ABSORBENT ARTICLE
20210282982 · 2021-09-16
Assignee
Inventors
Cpc classification
A61F13/51478
HUMAN NECESSITIES
A61F13/51108
HUMAN NECESSITIES
A61F13/513
HUMAN NECESSITIES
International classification
A61F13/511
HUMAN NECESSITIES
A61F13/513
HUMAN NECESSITIES
Abstract
An absorbent article comprising a top-surface sheet 3, a back-surface sheet 2, and absorber 4 interposed between, and a pair of left and right side sheets 7 over an entire length on both side portions of a skin-contact surface side. An inner side in a width direction of each of the side sheets 7 is folded back in the width direction to be laminated in a plurality of layers. A laminated portion 8 of the side sheets 7 includes lower layer side embossed portions 9 for joining the bottom layers of the side sheets 7 and a top-surface sheet 3, and skin-side embossed portions 10 obtained by integrally denting the side sheets 7 of the laminated portion 8 from the skin-contact surface side. The lower-layer-side embossed portions 9 and the skin-side embossed portions 10 are formed in different plane patterns. The absorbent article suppresses deterioration of touch to the skin and obtains good wearing feeling while ensuring sufficient joining strength in a joining portion of side sheets.
Claims
1. An absorbent article comprising a top-surface sheet, a back-surface sheet, an absorber interposed between the top-surface sheet and the back-surface sheet, and a pair of left and right side sheets over an entire length on both side portions of a skin-contact surface side, wherein an inner side in a width direction of each of the side sheets is folded back in the width direction to be laminated in a plurality of layers, and a laminated portion of the side sheet includes lower layer side embossed portions for joining a bottom layer of the side sheet and the top-surface sheet to each other, and a skin-side embossed portions obtained by integrally denting the side sheets of the laminated portion from the skin-contact surface side.
2. The absorbent article according to claim 1, wherein the lower layer side embossed portions and the skin-side embossed portions are formed in different plane patterns.
3. The absorbent article according to claim 1, wherein the skin-side embossed portions are formed to have a smaller area of the embossed portions per unit area than the lower layer side embossed portions.
4. The absorbent article according to claim 1, wherein the lower layer side embossed portions are formed in an intermittent plane pattern in which a pressed portion and a non-pressed portion are alternately disposed along a longitudinal direction of the absorbent article.
5. The absorbent article according to claim 1, wherein the lower layer side embossed portions and the skin-side embossed portions are formed in regions overlapping with each other in a thickness direction.
6. The absorbent article according to claim 1, wherein the lower layer side embossed portions are formed in a region at an inner side in the width direction, and the skin-side embossed portions are formed in a region at an outer side in the width direction, and thereby the lower layer side embossed portions and the skin-side embossed portions are formed in regions that do not overlap with each other in the thickness direction.
7. The absorbent article according to claim 1, wherein each of the side sheets is disposed so as to extend toward the inner side portion in the width direction in a state in which one side portion is substantially aligned to the side portion of the top-surface sheet, and is folded back toward the skin-contact surface side from the lower layer side embossed portions as a base such that another side portion extends to the side portion of the absorbent article.
8. The absorbent article according to claim 1, wherein an elastically stretchable member is disposed between the layers of the side sheets laminated in a plurality of layers along the longitudinal direction of the absorbent article, and the elastically stretchable member is disposed at the inner side in the width direction from the lower layer side embossed portions and the skin-side embossed portions.
9. The absorbent article according to claim 1, wherein the lower layer side embossed portions are formed to have a sectional shape bulging toward a skin-contact surface side.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040]
[0041]
[0042]
[0043]
DESCRIPTION OF EMBODIMENTS
[0044] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the drawings.
One Example of Basic Structure of Sanitary Napkin
[0045] A sanitary napkin 1 according to the present invention mainly includes, as shown in
[0046] For the back-surface sheet 2, a sheet material having at least water-blocking properties, for example, polyethylene, is used. In recent years, however, from the viewpoint of preventing a moist feeling, a sheet material having moisture permeability has tended to be used. As the water-blocking and moisture-permeable sheet materials, microporous sheets are suitably used. A microporous sheet is obtained by molding a sheet by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene, followed by stretching in uniaxial or biaxial direction. On a non-skin-contact surface side (outside surface) of the back-surface sheet 2, one or a plurality of stripes of sticking layers (not shown in the drawings) is formed, so that the sanitary napkin 1 is fixed to underwear when wearing on the body. As the back-surface sheet 2, a poly-laminate nonwoven fabric in which a plastic film and a nonwoven fabric are laminated may be used.
