JP4140840B2 - Method for manufacturing absorbent article - Google Patents

Description

The present invention is an absorbent article mainly used for sanitary napkins, cage sheets, incontinence pads, medical pads, toiletries, etc., and more specifically, while removing the crepe paper surrounding the absorber, reliably perform the shape retention of the fiber pulp, and a method of manufacturing a manufacturable absorbent material product with fewer manufacturing steps.

  Conventionally, as an absorbent article such as a panty liner, sanitary napkin, incontinence pad, a liquid-impervious back sheet such as a polyethylene sheet or a polyethylene sheet-laminated nonwoven fabric, and a liquid-permeable surface sheet such as a nonwoven fabric or a liquid-permeable plastic sheet There is known an intervening absorber made of cotton-like pulp or the like.

  Moreover, in the said absorbent article, as shown in FIG. 6, in order to satisfy the dry touch feeling with respect to skin and to increase the absorption speed of a bodily fluid, as the said liquid-permeable surface sheet, the porous plastic sheet 51 (henceforth) , A mesh sheet) and a hydrophilic fiber sheet 52 called a second sheet is interposed between the liquid-permeable surface sheet 51 and the absorber 53 (for example, the following patents). References 1-3).

  On the other hand, many improvements have been made to this type of absorbent article, and various measures have been taken to prevent leakage of body fluids. As one of these body fluid leakage prevention means, a middle-high part thickened on the surface side is formed in the substantially central region of the absorber to improve the fit to the blood drainage part, and the shape of the middle-high part is maintained. Therefore, an absorbent article is also known in which linear embossing is performed on the outer peripheral position of the middle-high part (see Patent Documents 4 to 6 below).

  In each of the absorbent articles described above, when defibrated pulp obtained by crushing pulp is used as an absorbent, the pulp piled up on the line may drop off, or the equipment may be adversely affected by transfer of pulp fibers, etc. It is surrounded by crepe paper immediately after the fiber pile so as not to reach. In this case, in the case of the defibrated pulp absorber having the middle and high parts, as shown in FIG. 7A, the defibrated pulp layer 54 constituting the general part absorber and the defibrated pulp constituting the middle and high part absorber. A mode in which the layers 55 are collectively surrounded by the crepe paper 56, and the defibrated pulp layer 54 constituting the general part absorbent body is surrounded by the crepe paper 56, and then the middle and high part absorbent body similarly surrounded by the crepe paper 56 is configured. There is an embodiment in which the defibrated pulp layer 55 is laminated thereon.

On the other hand, in recent years, various thin absorbent articles have been provided from the viewpoints of bag accommodation, portability, and wearability. As an absorbent body of this thin absorbent article, for example, a material using a pulp fiber mixed with a superabsorbent resin into a sheet (hereinafter also referred to as a pulp sheet) is often used. In the case where the middle and high portions are formed in the absorbent body made of a pulp sheet, many embodiments are employed in which defibrated pulp surrounded by crepe paper is laminated thereon.
JP-A-7-328060 JP-A-8-117277 JP-A-10-272152 JP 10-328233 A Japanese Patent Laid-Open No. 11-358 JP-A-11-33054

As described above, when defibrated pulp is used as an absorbent body, it is generally surrounded by crepe paper to prevent falling off of the line and transfer to equipment and to maintain the shape. It is. However, according to the knowledge of the present inventors, a conventional general absorbent article has a hydrophilic fiber sheet: diffusion rate of 1.07 cm ³ / sec, crepe paper: 0.25 cm ³ / sec, pulp + polymer: 0. Since the diffusion speed is low in the intermediate crepe paper as 38 cm ³ / sec, the following problems have occurred from the point of use.
(1) When the amount of menstrual blood is small, menstrual blood passes through the top sheet and reaches the crepe paper, but the amount that shifts to the absorber body is small, and most menstrual blood is transferred to the absorber body. Meanwhile, it remains on the crepe paper. As a result, when the posture at the time of use is sideways, menstrual blood flows on the crepe paper, and after menstrual blood reaches the end of the napkin, side leakage occurs.
(2) When the amount of menstrual blood is large, there is little transfer from the crepe paper to the absorbent body, so that most of the incoming menstrual blood does not move to the absorbent body and accumulates between the top sheet or the crepe paper. And if the amount of menstrual blood that enters exceeds the amount of body fluid retained between the top sheet or crepe paper, menstrual blood cannot flow under the top sheet, but liquid flows over the top sheet, causing side leakage. It will be.

