Absorbent article, and nonwoven fabric and method for manufacturing the same

Abstract

To provide: a nonwoven fabric containing cotton fibers and having an appearance very similar to that of cotton; a method for manufacturing the same; and an absorbent article comprising the same.SOLUTION: An absorbent article comprises an outer sheet disposed on a side farthest from the wearer's skin in a worn state. The outer sheet includes a nonwoven fabric containing cotton fibers and having a plurality of openings penetrating in the thickness direction. The outer sheet has: a plurality of first ridges, which comprises a fiber-entangled body containing cotton fibers and extends in a first direction; and a plurality of second ridges, which comprises a fiber-entangled body containing cotton fibers and extends in a second direction intersecting the first direction. A value of W2 / W1, which is a ratio of a width W2 of the second ridges to a width W1 of the first ridges, is from 0.5 to 1.1 inclusive. A value of S2 / S1, which is a ratio of an area S2 of the openings to a product S1 of the width W1 of the first ridges and the width W2 of the second ridges, is 0.7 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an absorbent article, and also to a nonwoven fabric and a method for producing the same. [Background technology]

[0002] In recent years, the idea of ​​product development based on the three perspectives of environment, society, and governance (ESG), has become increasingly popular in corporate management and growth. For example, when it comes to absorbent products such as disposable diapers and sanitary napkins, it is desirable to use nonwoven fabrics made from natural cotton fibers instead of the synthetic fiber nonwoven fabrics that have been used until now.

[0003] Many absorbent articles using nonwoven fabric made of cotton fibers have been proposed. For example, Patent Document 1 proposes using a spunlace nonwoven fabric made of cotton fibers as the top sheet of an incontinence pad. This spunlace nonwoven fabric has many openings formed in the areas corresponding to the wearer's excretory opening. Patent Document 2 describes an absorbent article comprising an absorbent body, a breathable liquid-impermeable sheet covering the back side of the absorbent body, and a cover nonwoven fabric covering the back side of the liquid-impermeable sheet, in which the cover nonwoven fabric is made of a perforated nonwoven fabric having a large number of through-holes. This perforated nonwoven fabric may be a spunlace nonwoven fabric containing cotton fibers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-099558 [Patent Document 2] Japanese Patent Application Publication No. 2020-099442 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have examined known nonwoven fabrics using cotton fibers and found that, although the nonwoven fabrics contain cotton fibers, they do not give users the impression of softness and the like that is characteristic of cotton. Therefore, an object of the present invention is to provide a nonwoven fabric containing cotton fibers, a method for producing the same, and an absorbent article including the nonwoven fabric, which can overcome the drawbacks of the prior art described above. [Means for solving the problem]

[0006] As a result of extensive research conducted by the present inventors to solve the above problems, it was discovered that the appearance of a nonwoven fabric containing cotton fibers strongly reminds users of cotton material. The present invention was made based on the above findings, and provides an absorbent article comprising a top sheet that is positioned closest to the wearer's skin when worn, an outer layer sheet that is positioned farthest from the wearer's skin when worn, and an absorbent body positioned between the top sheet and the outer layer sheet. In one embodiment, the outer layer sheet preferably includes a nonwoven fabric containing cotton fibers and having a plurality of openings penetrating through the thickness direction. In one embodiment, the outer layer sheet preferably has a plurality of first ribs made of a tangled fiber body containing the cotton fibers and extending in a first direction, and a plurality of second ribs made of a tangled fiber body containing the cotton fibers and extending in a second direction intersecting the first direction. In one embodiment, the apertures are preferably defined by the intersection of a plurality of first ridges and a plurality of second ridges. In one embodiment, the area of ​​the aperture is 0.07 mm 2 More than 0.7mm 2 It is preferable that: In one embodiment, the fibers contained in the tangled fiber body that constitutes the first rib portion preferably have a fiber orientation tendency along a first direction. In one embodiment, the fibers contained in the tangled fiber body constituting the second rib portion preferably have a fiber orientation tendency along the second direction. In one embodiment, it is preferable that the value of W2 / W1, which is the ratio of the width W2 of the second ridge portion to the width W1 of the first ridge portion, is 0.5 or more and 1.1 or less. In one embodiment, it is preferable that the value of S2 / S1, which is the ratio of the area S2 of the opening to the product S1 of the width W1 of the first ridge portion and the width W2 of the second ridge portion, is 0.7 or less.

[0007] The present invention also provides a nonwoven fabric containing cotton fibers and having a plurality of openings penetrating through the thickness direction. In one embodiment, the nonwoven fabric preferably has a plurality of first ribs made of a tangled fiber body containing cotton fibers and extending in a first direction, and a plurality of second ribs made of a tangled fiber body containing cotton fibers and extending in a second direction intersecting the first direction. In one embodiment, the apertures are preferably defined by the intersection of a plurality of first ridges and a plurality of second ridges. In one embodiment, the area of ​​the aperture is 0.07 mm 2 More than 0.7mm 2 It is preferable that: In one embodiment, the fibers contained in the tangled fiber body that constitutes the first rib portion preferably have a fiber orientation tendency along a first direction. In one embodiment, the fibers contained in the tangled fiber body constituting the second rib portion preferably have a fiber orientation tendency along the second direction. In one embodiment, it is preferable that the value of W2 / W1, which is the ratio of the width W2 of the second ridge portion to the width W1 of the first ridge portion, is 0.5 or more and 1.1 or less. In one embodiment, it is preferable that the value of S2 / S1, which is the ratio of the area S2 of the opening to the product S1 of the width W1 of the first ridge portion and the width W2 of the second ridge portion, is 0.7 or less.