[0047] Next, for the top-surface sheet 3, porous or non-porous non-woven fabric, a porous plastic sheet, or the like, are suitably used. As the material fibers constituting the nonwoven fabric, synthetic fibers such as olefin-based fibers such as polyethylene or polypropylene, polyester-based fibers, and polyamide-based fibers, regenerated fibers such as rayon and cupra, and natural fibers such as cotton can be used, and nonwoven fabrics obtained by appropriate processing methods such as a spun lace method, a spun bond method, a thermal bond method, a meltblown method, and a needle punch method can be used. Among these processing methods, the spun lace method is excellent in being rich in flexibility, and a drape property, and the thermal bond method is excellent in bulkiness and high compression restorability. When a large number of through holes are formed in the top-surface sheet 3, the body fluid is rapidly absorbed, so that excellent dry touch property is achieved. The non-woven fabric fibers may be long fibers or short fibers, but short fibers are preferably used in order to bring out the texture of towel fabric. Furthermore, in order to fabricate embossing treatment, olefin-based fibers such as polyethylene or polypropylene having a relatively low melting point is preferably used. Furthermore, a core-sheath type fiber including a core having a high melting point and a sheath having a low melting point, a side-by-side fiber, or composite fiber of dividing fibers can be suitably used.
[0048] The absorber 4 can absorb and retain the body fluid, and the absorber 4 used can be one in which a particulate superabsorbent polymer is dispersed and mixed in fluffy pulp fiber, or a polymer sheet including an upper layer sheet at a skin-contact surface side, a lower layer sheet at a non-skin-contact surface side, and the highly absorbent polymer interposed between the upper layer sheet and the lower layer sheet.
[0049] Examples of the pulp fiber include a fiber made of cellulose fibers such as chemical pulp obtained from timber or molten pulp, and artificial cellulose fibers such as rayon and acetate. From the viewpoint of function and price, softwood pulp having a fiber length longer than that of hardwood pulp is suitably used. The basis weight of the pulp fiber is set at 150 to 700 g/m.sup.2, and preferably 250 to 400 g/m.sup.2. The basis weight of the superabsorbent polymer is set at 15 to 470 g/m.sup.2, and preferably 15 to 100 g/m.sup.2.
[0050] Examples of the superabsorbent polymer include crosslinked polyacrylate, self-crosslinked polyacrylate, a saponified product of a crosslinked product of an acrylic acid ester-vinyl acetate copolymer, a crosslinked product of an isobutylene/maleic anhydride copolymer, a crosslinked product of polysulfonate, and a partially crosslinked water-swelling polymer such as polyethylene oxide or polyacrylamide. Among these examples, acrylic acid or acrylate salt-based being excellent in absorption amount and water absorption speed is suitable. In the manufacturing process, an absorption ratio (water absorption power) and an absorption speed of the superabsorbent polymer having absorbing performance may be adjusted by adjusting a crosslink density and a crosslink density gradient.
Side Sheet
[0051] In the example shown in the drawings, the top-surface sheet 3 is formed in a width to an extent that the top-surface sheet 3 has a width slightly larger than a width of the absorber 4 and only covers the absorber 4. The outer side in the width direction of the top-surface sheet 3 is covered with the side sheet 7 (a member other than the top-surface sheet 3) extending from the skin-contact surfaces of both side portions of the top-surface sheet 3. As the side sheet 7, depending on objectives, for example, prevention of permeation of a body fluid or enhancement of touch to the skin, a nonwoven fabric material, to which appropriate water repelling treatment or hydrophilic treatment has been applied, can be used. As such side sheet 7, one formed by an appropriate processing method using a natural fiber, a synthetic fiber, or a regenerated fiber as a raw material can be used. However, in order to eliminate a stiff feeling and to prevent a moist feeling, a nonwoven fabric having aeration properties with the basis weight reduced is preferable. Specifically, it is desirable to use a nonwoven fabric produced by setting the basis weight at 8 to 23 g/m.sup.2 is desirably used.
