WO2006134906A1

WO2006134906A1 - Absorbent article

Info

Publication number: WO2006134906A1
Application number: PCT/JP2006/311818
Authority: WO
Inventors: Takuo Nomura; Satoko Konawa
Original assignee: Daio Paper Corporation
Priority date: 2005-06-14
Filing date: 2006-06-13
Publication date: 2006-12-21

Abstract

[PROBLEMS] An absorbent article which has an absorbent comprising an upper-layer absorbent and a lower-layer absorbent underlying the upper-layer absorbent and which has improved liquid permeability through the upper-layer absorbent into the lower-layer absorbent while maintaining a rate of absorption in the upper-layer absorbent and hence has an excellent balance between the two properties. [MEANS FOR SOLVING PROBLEMS] The upper-layer absorbent (4A) comprises at least pulp fibers and synthetic fibers, the proportion of the pulp fibers to the synthetic fibers being (80-20):(20-80) by weight. The upper-layer absorbent (4A) has been superposed on the lower-layer absorbent (4B) without using any adhesive. That part of the upper-layer absorbent (4A) which extends from the upper side and/or periphery of the absorbent (4A) toward the lower-layer absorbent (4B) is embossed.

Description

Specification

Absorbent articles

Technical field

[0001] The present invention relates to an absorbent article such as a sanitary napkin, a panty liner, an incontinence pad, etc. for absorbing menstrual blood, cages, etc., and more specifically, the absorbent is composed of an upper layer absorbent and a lower layer absorbent. The present invention relates to an absorbent article having a laminated structure. Background art

[0002] Conventionally, as absorbent articles such as panty liners, sanitary napkins, and incontinence pads, liquid-impervious back sheets such as polyethylene sheets or polyethylene sheet-laminated nonwoven fabrics, and nonwoven fabrics or liquid-permeable plastic sheets such as It is known that an absorbent body made of cotton-like pulp or the like is interposed between the liquid-permeable surface sheet.

[0003] 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 bodily fluid leakage prevention means, a middle-high part thickened on the surface side is formed in a substantially central region of the absorber to improve the fit to the blood drainage part, and the shape of the middle-high part is formed. Absorbent articles are known in which a linear embossing is applied to the outer peripheral position of the middle-high portion for holding (see Patent Documents 1 to 3 below).

[0004] When each absorbent article described above uses defibrated pulp obtained by crushing pulp as an absorbent, pulp piled up on the line may fall off, or pulp fibers It is surrounded by crepe paper immediately after stacking so as not to adversely affect the equipment due to transfer or the like. In this case, in the case of the defibrated pulp absorber having the middle and high parts, as shown in FIG. 16 (A), the defibrated pulp layer 54 constituting the general part absorber and the defibrated pulp constituting the middle and high part absorber. After the layer 55 is surrounded by the crepe paper 56 as shown in FIG. 16 (B), the defibrated panolep layer 54 constituting the general absorbent is surrounded by the crepe paper 56, and then the crepe paper 56 is also used. There is a mode in which the defibrated panolep layer 55 constituting the middle and high part absorbent body surrounded by 56 is stacked thereon.

Patent Document 1: Japanese Patent Laid-Open No. 10-328233 Patent Document 2: JP-A-11 358

Patent Document 3: Japanese Patent Laid-Open No. 11 33054

Patent Document 4: Japanese Patent Publication No. 9 505218

Disclosure of the invention

Problems to be solved by the invention

[0005] As described above, in the case of an absorber in which a middle-high part absorber (upper layer absorber) is laminated on the upper surface of a general part absorber (lower layer absorber), body fluid such as menstrual blood is discharged to the upper layer absorber. It penetrates into the upper layer absorber, part of which is absorbed and retained by the upper layer absorber, and most of the remainder passes through the upper layer absorber and reaches the lower layer absorber to be absorbed and retained by the lower layer absorber. Desirably, in reality, most of the body fluid was absorbed and held in the upper absorbent body, becoming saturated in the upper absorbent body, or causing pressure to easily reverse.