[0008] Furthermore, the present invention provides a method for producing a textile web, comprising: a first hydroentanglement step of placing a fibrous web containing cotton fibers on an aperture pattern member having a plurality of first bars extending in a first direction and a plurality of second bars extending in a second direction intersecting the first direction, wherein a plurality of apertures are defined by the intersection of the plurality of first bars and the plurality of second bars; and spraying a water stream toward the fibrous web while transporting the fibrous web together with the aperture pattern member in the first direction; and a second hydroentangling step of spraying a water stream again onto the fiber web while transporting the fiber web together with the aperture pattern member in a second direction. [Effects of the Invention]

[0009] According to the present invention, there are provided a cotton fiber-containing nonwoven fabric that has a very cotton-like appearance, a method for producing the same, and an absorbent article including the same. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view schematically illustrating one embodiment of a nonwoven fabric provided in an absorbent article of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing one embodiment of a manufacturing apparatus that is preferably used to manufacture the nonwoven fabric included in the absorbent article of the present invention. [Figure 3] FIG. 3 is a perspective view schematically showing one embodiment of the aperture pattern member shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below based on preferred embodiments. The absorbent article of the present invention generally has an elongated shape having a longitudinal direction corresponding to the direction extending from the wearer's ventral side through the crotch region to the dorsal side, and a transverse direction perpendicular to the longitudinal direction. The absorbent article has a crotch region located in the wearer's crotch region, and ventral and dorsal regions extending in front and behind the crotch region. The crotch region has an excretory region-facing portion that is positioned opposite the wearer's excretory region when the absorbent article is worn, and the excretory region-facing portion is usually located in or near the longitudinal center of the absorbent article.

[0012] Absorbent articles generally comprise a topsheet positioned closer to the wearer's skin when worn, a backsheet positioned farther from the wearer's skin when worn, and an absorbent interposed between the two sheets. The topsheet can be a liquid-permeable sheet, such as a nonwoven fabric or perforated film. The skin-facing side of the topsheet may have an uneven surface. For example, the skin-facing side of the topsheet may have a plurality of scattered protrusions. Alternatively, the skin-facing side of the topsheet may have alternating ridges and grooves extending in one direction. For such purposes, the topsheet may be formed using two or more nonwoven fabrics.

[0013] On the other hand, the backsheet may be made of, for example, a liquid-impermeable film or a spunbond, meltblown, or spunbond laminated nonwoven fabric. A liquid-impermeable film may be provided with a plurality of micropores to impart water vapor permeability to the film. To further improve the feel of the absorbent article, a sheet made of a nonwoven fabric with a pleasant texture may be laminated on the outer surface of the backsheet. Details of this nonwoven fabric will be provided later.

[0014] The absorbent body has an absorbent core. The absorbent core is composed of, for example, a stack of hydrophilic fibers such as cellulose, including pulp, a mixed stack of the hydrophilic fibers and an absorbent polymer, a pile of absorbent polymer, or a laminated structure in which an absorbent polymer is supported between two absorbent sheets. At least the skin-facing surface of the absorbent core may be covered with a liquid-permeable core wrap sheet, or the entire surface, including the skin-facing and non-skin-facing surfaces, may be covered with the core wrap sheet. Examples of the core wrap sheet that can be used include tissue paper made of hydrophilic fibers and liquid-permeable nonwoven fabric.

[0015] In addition to the topsheet, backsheet, and absorbent core described above, leakage-preventing cuffs extending longitudinally may be arranged on both longitudinal sides of the skin-facing side, depending on the specific use of the absorbent article. The leakage-preventing cuffs generally have a base end and a free end. The base end of the leakage-preventing cuff is located on the skin-facing side of the absorbent article, and the cuffs stand upright from the skin-facing side. The leakage-preventing cuffs are made of a liquid-resistant or water-repellent, breathable material. An elastic member made of rubber thread or the like may be arranged in a stretched state at or near the free end of the leakage-preventing cuff. When the absorbent article is worn, contraction of this elastic member causes the leakage-preventing cuffs to stand up toward the wearer's body, effectively preventing fluid excreted on the topsheet from leaking along the topsheet outward in the width direction of the absorbent article.

[0016] The absorbent article may further have an adhesive layer on the non-skin-facing surface, which is used to secure the absorbent article to underwear or another absorbent article when the absorbent article is worn.

[0017] Examples of absorbent articles having the above-described configuration include, but are not limited to, flat-type disposable diapers, pants-type disposable diapers, sanitary napkins, and incontinence pads.

[0018] The absorbent article of the present invention comprises an outer layer sheet that is disposed farthest from the wearer's skin when worn. The outer layer sheet is made of a nonwoven fabric. The outer layer sheet is disposed on the outer surface of the back sheet and forms the outermost surface of the absorbent article. The outer layer sheet is located on the non-skin-facing side of the back sheet. An absorbent body is located between the top sheet and the outer layer sheet. Furthermore, it is preferable that the outer layer sheet is disposed continuously over the entire areas of the ventral side, crotch area, and back side. By arranging the outer layer sheet in this manner, it is possible to enhance the cotton-like appearance of most of the absorbent article.

[0019] As mentioned above, there is a demand for absorbent articles in which nonwoven fabrics containing synthetic fibers are replaced with nonwoven fabrics containing cotton fibers. However, even when nonwoven fabrics containing cotton fibers are used, depending on the appearance of the nonwoven fabric (e.g., the size of the mesh), it can be difficult for users to recognize that such nonwoven fabrics are used. The present inventors conducted extensive research to address this issue and discovered that providing predetermined apertures in the nonwoven fabric enhances the cotton-like appearance. In particular, they found that when a nonwoven fabric containing cotton fibers has an appearance similar to a woven fabric made of cotton fibers known as "cotton double gauze," the appearance of the nonwoven fabric strongly reminds users that it contains cotton fibers. Cotton double gauze is a fabric made of two layers of plain woven cotton yarns with loosely twisted yarns.

[0020] FIG. 1 shows one embodiment of a nonwoven fabric 1 constituting the outer layer sheet. The nonwoven fabric 1 of this embodiment contains cotton fibers 2 and has a plurality of apertures penetrating in the thickness direction Z. This makes it easier to enhance the cotton-like appearance of the absorbent article and improves the texture. To maximize this effect, the content of cotton fibers 2 contained in the nonwoven fabric 1 is preferably 10% by mass or more, more preferably 50% by mass or more, and even more preferably 90% by mass or more. The higher the content of cotton fibers 2, the better, and it may be 100% by mass.

[0021] The cotton fibers 2 preferably have a fineness within a predetermined range. Specifically, from the viewpoint of enhancing the cotton-like appearance of the absorbent article and improving the texture, the micronaire fineness of the cotton fibers 2 measured in accordance with JIS L 1019:2006 is preferably 3.81 μg / inch or more, and more preferably 5.08 μg / inch or more. From the same viewpoint, the micronaire fineness of the cotton fibers 2 is preferably 15.24 μg / inch or less, and more preferably 12.7 μg / inch or less.

