact with menstrual blood, and thus fluffing and aging are not easily caused.

By positioning the woven fabric 40 on the skin side of the fiber web 50, menstrual blood adhering to the skin can be scraped off by the constituent yarn 41 having a larger fineness and a higher rigidity than the constituent fibers 51 of the fiber web 50. In particular, menstrual blood adheres to the skin when it solidifies over time by contact with air, and therefore cannot be scraped off only by sliding contact with a surface sheet made of a conventional soft fibrous nonwoven fabric, but the menstrual blood adhering to the skin can also be wiped off by the plurality of mesh grids 45 by directly or indirectly contacting the textile fabric 40 with the skin, the strength of which is not easily reduced whether the textile fabric is subjected to body pressure or is in contact with menstrual blood. When the constituent yarn 41 of the woven fabric 40 is formed of twisted yarn, the entire outer peripheral surface is uneven, and therefore the scratch resistance is further improved.

Preferably, the thickness D3 of the upper protruding portion 53 of the fiber web 50 extending upward from the upper surface 40b of the woven fabric 40 is 1.1 to 4.0 times the thickness D2 of the woven fabric 40. When the thickness D3 has such a relative size, both scratch resistance and rewetting phenomenon suppression can be achieved. That is, in the case where the thickness dimension D3 is less than 1.1 times the thickness dimension D2, the woven fabric 40 comes closer to the skin, so it can be said that the scratch becomes higher, but only the portion of the fiber web 50 is relatively thin and the rewetting phenomenon cannot be effectively suppressed by the fiber web 50 containing the hydrophobic fibers. On the other hand, when the thickness D3 is greater than 4.0 times the thickness D2, it can be said that the rewetting phenomenon can be suppressed by the upper protruding portion 53 of the relatively thick fibrous web 50 and the bodily fluid can be absorbed along the constituent fibers 51, but since the woven fabric 40 is located at a position away from the skin, it is difficult to scrape off menstrual blood adhering to the skin.

< method for measuring thickness dimension >

The thickness D2 of the textile fabric 40 can be measured in the raw material state using a "PEACOCK pointer thickness gauge J-B manufactured by kawasaki corporation" having a gauge head with a diameter of 50 mm. On the other hand, the thickness D1 of the surface sheet 11 is an apparent thickness, and as shown in fig. 6, it is preferable to cut the surface sheet 11 along the machine moving direction of the fiber web 50, take an enlarged photograph of the cut surface using a digital microscope VHX-1000 manufactured by keyence corporation, measure the maximum thickness of the surface sheet 11 based on the enlarged photograph, measure the same at 5 randomly specified positions to obtain an average value, and set the average value as the thickness D1 of the surface sheet 11. Further, a value obtained by subtracting the thickness dimension D2 of the woven fabric 40 and the thickness dimension of the lower extension 52 from the thickness dimension D1 of the surface sheet 11 is used as the thickness dimension (the dimension of separation from the upper surface 40b of the woven fabric 40 to the apex 53a of the upper extension 53) D3 of the upper extension 53 of the fiber web 50. The measurement was carried out in a measurement chamber under a standard atmosphere (temperature 20. + -. 5 ℃ C., relative humidity 65% or less).

The upper extended portion 53 of the fibrous web 50 has a plurality of densified portions 54 having a relatively small thickness dimension D3 and a plurality of lofted portions 55 having a relatively large thickness dimension D3. By providing the protruding portion 52 of the fiber web 50 with the concave-convex shape, menstrual blood adhering to the skin can be effectively scraped off together with the woven fabric 40 located therebelow.

In addition, in the case of forming the surface sheet 11 by the fluid interlacing method, in the lower extending portion 52 where the fluid jetted from the high-pressure jet directly collides, the portion of the fiber web 50 where the fluid jetted from the nozzle directly collides is denser than the other portions. The solid portion 56 includes a portion where the fluid directly collides, and in this case, the solid portion 56 has a higher fiber density than the fluffy portion 57. Thus, the body fluid transferred from the woven fabric 40 to the lower projecting portion 52 can be quickly transferred to the absorbent body located further below at the solid portion 56 having a relatively high fiber density than at the bulky portion 57.

Since the fiber web 50 is integrated with the woven fabric 40 by being entangled without using an adhesive or the like, flexibility is superior to that in the case of being joined to each other with an adhesive or the like. In a state where the constituent fibers 51 of the fiber web 50 are interlaced with the woven fabric 40, the constituent fibers 51 may be partially entangled or closely wound with the warp and weft of the woven fabric 40, or partially interlaced with the original yarns of the warp 42 and the weft 43 formed of twisted yarns. By thus interlacing the constituent fibers 51 with the outer and inner surfaces of the warp yarns 42 and the weft yarns 43, the fiber web 50 is stably integrated with the woven fabric 40.

The constituent fibers 51 of the fiber web 50 are staple fibers having a fineness of 0.8dtex to 6.0dtex, preferably 1.0dtex to 4.4dtex, more preferably 1.3dtex to 3.3dtex and a fiber length of 25mm to 64mm, preferably 32mm to 58mm, more preferably 38mm to 51mm, and the fineness of the constituent yarn 41 formed of twisted yarns is 10 to 100, preferably 20 to 60, more preferably 30 to 45. Since the constituent fibers 51 of the fiber web 50 are short fibers, a plurality of fiber ends are present in the fiber web 50, and the fiber ends are inserted into a gap between twists of a base yarn having a larger fineness than the fiber ends or are wound around the constituent yarn 41 in a close contact manner, whereby the fiber web 50 is stably entangled with the woven fabric 40.

Referring again to fig. 4, the staple fibers of fibrous web 50 have a fiber length greater than at least one of the separation dimension R1 between parallel warp yarns 42 adjacent to each other and the separation dimension R2 between parallel weft yarns 43 adjacent to each other. In this case, the short fibers do not fall off from the mesh 45 of the woven fabric 40, and the short fibers extend across the mesh 45, whereby the sheet strength and the liquid diffusibility of the entire surface sheet 11 can be improved.