[0006] On the other hand, the upper-layer absorber and the lower-layer absorber are bonded to each other by embossing the peripheral portion of the upper-layer absorber to prevent positional misalignment, and by bonding the upper-layer absorber and the lower-layer absorber with an adhesive. However, there is a problem that the liquid permeability is hindered by the adhesive and the amount of body fluid passing to the lower layer absorber is reduced.

[0007] Further, according to the knowledge of the present inventors, the diffusion rate is relatively low in the crepe paper, such as crepe paper: 0.25 cm ³ / sec, pulp + polymer: 0.38 cm ³ / sec. It is summer. As described above, when the upper layer absorber is surrounded by crepe paper and the lower layer absorber is surrounded by crepe paper, multiple layers of crepe paper are interposed between the upper layer absorber and the lower layer absorber. As a result, the body fluid remains absorbed and retained on the multilayer crepe paper, which causes a decrease in the transfer of body fluid to the lower layer absorber.

[0008] Therefore, a main problem of the present invention is to improve liquid permeability from the upper layer absorber to the lower layer absorber in an absorbent article including an absorber in which an upper layer absorber and a lower layer absorber are laminated. At the same time, it is an object of the present invention to provide an absorbent article that maintains the absorption rate in the upper absorbent body and is excellent in mutual balance.

Means for solving the problem

[0009] In the present invention according to claim 1 for solving the above-mentioned problem, an absorbent body is interposed between a liquid-permeable top sheet and a back sheet, and the absorbent body includes an upper-layer absorbent body and a lower-layer absorbent body. In an absorbent article having a laminated structure with the body,

The upper absorbent body includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers: synthetic fibers is 80 to 20:20 to 80 in terms of weight,

The upper-layer absorber and the lower-layer absorber are laminated without using an adhesive, and embossing is given from the upper surface and Z or the outer periphery of the upper-layer absorber toward the lower-layer absorber. An absorbent article is provided.

[0010] In the present invention according to Claim 1, the upper absorbent body includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers to the synthetic fibers is 80 to 20:20 to 80 in terms of weight. It is what. The larger the synthetic fiber mixing ratio, the higher the body fluid permeability from the upper absorbent to the lower absorbent, but the synthetic fibers have no water absorption or are water absorbent even if they have been subjected to hydrophilic treatment. Is low, the body fluid absorption rate is reduced. However, by setting the mixing ratio of the synthetic fiber to 20 to 80% by weight, it is possible to sufficiently secure the liquid permeability of the upper-layer absorbent body and to keep the absorption rate higher than required.

[0011] Further, the upper-layer absorber and the lower-layer absorber are laminated without using an adhesive, and are embossed from the upper surface and / or the outer periphery of the upper-layer absorber toward the lower-layer absorber. Therefore, the adhesive does not hinder the liquid permeability from the upper layer absorber to the lower layer absorber, and the liquid permeability of the upper layer absorber can be sufficiently ensured.

[0012] As the present invention according to claim 2, there is provided the absorbent article according to claim 1, wherein the body fluid permeability of the upper absorbent body is 85% or more.

[0013] Specifically, the liquid permeability in the upper-layer absorber is desirably 85% or more. As defined in the invention of claim 1, the liquid permeability is such that the mixing ratio of the synthetic fibers in the upper absorbent body is 20% by weight or more based on the total amount of pulp fibers and synthetic pulp, The lower layer absorber can be achieved by laminating without using an adhesive.

[0014] In the present invention according to claim 3, the absorption speed of the seventh time when 3.5 cc of artificial menstrual blood is absorbed seven times every 8.5 minutes on the surface of the liquid-permeable top sheet is 25 seconds. Claims 1 and 2 An absorbent article according to any of the above is provided.

[0015] It is desirable that the absorption rate of the seventh time when absorbing 5 cc of artificial menstrual blood 7 times every 8.5 minutes is 25 seconds or less on the liquid-permeable top sheet surface. This absorption rate is achieved by setting the mixing ratio of the synthetic fibers of the upper-layer absorbent body to 80% by weight or less based on the total amount of pulp fibers and synthetic pulp as defined in the invention of claim 1. Can do.