[0022] The fiber length of the cotton fibers 2 is preferably within a predetermined range. Specifically, from the viewpoint of enhancing the cotton-like appearance of the absorbent article and improving the texture, the fiber length of the cotton fibers 2 measured in accordance with JIS L 1019:2006 is preferably 15 mm or more, more preferably 21 mm or more. From the same viewpoint, the fiber length of the cotton fibers 2 is preferably 35 mm or less, more preferably 28 mm or less.

[0023] Examples of cotton fibers 2 that can be used include Giza cotton, Supima cotton, Sea Island cotton, Upland cotton, Desi cotton, Indian cotton, Brazilian cotton, Peruvian cotton, Zimbabwean cotton, Australian cotton, and dwarf cotton. Organic cotton fibers can also be used as the cotton fibers 2. "Organic cotton fibers" here refers to cotton fibers that are certified by the Global Organic Textile Standard (GOTS).

[0024] In the nonwoven fabric 1, the cotton fibers 2 form a tangled fiber structure 3 by, for example, stacking, entangling, or bonding. The tangled fiber structure 3 may contain other fibers, such as synthetic fibers and natural fibers, in addition to the cotton fibers 2, as long as the effects of the present invention are not impaired. Synthetic fibers can be fibers made from thermoplastic resins, which are fiber-forming resins. Examples of thermoplastic resins include polyolefin resins such as polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), polyamide resins, vinyl resins such as polyvinyl chloride and polystyrene, acrylic resins such as polyacrylic acid and polymethyl methacrylate, and fluororesins such as polyperfluoroethylene. These thermoplastic resins can be used alone or in combination. When the tangled fiber structure 3 contains synthetic fibers, the fibers constituting the tangled fiber structure 3 may or may not be partially fused to each other. The proportion of other fibers in all the fibers contained in the tangled fiber body 3 is preferably 90 mass % or less, and more preferably 50 mass % or less. Most preferably, the nonwoven fabric 1 is made substantially only of cotton fibers, and the nonwoven fabric form is maintained only by the entanglement of the cotton fibers.

[0025] The nonwoven fabric 1 of this embodiment has a predetermined structure formed by tangled fiber bodies 3 containing cotton fibers 2. Specifically, as shown in FIG. 1 , the nonwoven fabric 1 has a plurality of first ribs 31 made of tangled fiber bodies 3 and extending in a first direction X. The first ribs 31 are arranged in the same direction at regular intervals along a second direction Y. The intervals between adjacent first ribs 31 in the second direction Y may be the same or different. The nonwoven fabric 1 is made of tangled fibers 3 and has a plurality of second ribs 32 extending in a second direction Y intersecting the first direction X. The second ribs 32 are arranged in the same direction at regular intervals along the first direction X. The intervals between adjacent second ribs 32 in the first direction X may be the same or different.

[0026] In the nonwoven fabric 1 of this embodiment, the first direction X and the second direction Y are preferably substantially perpendicular to each other. By arranging the first rib portions 31 and the second rib portions 32 along these directions X and Y, the nonwoven fabric 1 takes on the appearance of cotton double gauze, enhancing its cotton-like appearance. In this specification, "substantially perpendicular" means that the angle θ between the first direction X and the second direction Y is preferably 80° or more and 100° or less, more preferably 85° or more and 95° or less. In this embodiment, the nonwoven fabric 1 can be arranged so that the first direction X or the second direction Y in the nonwoven fabric 1 coincides with the longitudinal direction (the direction from the ventral portion through the crotch portion to the dorsal portion) or the lateral direction (the direction perpendicular to the longitudinal direction) in an absorbent article including the nonwoven fabric 1.

[0027] In nonwoven fabric 1, the thickness of first rib portion 31, second rib portion 32, and intersections 33 may be the same as or different from the thickness of portions other than the intersections in first rib portion 31 and / or second rib portion 32. In nonwoven fabric 1 of this embodiment, the thickness of intersections 33 is approximately the same as the thickness of portions other than the intersections, making both the front and back surfaces of nonwoven fabric 1 approximately flat.

[0028] In the nonwoven fabric 1 of this embodiment, a plurality of first ribs 31 and a plurality of second ribs 32 intersect to define a plurality of openings 4. The openings 4 penetrate the nonwoven fabric 1 in the thickness direction. Each opening 4 is generally rectangular. The apertures 4 are arranged in a row at regular intervals along the first direction X. Aperture rows 40A each consisting of a plurality of apertures 4 are arranged in a plurality of rows at intervals along the second direction Y. The apertures 4 are arranged in rows at regular intervals along the second direction Y. Aperture rows 40B, each consisting of a plurality of apertures 4, are arranged in a plurality of rows at intervals along the first direction X. When viewed along the first direction X, the apertures 4 in each aperture row 40A are in the same position. Similarly, when viewed along the second direction Y, the apertures 4 in each aperture row 40B are in the same position. Therefore, the apertures 4 are arranged in a square lattice pattern when the nonwoven fabric 1 is viewed in a plan view. In the nonwoven fabric 1 of this embodiment, some of the constituent fibers of the first rib portion 31 and / or the second rib portion 32 may penetrate into the openings 4 as long as the effect of the present invention is not impaired.

[0029] In the nonwoven fabric 1, it is preferable that the area of ​​the openings 4 is within a predetermined range. Specifically, in order for the nonwoven fabric 1 to have the appearance of cotton double gauze and to enhance the cotton-like appearance, the area of ​​the openings is 0.07 mm 2 It is preferable that it is 0.1 mm or more. 2 More preferably, it is 0.13 mm or more. 2 From the same viewpoint, the area of ​​the opening is preferably 0.7 mm or more. 2 Preferably, it is less than 0.5 mm 2 More preferably, it is 0.3 mm or less. 2 It is even more preferred that: In this specification, the "area of ​​an opening" refers to the area in a plan view of the space defined by the first rib portion 31 and the second rib portion 32. When the area of ​​each opening 4 in the nonwoven fabric 1 is not constant, it is preferable that the average area of ​​the openings 4 is within the above range.