[0052] As shown in
[0053] On the other hand, the inner side in the width direction of the side sheet 7 is folded back in the width direction to form the laminated portion 8 of a plurality of layers. The laminated portion 8 of the side sheet 7 is formed over the entire length of the side sheet 7 at substantially equal width along the longitudinal direction of the sanitary napkin 1, and is formed in a range including a region overlapping with the top-surface sheet 3 in the thickness direction. In other words, at least a part of the inner side in the width direction of the laminated portion 8 has an overlapping allowance with the top-surface sheet 3 in the thickness direction, preferably an entire part of the laminated portion 8 overlaps with the top-surface sheet 3 in the thickness direction, and more preferably, the outer side edge portion in the width direction of the laminated portion 8 is substantially aligned to side edge portion of the surface sheet 3.
[0054] As shown in
[0055] The lower layer side embossed portions 9 and the skin-side embossed portions 10 are portions in which fibers are thermally fused by applying heat or ultrasonic waves at the time of pressing. In view of making the skin contact soft, at least the skin-side embossed portions 10 preferably uses ultrasonic waves as thermally fusing means.
[0056] In the embodiment example in
[0057] In this way, in the sanitary napkin 1, a sheet portion in the laminated portion 8 of the side sheet 7 in which the lower layer side embossed portions 9 are not provided is laminated at the skin-contact surface side of the lower layer side embossed portions 9, and thereby the lower layer side embossed portions 9 are not brought into direct contact with the skin when wearing. Therefore, even if the lower layer side embossed portions 9 are an embossed portion formed in a large area having a sufficient joining strength, the deterioration of touch to the skin can be suppressed. On the other hand, the skin-side embossed portions 10 formed on the skin-contact surface side of the laminated portion 8 is only required to be formed with a joining strength sufficient to prevent peeling of the side sheets 7 from each other in the laminated portion 8, uncomfortable feeling does not occur even when the side sheets 7 are brought into direct contact with the skin surface. Therefore, excellent wearing feeling is obtained.
[0058] Furthermore, since the skin-side embossed portions 10 can prevent peeling of the side sheets 7, 7 from each other in the laminated portion 8, twisting and wrinkling do not easily occur in the side sheet 7 of the laminated portion 8. Furthermore, by forming the skin-side embossed part 10 in a wavy plane pattern or adding a pattern such as a flower pattern, the appearance of the absorbent article seen from the skin-contact surface side becomes good, and the decorativeness can be improved.
[0059] As shown in
[0060] In order not to deteriorate the touch to the skin when wearing, it is preferable that an area of the embossed portions per unit area of the skin-side embossed portions 10 is smaller than that of the lower layer side embossed portions 9. The area of the embossed portions per unit area is a value obtained by dividing a total area of the lower layer side embossed portions 9 or a total area of the skin-side embossed portions 10 by an area of the laminated portion 8. When the skin-side embossed portions 10 are formed to have a smaller area than the area of the lower layer side embossed portions 9, the deterioration of touch to the skin can be suppressed while the sufficient joining strength of the side sheet 7 and the top-surface sheet 3 is ensured by the lower layer side embossed portions 9. As the rate of the area, the area of the skin-side embossed portions 10 is preferably ½ to 1/50, and preferably ⅕ to 1/20 with respect to the area of the lower layer side embossed portions 9.