[0016] In the present invention according to claim 4, the upper layer absorber and the lower layer absorber are surrounded by crepe paper, and at least at the lower surface of the upper layer absorber and Z or the upper surface of the lower layer absorber, an opening is formed in the crepe paper. An absorbent article according to any one of claims 1 to 3 is provided.

[0017] The invention according to claim 4 defines the surrounding form of the absorbent body by crepe paper. The smaller the crepe paper existing at the interface between the upper layer absorber and the lower layer absorber, the better the liquid permeability. However, it is also necessary to surround the absorbent body with crepe paper so that the pulp piled up on the line does not fall off or adversely affect the equipment due to transfer of pulp fibers. By forming the openings in the paper, the number of layers of the crepe paper can be reduced, or by omitting the crepe paper, the obstruction factor of the liquid permeability can be reduced or eliminated.

[0018] As the present invention according to claim 5, in a state where the upper layer absorber and the lower layer absorber are laminated, the upper layer absorber and the lower layer absorber are surrounded by crepe paper. An absorbent article as described in 1 above is provided.

[0019] The invention according to claim 5 prescribes the form of the absorbent body made of crepe paper. The smaller the crepe paper existing at the interface between the upper layer absorber and the lower layer absorber, the better the liquid permeability. However, it is also necessary to surround the absorber with crepe paper so that the pulp piled up on the line does not fall off or adversely affect the equipment due to transfer of pulp fibers. In a state where the upper layer absorber and the lower layer absorber are laminated, the upper layer absorber and the lower layer absorber are surrounded by crepe paper, and the upper layer absorber and the lower layer absorber are brought into direct contact with each other. It can be lost.

The invention's effect

[0020] As described above in detail, according to the present invention, an absorption structure in which an upper layer absorber and a lower layer absorber are laminated. The absorbent article provided with a body improves the permeability of the body fluid from the upper absorbent body to the lower absorbent body, and at the same time maintains the absorption rate in the upper absorbent body and is excellent in mutual balance. Become.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Basic structure of sanitary napkin 1]

1 is a development view of the sanitary napkin 1 according to the first embodiment of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. 3 is a view taken along the line III-III in FIG.

[0022] The sanitary napkin 1 includes a liquid-impervious back sheet 2 made of a polyethylene sheet, a liquid-permeable top sheet 3 that allows permeation of menstrual blood, cages, and the like, and a space between these two sheets 2, 3. Absorbent bodies 4 and 6 made of cotton-like pulp or synthetic pulp interposed between the absorbent body 4 and crepe paper 5 surrounding the absorbent body 4 in order to maintain the shape and improve the diffusibility of the absorbent body 4, and the absorbent body Mainly from a pair of left and right three-dimensional gathers BS, BS provided with a substantially side edge of the body 4 as a standing base end and protruding at the surface side in a predetermined section in the front-rear direction so as to include at least a body fluid discharge part The outer periphery of the liquid-impervious backsheet 2 and the liquid-permeable topsheet 3 is formed of an adhesive such as hot melt, heat seal, etc. Joined by adhesive means In addition, the liquid-impervious backsheet 2 extending to the side of the absorbent body 4 at both side edges and the side nonwoven fabric 7 forming the three-dimensional gather BS are bonded to each other by hot melt or the like. Wing-like flaps W and W that protrude sideways are formed by the laminated sheet part of these liquid-impervious backsheet 2 and side nonwoven fabric 7 and bonded together by an adhesive or heat seal. The second wing-shaped flaps W and W are formed in the part located on the heel side.

B B

It is made.

[0023] Hereinafter, the structure of the sanitary napkin 1 will be further described in detail.

The liquid-impervious backsheet 2 has a tendency to use a sheet material having at least water-impervious properties such as polyethylene. As this water-insulating and moisture-permeable sheet material, a sheet is formed by melting and kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, and then uniaxial or biaxial. A microporous sheet obtained by stretching in the direction is preferably used. One or more adhesive layers (not shown) are formed on the non-use side (outer surface) of the liquid-impermeable back sheet 2 so that the sanitary napkin 1 is fixed to the underwear when worn on the body. It has become. As the liquid-impervious back sheet 2, a polypropylene nonwoven fabric in which a plastic film and a nonwoven fabric are laminated may be used.