The content of the hydrophilic fibers in the fibrous web 50 is less than 50% by mass, preferably 10% to 49% by mass, and the content of the hydrophobic fibers is more than 50% by mass, preferably 51% to 90% by mass, and the proportion of the hydrophobic fibers in the fibrous web 50 is higher than the proportion of the hydrophilic fibers in the fibrous web 50. By increasing the proportion of the hydrophobic fibers, the diffusion property can be suppressed and the rewetting phenomenon can be suppressed.

When the content of the hydrophilic fiber is less than 10% by mass, the proportion of the hydrophobic fiber is relatively large, and the rewetting phenomenon can be suppressed, but the absorbability of sucking menstrual blood from the skin is reduced. On the other hand, when the content of the hydrophilic fiber is 50% by mass or more, the rewetting phenomenon is likely to occur although more menstrual blood can be absorbed quickly. In the top sheet 11, the hydrophilic fibers and the hydrophobic fibers are preferably contained in a balanced manner, so that the liquid absorption property, the liquid diffusion property, and the rewetting phenomenon can be favorably suppressed.

Fig. 7 is an enlarged view of a modified cross-sectional fiber having an irregular cross-sectional shape as an example of the hydrophilic fiber. The hydrophilic fibers 60 are thermoplastic resin fibers subjected to hydrophilization treatment, for example, hydrophilic PET fibers, and have a plurality of grooves 61 extending in the extending direction thereof. By providing the hydrophilic fibers 60 with the plurality of grooves 61 extending in the extending direction, the surface area in contact with menstrual blood is larger than when the outer peripheral surface is flat, and the suction ability of menstrual blood is improved.

In another example of the present embodiment, unbleached pulp fibers that have not been completely delignified can be used as the material of the base yarn of the textile fabric 40. In this case, the unbleached pulp fiber containing a large amount of lignin component has a light brown color derived from a natural material, and thus the entire surface sheet 11 has a natural color tone of light brown. By giving the top sheet 11a light brown color, the wearer can be given an impression that the product is a product having a high natural intention of being mild to the skin using a natural material. In addition, the redness of menstrual blood absorbed by the absorbent body 20 is suppressed as compared with the case of using a white sheet subjected to a bleaching treatment, and therefore, the feeling of discomfort caused to menstruation by the fact that a minor who has just started menstruation sees menstrual blood directly. Further, since the lignin component has an excellent antibacterial effect, the sanitary napkin 10 can be worn and discarded more hygienically.

In addition, at least one of the 1 st covering portion 25 and the 2 nd covering portion 26 of the core covering sheet 22 covering the liquid-absorbent core 21 may contain unbleached pulp fibers. In this case, the surface sheet 11 containing unbleached pulp fibers can provide a gentle impression to the skin with a natural color tone, and contribute to the concealing property of menstrual blood and antibacterial property.

In the present description, the embodiment relating to the topsheet 11 disposed on the skin-facing surface side of the absorbent core 20 has been described as the liquid-permeable sheet for the absorbent article 10 of the invention 1, but it can also be used as a sheet used for the absorbent article 10, for example, an intermediate sheet, a core wrap sheet, or the like, positioned on the inner surface side of the topsheet. The absorbent article 10 is not limited to use as a sanitary napkin, and can be used as a liquid-permeable sheet that allows urine and loose stool to pass therethrough, including diapers for adults and children and urine pads.

The disclosure related to the above-described invention 1 can be organized into at least the following matters.

The textile fabric comprises a textile fabric having a 1 st surface and a 2 nd surface opposed to each other in a thickness direction, and a fiber web integrated with the 1 st surface of the textile fabric by being woven, wherein a constituent yarn of the textile fabric is formed of a cellulose fiber, and a constituent fiber of the fiber web is substantially flush with the 2 nd surface of the textile fabric or extends to a position outside the 2 nd surface in the thickness direction.

The liquid-permeable sheet for an absorbent article according to claim 1 disclosed above includes the following embodiments.

(1) The thickness dimension of the portion of the fibrous web extending from the 2 nd side of the textile fabric is 1.1 to 4.0 times the thickness dimension of the textile fabric.

(2) The constituent fibers of the fiber web are partially wound around the constituent yarns of the woven fabric and extend to the 2 nd surface side through a plurality of meshes of the woven fabric.

(3) The constituent fibers of the fiber web include hydrophilic fibers and hydrophobic fibers, and the content of the hydrophobic fibers is higher than the content of the hydrophilic fibers.

(4) The cross section of the hydrophilic fiber is irregular and the hydrophilic fiber has a plurality of grooves extending along the extending direction thereof.

(5) The fiber web and the textile fabric are interwoven into a whole through a fluid interweaving process.

(6) The fiber web is composed of short fibers, the fiber length of the short fibers is 25 mm-64 mm, the fineness of the short fibers is 0.8 dtex-6.0 dtex, the constituent yarns of the textile fabric are composed of twisted yarns containing a plurality of raw yarns, and the fineness of the twisted yarns is 10-100 counts.

(7) The absorbent article further includes an absorber, and the liquid-permeable sheet for the absorbent article is disposed on the skin-facing surface side of the absorber.

(8) The staple fibers have a fiber length greater than at least one of a separation dimension of the warp yarns from each other in parallel adjacent to each other and a separation dimension of the weft yarns from each other in parallel adjacent to each other.

< invention 2 >)

The following embodiments relate to the absorbent article shown in the drawings, and include not only the indispensable structure of the invention but also alternative and preferable structures. Hereinafter, an embodiment of a sanitary napkin 210 as an example of an absorbent article of the present invention will be described with reference to the drawings. The sanitary napkin 210 has a longitudinal direction Y, a transverse direction X, and a thickness direction Z.