  On the other hand, when the defibrated pulp is surrounded by crepe paper, the surrounding process becomes necessary and the manufacturing process becomes complicated, and the material cost of the crepe paper increases. There was a problem of getting higher.

Therefore, the main problem of the present invention is to omit the crepe paper surrounding the defibrated pulp, thereby reducing the material cost and promptly absorbing the body fluid, but also in the manufacturing process. reliably perform the shape retention of the pulp, and with eliminating the adverse effect of the material losses and equipment, to provide fewer manufacturing process enables the manufacture and the manufacturing method for absorbent products products.

In order to solve the above problems, as the present invention according to claim 1, an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and between the liquid-permeable top sheet and the absorbent body. , hydrophilic fiber sheet comprising hydrophilic nonwoven fabric is disposed Rutotomoni, wherein said absorbent body includes a lower layer absorbent body comprising a pulp sheet obtained by processing in advance into a sheet of pulp fibers mixed with superabsorbent resin, the lower layer side A manufacturing method for obtaining an absorbent article composed of an upper absorbent body mainly composed of defibrated pulp, which is laminated on the upper surface side of the substantially central portion of the absorbent body and is not surrounded by crepe paper,
In the first step of the production line or in another step, one of the lower layer side absorbent body and the hydrophilic fiber sheet made of the pulp sheet is fed to the production line, and the defibrated pulp to be the upper layer side absorbent body is loaded on this sheet. After fibering, if the upper layer side absorbent body is covered with the other one of the lower layer side absorbent body and the hydrophilic fiber sheet made of the pulp sheet, a needle punch is applied to the peripheral portion of the upper layer side absorbent body. After the step of obtaining the laminated body holding the upper layer side absorbent body, a step of laminating a back sheet on the lower surface side of the laminated body, and a step of laminating a liquid-permeable surface sheet on the upper surface side of the laminated body, The manufacturing method of the absorbent article characterized by including is provided.

As described in detail above, in the present invention, the upper layer absorbent body made of defibrated pulp constituting the middle and high portions is not surrounded by crepe paper, but in the production process, between the hydrophilic fiber sheet and the lower layer side absorbent body. during the three-layer state, the two Dorupanchi granted the peripheral portion of the upper absorber so as to hold so that there is no positional displacement or deformation on being interposed. As a result, material costs can be reduced by omitting crepe paper, and body fluid can be quickly absorbed by defibrated pulp and absorbent sheets due to the absence of crepe paper, which is an obstacle to body fluid. Will come to be. In addition, the manufacturing process can be simplified by eliminating the step of surrounding the absorbent body with crepe paper from the manufacturing line.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a partially broken plan view of an absorbent article 1 according to the present invention, and FIG. 2 is a view taken along the line II-II.

  The absorbent article 1 is mainly used for applications such as panty liners, sanitary napkins, cage sheets, incontinence pads, etc., for example, as shown in FIG. An absorber unit 4 is interposed between the liquid-permeable surface sheet 3 (hereinafter, also simply referred to as a surface sheet), and absorption is performed between the liquid-permeable surface sheet 3 and the absorber unit 4. In order to improve diffusibility, wearing feeling, and concealment, a hydrophilic fiber sheet 7 is disposed. In addition, in the circumference | surroundings of the said absorber unit 4, the said liquid-impermeable back surface sheet 2 and the liquid-permeable surface sheet 3 are joined by adhesion means, such as a hot-melt-adhesive, or heat seal.

  The liquid-impervious back sheet 2 is made of a sheet material having at least water shielding properties, such as polyethylene and polypropylene. In addition to this, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet or the like, and further a waterproof film interposed. After substantially ensuring liquid impermeability, a nonwoven fabric sheet (in this case, a waterproof film and a nonwoven fabric constitute a liquid impervious back sheet) or the like can be used. In recent years, those having moisture permeability tend to be suitably used from the viewpoint of preventing stuffiness. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used.