[0024] Next, the liquid-permeable top sheet 3 is preferably a porous or non-porous nonwoven fabric, a porous plastic sheet, or the like. The material fibers that make up the nonwoven fabric can be synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a succe method, a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Of these processing methods, the spunlace method is excellent in terms of flexibility and drape, and the thermal bond method is excellent in terms of being bulky and soft. When a large number of through holes are formed in the liquid permeable top sheet 3, menstrual blood, urine, etc. (hereinafter collectively referred to as body fluid) are quickly absorbed, and the dry touch property is excellent. It will be a thing.

[0025] The absorber 4 has a structure in which an upper layer absorber 4A and a lower layer absorber 4B are laminated. The lower layer absorber 4B has a planar shape that defines the outer edge of the absorber arrangement region, and the upper layer absorber 4A is used in a region that is elongated in the longitudinal direction of the napkin at the center in the width direction. It is arranged to form a middle-high part 6 of a high absorber. The thickness of the middle-high portion 6 is preferably 3 to 20 mm, preferably 5 to 15 mm, because if the thickness is too large, the rigidity of the absorbent body 4 increases and the adhesion to the body decreases. Embosses 8 that are closed in the circumferential direction are provided along the peripheral edge of the upper layer absorbent body 4A, and embosses 9, 10, and 11 are formed respectively. The emboss 8 is an emboss provided to prevent the upper-layer absorber 4A from being displaced and to precisely define the middle and high portions 6. The embosses 8 to 11 will be described in detail later.

[0026] The upper layer absorbent body 4A includes at least pulp fibers and synthetic fibers, and the ratio of the pulp fibers to the synthetic fibers is 80 to 20:20 to 80, preferably 40 to 60: 6 in terms of weight. It shall be mixed in 0-40. According to the examples described later, the upper layer absorbent body 4A synthetic fiber The liquid permeability from the upper absorbent body 4A to the lower absorbent body 4B can be increased to 85% or more by making the mixing ratio of 20% by weight or more based on the total amount of pulp fiber and synthetic pulp, and the upper layer Absorbent 4A synthetic fiber mixing ratio of not more than 80% by weight with respect to the total amount of pulp fiber and synthetic pulp. Suppressing the absorption rate of the 7th time when absorbed 7 times is 25 seconds or less. When the mixing ratio of the synthetic fibers of the upper absorbent body 4A is 40 to 60% by weight with respect to the total amount of pulp fibers and synthetic pulp, the liquid permeability from the upper absorbent body 4A to the lower absorbent body 4B is 88. /. As described above, the absorption rate can be 24 seconds or less.

[0027] The upper layer absorbent body 4A functionally expedites body fluid, but has a first function of permeating the absorbed body fluid into the lower layer absorbent body 4B side without holding it inside, and the upper surface of the liquid-permeable top sheet 3 It is necessary to satisfy both the second function that quickly absorbs body fluids discharged in a well-balanced manner. However, if synthetic fibers are mixed too much in order to improve the permeability of the first function, the synthetic fibers absorb water. Even if it has no water content or has been subjected to a hydrophilic treatment, the water absorption rate is low, so the absorption rate of body fluids will be reduced. To prevent leakage after wearing a napkin for 1 hour, it is desirable that the upper layer absorber 4A has a liquid permeability of 85% or more and an absorption rate of 25 seconds or less. By setting the mixing ratio of the fiber and the pulp fiber to the above value, the first function and the second function can be achieved in a balanced manner. Further, by mixing synthetic fibers with the upper absorbent body 4A, the bulk can be maintained and the cushioning property can be maintained without being deflated even when the body fluid is absorbed.

[0028] As the synthetic fiber, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used. It may be a mixture of these two types. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be used. In the case of a hydrophobic fiber, it is desirable to use a synthetic fiber that has been surface-treated with a hydrophilizing agent so as to have an affinity for body fluids.