Referring to fig. 8 to 10, the sanitary napkin 210 has a longitudinal center line P bisecting the dimension in the width direction thereof and a transverse center line Q bisecting the dimension in the longitudinal dimension thereof, and includes a skin-facing surface (inner surface) side and a non-skin-facing surface (outer surface) side opposite to the skin-facing surface side, a convex first end edge 210a and a convex second end edge 210b, a convex first side edge 210c and a convex second side edge 210d at the center of the transverse center line Q, a liquid-permeable front sheet 211 positioned on the skin-facing surface side, a liquid-impermeable back sheet 212 positioned on the non-skin-facing surface side, and a liquid-absorbent body 220 positioned between these two

sheets

211, 212. The topsheet 211 and the absorbent body 220 are joined to each other by a known joining means such as a hot-melt adhesive to form the liquid absorbent layer 213.

Further, although not shown, an intermediate sheet made of a relatively bulky fibrous nonwoven fabric may be disposed between the top sheet (liquid-permeable sheet) 211 and the absorbent member 220 in order to improve the flexibility of the sanitary napkin 210. In order to suppress leakage of bodily fluids, a leakage preventing sheet, preferably having air permeability and formed of a liquid impermeable fibrous nonwoven fabric or plastic film, may be disposed between the absorbent body 220 and the back sheet 212.

The absorbent body 220 has a 1 st end edge 220a opposite to the 1 st end edge 210a, a 2 nd end edge 220b opposite to the 2 nd end edge 210b, and a 1 st side edge 220c and a 2 nd side edge 220d extending in the longitudinal direction Y between the 1 st end edge 220a and the 2 nd end edge 220 b. The front sheet 211 and the back sheet 212 extend outward from the outer periphery of the absorbent body 220, and a pair of side sheets 214 extending in the longitudinal direction Y so as to face each other in the transverse direction X are arranged on the skin-facing surface side of the front sheet 211. The pair of side sheets 214 are joined to the front sheet 211 by side joining portions (not shown) formed by a known adhesive means or welding means. Although not shown, in the side sheet 214, in order to form a leakage preventing wall that rises toward the body side in the worn state, an elastic material extending in the longitudinal direction Y may be disposed on the side sheet 214 so as to be contractible in the extended state. The side joining portion for fixing the side sheet 214 may be a seal line extending in the longitudinal direction Y and having design elements such as a pattern and a geometric pattern.

The sanitary napkin 210 has both end portions 216 formed of the front sheet 211, the back sheet 212 and the side sheets 214 and extending in the transverse direction X outside the longitudinal direction Y of the 1 st end edge 220a and the 2 nd end edge 220b of the absorbent body 220, and both side edge portions 217 extending in the longitudinal direction Y outside the transverse direction X of the 1 st side edge 220c and the 2 nd side edge 220d of the absorbent body 220. The flaps 218 formed by the parts of the both side edges 217 projecting outward in the transverse direction X are located in the central part in the longitudinal direction Y of the sanitary napkin 210. The

sheets

211, 212, 214 stacked on each other are joined to each other by an outer peripheral seal portion 219 located along the outer peripheral edge of the sanitary napkin 210.

Referring to fig. 9, a plurality of fastening regions 230 are disposed on the back side of the sanitary napkin 210. The plurality of fastening regions 230 are used for fastening the sanitary napkin 210 to clothing such as underwear, and the plurality of fastening regions 230 are formed by an adhesive or a pressure-sensitive adhesive applied in a plurality of lines extending in the longitudinal direction Y. The fastening region 230 has a central region 231 extending in the longitudinal direction Y in a region overlapping with the absorbent body 220 and side regions 232 at the wings 218. The fixing region 230 is covered with a spacer (not shown) made of a plastic film.

The top sheet 211 is liquid-permeable and has a skin-facing surface 211a and a non-skin-facing surface 211b located on the opposite side of the skin-facing surface 211a, and the top sheet 211 is formed of a laminate of a woven fabric 240 and a fibrous web 250. The back sheet 212 may be formed of a liquid-impermeable and moisture-permeable plastic film, a liquid-impermeable fibrous nonwoven fabric, a laminate sheet of the above materials, or the like. As the side sheet 214, a known nonwoven fabric can be used, but in order to effectively prevent the side leakage of body fluid, a sheet having hydrophobicity or waterproofness is preferably used.

The outer peripheral seal portion 219 can be bonded by an adhesive, by a known welding means such as ultrasonic welding, thermal welding, laser welding, or high-frequency welding, or by embossing, either alone or in combination. The

sheets

211, 212, 214 stacked in the thickness direction Z are bonded to each other by an adhesive such as a hot melt adhesive. Examples of the method for applying the hot melt adhesive include various known coating methods such as spiral coating, coater coating, curtain coater coating, and spray coating.

Referring to fig. 10 and 11, the absorbent body 220 includes a liquid-absorbent core 221 formed by mixing superabsorbent polymer particles (SAP) and cellulose fibers such as fluffed wood pulp and rayon fibers and shaping the mixture into a predetermined shape, and a liquid-permeable core wrap sheet 222 wrapping the entire liquid-absorbent core 221 to improve shape retention and liquid diffusion properties of the liquid-absorbent core 221.

The dimension of the core wrap sheet 222 in the longitudinal direction Y is larger than the dimension of the liquid-absorbent core in the longitudinal direction Y, and both

side edge portions

222a and 222b thereof are positioned so as to overlap each other on the bottom surface side of the central portion of the liquid-absorbent core 221 in the transverse direction X so as to wrap the entire liquid-absorbent core 221. By stacking the both

side edge portions

222a, 222b, an overlapping portion 223 is formed in the central portion of the absorbent body 220 in the lateral direction X, and the overlapping portion 223 is formed by stacking the both

side edge portions

222a, 222b extending in the longitudinal direction Y.