  As the surface sheet 3, a non-porous or perforated nonwoven fabric or a porous plastic sheet is used, and the surface sheet suitably used for the sanitary napkin 1 is a porous plastic sheet.

  Examples of the material fibers constituting the non-woven fabric include synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton. In addition, composite fibers such as a core-sheath fiber, a side-by-side fiber, and a split fiber that have a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be suitably used. Regarding the processing method, a nonwoven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of being bulky and soft. Moreover, the nonwoven fabric which consists of synthetic fibers is used suitably at the point which is easy to give embossing.

As the material for the porous plastic sheet, for example, an olefin resin such as polyethylene or polypropylene is preferably used, but a polyamide resin such as polyester or nylon, EVA, or the like can also be used. The diameter of the apertures 3a, 3a ... of the porous plastic surface sheet 3 is 0.05 to 3.0 mm, preferably 0.1 to 2.0 mm, more preferably 0.5 to 1.5 mm. The number is 100 to 500 / cm ² , preferably about 200 to 400 / cm ² . In order to form the openings 3a, the synthetic resin sheet is softened near the softening temperature and is positioned on the upper surface of the support having a large number of openings, and is sucked from below the support, There are a method of pressurizing air pressure from the upper surface of the sheet, a method of drawing a large number of slits in the synthetic resin sheet material, and then stretching and opening the sheet material, and it can be formed by an appropriate method.

Further, in the case of the porous plastic surface sheet 3, depending on the pore diameter, there is a case where it is difficult to shift from the aperture to the hydrophilic fiber sheet 7 due to its hydrophobicity. Therefore, it is desirable to apply a surfactant with a basis weight of 1.20 g / m ² or more to the back side of the porous plastic sheet 3 so that the body fluid can easily migrate from the apertures 3 a to the hydrophilic fiber sheet 7.

  The said absorber unit 4 consists of the lower layer side absorber 5 which consists of a pulp sheet, and the defibrated pulp laminated | stacked on the approximate center part upper surface side of this lower layer side absorber 5, and forms the middle-high part which protrudes to the surface side. The upper-layer side absorber 6 for this is comprised.

The lower layer side absorbent body 5 is a so-called pulp sheet obtained by processing a pulp fiber mixed with a highly water-absorbent resin into a sheet shape in advance, and has a thickness of 1 to 3 mm, the composition is 10 to ²⁰⁰ g / m ^{2 of} pulp fiber, and has a high water absorption property. Those having a resin of 0 to 100 g / m ² are preferably used.

  Examples of the superabsorbent resin include cross-linked polyacrylate, self-crosslinked polyacrylate, saponified acrylate-vinyl acetate copolymer cross-linked product, cross-linked isobutylene / maleic anhydride copolymer, Examples include cross-linked polysulfonates, and partially cross-linked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. In the production process of the highly water-absorbent resin having the water absorption performance, the water absorption force and the water absorption speed can be adjusted by adjusting the crosslinking density and the crosslinking density gradient. In addition, when the high water-absorbing resin content exceeds 50%, the entanglement between the pulp fibers is lost, the sheet strength is lowered, and tearing, cracking, and the like are likely to occur. The planar shape of the lower layer side absorbent body 5 may be an oval shape as shown in the figure, or may be a fit cut shape (gourd shape) in order to reduce the contact with the crotch portion.

  On the other hand, the upper layer absorbent body 6 is an absorbent layer mainly composed of defibrated pulp obtained by defibrating a pulp original fabric with a drum fiber spreader or the like, and is laminated on the upper surface side of a substantially central portion of the lower absorbent body 5. Thus, the middle and high part absorbent body is formed.

  Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as molten pulp, and artificial cellulose fibers such as rayon and acetate. Softwood pulp having a longer fiber length than hardwood pulp functions and It is preferably used in terms of price. Moreover, although the planar shape of the upper layer side absorbent body 6 is substantially rectangular in the drawing, it may be formed in an oval shape. The upper layer absorbent body 6 has a thickness of 1.5 to 8.0 mm, preferably 2.0 to 4.0 mm. In addition, it is desirable that the upper-layer absorbent body 6 is mixed with a powder of a superabsorbent resin at a predetermined rate, for example, 10 to 60% at the time of fiber stacking.