[0029] The upper-layer absorbent body 4A can contain a superabsorbent resin. Examples of the superabsorbent resin include polyacrylate cross-linked products, self-crosslinked polyacrylates, and attalinole. Acid ester A saponified product of a cross-linked butyl acetate copolymer, a cross-linked product of isobutylene 'maleic anhydride copolymer, a cross-linked polysulfonate salt, and a water-swellable polymer such as polyethylene oxide or polyacrylamide Etc. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. The water-absorbing resin having the water-absorbing performance can be adjusted in water-absorbing force and water-absorbing speed by adjusting the crosslinking density and the crosslinking density gradient in the production process. The blending amount needs to promote penetration of the upper absorbent body 4A into the lower absorbent body 4B side, and so-called gel blocking phenomenon occurs when the blending amount is increased. Therefore, the weight of the total weight of pulp fiber and synthetic fiber is 1 ~: It is desirable to blend at a ratio of 10%. The superabsorbent resin content is 50

If it exceeds%, the entanglement between the pulp fibers will be lost, and the sheet strength will decrease, and tearing and cracking will easily occur.

[0030] Examples of the pulp fiber include cellulose fibers such as chemical pulp and molten pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Softwood pulp having a fiber length longer than that of hardwood pulp is used. Is better used in terms of function and price.

[0031] On the other hand, the lower layer absorbent body 4B is not required to contain synthetic fibers, and can be made of pulp fibers alone or a mixture of pulp fibers and a superabsorbent resin. The lower absorbent body 4 B does not place importance on permeability, and it is desirable to retain the body fluid that has permeated from the upper absorbent body 4A so that it does not ooze out to the outside. It is rather preferable to do so. The content of the superabsorbent resin is desirably 1 to 20% by weight based on the total weight of the fibers constituting the lower layer absorbent body 4B in order to absorb the body fluid and retain water.

[0032] The upper-layer absorber 4A and the lower-layer absorber 4B are surrounded by the crepe paper 5. Each of the absorbers 4A and 4B is surrounded by the crepe paper 5 and the upper-layer absorption surrounded by the crepe paper 5. When laminating the body 4A and the lower layer absorber 4B, as shown in the schematic diagram of FIG. 4 (A) without using an adhesive for bonding them, the positional shift of the upper layer absorber 4A is the upper layer. The embossing 8 provided around the absorbent body 4A is preferable.

[0033] The upper absorbent body 4A surrounded by the crepe paper 5 and the crepe paper 5 When laminating the lower layer absorbent 4B, the crepe paper 5 is layered on the boundary surface between the upper layer absorbent 4A and the lower layer absorber 4B, and this crepe paper 5 inhibits liquid permeability. To do. However, it is also necessary to surround the absorbent bodies 4A and 4B with crepe paper 5 so that the pulp piled on the line does not fall off or adversely affect the equipment due to transfer of pulp fibers, etc. Therefore, it is desirable to form an opening in the crepe paper 5 on the lower surface of the upper absorbent body 4A and the upper surface of Z or the lower absorbent body 4B. Fig. 4 (B) is an example in which an opening is formed in the crepe paper 5 on the upper surface of the lower layer absorber 4B, and Fig. 4 (C) is an example in which an opening is formed in the crepe paper 5 on the lower surface of the upper layer absorber 4A. FIG. 4D shows an example in which openings are formed in the crepe paper 5 on the upper surface of the lower layer absorber 4B and the lower surface of the upper layer absorber 4A. Further, the emboss 8 for preventing displacement of the upper absorber 4A is not limited to the outer periphery of the upper absorber 4A, and the emboss 8 is applied from the upper surface of the upper absorber 4A toward the lower absorber 4B. Anyway. In this case, the embossing 8 should be performed under high pressure so that the dents in the lower layer absorber 4B are eaten.

[0034] Further, in order to eliminate the inhibition of the liquid permeability by the crepe paper 5, as shown in FIG. 5 (A), these upper layer absorbent body 4A and lower layer absorbent body 4B are laminated in the state described above. The upper absorber 4A and the lower absorber 4B may be surrounded by crepe paper 5. FIG. 5 (B) shows an example in which the emboss 8 is further provided from the outer periphery and the center of the upper absorbent body 4A.