The core wrap sheet 222 has a 1 st wrap portion 225 that wraps the skin-facing surface side of the liquid-absorbent core 221 and a 2 nd wrap portion 226 that wraps the non-skin-facing surface side of the liquid-absorbent core 221. In the present embodiment, the core wrap sheet 222 is formed of one continuous sheet, but may be formed of a 1 st core wrap sheet forming the 1 st clad 225 and a 2 nd core wrap sheet independent of the 1 st core wrap sheet and forming the 2 nd clad 226.

Fig. 11 is a partially enlarged view of the surface sheet 211, and fig. 12 is an exploded perspective view of the surface sheet 211. The surface sheet 211 comprises a woven fabric 240 on the skin-facing side and a fibrous web 250 on the non-skin-facing side. The woven fabric 240 has a lower surface (No. 1) 240a opposite the fibrous web 250 and an upper surface (No. 2) 240b opposite the lower surface 240 a. The woven fabric 240 and the fiber web 250 are integrated by being interwoven with each other. Depending on the wearing state of the absorbent article, the upper surface 240b of the woven fabric 240 may be positioned below and the lower surface 240a may be positioned above.

The textile fabric 240 is composed of a mesh-like woven-in component yarn 241. The constituent yarn 241 has a plurality of warp yarns 242 and a plurality of weft yarns 243 intersecting with the warp yarns 242, and a plurality of cells 245 are formed by intersecting the warp yarns 242 and the weft yarns 243 with each other in the thickness direction Z. The constituent yarn 241 of the woven fabric 240 is a twisted yarn formed by twisting a base yarn made of cotton yarn (cotton fiber). As the material of the base yarn, cellulose-based fibers such as natural cellulose fibers such as pulp fibers, regenerated cellulose fibers such as rayon, and semi-synthetic cellulose fibers such as acetate fibers can be suitably used in addition to cotton fibers. In particular, thermoplastic resin fibers such as polyethylene and polypropylene, cellulose fibers, and mixtures of these fibers can be suitably used as long as the technical effects described later in the present invention can be achieved. The number of yarns (the total of the warp and the weft) constituting the yarn 241 is 60 to 100, and a material having a thickness of 10 to 100 counts can be suitably used as the cotton yarn used as the base yarn.

The fiber web 250 is a fiber aggregate formed in a former stage of forming (forming) a nonwoven fabric by a known production method such as a spunbond method using long fibers or a dry method in which short fibers are aligned in a certain direction by a carding machine to form a web, and is formed of the constituent fibers 251 containing hydrophilic fibers and hydrophobic fibers. As the hydrophobic fiber, various composite fibers such as a sheath-core composite fiber, a side-by-side composite fiber, and a sea-island composite fiber can be used in addition to single fibers such as polyolefin thermoplastic fibers including polypropylene (PP) and Polyethylene (PE) and polyester thermoplastic fibers including polyethylene terephthalate (PET).

Examples of the hydrophilic fiber include natural cellulose fibers such as cotton and ground pulp, regenerated cellulose fibers such as rayon and fibrillated rayon, and semi-synthetic cellulose fibers such as acetate fibers; and hydrophilized thermoplastic resin fibers and composite fibers. In the present embodiment, the constituent fibers 251 of the fiber web 250 have a hydrophobic fiber content of 10gsm to 20gsm and a hydrophilic fiber content of 5gsm to 10 gsm.

As a method of integrating the woven fabric 240 and the fiber web 250 by weaving, for example, a known fluid weaving treatment method can be used. In the step of producing a liquid-permeable sheet by the fluid interlacing method, a continuous laminate in which a continuous fiber web as a material of the fiber web 250 is laminated on the upper surface of a continuous web structure as a material of a woven fabric 240 is subjected to high-pressure jet of a fluid such as air or water from above to the continuous laminate from a plurality of nozzles arranged at intervals in a direction intersecting the conveyance direction of the continuous laminate, and fibers (including long fibers and short fibers) of the continuous fiber web and constituent yarns of the continuous web can be interlaced and integrated.

When a fluid is ejected from a nozzle onto the upper surface of the continuous laminate, the fibers of the continuous fiber web and the yarns constituting the continuous mesh structure are interlaced at the upper surface side, and the fluid that bounces off the conveying member is also interlaced at the lower surface side opposite to the conveying member. Since the surface sheet 211 is formed by interlacing the fiber web 250 made of an aggregate of fibers with the woven fabric 240 by the fluid interlacing method, it can be said that the constituent fibers 251 of the fiber web 250 are easily interlaced with the woven fabric 240 and the layered state can be maintained more stably than in the case of laminating a nonwoven fabric sheet and performing fluid interlacing. Further, according to the fluid interlacing method, the surface sheet 211 having desired sheet properties in terms of thickness, mass, absorption rate, sheet strength, and the like can be obtained by appropriately changing the structure of the mesh belt of the conveying member.

Since the top sheet 211 is formed by integrating the woven fabric 240 on the skin-facing surface side and the fiber web 250 on the non-skin-facing surface side by the interweaving, the strength is higher than the case where the top sheet 211 is formed of only a nonwoven fabric, and a stiff texture like a cloth can be provided. Further, since the woven fabric 240 has a mesh structure, the contact area with the skin is reduced, and a soft touch can be given.

The menstrual blood excreted in the top sheet 211 spreads along the warp 242 and the weft 243 of the woven fabric 240, and is transferred to the absorbent body 220 below along the constituent fibers 251 of the fiber web 250 extending below the mesh 245 of the woven fabric 240. Further, compared to the case where the top sheet 211 is formed of a liquid-permeable fibrous nonwoven fabric, the rigidity is higher even if the sheet has the same mass, because the mesh-like woven fabric 240 is formed of the constituent yarn 241 having a larger fineness than the constituent fiber 251 of the fiber web 250. This can effectively prevent the top sheet 211 from collapsing or lifting from the absorber 220.