[0030] The area of ​​the opening 4 can be measured by the following method. Specifically, first, the nonwoven fabric is placed on the base of a microscope with one side of the nonwoven fabric facing up. If the nonwoven fabric is bonded to a constituent member of the absorbent article with an adhesive, the adhesive is solidified using a cooling means such as cold spray and then separated. Next, the magnification is increased to 50x and the nonwoven fabric is focused, and the microscope's function for measuring the distance between two points is used to measure the width of the opening along the first direction and the width of the opening along the second direction. The two measurements are multiplied together to calculate the area of ​​the opening. Even if the opening is not rectangular, the opening is assumed to be rectangular, and the two measurements are multiplied together to calculate the area of ​​the opening. This operation is performed for any five openings, and the respective measurements are arithmetically averaged. The obtained value is the area of ​​the opening. If the constituent fibers of the first rib portion and / or the second rib portion have penetrated into the opening, the opening is measured as a unit area of ​​0.02 mm. 2 Areas with seven or more constituent fibers per unit area of ​​0.02 mm 2 The boundary line between the area where there are less than seven constituent fibers per hole is defined as the periphery of the hole.

[0031] In the nonwoven fabric 1, the first rib portion 31 and the second rib portion 32 preferably each have a predetermined dimension. Specifically, from the viewpoint of providing the nonwoven fabric 1 with the appearance of cotton double gauze and enhancing the appearance of cotton, the value of W2 / W1, which is the ratio of the width W2 (mm) of the second rib portion 32 to the width W1 (mm) of the first rib portion 31, is preferably 0.5 or more, more preferably 0.6 or more, and even more preferably 0.7 or more. From the same viewpoint, the value of W2 / W1 is preferably 1.1 or less. In the nonwoven fabric 1, when the widths W1 and W2 are not constant, it is preferable that the ratio of the average value of the width W1 to the average value of the width W2 be within the above-mentioned range.

[0032] The value of width W1 itself is preferably 0.3 mm or more, more preferably 0.4 mm or more, and even more preferably 0.5 mm or more, provided that the value of W2 / W1 is within the above-mentioned range. Furthermore, the value of width W1 itself is preferably 1.2 mm or less, more preferably 1.1 mm or less, and even more preferably 1.0 mm or less, provided that the value of W2 / W1 is within the above-mentioned range. Having width W1 within the above-mentioned range gives nonwoven fabric 1 the appearance of cotton double gauze, enhancing its cotton-like appearance. If the width W1 of each nonwoven fabric 1 is not constant, it is preferable that the average value of width W1 be within the above-mentioned range.

[0033] The value of width W2 itself is preferably 0.35 mm or more, more preferably 0.45 mm or more, and even more preferably 0.55 mm or more, provided that the value of W2 / W1 is within the above-mentioned range. Furthermore, the value of width W2 itself is preferably 1.2 mm or less, more preferably 1.1 mm or less, and even more preferably 1.0 mm or less, provided that the value of W2 / W1 is within the above-mentioned range. Having width W2 within the above-mentioned range allows nonwoven fabric 1 to have the appearance of cotton double gauze, giving it a cotton-like appearance. If the width W2 of each nonwoven fabric 1 is not constant, it is preferable that the average value of width W2 be within the above-mentioned range.

[0034] The widths W1 and W2 can be measured using the following method. Specifically, first, the nonwoven fabric is placed on the base of a microscope with one side of the nonwoven fabric facing up. If the nonwoven fabric is bonded to a component of the absorbent article with an adhesive, the adhesive is solidified using a cooling means such as cold spray and then separated. Next, the magnification is increased to 50x and the focus is adjusted to the first rib portion in the nonwoven fabric, and the width of the first rib portion is measured using the microscope's two-point distance measurement function. This operation is performed for any five first rib portions, and the respective measured values ​​are arithmetically averaged. The obtained value is defined as width W1. The second rib portion is also measured in the same manner, and the measured values ​​are arithmetically averaged. The obtained value is defined as width W2.

[0035] In the nonwoven fabric 1, it is preferable that the width W1, the width W2, and the area of ​​the openings 4 have a predetermined relationship. Specifically, in order for the nonwoven fabric 1 to have the appearance of cotton double gauze, to enhance the cotton-like appearance, and to improve the texture, the product S1 (mm 2 ) to the area of ​​the opening S2 (mm 2 ) is preferably 0.7 or less, and more preferably 0.6 or less. From the viewpoints of making the nonwoven fabric 1 appear like cotton double gauze, enhancing the cotton-like appearance, and improving breathability, the S2 / S1 ratio is preferably 0.2 or more, more preferably 0.3 or more, and even more preferably 0.4 or more.

[0036] The value of the product S1 itself is 0.15 mm, provided that the value of S2 / S1 is within the above range. 2 It is preferable that the thickness is 0.20 mm or more. 2 More preferably, it is 0.30 mm or more. 2 It is more preferable that the value of the product S1 itself is 1.0 mm or more, provided that the value of S2 / S1 is within the above range. 2 Preferably, it is less than 0.9 mm 2 More preferably, it is 0.8 mm or less. 2 It is more preferable that the value of the product S1 is within the above range, so that the nonwoven fabric 1 has the appearance of cotton double gauze, and the appearance is more like cotton.

[0037] In the nonwoven fabric 1, it is preferable that the width of the ribs in one direction and the width of the openings 4 have a predetermined relationship. Specifically, from the viewpoint of making the nonwoven fabric 1 have the appearance of cotton double gauze and enhancing the cotton-like appearance, the value of P1 / W1, which is the ratio of the width P1 (mm) of the openings 4 along the second direction Y to the width W1 (mm) of the first rib portion 31, is preferably 0.3 or more, more preferably 0.6 or more, and even more preferably 0.8 or more. From the same viewpoint, the value of P1 / W1 is preferably 1.1 or less. When the widths W1 and P1 of the nonwoven fabric 1 are not constant, it is preferable that the ratio of the average value of the width W1 to the average value of the width P1 be within the above-mentioned range. Additionally or alternatively, in order to provide the nonwoven fabric 1 with the appearance of cotton double gauze and enhance its cotton-like appearance, the ratio of the width P2 (mm) of the openings 4 along the first direction X to the width W2 (mm) of the second rib portions 32, P2 / W2, is preferably 0.3 or greater, and more preferably 0.4 or greater. From the same perspective, the value of P2 / W2 is preferably 1.1 or less, and more preferably 1.0 or less. When the widths W2 and P2 of the nonwoven fabric 1 are not constant, it is preferable that the ratio of the average width W2 to the average width P2 be within the above-mentioned range. In nonwoven fabric 1, from the viewpoint of enhancing the appearance of cotton, it is preferable that the value of P1 / W1 or the value of P2 / W2 is within the above-mentioned range, and it is even more preferable that the value of P1 / W1 and the value of P2 / W2 are within the above-mentioned range.