[0061] As shown in
[0062] As shown in
[0063] Furthermore, as shown in
[0064] A planar shape of the pressed portion 9a of the lower layer side embossed portions 9 in the example shown in
[0065] The lower layer side embossed portions 9 can be formed by pressing from the outer surface side of the top-surface sheet 3 or the outer surface side of the side sheet 7 in a state in which the top-surface sheet 3 and the side sheet 7 are laminated. In other words, the pressing direction may be any directions, and furthermore, pressing may cause bulging toward the opposite side of the pressing or may not cause bulging. Preferable embodiment is a form in a dome-shaped cross sectional shape bulging toward the skin-contact surface side as shown in
[0066] Next, the skin-side embossed portions 10 are described. The skin-side embossed portions 10 may be formed continuously along substantially the longitudinal direction as shown in
[0067] The skin-side embossed portions 10 preferably includes a wavy line, reciprocating in the width direction, along the substantially longitudinal direction of the sanitary napkin 1 as shown in
[0068] Furthermore, similar to the lower layer side embossed portions 9, the skin-side embossed portions 10 may include one or a plurality of intermittent patterns located intermittently along the longitudinal direction of the sanitary napkin 1, in the width direction of the sanitary napkin 1. In this case, the joining strength of the skin-side embossed portions 10 is preferably smaller than the joining strength of the lower layer side embossed portions 9. This can make the skin contact of the skin-side embossed portions 10 soft. The joining strength can be reduced by both or either means of reducing the pressing depth during pressing, and means of reducing the heating temperature.
[0069] Furthermore, as shown in
[0070] As shown in
[0071] Furthermore, as a modified example, as shown in
[0072] When the skin-side embossed portions 10 are formed in a region at the outer side in the width direction, the skin-side embossed portions 10 are disposed preferably at the outer side from the absorber 4. Thus, the skin-side embossed portions 10 are disposed in a position dented from the region in which the absorber 4 is disposed to the non-skin-side only by a thickness part of the absorber 4, the opportunity for the skin-side embossed part 10 to be brought into contact with the skin surface is further reduced, and the skin contact can be further made to be soft.
[0073] By the way, as shown in
[0074] Next, in a method for manufacturing the sanitary napkin 1, a method for joining the top-surface sheet 3 and the side sheet 7 is described. As shown in
[0075] Note here that in the above embodiment example, the lower layer side embossed portions 9 are formed in a shape in which the top-surface sheet 3 and the side sheet 7 are allowed to integrally bulge toward the skin-contact surface side or the non-skin-contact surface side by allowing the lower layer side embossed portions 9 between the convex roll 20 and the concave roller 21, but may be formed in a shape dented within a range of a thickness of a laminate of the top-surface sheet 3 and the side sheet 7 by allowing the lower layer side embossed portions 9 to pass between a convex roll and a flat roll, and pressing from the non-skin-contact surface side of the top-surface sheet 3 or the skin-contact surface side of the side sheet 7. Furthermore, in the above embodiment example, the skin-side embossed portions 10 are formed in a shape dented within a range of a thickness of a laminate of the top-surface sheet 3 and the folded side sheet 7 by allowing the skin-side embossed portions 10 to pass between the convex roll 22 and the flat roll 23, and pressing from the skin-contact surface side of the top-surface sheet 3, but may be formed in a shape in which the top-surface sheet 3 and the folded side sheet 7 are allowed to integrally bulge toward the non-skin-contact surface by allowing the skin-side embossed portions 10 to pass between the convex roll and a flat roll.
Other Embodiment Example
[0076] In the above embodiment example, the laminated portion 8 of the side sheet 7 is formed of two layers, but may be formed of three or more layers. When the laminated portion 8 is formed of three or more layers, the lower layer side embossed portions 9 may join at least the bottom layer of the side sheet 7 and the top-surface sheet 3, and may integrally join the bottom layer of the side sheet 7 or the layer above it to the top-surface sheet 3. In other words, it is only required that the lower layer side embossed portions 9 are prevented from being applied to the top layer of the side sheet 7. When the laminated portion 8 is formed of three or more layers, a thickness of the laminated portion 8 is increased, thus improving an effect of both side portions of the top-surface sheet 3 as a barrier.
[0077] Furthermore, when, for example, the laminated portion 8 is formed of three layers, as shown in
REFERENCE SIGNS LIST
[0078] 1 . . . sanitary napkin, 2 . . . back-surface sheet, 3 . . . top-surface sheet, 4 . . . absorber, 5 . . . encapsulation sheet, 7 . . . side sheet, 8 . . . laminated portion, 9 . . . lower layer side embossed portion, 10 . . . skin-side embossed portion, 11 . . . elastically stretchable member