In general, since the topsheet used in a sanitary napkin is relatively thin and contains a large amount of hydrophilic fibers, fibers swollen after absorption of menstrual blood tend to stick to each other. Therefore, there is a possibility that the sanitary napkin may be bent habitually due to a bending line formed when the sanitary napkin is stored in the individual package in a folded state. When a sanitary napkin with a habitually folded portion is attached to underwear or the like, a gap is formed between a part of the sanitary napkin and the body, and this may cause side leakage of menstrual blood and reduce the wearing feeling.

Since the surface sheet 211 contains hydrophilic fibers and hydrophobic fibers and the proportion of the hydrophobic fibers is higher than that of the hydrophilic fibers, the fibers can be prevented from being stuck to each other and from being bent habitually. Further, by positioning the woven fabric 240 having higher rigidity than the sheet material such as nonwoven fabric on the skin-facing surface (inner surface) side, it can be said that the surface sheet 211 is less likely to be bent habitually. Therefore, it can be said that the sanitary napkin is less likely to be bent habitually along the bending line, which may cause side leakage of menstrual blood, when the sanitary napkin is taken out from the individual package stored in the folded state.

When the top sheet is formed of only a nonwoven fabric containing hydrophilic fibers, the absorption rate and liquid diffusibility are excellent, and therefore even if the amount of menstrual blood excreted is small, the menstrual blood rapidly diffuses over a wide range, and stains the skin, causing skin problems, and the like. In the present embodiment, the top sheet 211 is formed of a laminate of the woven fabric 240 and the fiber web 250, and menstrual blood is less likely to spread along the constituent yarns of the woven fabric 240 and is absorbed in a dotted manner when the excretion amount is small, so that it is possible to suppress skin contamination in a wide range and cause skin problems.

Fig. 13 is a cross-sectional view taken along line XIII-XIII in fig. 11, showing the absorbent body 220 located below the top sheet 211 by a phantom line. Referring to fig. 13, in the surface sheet 211, the constituent fibers 251 of the fiber web 250 extend outward in the thickness direction Z from the woven fabric 240. Specifically, the fibrous web 250 has a lower extending portion 252 extending downward from the lower surface (1 st surface) 240a of the woven fabric 240 and an upper extending portion (2 nd surface extending portion) 253 extending upward from the upper surface (2 nd surface) 240b of the woven fabric 240.

That is, the fiber web 250 is partially positioned on the same plane as the upper surface 240b of the woven fabric 240 or above the upper surface 240 b. When the surface sheet 211 is formed by a fluid-interlacing method, the lower extension 252 of the fiber web 250 is a continuous fiber web to which a fluid is sprayed at a high pressure, and the upper extension 253 is a portion in which a part of the constituent fibers of the continuous fiber web penetrates a continuous web body as a raw material of the woven fabric 240 located below and extends toward the mesh belt side as a conveying member.

The body fluid discharged on the surface sheet 211 is absorbed and diffused by the hydrophilic fiber contained in the upper extension 253 of the fibrous web 250, and is spread in the longitudinal direction Y and the transverse direction X by the warp yarn 242 and the weft yarn 243 of the woven fabric 240, and is rapidly transferred to the absorbent body 220. At this time, the fiber web 250 is partially positioned on the same plane as the upper surface 240b of the woven fabric 240 or above the upper surface 240b, so that the area for absorbing menstrual blood can be increased while being close to the skin, and more menstrual blood can be absorbed. Further, by locally positioning the fiber web 250 containing hydrophobic fibers above the upper surface 240b of the woven fabric 240, it is possible to suppress the occurrence of a so-called rewet phenomenon (rewet) in which the body fluid absorbed and held by the woven fabric 240 and the absorbent body 220 flows back by the action of body pressure or the like.

Since the woven fabric 240 is composed of the plurality of warp yarns 242 extending continuously and the plurality of weft yarns 243 extending continuously so as to cross the warp yarns 242 in the thickness direction Z, it can be said that the strength is not easily lowered even if the fabric is in direct contact with the skin and receives a body pressure during wearing or is in contact with menstrual blood, and thus fluffing and aging are not easily caused.

By positioning the textile 240 on the skin side of the fiber web 250, menstrual blood adhering to the skin can be scraped off by the constituent yarn 241 having a larger fineness and a higher rigidity than the constituent fibers 251 of the fiber web 250. In particular, menstrual blood adheres to the skin when it solidifies over time by contact with air, and therefore cannot be scraped off only by sliding contact with a surface sheet made of a conventional soft fibrous nonwoven fabric, but the menstrual blood adhering to the skin can also be wiped off by the plurality of mesh grids 245 by bringing the textile fabric 240 into direct or indirect contact with the skin, the strength of which is not easily reduced whether the textile fabric is subjected to body pressure or in contact with menstrual blood. When the constituent yarn 241 of the woven fabric 240 is formed of twisted yarn, the entire outer peripheral surface is uneven, and therefore, the scratch resistance is further improved.

Preferably, the thickness dimension D3 of the upper protruding part 253 extending upward from the upper surface 240b of the woven fabric 240 in the fiber web 250 is 1.1 to 4.0 times the thickness dimension D2 of the woven fabric 240. When the thickness D3 has such a relative size, both scratch resistance and rewetting phenomenon suppression can be achieved. That is, in the case where the thickness dimension D3 is less than 1.1 times the thickness dimension D2, the woven fabric 240 comes closer to the skin, so it can be said that the scratch becomes higher, but only a portion of the fiber web 250 is relatively thin and the rewetting phenomenon cannot be effectively suppressed by the fiber web 250 containing the hydrophobic fibers. On the other hand, when the thickness dimension D3 is greater than 4.0 times the thickness dimension D2, it can be said that the rewetting phenomenon can be suppressed by the upper protruding portion 253 of the relatively thick fibrous web 250 and the bodily fluid can be sucked along the constituent fibers 251, but since the woven fabric 240 is located at a position away from the skin, it is difficult to scrape off menstrual blood adhering to the skin.