[0038] The value of width P1 itself is preferably 0.25 mm or more, more preferably 0.35 mm or more, and even more preferably 0.45 mm or more, provided that the value of P1 / W1 is within the above-mentioned range. Furthermore, the value of width P1 itself is preferably 1.1 mm or less, more preferably 0.9 mm or less, and even more preferably 0.7 mm or less, provided that the value of P1 / W1 is within the above-mentioned range. Having width P1 within the above-mentioned range gives nonwoven fabric 1 the appearance of cotton double gauze, enhancing its cotton-like appearance. If the width P1 of each nonwoven fabric 1 is not constant, it is preferable that the average value of width P1 be within the above-mentioned range.

[0039] The value of width P2 itself is preferably 0.15 mm or more, and more preferably 0.25 mm or more, provided that the value of P2 / W2 is within the above-mentioned range. Furthermore, the value of width P2 itself is preferably 0.8 mm or less, more preferably 0.6 mm or less, and even more preferably 0.5 mm or less, provided that the value of P2 / W2 is within the above-mentioned range. Having width P2 within the above-mentioned range gives nonwoven fabric 1 the appearance of cotton double gauze, enhancing its cotton-like appearance. When the width P2 of each nonwoven fabric 1 is not constant, it is preferable that the average value of width P2 be within the above-mentioned range.

[0040] The widths P1 and P2 can be measured by the following method. Specifically, first, the nonwoven fabric is placed on the base of a microscope with one side of the nonwoven fabric facing up. If the nonwoven fabric is bonded to a constituent member of the absorbent article with an adhesive, the adhesive is solidified using a cooling means such as cold spray before separation. Next, the magnification is increased to 50x, the nonwoven fabric is focused, and the width of the openings along the second direction is measured using the microscope's two-point distance measurement function. This operation is performed for any five openings, and the respective measured values ​​are arithmetically averaged. The obtained value is defined as width P1. The width of the openings along the first direction is also measured in the same manner, and the measured values ​​are arithmetically averaged. The obtained value is defined as width P2. If the constituent fibers of the first rib portion and / or second rib portion have penetrated into the openings, the unit area is 0.02 mm. 2 Areas with seven or more constituent fibers per unit area of ​​0.02 mm 2 The boundary line between the area where there are less than seven constituent fibers per hole is defined as the periphery of the hole.

[0041] In order to make the above-mentioned values ​​of the nonwoven fabric 1 fall within the above-mentioned ranges, it is preferable to employ a spunlace method or adjust the dimensions of the aperture pattern member in the manufacturing method described below.

[0042] In the nonwoven fabric 1 of this embodiment, the fibers contained in the tangled fiber body 3 that constitutes the first rib portion 31 preferably have a fiber orientation tendency along the first direction X. Furthermore, the fibers contained in the tangled fiber body 3 that constitutes the second rib portion 32 preferably have a fiber orientation tendency along the second direction Y. This allows the ribs 31, 32 to coincide with the direction in which they extend, making it easier for the openings 4 to form a square lattice pattern in a plan view, and giving the nonwoven fabric 1 the appearance of cotton double gauze, enhancing the cotton-like appearance. To enhance this effect, the fiber orientation rate in the first rib portion 31 and the fiber orientation rate in the second rib portion 32 are each independently preferably 50% or more, more preferably 75% or more, and even more preferably 90% or more. The higher the fiber orientation rate, the better, with 100% being particularly preferred. In this specification, the term "fiber orientation rate" refers to an index that indicates the degree of variation in the orientation direction of fibers in one direction when nonwoven fabric 1 is viewed in plan.

[0043] The fiber orientation rate can be measured by the following method. Specifically, first, a nonwoven fabric is placed on a microscope base with one side of the nonwoven fabric facing up. If the nonwoven fabric is bonded to a component of the absorbent article with an adhesive, the adhesive is solidified using a cooling method such as cold spray and then separated. Next, the magnification is increased to 50x, the focus is adjusted to the nonwoven fabric, and an observation image of the first rib portion is obtained. A square consisting of two parallel first reference lines and two second reference lines perpendicular to the two first reference lines is added to this observation image. The extension direction of the first reference lines is aligned with the first direction, and the extension direction of the second reference lines is aligned with the second direction. The square is added so that the entire width of the first rib portion is included within the square. The lengths of the first and second reference lines are each 500 μm. Next, the "number of longitudinal fibers," which is the total number of fibers passing through the two first reference lines, and the "number of transverse fibers," which is the total number of fibers passing through the two second reference lines, are measured. The fiber orientation rate (%) is calculated based on the following formula (1). This operation is performed for any five first rib portions, and the respective values ​​are arithmetically averaged. The obtained value is the fiber orientation rate in the first rib portion. The fiber orientation rate in the second rib portion is also calculated in the same manner, and the values ​​are arithmetically averaged. The obtained value is the fiber orientation rate in the second rib portion. Fiber orientation rate (%) = (number of vertical fibers) / (number of horizontal fibers + number of vertical fibers) × 100 (1)

[0044] The nonwoven fabric 1 preferably has a predetermined thickness. Specifically, from the viewpoints of making the nonwoven fabric 1 appear like cotton double gauze, enhancing the cotton-like appearance, and improving the texture, the thickness of the nonwoven fabric 1 at a load of 0.05 kPa is preferably 0.5 mm or more, and more preferably 0.6 mm or more. Furthermore, from the viewpoints of enhancing the cotton-like appearance and improving breathability, the thickness of the nonwoven fabric 1 at a load of 0.05 kPa is preferably 1.5 mm or less, more preferably 1.3 mm or less, and even more preferably 1.1 mm or less.

[0045] The thickness of the nonwoven fabric (i.e., the outer layer sheet) can be measured by the following method. Specifically, first, a 5 cm square area in plan view is cut out from the nonwoven fabric and used as the measurement sample. If the nonwoven fabric is bonded to a constituent member of the absorbent article with an adhesive, the adhesive is solidified using a cooling means such as cold spray and then separated. If the area cannot be secured due to reasons such as the nonwoven fabric being small, a region with as large an area as possible is cut out and used as the measurement sample. Next, the measurement sample is placed on the base of a microscope and placed in an unfolded, unfolded state. A load of 0.05 kPa is applied vertically from above the measurement sample, and the cross section of the measurement sample is observed with the microscope to measure the thickness of the measurement sample. This procedure is performed on any five measurement samples, and the respective values ​​are arithmetically averaged. The obtained value is the thickness of the nonwoven fabric.