  The hydrophilic fiber sheet 7 disposed between the liquid-permeable surface sheet 3 and the absorbent body unit 4 is used for transferring body fluid discharged onto the liquid-permeable surface sheet 3. As the hydrophilic fiber sheet 7, a fiber having a hydrophilic property such as regenerated fiber such as rayon or cupra, natural fiber such as cotton, or an olefin-based, polyester-based, or polyamide-based material such as polyethylene or polypropylene is used. It is made to have hydrophilicity by using a surface-treated synthetic fiber such as a hydrophilizing agent and imparting hydrophilicity. One of the causes of the return of the body fluid is that the body fluid is retained in the minute space between the fibers of the hydrophilic fiber sheet 7, and this body fluid moves to the surface sheet 3 side when receiving pressure. Therefore, in order to make the space between fibers of the hydrophilic fiber sheet 7 minute, a fiber layer made of ultrafine fibers of 3.0 d or less, preferably 2.5 d or less is used to prevent the return of body fluid. Is desirable.

  In the present absorbent article 1, the upper layer absorbent body 6 is not surrounded by crepe paper, and the upper layer is in the three-layer state interposed between the hydrophilic fiber sheet 7 and the lower layer absorbent body 5. It is hold | maintained by the heat embossing 8,8 ... given to the outer side adjacent position of the side absorber 6. FIG.

  The heat embossing 8 is preferably applied to the front, rear, left and right parts of the upper layer side absorbent body 6 as shown in the drawing in order to prevent displacement and deformation of the upper layer side absorbent body 6. In the illustrated example, one circular hot emboss 8 is provided for each side, but the embossed shape and pattern are arbitrary. For example, a plurality may be given to each side, or linear heat embossing may be used.

  For example, as the pattern of the heat embossing 8, the modes shown in FIGS. 3A to 3E can be exemplified. FIG. 3A shows an example in which heat embosses 8 and 8 are respectively provided before and after the upper layer absorbent body 6, and FIG. 3B shows an example in which heat embosses 8 and 8 are provided on the left and right sides of the upper layer absorbent body 6. It is. 3 (C), circular heat embosses 8 and 8 are provided on the left and right sides of the upper-layer absorbent body 6 respectively, and linear embosses 9 and 9. FIG. 3 (D) is an example in which linear embossing 10 is provided in an elliptical shape so as to surround the upper layer side absorbent body 6, and FIG. 3 (E) is shown before and after the upper layer side absorbent body 6. In this example, hot embosses 8 and 8 are provided, and linear linear embosses 11 are provided on the side portions along the longitudinal direction. The linear embosses 9 to 11 are also embosses for diffusing bodily fluids along the squeezing grooves in order to suppress side leakage, and control the squeezing area in order to control the excessive diffusion of bodily fluids in the squeezing grooves. You may adjust it.

By the way, the manufacturing procedure for obtaining the sanitary napkin 1 is roughly as shown in FIG. 4 (step 1). First, in the first step or another step of the manufacturing line, The upper layer side absorbent body 6 is interposed between the hydrophilic fiber sheet 7 and the upper layer side absorbent body 6 includes an absorbent body held by heat embossing 8, 8. After obtaining the laminate 12, as shown in FIG. 4 (step 2), the back sheet 2 is laminated on the lower surface side of the laminate 12, and then as shown in FIG. 4 (step 3), According to the procedure of laminating the liquid-permeable surface sheet 3 on the upper surface side. The procedure of FIG. 4 (step 2) and FIG. 4 (step 3) may be reversed. In addition, the procedure may include a procedure of disposing side nonwoven fabrics on both sides of the surface side, a procedure of forming a three-dimensional gather, a procedure of disposing an elastic elastic material, and the like. In short, the laminated body 12 may be manufactured before it is assembled with the back sheet 2 and the top sheet 3. In the laminated body 12 including the absorbent body, the heat embossing applied to hold the upper-layer absorbent body 6 is concealed by the liquid-permeable surface sheet 3. However, it is not exposed to the outside and the appearance is improved.