< method for measuring thickness dimension >

The thickness D2 of the woven fabric 240 can be measured in the raw material state using a "PEACOCK pointer thickness gauge J-B manufactured by kawasaki corporation" having a gauge head with a diameter of 50 mm. On the other hand, the thickness D1 of the surface sheet 211 is an apparent thickness, and as shown in fig. 13, it is preferable to cut the surface sheet 211 along the machine moving direction of the fiber web 250, take an enlarged photograph of the cut surface using a digital microscope VHX-1000 manufactured by keyence corporation, measure the maximum thickness of the surface sheet 211 based on the enlarged photograph, perform the same measurement at 5 randomly designated positions to obtain an average value, and use the average value as the thickness D1 of the surface sheet 211. Further, a value obtained by subtracting the thickness dimension D2 of the woven fabric 240 and the thickness dimension of the lower extension 252 from the thickness dimension D1 of the surface sheet 211 is used as a thickness dimension (a separation dimension from the upper surface 240b of the woven fabric 240 to the apex 253a of the upper extension 253) D3 of the upper extension 253 of the fiber web 250. The measurement was carried out in a measurement chamber under a standard atmosphere (temperature 20. + -. 5 ℃ C., relative humidity 65% or less).

The upper extended portion 253 of the fibrous web 250 has a plurality of densified portions 254 having a relatively small thickness dimension D3 and a plurality of lofted portions 255 having a relatively large thickness dimension D3. By providing the fiber web 250 with the concave-convex lower protruding portion 252, menstrual blood adhering to the skin can be effectively scraped off together with the lower woven fabric 240.

In addition, in the case of forming the surface sheet 211 by the fluid interlacing method, in the lower extension portion 252 on which the fluid sprayed from the nozzle directly collides with the high-pressure spray, the portion of the fiber web 250 on which the fluid sprayed from the nozzle directly collides is denser than the other portions. The dense portion 256 includes a portion where the fluid directly collides, and in this case, the dense portion 256 has a higher fiber density than the fluffy portion 257. Thus, body fluid transferred from the woven fabric 240 to the underlying lower extension 252 can be transferred more quickly to the absorbent body located further down in the solid portion 256 having a higher fiber density than in the bulky portion 257.

Since the fiber web 250 is integrated with the woven fabric 240 by being woven without using an adhesive or the like, flexibility is superior to the case where the fiber web is joined to each other by using an adhesive or the like. In a state where the constituent fibers 251 of the fiber web 250 are entangled with the woven fabric 240, the constituent fibers 251 may be partially entangled or wound in close contact with the warp and weft yarns of the woven fabric 240, or partially entangled with the original yarns of the warp yarn 242 and the weft yarn 243 formed of twisted yarns. By thus interlacing the constituent fibers 251 with the outer and inner surfaces of the warp 242 and weft 243, the fiber web 250 is stably integrated with the woven fabric 240.

The constituent fiber 251 of the fiber web 250 is a short fiber having a fineness of 0.8dtex to 6.0dtex, preferably 1.0dtex to 4.4dtex, more preferably 1.3dtex to 3.3dtex and a fiber length of 25mm to 64mm, preferably 32mm to 58mm, more preferably 38mm to 51mm, and the fineness of the constituent yarn 241 formed by twisted yarn is 10 to 100, preferably 20 to 60, more preferably 30 to 45. Since the constituent fibers 251 of the fiber web 250 are short fibers, a plurality of fiber ends are present in the fiber web 250, and the fiber ends are inserted into a gap between twists of a base yarn having a larger fineness than the fiber ends or are wound around the constituent yarn 241 in a close contact manner, whereby the fiber web 250 is stably entangled with the woven fabric 240.

Referring again to fig. 11, the staple fibers of fibrous web 250 have a fiber length greater than at least one of the mutual separation dimension R1 of the warp yarns 242 that are parallel to each other and the mutual separation dimension R2 of the weft yarns 243 that are parallel to each other. In this case, the short fibers do not fall off from the mesh 245 of the woven fabric 240, and the short fibers extend across the mesh 245, whereby the sheet strength and liquid diffusibility of the entire surface sheet 211 can be improved.

The content of the hydrophilic fibers in the fibrous web 250 is less than 50% by mass, preferably 10% by mass to 49% by mass, and the content of the hydrophobic fibers is more than 50% by mass, preferably 51% by mass to 90% by mass, and the proportion of the hydrophobic fibers in the fibrous web 250 is higher than the proportion of the hydrophilic fibers in the fibrous web 250. By increasing the proportion of the hydrophobic fibers, the diffusion property can be suppressed and the rewetting phenomenon can be suppressed.

When the content of the hydrophilic fibers is less than 10%, the proportion of the hydrophobic fibers is relatively large, and the rewetting phenomenon can be suppressed, but the absorbability of menstrual blood drawn into the skin is reduced. On the other hand, when the content of the hydrophilic fiber is 50% or more, the rewetting phenomenon is likely to occur although more menstrual blood can be absorbed quickly. In the top sheet 211, the hydrophilic fibers and the hydrophobic fibers are preferably contained in a balanced manner, so that favorable liquid absorption properties, liquid diffusion properties, and rewetting phenomena can be suppressed.

< evaluation of torsion >

First, as a sample A corresponding to the example, a surface sheet 211 having a thickness of 0.57mm and a mass of 47g/m was prepared²The liquid-permeable sheet of (2) was cut into a sample having a length of 100mm × a width of 50mm, and a sample B having a thickness of 0.33mm and a mass of 31g/m was prepared as a sample B corresponding to the comparative example²The cotton piece (cotton 100%) was cut into a sample having a length dimension of 100mm × a width dimension of 15 mm. Next, each sample was rubbed under predetermined measurement conditions (degree of abrasion 100 times, load 50g) using a chemical shock fastness rubbing tester, thereby reproducing the state of rubbing of the surface sheet against the surface of the body during wearing.