[0046] The nonwoven fabric 1 preferably has a predetermined basis weight. Specifically, from the viewpoint of making the nonwoven fabric 1 have the appearance of cotton double gauze, enhancing the cotton-like appearance, and improving the texture, the nonwoven fabric 1 has a basis weight of 20 g / m 2 It is preferable that the weight is 25 g / m or more. 2 More preferably, it is 30 g / m or more. 2 It is more preferable that the nonwoven fabric 1 has a basis weight of 75 g / m or more, from the viewpoint of enhancing the cotton-like appearance and improving breathability. 2 Preferably, it is 65 g / m or less. 2 More preferably, it is 50 g / m or less. 2 It is even more preferred that:

[0047] The basis weight of a nonwoven fabric can be measured by the following method. Specifically, first, a 5 cm square area in plan view is cut out from the nonwoven fabric and used as the measurement sample. If the nonwoven fabric is bonded to a constituent member of the absorbent article with an adhesive, the adhesive is solidified using a cooling means such as cold spray and then separated. If the area of ​​the nonwoven fabric cannot be secured due to reasons such as a small area, an area with as large an area as possible is cut out and used as the measurement sample. Next, the mass (g) of the measurement sample is measured, and the measured value is divided by the area of ​​the measurement sample to calculate the basis weight. This operation is performed for any five measurement samples, and the respective values ​​are arithmetically averaged. The obtained value is used as the basis weight of the nonwoven fabric.

[0048] Next, a method for manufacturing the nonwoven fabric 1 used in the absorbent article of the present invention will be described with reference to Figures 2 and 3. Figure 2 shows a manufacturing apparatus 50 that is preferably used for manufacturing the nonwoven fabric 1. The manufacturing apparatus 50 includes a web forming section 60 and a hydroentanglement section 70, arranged in this order along the conveyance direction (hereinafter also referred to as the "first direction") X1. The configuration of the manufacturing apparatus 50 shown below is similar to that of a general manufacturing apparatus for nonwoven fabrics using the spunlace method.

[0049] The web forming unit 60 forms a fibrous web 1a containing cotton fibers. The web forming unit 60 is equipped with a carding machine 61 that forms a web from cotton fibers, which are the raw material for nonwoven fabric. Other fibers, such as synthetic fibers, may be supplied to the carding machine 61 as needed in addition to cotton fibers. The fibrous web 1a formed by the carding machine 61 is transported by a conveyor belt 62 to the hydroentangling unit 70.

[0050] The hydroentangling unit 70 entangles the fibrous web 1a with a water flow. The hydroentangling unit 70 includes a water flow nozzle 71 that sprays a water flow onto the fibrous web 1a and an endless support belt 72. A perforated pattern member 80, which will be described later, is disposed between the water flow nozzle 71 and the support belt 72. The water flow nozzle 71 is positioned above the fibrous web 1a and the support belt 72 and is capable of spraying a high-pressure water flow across the entire width direction Y1 (hereinafter also referred to as the "second direction") of the fibrous web 1a, which intersects with the conveying direction X1. The support belt 72 is disposed opposite the water flow nozzle 71 and the perforated pattern member 80 and has a water-permeable structure with holes formed in various patterns, such as a lattice, to allow the sprayed water to pass through (not shown).

[0051] 3 shows a portion of an aperture pattern member 80 that is preferably used in this manufacturing method. The aperture pattern member 80 is used to form apertures 4 in the nonwoven fabric 1. The aperture pattern member 80 of this embodiment is in the form of a thin plate, and has a plurality of apertures 8a that penetrate in the thickness direction Z1. The apertures 8a are formed by punching the thin plate using, for example, a press or the like.

[0052] The aperture pattern member 80 has a plurality of first aperture rows 80A formed at intervals along the second direction Y1, each row being made up of a plurality of apertures 8a spaced apart along the first direction X1. The aperture pattern member 80 also has a plurality of second aperture rows 80B formed at intervals along the first direction X1, each row being made up of a plurality of apertures 8a spaced apart along the second direction Y1. The apertures 8a thus arranged are arranged in a rectangular lattice pattern in a plan view of the aperture pattern member 80. As a result, the aperture pattern member 80 has a plurality of first crosspieces 81 extending in the first direction X1 formed between adjacent aperture rows 80A in the second direction Y1. Furthermore, a plurality of second crosspieces 82 extending in the second direction Y1 formed between adjacent aperture rows 80B in the first direction X1. That is, in the aperture pattern member 80 of this embodiment, the apertures 8a are defined by the intersection of a plurality of first crosspieces 81 and a plurality of second crosspieces 82.

[0053] As described above, when the openings 8a are formed by punching a thin plate, the thicknesses of the first crosspiece 81 and the second crosspiece 82 are generally constant. Furthermore, the thickness at the intersection 83 between the first crosspiece 81 and the second crosspiece 82 is the same as the thickness of the first crosspiece 81 and the second crosspiece 82 at locations other than the intersection 83. As a result, both the front and back surfaces of the opening pattern member 80 are generally flat.

[0054] In a plan view of the aperture pattern member 80, each aperture 8a may be rectangular. X The other side perpendicular to it is L Y When L X and L Y and may be the same length or may be different. The opening 8a has one side L X is the same direction as the first direction X1 of the aperture pattern member 80, and one side L Y is preferably formed in the aperture pattern member 80 so that it is in the same direction as the second direction Y1.

[0055] In the aperture pattern member 80 of this embodiment, the first direction X1 and the second direction Y1 are preferably substantially perpendicular to each other. By arranging the first and second crosspieces 81 and 82 along the directions X1 and Y1, a nonwoven fabric that has the appearance of cotton double gauze and has a highly cotton-like appearance can be successfully obtained in the process described below.

