ABSORBABLE ARTICLE
20210045940 ยท 2021-02-18
Assignee
Inventors
Cpc classification
A61F13/515
HUMAN NECESSITIES
A61F13/4755
HUMAN NECESSITIES
A61F13/4942
HUMAN NECESSITIES
International classification
Abstract
An absorber 4 is interposed between a front-surface sheet 3 and a back-surface sheet 2, and side sheets 7 are respectively disposed along a longitudinal direction on both side parts of a skin side. The front-surface sheet 3 contains non-thermally fusible fiber, and the back-surface sheet 2 and the side sheets 7 contain thermally fusible resin. Fusion parts 10 allowing the side sheets 7 and the back-surface sheet 2 to be thermally fused under a state of the front-surface sheet 3 interposed therebetween are arranged in areas corresponding to side parts outer than the absorber 4 in a width direction, and the areas include the front-surface sheet 3 interposed between the side sheets 7 and the back-surface sheet 2, and include at least front and back end parts of a sanitary napkin 1. The front-surface sheet is prevented from delaminating and tearing accompanied therewith when non-thermally fusible fiber is used in the front-surface sheet.
Claims
1. An absorbable article comprising: a front-surface sheet in a skin side and a back-surface sheet in a non-skin side with an absorber interposed therebetween; and side sheets respectively arranged on both side parts of the skin side along a longitudinal direction, wherein the front-surface sheet contains non-thermally fusible fiber, and the back-surface sheet and the side sheets contain thermally fusible resin, and wherein fusion parts allowing the side sheets and the back-surface sheet to be thermally fused under a state of the front-surface sheet interposed therebetween are arranged in areas corresponding to side parts outer than the absorber in a width direction, and the areas include the front-surface sheet interposed between the side sheets and the back-surface sheet, and include at least front and back end parts of the absorbable article.
2. The absorbable article according to claim 1, wherein the fusion parts are arranged individually in a front-side area and a back-side area of the absorbable article.
3. The absorbable article according to claim 1, wherein the fusion parts are arranged over a full length in the longitudinal direction of the absorbable article so as to connect between a front side end edge part and a back side end edge part of the absorbable article.
4. The absorbable article according to claim 1, wherein the fusion parts are continuously thermally fused, or the fusion parts are intermittently thermally fused.
5. The absorbable article according to claim 1, wherein the side sheets are formed each in one layer, the side sheets are folded each into two layers with a folded end part arranged toward an inside in the width direction of the absorbable article, or the folded two-layered sheets include elastic stretchable members inside, and the two-layered sheets are folded outward and bonded at the front and back end parts of the absorbable article so as to form standing gathers standing on the skin side of the absorbable article in middle portions of the longitudinal direction.
6. The absorbable article according to claim 5, wherein when the side sheets form the standing gathers, outward folded portions of the two-layered sheets cover the skin sides of the fusion parts in the front and back end parts of the absorbable article.
7. The absorbable article according to claim 1, wherein the front-surface sheet has many openings penetrating through the sheet from the skin side to the non-skin side, and the fusion parts are disposed in areas covering the openings.
8. The absorbable article according to claim 1, wherein the side sheets and the back-surface sheet contain a same kind of thermally fusible fiber.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DESCRIPTION OF EMBODIMENTS
[0035] Hereinafter, some embodiments according to the present invention will be detailed with reference to the drawings. As shown in
[0036] Back-Surface Sheet
[0037] As the back-surface sheet 2, a sheet material having at least water impermeability such as polyethylene is used. Recently, material having moisture permeability tends to be used from the viewpoint of stuffiness prevention. As such a water impermeable and moisture permeable sheet material, a microporous sheet is preferably used, which is obtained by melt-kneading inorganic filler in olefin resin such as polyethylene or polypropylene and forming a sheet, and thereafter extending the sheet in one axial direction or two axial directions.
[0038] The back-surface sheet 2 is formed of thermally fusible fiber. As the thermally fusible fiber, any type of fiber is available, as long as it is melted by heating and expresses mutual bonding property. The thermally fusible fiber may be made of a single type of fiber, or may be composite fiber or the like obtained by combining two types or more of synthetic resin. Specifically, such fiber may be a single polyolefin fiber such as polyethylene, polypropylene or polyvinyl alcohol, sheath/core composite fiber or eccentric sheath/core composite fiber with a sheath part having a relatively low melting point, made of polyethylene terephthalate/polyethylene, polyethylene terephthalate/polypropylene, polypropylene/polyethylene, polyethylene-terephthalate-ethylene-propylene copolymer or low-melting polyester-polyester, split-type composite fiber with a component partially exposed to a surface, made of polyethylene terephthalate/polypropylene, polyethylene terephthalate/nylon or polo propylene/polyethylene, or thermally-spit-type composite fiber split by thermal shrinking of one component, made of polyethylene terephthalate/ethylene-propylene copolymer. In the case of focusing on productivity and dimensional stability, sheath/core composite fiber is preferably used. In the case of focusing on voluminous feeling of nonwoven fabric, eccentric sheath/core composite fiber is preferably used. In the case of focusing on softness, split-type composite fiber or thermally-split-type composite fiber is used, in which each component is easily split and made into ultrafine fiber during high-pressure water stream treatment.