  As a specific example of the manufacturing process of the laminate 12, as shown in FIG. 5, for example, a pulp sheet to be the lower layer absorbent body 5 is fed out from the pulp sheet original fabric, and the upper layer in the drum stacker 14 in the conveying process. The defibrated pulp to be the side absorbent body 6 is piled on the lower absorbent body 5. Then, if the hydrophilic fiber sheet 7 is laminated on the upper layer side absorbent bodies 6, 6..., The heat embossing 8, By giving 8 ..., the laminated body 12 including the absorber is obtained. After this laminated body 12 is cut into a predetermined shape, it is sent to the lamination process of the back sheet 2 and the lamination process of the top sheet 3. In addition, in the said manufacturing process, although the lower layer side absorber 5 which consists of a pulp sheet is first drawn out and the upper layer side absorber 6 which consists of a defibrated pulp is piled up on this, the hydrophilic fiber sheet 7 is drawn out and on this The upper layer absorbent body 6 made of defibrated pulp may be stacked, and then a pulp sheet to be the lower layer absorbent body 5 may be laminated.

[Other examples]
(1) Although the embossing from the upper surface side of the liquid-permeable surface sheet 3 is not described in the above embodiment, this surface embossing can be arbitrarily formed.
(2) In the above-described embodiment, a ready-made pulp sheet available from a manufacturer is used as the absorbent sheet. However, any sheet having an absorbent property may be used.
(3) In the above embodiment, a hydrophilic non-woven fabric called a so-called second sheet is used as the hydrophilic fiber sheet 7. However, any hydrophilic sheet that can be heat-sealed may be used.
(4) In the above embodiment, the upper-layer absorbent body 6 is held by the heat embossing 8, 8,... The heat embossing 8, 8,... May be applied to the inner peripheral portion of the outer edge of the upper layer absorbent body 6.
(5) In the above-described embodiment, the upper-layer absorbent body 6 is held by the heat embossing 8, 8,... Instead of the heat embossing 8, the upper layer absorbent body 6 may be held by entanglement of fibers with a needle punch. In this case, an absorptive sheet that is not thermally fused can also be used.

It is a partially broken top view of the absorbent article 1 which concerns on this invention. It is the II-II arrow directional view. (A)-(E) are the formation pattern figures of a heat embossing, respectively. It is a manufacturing procedure figure of this absorbent article 1. FIG. 4 is a manufacturing process example diagram for obtaining a laminated body 12. It is a partially broken perspective view of the conventional absorbent article 50. It is a figure which shows the example of the surrounding of the bulky absorber by a crepe paper.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Absorbent article, 2 ... Liquid-impermeable back sheet, 3 ... Liquid-permeable surface sheet, 4 ... Absorber unit, 5 ... Lower layer side absorber (pulp sheet), 6 ... Upper layer side absorber (defibrated pulp) 7 ... Hydrophilic fiber sheet, 8 ... Hot emboss

Claims (1)

A liquid-permeable topsheet, with the absorber is interposed between the back sheet, between the liquid-pervious topsheet and the absorbent body, the hydrophilic fiber sheet comprising hydrophilic nonwoven fabric is disposed Rutotomoni, The absorbent body is laminated on a lower layer side absorbent body made of a pulp sheet in which pulp fibers mixed with a superabsorbent resin are previously processed into a sheet shape, and on the upper surface side of a substantially central portion of the lower layer side absorbent body, and crepe paper A manufacturing method for obtaining an absorbent article composed of an upper absorbent body mainly composed of defibrated pulp, which is not surrounded by
In the first step of the production line or in another step, one of the lower layer side absorbent body and the hydrophilic fiber sheet made of the pulp sheet is fed to the production line, and the defibrated pulp to be the upper layer side absorbent body is loaded on this sheet. After fibering, if the upper layer side absorbent body is covered with the other one of the lower layer side absorbent body and the hydrophilic fiber sheet made of the pulp sheet, a needle punch is applied to the peripheral portion of the upper layer side absorbent body. After the step of obtaining the laminated body holding the upper layer side absorbent body, a step of laminating a back sheet on the lower surface side of the laminated body, and a step of laminating a liquid-permeable surface sheet on the upper surface side of the laminated body, The manufacturing method of the absorbent article characterized by including this.

Images