[0056] The aperture pattern member 80 preferably has predetermined dimensions. Specifically, from the viewpoint of successfully obtaining a nonwoven fabric that has a highly cotton-like appearance in the process described below, the spacing between adjacent first crosspieces 81 (i.e., openings) and the spacing between adjacent second crosspieces 82 in the aperture pattern member 80 are each independently preferably 300 μm or more, more preferably 400 μm or more, and even more preferably 600 μm or more. From the same viewpoint, the spacing between adjacent first crosspieces 81 and the spacing between adjacent second crosspieces 82 in the aperture pattern member 80 are each independently preferably 900 μm or less, more preferably 800 μm or less, and even more preferably 700 μm or less. Furthermore, from the viewpoint of successfully obtaining a nonwoven fabric that has the appearance of cotton double gauze and has a highly cotton-like appearance, the number of bars per inch (i.e., mesh count) in the perforated pattern member 80 is preferably 15 bars / inch or more, and more preferably 25 bars / inch or more. From the same viewpoint, the number of bars per inch in the perforated pattern member 80 is preferably 55 bars / inch or less, and more preferably 40 bars / inch or less. Furthermore, from the viewpoint of successfully obtaining a nonwoven fabric that has the appearance of cotton double gauze and has a highly cotton-like appearance, the widths of the first and second crosspieces 81 and 82 in the perforated pattern member 80 are each independently preferably 100 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more. From the same viewpoint, the widths of the first and second crosspieces 81 and 82 in the perforated pattern member 80 are each independently preferably 400 μm or less, more preferably 350 μm or less, and even more preferably 300 μm or less.

[0057] The aperture pattern member 80 can be made of metal or synthetic resin. Examples of metal include aluminum and stainless steel. Examples of synthetic resin include polyamide, polyester, polyphenylene sulfide, etc.

[0058] The aperture pattern member 80 is installed in the manufacturing apparatus 50 so that the first direction X1 or the second direction Y1 is the same as the transport direction of the fiber web 1a.

[0059] The fibrous web 1a transported to the hydroentangling section 70 is placed on the perforated pattern member 80, as shown in FIG. 2. The fibrous web 1a is transported together with the perforated pattern member 80. The transport direction coincides with the first direction X1 or the second direction Y1 of the perforated pattern member 80. In this state, a water stream is sprayed toward the fibrous web 1a (first hydroentangling step). The water stream sprayed from above the fibrous web 1a presses the fibrous web 1a against the perforated pattern member 80. The fibrous web 1a is pressed particularly strongly against the intersections 83 of the perforated pattern member 80. As a result, the fibrous web 1a located on the intersections 83 are split and holes are formed.

[0060] The fibrous web 1a, which has been entangled by the water jets from the water jet nozzles 71, is rotated 90° downstream of the hydroentangling section 70 while still placed on the perforated pattern member 80. The rotated fibrous web 1a is returned downstream of the web forming section 60 and upstream of the hydroentangling section 70, where it is again subjected to hydroentangling in the hydroentangling section 70 (second hydroentangling step). In the first hydroentangling step described above, the conveying direction coincides with the first direction X1 or the second direction Y1 of the perforated pattern member 80, but in the second hydroentangling step, the conveying direction coincides with the second direction Y1 or the first direction X1. That is, water is again sprayed toward the fibrous web 1a while the fibrous web 1a is conveyed together with the perforated pattern member 80 in the second direction Y1. As a result, the water jets sprayed from above the fibrous web 1a press the fibrous web 1a against the perforated pattern member 80. The fibrous web 1a is pressed particularly strongly against the intersections 83 of the perforated pattern member 80. By changing the direction of the fibrous web 1a and performing hydroentanglement again, the fibrous web 1a facing the intersections 83 is separated into a single layer, and clear square lattice-shaped openings are formed.

[0061] By the above-mentioned operation, a plurality of ribs consisting of tangled fibers oriented in the first direction X1 and the second direction Y1 are formed. Also, a plurality of clear apertures are formed in the nonwoven fabric. As a result, the nonwoven fabric has the appearance of cotton double gauze and has a more cotton-like appearance. From the viewpoint of improving the orientation of fibers in each rib portion and successfully forming openings, the water pressure of the water streams sprayed onto the fibrous web 1a in the first hydroentangling step and the second hydroentangling step is preferably 1.0 MPa or more, more preferably 2.0 MPa or more, and even more preferably 3.0 MPa or more. From the same viewpoint, the water pressure of the water streams sprayed onto the fibrous web 1a is preferably 7.0 MPa or less, more preferably 6.0 MPa or less, and even more preferably 5.0 MPa or less.

[0062] In the first hydroentangling step and the second hydroentangling step, the conveying speed of the fibrous web 1a is preferably 3.0 m / min or more, more preferably 4.0 m / min or more, from the viewpoint of successfully forming apertures. From the same viewpoint, the conveying speed of the fibrous web 1a is preferably 7.0 m / min or less, more preferably 6.0 m / min or less, from the same viewpoint.

[0063] Through these steps, a nonwoven fabric 1 can be obtained that has the appearance of cotton double gauze and has a highly cotton-like appearance. After forming the nonwoven fabric 1, the nonwoven fabric 1 may be dried, if necessary, using a heater or the like (not shown).

[0064] Although the present invention has been described above based on its preferred embodiment, the present invention is not limited to the above embodiment. In the above embodiment, the first direction X and the second direction Y are perpendicular to each other at approximately 90 degrees, but the intersecting angle between them is not limited to 90 degrees. [Example]

[0065] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, "%" means "% by mass."

[0066] Example 1 Only cotton fibers (micron fineness 6.35 μg / inch, fiber length 25 mm) are used, with a basis weight of 35 g / m 2 The above-mentioned fiber web was formed, and the fiber web was placed on a square lattice-shaped open pattern member as shown in Fig. 3. The dimensions of the open pattern member are shown in Table 1 below. The first direction of the open pattern member was aligned with the transport direction, and the fiber web was hydroentangled while being transported together with the open pattern member (first hydroentanglement step). Next, the fiber web placed on the perforated pattern member was rotated by 90° together with the member, and the second direction of the perforated pattern member was aligned with the conveying direction, and the fiber web was conveyed together with the perforated pattern member while hydroentangling was again carried out (second hydroentangling step). The hydroentangling conditions for both the first hydroentangling step and the second hydroentangling step were a water pressure of 4.0 MPa and a fiber web conveying speed of 5.0 m / min. The resulting sheet was air-dried for one day to obtain the desired nonwoven fabric.