On the other hand, the width dimension of the liquid-permeable top sheet 3 is slightly longer than the width of the absorbent body 4 as shown in the cross-sectional views of FIGS. 2 and 3 in the illustrated example. The three-dimensional gather BS prevents the penetration of the menstrual blood or the like or specifically enhances the feeling of touch. Depending on the purpose, etc., it is configured using a non-woven fabric material subjected to appropriate water repellent treatment or hydrophilic treatment. The side nonwoven fabric 7 can be made of natural fiber, synthetic fiber, or recycled fiber, and formed by an appropriate processing method. In order to prevent this, it is preferable to use a non-woven fabric with reduced basis weight and air permeability. Specifically, it is desirable to use a non-woven fabric prepared with a basis weight of 18-23 g / m ² and in order to reliably prevent permeation of body fluids A water repellent nonwoven fabric coated with a laffin or alkyl chloride water repellent is preferably used.

[0036] As shown in Fig. 2 and Fig. 3, the side nonwoven fabric 7 has a liquid-impermeable back sheet 2 slightly outside the widthwise intermediate portion and slightly beyond the absorber side edge from the inner position of the absorber 4. Adhering with an adhesive such as hot melt over a range up to the outer edge, the laminated sheet portion of the side nonwoven fabric 7 and the liquid-impervious backsheet 2 absorbs approximately the body fluid discharge portion. A pair of left and right wing flaps W, W are formed at the body side position, and second wing-shaped flaps W, W are formed at the buttock side position. These wing-shaped flats

B B

Adhesive layer 12 on the outer surface of W and W and the second wing-shaped flaps W and W respectively.

B B

..., 13 ..., as shown in Fig. 14, when attached to the shorts 30, the wing-shaped flaps W and W are folded back to the opposite side at the folding line RL, and wrapped around the crotch part of the shorts and stopped. I'm wearing it.

[0037] On the other hand, the inner side portion of the side nonwoven fabric 7 is folded almost double, and a thread-like shape in which both ends or appropriate positions in the longitudinal direction are fixed to the middle portion in the height direction inside the double sheet. The elastic elastic member 19 is disposed, and a plurality of, in the illustrated example, the two elastic elastic members 20 and 20 in the illustrated example are fixed at both ends or at appropriate positions in the longitudinal direction. It has been arranged in the state. As shown in FIG. 3, the double sheet portion is folded and laminated in a Z-shaped cross section at the front and rear end portions, and bonded to the absorbent body 4 side, whereby the thread elastic elastic member 19 is disposed. As the bending points, three-dimensional gathers BS and BS standing on the surface side are formed while forming pockets P and P with openings facing inward in the shape of a cross-section.

[Method for producing upper-layer absorber 4A]

The upper layer absorbent body 4A is an absorbent body in which pulp fibers and synthetic fibers are mixed at a predetermined ratio as described above, and the following apparatus is preferably used to manufacture the upper layer absorbent body 4A. The

[0039] First, the upper-layer absorber 4A is manufactured by, for example, the manufacturing apparatus 30 shown in FIG. The absorber manufacturing apparatus 30 includes a first defibrating machine 31 for defibrating the bale-like synthetic fibers 15, 15, and a first feeding path 32 for feeding the defibrated synthetic fibers 32. And in between From the feeding fan 33, the synthetic fiber fed through the first feeding path 32, and the quantitative feeder 34 for temporarily storing the synthetic fiber, and the quantitative feeder 34. The second feeding path 35 for feeding the fibers and the feeding fan 36 provided in the middle thereof, the feeding amount adjusting damper 37, and the supplied pulp fiber sheet 14 are defibrated, and the second A second defibrator 38 in which the synthetic fibers fed through the feed path 35 are mixed, and a supply casing 39 for transporting the mixed fibers composed of pulp fibers and synthetic fibers in an air stream 39 And a stacking machine 40 for stacking the mixed fibers sent via the supply casing 39, and a transfer drum 41 provided facing the stacking machine 40.