Next, the torque value of each sample A, B was measured under the following measurement conditions using a Toyota Torque tester (EX-0762).

Rotation speed: 50rpm

Distance between the clamps: 25mm

Rotation angle (measurement angle): 90 ° (60 °)

The torque value in the longitudinal direction Y and the torque value in the lateral direction Y of each sample A, B are obtained, and the average value is obtained, and this value is used as the torque value of each sample. Further, for each sample A, B, both a sample in a state in which surface friction was applied and a sample in a state in which surface friction was not applied were prepared and measured by a fastness friction tester.

As a result of the measurement, the torque value of the sample a corresponding to the example in the state where no surface friction was applied was 7.1, the torque value of the sample B corresponding to the comparative example in the state where no surface friction was applied was 6.8, the torque value of the sample B corresponding to the comparative example in the state where no surface friction was applied was 3.9, and the torque value of the sample B corresponding to the comparative example in the state where surface friction was applied was 2.2. It can be said that the torque value of the surface sheet 211 of the embodiment does not largely vary depending on the presence or absence of surface friction, and does not collapse even if friction is generated between it and the body during use. Further, the surface sheet 211 is higher in sheet rigidity than the cotton sheet of the comparative example, and is less likely to collapse. The reason why the torque value of the cotton sheet of the comparative example was 55% or less of that of the surface sheet 211 of the example was considered to be due to the decrease in sheet strength caused by the separation of the interlaces of the cotton fibers when the surface friction was applied in the case of the cotton sheet.

< evaluation of shrinkage >

For measurement of the shrinkage evaluation, sample C was produced as a sanitary napkin of the example, and sample D was produced as a sanitary napkin of the comparative example. The sample C and the sample D have the same structure except for the structure of the surface sheet, the surface sheet used for the sample C is the liquid-permeable sheet of the sample a used for the torsion evaluation measurement, and the surface sheet used for the sample D is the liquid-permeable sheet of the sample B. First, a mannequin imitating the lower half of a human body is prepared, and the mannequin is worn with sanitary napkins of the specimens C, D. Then, it is assumed that the femoral region of the mannequin is continuously moved forward and backward for 5 minutes during walking, and thereafter, 2g of artificial menstrual blood is discharged from the opening portion corresponding to the vaginal opening of the mannequin and dropped onto the surface of the sanitary napkin. Then, assuming the sitting position, the upper leg of the mannequin is moved to the left and right sides by changing the legs. This action was performed 5 times (5 groups) with 1 group, and the sample was detached from the manikin. The narrowest width dimension (mm) of the absorber in the narrowest portion in contact with the vicinity of the crotch was measured with a ruler for sample C, D in a state detached from the manikin. This measurement was performed 3 times, and the average value thereof was taken as the narrowest width dimension of the absorbent body of each sample.

As a result of the measurement, the narrowest width dimension of the absorber of the sample C using the surface sheet 211 was 30mm, and the narrowest width dimension of the absorber of the sample D using the cotton sheet was 14 mm. In the top sheet 211 used in sample C, it can be said that the constituent fibers 251 of the fibrous web 250 do not adhere to each other and are not easily collapsed even in a state where surface friction is applied by absorbing artificial menstrual blood. On the other hand, in the cotton sheet used in sample D, it can be said that the width dimension of the absorber becomes smaller and a large wrinkle is generated. As the reason for this, it is considered that the cotton fibers are entangled and separated from each other by surface friction, and the fibers entangled and separated from each other at the gathers formed during wearing adhere to each other, thereby forming large grooves extending in the longitudinal direction.

Fig. 14 is an enlarged view of a deformed cross-sectional fiber having an irregular cross-sectional shape as an example of the hydrophilic fiber. The hydrophilic fibers 260 are thermoplastic resin fibers subjected to hydrophilization treatment, and are, for example, hydrophilic PET fibers having a plurality of grooves 261 extending in the extending direction thereof. By providing the hydrophilic fibers 260 with the plurality of grooves 261 extending in the extending direction, the surface area in contact with menstrual blood is larger than when the outer peripheral surface is flat, and the suction ability of menstrual blood is improved.

In another example of the present embodiment, unbleached pulp fiber which is not completely delignified can be used as a material of the base yarn of the textile fabric 240. In this case, the unbleached pulp fiber containing a large amount of lignin component has a light brown color derived from a natural material, and therefore the entire surface sheet 211 has a natural light brown color. By giving the surface sheet 211a light brown color, the wearer can be given an impression that the natural product is gentle to the skin and has a high natural intention using a natural material. In addition, the redness of menstrual blood absorbed by the absorbent body 220 is suppressed as compared with the case of using a white sheet subjected to a bleaching treatment, and therefore, the feeling of discomfort caused to menstruation by the fact that a minor who has just started menstruation sees menstrual blood directly. Further, since the lignin component has an excellent antibacterial effect, the sanitary napkin 210 can be worn and discarded more hygienically.

In addition, at least one of the 1 st covering portion 225 and the 2 nd covering portion 226 of the core covering sheet 222 covering the liquid-absorbent core 221 may contain unbleached pulp fibers. In this case, the surface sheet 211 containing the unbleached pulp fibers can provide a gentle impression of natural color tone to the skin, and contribute to the concealing property of menstrual blood and antibacterial property.