[0039] Front-Surface Sheet
[0040] The front-surface sheet 3 forms a skin-contact surface covering the skin side of the absorber 4, and is formed of non-thermally fusible fiber. As the non-thermally fusible fiber, any type of fiber is available, as long as it is not melted by heating or expresses no bonding property between the non-thermally fusible fiber. Examples of the non-thermally fusible fiber are natural fiber such as cotton, pulp, silk and lyocell, regenerated cellulose fiber such as rayon and cupra, and semi-synthetic fiber such as acetate. Among them, natural fiber is preferably used owing to its good touch. Particularly, cotton fiber or lyocell fiber, among the natural fiber, may be used owing to its excellent touch and its excellent water absorbency and hygroscopicity. The front-surface sheet 3 may be formed of spun lace nonwoven fabric with 100 wt. % of cotton fiber, alternatively may be formed of laminated spun lace nonwoven fabric with 100 wt. % of cotton fiber as the skin side layer and with thermally fusible fiber as the non-skin side layer. The spun lace nonwoven fabric has advantages such as softness and none-use of adhesive.
[0041] As the cotton fiber, any type of cotton is available, such as raw cotton, scoured and bleached cotton fiber or dyed cotton fiber after subjected to scouring and bleaching, scoured and bleached degreased cotton, and recovered wool obtained by defibrating yarn or fabric. Especially, non-degreased cotton is preferably used, having slight water-repellant property even under the state of fiber owing to the natural fat and oil of cotton wax attached to the surface of the cotton fiber.
[0042] The front-surface sheet 3 has a fabric weight per unit area in a range from 20 g/m.sup.2 to 40 g/m.sup.2, preferably in a range from 27 g/m.sup.2 to 34 g/m.sup.2, more preferably in a range from 29 g/m.sup.2 to 32 g/m.sup.2, and has a thickness in a range from 0.25 mm to 0.50 mm, preferably in a range from 0.3 mm to 0.4 mm. The fabric weight per unit area is obtained by measuring the weight of 10 sheets each having the size of 5 cm4 cm with an electronic balance and calculating weight per square meter. The thickness is able to be measured by Digital Type FFD-7 of Constant Pressure Thickness Gauge manufactured by OZAKI MFG. CO., LTD.
[0043] The front-surface sheet 3 may be formed to have many openings penetrating through the sheet from the skin side to the non-skin side in the thickness direction, in order to enhance the fluid permeability. Specifically, the openings may be formed by making a mesh-like support body support fiber material in a hydroentanglement step during spun lace production. In this case, the change of the conditions of the mesh to be used allows to adjust the individual opening size and the opening ratio. The openings may be simply formed in the manner that the nonwoven fabric after production is subjected to punching. The openings are formed in at least the area where the fusion part 10 to be described later is provided, preferably additionally formed in a body fluid expelling portion H and its vicinity in order to provide higher water permeability in the body fluid expelling portion H, further preferably formed on the entire surface sheet.
[0044] In the case where the front-surface sheet 3 is formed of the spun lace nonwoven fabric made of 100 wt. % of cotton fiber coated with water-repellant agent and is formed to have many openings penetrating through the sheet from the skin side to the non-skin side, the front-surface sheet 3 has advantages of providing soft touch and hardly causing skin trouble during wearing such as itching and rash even after wearing for a long time, and further suppressing a wearer from feeling stuffiness before expelling of body fluid owing to the hygroscopicity of the cotton fiber. In this case, the problem in terms of the residue of the fluid on the surface is sufficiently solved by the coated water-repellant agent. In the case of the front-surface sheet 3 having many openings in the area including the body fluid expelling portion H, the front-surface sheet 3 is capable of promptly transmitting body fluid through the openings.