[0040] The fiber stacking device 40 has absorbent molding recesses 42a, 42a, ... at appropriate intervals on the outer peripheral surface, and a plurality of suction holes (not shown) on the bottom surface of the absorbent molding recess 42a. And a suction chamber 43 disposed on the inner side of the spinning drum 42. The suction chamber 43 is maintained at a negative pressure by suction means (not shown). By holding, the absorbent constituent fibers conveyed in the air into the absorbent body forming recess 42a are stacked. The supply casing 39 is provided with a polymer inlet 44 for supplying the superabsorbent polymer powder together with the pulverized pulp.

[0041] The absorber 4A transferred to the transfer drum 41 is transferred to the upper surface of the crepe paper 5 conveyed on the vacuum conveyor by suction by the vacuum device 45, and is conveyed on the conveyor.

[0042] In order to manufacture the upper absorbent body 4A by the powerful absorber manufacturing apparatus 30, the synthetic fiber formed into a bale (compressed package) is defibrated by the first defibrator 31 and defibrated. Fiber is sent to the quantitative feeder 34 and temporarily stored. The synthetic fiber stored in the quantitative feeder 34 is cut out by a predetermined amount by the feeder drum 34a and sent to the second defibrator 38 via the second feeding path 35. The feeding amount of the synthetic fiber is further adjusted by adjusting the opening degree of the feeding amount adjusting damper 37.

[0043] In the second defibrator 38, a pulp fiber coil 14 (not shown) that has been wound in advance in a coil shape is fed at a predetermined speed, and is pulverized by a grinding drum 38a. And is mixed with the synthetic fiber sent through the second feeding path 35. The

[0044] The mixed fiber made of pulp fiber and synthetic fiber passes through the supply casing 39 and is sent to the stacking machine 40, where it is stacked by the stacking rotary drum 42 and formed into a mat shape.

[0045] In the absorbent body manufacturing apparatus 30, the defibrated synthetic fiber is once stored in the quantitative feeder 34, cut out and fed in a fixed amount, and the feed amount provided in the second feed path 35 By adjusting the opening of the damper 37 for adjustment, it is possible to accurately adjust the synthetic fiber to the desired feed rate, and the pulp fiber and synthetic fiber can be accurately mixed at the designed mixing ratio. It becomes possible to manufacture efficiently.

[0046] By the way, the pulp fiber and the synthetic fiber are separated in the vicinity of the conveying path of the supply casing 39 from the second defibrator 38 to the stacker 40 and the rotary drum 42 for stacking of the stacker 40. Due to the difference in mass, pulp fibers with a relatively large mass ride on the airflow and efficiently reach the spinning drum 42 for stacking, but the synthetic fibers with relatively small mass partly deviate from the airflow. In addition to being directed toward the annular casing 39a that covers the spinning drum 42 for stacking fibers, in some cases, it was deposited on the wall surface of the annular casing 39a over time. For this reason, the mixing ratio of the pulp fiber and the synthetic fiber is a cause of fluctuation.

[0047] As a first method for solving the above problem, as shown in FIG. 7, in the conveyance path of the supply casing 39 from the second defibrator 38 to the stacker 40, the casing width (planar width) ) Is reduced to 100-300% with respect to the pile width (the width of the recess 42a for forming the absorber). Generally, the casing width (casing plane width) is approximately 400% of the pile width (absorber forming recess 42a width), but the casing width is approximately 42% (absorber forming recess 42a). The airflow speed is increased by reducing the width to 100 to 300%, preferably 100 to 200%, and the fiber is guided to the spinning drum 42 before the separation of pulp fibers and synthetic fibers. Can be made fine.