In the present description, the embodiment relating to the topsheet 211 disposed on the skin-facing surface side of the absorbent core 220 has been described as the liquid-permeable sheet for the absorbent article 210 of the invention 2, but it can also be used as a sheet used for the absorbent article 210, for example, an intermediate sheet, a core wrap sheet, or the like, positioned on the inner surface side of the topsheet. The absorbent article 210 is not limited to use as a sanitary napkin, and may be used as a liquid-permeable sheet that allows urine and loose stool to pass therethrough, including diapers for adults and children and urine pads.

The disclosure related to the above-described invention 2 can be organized into at least the following items.

The textile comprises a textile having a 1 st surface and a 2 nd surface opposite to each other in the thickness direction, and a fiber web integrated with the 1 st surface of the textile by being interwoven, wherein the constituent yarns of the textile are formed by continuous twisted threads containing cellulose-based fibers, and the fiber web contains hydrophilic fibers and hydrophobic fibers.

The liquid-permeable sheet for an absorbent article disclosed in claim 2 includes the following embodiments.

(1) The constituent yarns of the textile formed of the twisted yarns include a plurality of warp yarns extending continuously and a plurality of weft yarns extending continuously in the thickness direction while crossing the warp yarns with each other.

(2) The content of the hydrophobic fibers is higher than the content of the hydrophilic fibers.

(3) The content of the hydrophobic fibers is 51 to 90 mass%, and the content of the hydrophilic fibers is 10 to 49 mass%.

(5) The fiber web and the textile fabric are interwoven into a whole through water flow interweaving treatment.

Description of the reference numerals

10. Absorbent articles (sanitary napkins); 11. a liquid-permeable sheet (topsheet); 20. an absorbent body; 40. a textile fabric; 40a, 1 st surface (lower surface); 40b, 2 nd face (upper face); 41. forming a yarn; 45. a grid; 50. a fibrous web; 51. forming fibers; 53. a portion of the fibrous web extending from the 2 nd side of the textile; 60. a hydrophilic fiber; 61. a groove; d2, thickness dimension of textile; d3, the thickness dimension of the portion of the fibrous web extending from the 2 nd face; z, thickness direction; 210. absorbent articles (sanitary napkins); 211. a liquid-permeable sheet (topsheet); 220. an absorbent body; 240. a textile fabric; 240a, 1 st surface (lower surface); 240b, face 2 (upper surface); 241. forming a yarn; 245. a grid; 250. a fibrous web; 251. forming fibers; 260. a hydrophilic fiber; 261. a groove; r1, the separation of parallel warp yarns adjacent to each other from each other; r2, the separation of parallel weft yarns adjacent to each other; z, thickness direction.

Claims

1. A liquid-permeable sheet for an absorbent article, wherein,

the liquid-permeable sheet for an absorbent article comprises: a textile fabric having a 1 st side and a 2 nd side opposed to each other in a thickness direction; and a fibrous web integrated with the 1 st surface of the woven fabric by a fluid interlacing process,

the constituent yarn of the woven fabric is formed of a cellulose fiber,

the constituent fibers of the fiber web are partially wound around the constituent yarn of the woven fabric and extend to the 2 nd surface side through a plurality of meshes of the woven fabric,

the constituent fibers are substantially the same as the 2 nd surface of the woven fabric or extend outward in the thickness direction from the 2 nd surface.

2. The liquid-permeable sheet for an absorbent article according to claim 1,

the constituent fibers of the fibrous web comprise hydrophilic fibers and hydrophobic fibers.

3. The liquid-permeable sheet for an absorbent article according to claim 1,

the thickness dimension of the portion of the fibrous web extending from the 2 nd side of the textile fabric is 1.1 to 4.0 times the thickness dimension of the textile fabric.

4. The liquid-permeable sheet for an absorbent article according to claim 2,

the content of the hydrophobic fibers is higher than the content of the hydrophilic fibers.

5. The liquid-permeable sheet for an absorbent article according to claim 2 or 4, wherein,

the cross section of the hydrophilic fiber is irregular and the hydrophilic fiber has a plurality of grooves extending along the extending direction thereof.

6. A liquid-permeable sheet for an absorbent article according to any one of claims 1 to 4,

the absorbent article further includes an absorber, and the liquid-permeable sheet for the absorbent article is disposed on the skin-facing surface side of the absorber.

7. A liquid-permeable sheet for an absorbent article, wherein,

the liquid-permeable sheet for an absorbent article comprises: a textile having a 1 st side and a 2 nd side opposite in a thickness direction; and a fiber web integrated with the 1 st surface of the woven fabric by a fluid interlacing process,

the constituent yarns of the textile are formed of continuous twisted yarns containing cellulose-based fibers,

the constituent fibers of the fiber web partially wound around the constituent yarn of the woven fabric extend to the 2 nd surface side through a plurality of meshes of the woven fabric, and the constituent fibers include hydrophilic fibers and hydrophobic fibers.

8. The liquid-permeable sheet for an absorbent article according to claim 7,

the constituent yarns of the textile formed of the twisted yarns include a plurality of warp yarns extending continuously and a plurality of weft yarns extending continuously in the thickness direction while crossing the warp yarns with each other.

9. The liquid-permeable sheet for an absorbent article according to claim 7,

10. The liquid-permeable sheet for an absorbent article according to claim 7 or 9, wherein,

11. The liquid-permeable sheet for an absorbent article according to claim 8,

the fiber web is composed of short fibers, the fiber length of the short fibers is 25 mm-64 mm, the fineness of the short fibers is 0.8 dtex-6.0 dtex, the constituent yarns of the textile fabric are composed of twisted yarns containing a plurality of raw yarns, and the fineness of the twisted yarns is 10-100 counts.

12. The liquid-permeable sheet for an absorbent article according to any one of claims 7 to 9 and 11, wherein,

13. The liquid-permeable sheet for an absorbent article according to claim 11,

the staple fibers have a fiber length greater than at least one of a separation dimension of the warp yarns from each other and a separation dimension of the weft yarns from each other, which are parallel to each other, of the woven fabric.