[0045] Absorber 4
[0046] The absorber 4 interposed between the back-surface sheet 2 and the front-surface sheet 3 includes, for example, cotton-like pulp and a water absorbent polymer. The water absorbent polymer, for example, as granular powder, is mixed in the pulp included in the absorber. The pulp is made of cellulose fiber such as chemical pulp or melted pulp obtained from wood, or artificial cellulose fiber such as rayon or acetate. Needle leaved tree pulp having a longer fiber length than that of broad-leaved tree pulp is preferably used from the viewpoint of function and cost. The absorber 4 has a fabric weight per unit area in a range from 290 g/m.sup.2 to 1000 g/m.sup.2, preferably in a range from 390 g/m.sup.2 to 850 g/m.sup.2, more preferably in a range from 630 g/m.sup.2 to 720 g/m.sup.2.
[0047] The absorber 4 may include mixed synthetic fiber. Specifically, the synthetic fiber may be polyolefin system such as polyethylene or polypropylene, polyester system such as polyethylene terephthalate or polybutylene terephthalate, polyamide system such as nylon, or a copolymer thereof. Two kinds among them may be mixed and used. Furthermore, composite fiber is available, such as sheath/core fiber with high-melting point fiber as a core and low-melting point fiber as a sheath, side-by-side fiber, and split-type fiber. In the case where the synthetic fiber is hydrophobic fiber, the synthetic fiber is desirably used after subjected to surface treatment with a hydrophilizing agent, so as to impart affinity to body fluid.
[0048] As the absorber 4, a polymer sheet with granular powder superabsorbent polymer supported between two upper and lower layers of hydrophilic sheets made of unwoven fiber, paper or the like may be used. The polymer sheet has only superabsorbent polymer supported between two layers of sheets, without pulp fiber. Between the pulp sheet and the front-surface sheet 3, an intermediate sheet made of hydrophilic nonwoven fabric may be arranged, when needed.
[0049] Furthermore, the absorber 4 may be formed by pilling up an absorber including pulp fiber and superabsorbent polymer on the skin side or the non-skin side of the polymer sheet. As for the combination of the polymer sheet and the absorber including the pulp fiber and the superabsorbent polymer, the absorber may be formed by pilling up one layer for each, or may be formed by making plural layers of either one of them or both of them, and pilling up them alternately.
[0050] Examples of the superabsorbent polymer are cross-linking polyacrylate, self-cross-linking polyacrylate, saponified substance of cross-linking copolymer of acrylic acid ester and vinyl acetate, cross-linking substance of copolymer of isobutylene and maleic anhydride, cross-linking polysulfonate, and partially cross-linking substance of water swelling polymer such as polyethylene oxide and polyacrylamide. Among them, substance of acryl acid or acrylate-based substance excellent in amount of water absorption and water absorption rate is preferably used. The absorption ratio (water absorbing power) and the absorption rate of the superabsorbent polymer having the above-described water absorbing property are adjustable, by adjusting the cross-linking density and the cross-linking density gradient in its manufacturing process.
[0051] In the case of the absorber 4 containing the pulp fiber, the absorber 4 is desirably wrapped by an encapsulating sheet 5 formed of a crepe paper sheet, nonwoven fabric or the like, in order to retain the shape and support polymer powder, and other reasons.
[0052] The absorber 4 has, on the skin side surface thereof, an emboss groove 8 forming an appropriate planar shape where the front-surface sheet 3 and the absorber 4 are integrally dented to the non-skin side, so as to cover at least the area corresponding to the body fluid expelling portion H of a wearer at least in the width direction. The formation of the emboss groove 8 allows the absorber 4 to reliably absorb the body fluid flowing into the emboss groove 8. The planar shape of the emboss groove 8 may be in, for example, a substantially oval shape as shown in
[0053] As shown in
[0054] Side Sheet
[0055] As in the illustrated example, the front-surface sheet 3 is formed wider by a predetermined width than the width of the absorber 4. The outside parts of the front-surface sheet 3 in the width direction are covered by the side sheets 7 (different members from the front-surface sheet 3) respectively extending from the both side parts of the skin side surface of the front-surface sheet 3. The side sheets 7 are arranged respectively on the both side parts separated by the center in the width direction.