[0067] Examples 2 and 3 In Example 1, the aperture pattern member used had the dimensions shown in Table 1. Other than this, the same procedure as in Example 1 was carried out to obtain the target nonwoven fabric.

[0068] Comparative Example 1 A commercially available pants-type disposable diaper (Pampers® Pure, manufactured by P&G Japan LLC) was prepared. A cold spray was sprayed onto the outer layer sheet forming the outermost surface of this diaper, and the outer layer sheet was slowly separated from the diaper so as not to lose its shape. This outer layer sheet contained approximately 5% by mass of cotton fiber. This outer layer sheet had a plurality of circular apertures. The apertures were arranged at predetermined intervals so as to trace a wave-like path. This outer layer sheet was used in Comparative Example 1.

[0069] 〔evaluation〕 For the nonwoven fabrics obtained in the Examples and Comparative Examples, the rib widths W1 and W2, the open hole area S2, and the open hole widths P1 and P2 were measured according to the methods described above. Based on the obtained values, the values ​​of W2 / W1, S2 / S1, P1 / W1, and P2 / W2 were calculated. Furthermore, the fiber orientation rate, thickness, and basis weight in the rib portions were measured according to the methods described above. Furthermore, the nonwoven fabrics obtained in the Examples and Comparative Examples were evaluated for their cotton-like appearance according to the method described below. The results are shown in Table 1 below.

[0070] [Cotton-like appearance] Two expert panelists were informed in advance that the nonwoven fabrics "contain 100% cotton fiber," and then visually inspected the nonwoven fabrics obtained in the Examples and Comparative Examples. They were asked to evaluate the cotton-like appearance on a nine-point scale according to the following evaluation criteria. The average evaluation scores are shown in Table 1 below.

[0071] [Evaluation criteria] 9: Looks very cotton-like. 8: It looks very cotton-like. 7: It looks very cotton-like. 6: Looks somewhat like cotton. 5: Neither. 4: It doesn't look like cotton at all. 3: It looks very unlike cotton. 2: It doesn't look like cotton at all. 1: It looks very unlike cotton.

[0072] [Table 1]

[0073] As is clear from the results shown in Table 1, the nonwoven fabrics obtained in the examples had a more cotton-like appearance than the nonwoven fabrics obtained in the comparative examples. [Explanation of symbols]

[0074] 1. Nonwoven fabric 2. Cotton fiber 3. Fiber entanglement 31 First furrow 32 Second furrow 33 intersection 4 hole 50 Manufacturing equipment 60 Web forming section 61 Card machine 70 Water flow intertwining section 71 Water nozzle 72 Support Belt 80 Opening pattern member 81 First crosspiece 82 Second crosspiece 83 intersection 8a hole X first direction Y Second direction Z thickness direction

Claims

1. An absorbent article comprising a top sheet arranged on the side closest to the wearer's skin when worn, an outer layer sheet arranged on the side farthest from the wearer's skin when worn, and an absorbent body arranged between the top sheet and the outer layer sheet, the outer layer sheet includes a nonwoven fabric containing cotton fibers and having a plurality of openings penetrating in the thickness direction, the outer layer sheet is made of a tangled fiber body containing cotton fibers and has a plurality of first ribs extending in a first direction, and a plurality of second ribs is made of a tangled fiber body containing cotton fibers and has a plurality of second ribs extending in a second direction intersecting the first direction, the openings are defined by the intersection of a plurality of first ridges and a plurality of second ridges; The area of ​​the opening is 0.07 mm ２ More than 0.7 mm ２ is as follows: The fibers contained in the tangled fiber body constituting the first rib portion have a fiber orientation tendency along a first direction, The fibers contained in the tangled fiber body constituting the second rib portion have a fiber orientation tendency along a second direction, the value of W2 / W1, which is the ratio of the width W2 of the second ridge portion to the width W1 of the first ridge portion, is 0.5 or more and 1.1 or less; An absorbent article, wherein the value of S2 / S1, which is the ratio of the area S2 of the opening to the product S1 of the width W1 of the first rib portion and the width W2 of the second rib portion, is 0.7 or less.

2. The absorbent article according to claim 1, wherein the outer layer sheet has a thickness of 0.5 mm or more and 1.5 mm or less under a load of 0.05 kPa.

3. 3. The absorbent article according to claim 1, wherein the value of P1 / W1, which is the ratio of the width P1 of the opening along the second direction to the width W1 of the first rib portion, or the value of P2 / W2, which is the ratio of the width P2 of the opening along the first direction to the width W2 of the second rib portion, is 0.3 or more and 1.1 or less.

4. The absorbent article according to claim 1 or 2, wherein the first direction and the second direction are generally perpendicular to each other.

5. 3. The absorbent article according to claim 1, wherein the fiber orientation rate in the first rib portion and the fiber orientation rate in the second rib portion are each independently 50% or more.

6. A nonwoven fabric containing cotton fibers and having a plurality of openings penetrating through the thickness direction, The nonwoven fabric has a plurality of first ribs formed of a tangled fiber body containing the cotton fibers and extending in a first direction, and a plurality of second ribs formed of a tangled fiber body containing the cotton fibers and extending in a second direction intersecting the first direction, the openings are defined by the intersection of a plurality of first ridges and a plurality of second ridges; The area of ​​the opening is 0.07 mm ２ More than 0.7 mm ２ is as follows: The fibers contained in the tangled fiber body constituting the first rib portion have a fiber orientation tendency along a first direction, The fibers contained in the tangled fiber body constituting the second rib portion have a fiber orientation tendency along a second direction, the value of W2 / W1, which is the ratio of the width W2 of the second ridge portion to the width W1 of the first ridge portion, is 0.5 or more and 1.1 or less; A nonwoven fabric, wherein the value of S2 / S1, which is the ratio of the area S2 of the opening to the product S1 of the width W1 of the first rib portion and the width W2 of the second rib portion, is 0.7 or less.

7. a first hydroentanglement step of placing a fibrous web containing cotton fibers on an aperture pattern member having a plurality of first crossbars extending in a first direction and a plurality of second crossbars extending in a second direction intersecting the first direction, wherein a plurality of apertures are defined by the intersection of the plurality of first crossbars and the plurality of second crossbars, and spraying a water stream toward the fibrous web while transporting the fibrous web together with the aperture pattern member along the first direction; a second hydroentangling step of spraying a water stream again onto the fiber web while transporting the fiber web together with the aperture pattern member in a second direction.

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