[0056] Each of the side sheets 7, as with the back-surface sheet 2, is made of thermally fusible fiber. As the thermally fusible fiber, any type of fiber is available, as long as it is melted by heating and expresses mutual bonding property. As with the back-surface sheet 2, the thermally fusible fiber may be made of a single type of fiber, or may be composite fiber or the like obtained by combining two types or more of synthetic resin. Specifically, such fiber may be single polyolefin fiber such as polyethylene, polypropylene or polyvinyl alcohol, sheath/core composite fiber or eccentric sheath/core composite fiber with a sheath part having a relatively low melting point, made of polyethylene terephthalate/polyethylene, polyethylene terephthalate/polypropylene, polypropylene/polyethylene, polyethylene-terephthalate-ethylene-propylene copolymer or low-melting polyester-polyester, split-type composite fiber with a component partially exposed to a surface, made of polyethylene terephthalate/polypropylene, polyethylene terephthalate/nylon or polo propylene/polyethylene, or thermally-spit-type composite fiber split by thermal shrinking of one component, made of polyethylene terephthalate/ethylene-propylene copolymer. In the case of focusing on productivity and dimensional stability, sheath/core composite fiber is preferably used. In the case of focusing on voluminous feeling of nonwoven fabric, eccentric sheath/core composite fiber is preferably used. In the case of focusing on softness, split-type composite fiber or thermally-split-type composite fiber is used, in which each component is easily split and made into ultrafine fiber during high-pressure water stream treatment.
[0057] As the side sheet 7, nonwoven fabric material appropriately subjected to appropriate water-repellant treatment or hydrophilic treatment is available depending on the purpose such as of preventing body fluid and the like from permeating or enhancing the texture.
[0058] As shown in
[0059] The side sheets 7 are formed each in one layer in the example shown in
[0060] Fusion Part
[0061] As shown in
[0062] The thermo-fusion parts 10 are formed on the flap parts where the side sheets 7, the front-surface sheet 3 and the back-surface sheet 2 are adjacently layered in this order from the skin side, without the absorber 4 interposed, in the areas which are the side parts outer than the absorber 4 in the width direction and do not cover the absorber 4 in the thickness direction.
[0063] The fusion parts 10 are formed in the areas at least including the front and back end parts of the sanitary napkin 1. The description of including the front and back end parts of the sanitary napkin 1 means being formed to cover the end edge parts of the sanitary napkin 1 in the longitudinal direction (front-and-back direction). This allows the end edge parts of the front-surface sheet 3 arranged in the front and back end edge parts of the sanitary napkin 1 to be firmly fixed to the side sheets 7 and the back-surface sheet 2, thereby enabling to reliably prevent delamination from the edge parts.
[0064] In forming each of the fusion parts 10, as shown in
[0065] As shown in
[0066] Alternatively, as shown in
[0067] The dimensions of the fusion parts 10 are described on the basis of
[0068] A width b of the fusion parts 10 is preferably set to a range from 2 mm to 15 mm. If the width b is shorter than 2 mm, the fusion parts 10 have low strength in bonding, and thus delamination occurs easily. If the width b is longer than 15 mm, the fusion parts 10 are formed too hard and thus the wearing feeling is deteriorated. In order to ensure the width b of the fusion parts 10, the side sheets 7, the front-surface sheet 3 and the back-surface sheet 2 are respectively extended by predetermined lengths to the outer sides in the width direction from the absorber 4. The fusion parts 10 are disposed on the center parts in the width direction of the flap parts disposed outside the absorber 4 in the width direction, so as not to reach the side edge parts of the sanitary napkin 1. That is, outside the fusion parts 10 in the width direction, the flap parts are formed, in which at least the side sheets 7 and the back-surface sheet 2 are layered but the fusion parts 10 are not formed. Therefore, the side edge parts of the sanitary napkin 1 provides a soft feeling to the skin during wearing the sanitary napkin 1, thereby suppressing deterioration in wearing feeling.
[0069] As shown in
[0070] As shown in
[0071] As shown in
[0072] Alternatively, as shown in
[0073] As shown in
[0074] To form the standing gathers BS shown in
[0075] At this time, as shown in
[0076] The side sheets 7 and the back-surface sheet 2 shall contain the same kind of thermally fusible fiber. The containing of the same kind of thermally fusible fiber allows the both sheets to be thermally melted at a constant temperature during thermo-fusing, and facilitates mutual bonding because the thermally melted fiber of the side sheets 7 and the back-surface sheet 2 permeates the front-surface sheet 3, resulting in further enhancing the effect of thermo-fusing.
REFERENCE SIGNS LIST
[0077] 1: SANITARY NAPKIN, 2: BACK-SURFACE SHEET, 3: FRONT-SURFACE SHEET, 4: ABSORBER, 5: ENCAPSULATING SHEET, 7: SIDE SHEET, 8: EMBOSS GROOVE, 9a: CENTRAL AREA, 9b: FRONT SIDE AREA, 9c: BACK SIDE AREA, 10: FUSION PART, 11: THREADLIKE ELASTIC STRETCHABLE MEMBER