[0048] As the second method, as shown in Fig. 8, the bottom side wall surface of the supply casing 39 is located in the vicinity of the stacking machine 40, in the direction toward the annular casing 39a covering the spinning drum 42 for stacking, that is, The stacking fiber rotating drum 42 is bent in the conveying direction so that pulp fibers and synthetic fibers are stacked on the rotating fiber drum 42 by a force in an inclined direction. In this case, the pulp fibers riding on the air current are carried along with the synthetic fibers in the vicinity of the rotary drum 42 for stacking fibers. By changing the feeding direction, separation of the pulp fiber and the synthetic fiber is prevented, and the fiber is guided to the rotary drum 42 for stacking to be stacked.

[0049] As a third method, as shown in Fig. 6, the force in which the second defibrator 38 is provided with an air introduction damper 38b is fully closed, and the casing It is possible to prevent the separation of the synthetic fiber by increasing the flow rate of the synthetic fiber in the quantitative feeder 34 and later by increasing the opening of the feed amount adjusting damper 37 by the corresponding amount and increasing the negative pressure in 39. it can.

[0050] [Embossed structure]

As shown in detail in FIG. 9, the sanitary napkin 1 has a middle part 6 of a high absorbent body on the use surface side at the center in the width direction, and surrounds the middle part 6 so as to surround the middle part 6. An elongated emboss 8 is formed in the longitudinal direction of 1. This emboss 8 is composed of front end embossed 8a, reduced shape embossed 8b, first bulge shaped embossed 8c, intermediate arc shaped embossed 8d, second bulged shaped embossed 8e, and rear side embossed 8f in order of front side force. It has been. Each of these embosses is formed continuously without being divided, and is closed in the circumferential direction as a whole.

[0051] The front end emboss 8a is an emboss formed in a substantially semicircular arc shape, and a pair of left and right embosses formed on both sides of the middle and high portions 6 along the substantially longitudinal direction are arranged at the front end of the napkin. Embossing combined with curved lines.

[0052] The reduced shape embossed 8b is a pair of left and right embossed lines formed so as to extend in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the front end embossed 8a. The embossed lines on both sides are formed by curves having a curvature center on the outer side of the napkin 1 so as to form a reduced region with an embossed separation width as shown in the figure, located on the front side of the thigh. .

[0053] The first bulge-shaped emboss 8c is a pair of left and right emboss lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the reduced-shape emboss 8b. The emboss lines on both sides are each formed by a curve having a center of curvature on the center side of the napkin 1 so as to form an enlarged region of the embossing separation width and located on the rear side of the thigh. Yes. [0054] The intermediate arc-shaped emboss 8d is a pair of left and right emboss lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the first bulge-shaped emboss 8c. In detail, as shown in Fig. 10, the embossed lines on both sides are extremely short with a curve having the center of curvature on the outer side of the napkin 1, with the inflection point where the center of curvature is reversed as the boundary. It is formed by sections.

[0055] The second bulge-shaped embossing 8e is a pair of left and right embossing lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the intermediate arc-shaped embossing 8d. In detail, as shown in FIG. 10, the embossed lines on both sides are formed by curves having the center of curvature on the center side of the napkin 1, with the inflection point where the position of the center of curvature is reversed as the boundary. Yes. The second bulge-shaped emboss 8e is formed with a relatively short section width as compared with the first bulge-shaped emboss 8c.

[0056] The rear-side embossed 8f is a pair of left and right emboss lines formed so as to extend substantially in the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6 continuously to the second bulge-shaped embossed 8e. In the example shown in the figure, the emboss is spaced little by little so that it gradually extends to the rear side, and the embosses on both sides are joined by arcuate curved embosses on the rear side. This rear embossing 8f has a third bulge-shaped embossing in a middle position closer to the rear side of the rear embossing 8f by a curve in which each embossing has a center of curvature on the center side of the napkin 1 so as to form an enlarged emboss separation width. 8g is formed.

[0057] On the outside of the rear side embossing 8f, second rear side embossing 10, 10 extending in the longitudinal direction of the napkin 1 with a space between the rear side embossing 8f is formed. In the illustrated example, each of the second rear embosses 10 is an arcuate curve having a center of curvature on the outside of the napkin 1.

[0058] In addition, a substantially umbrella-shaped front end independent emboss 9 is formed on the front side of the front end emboss 8a, and a space is provided on the rear side of the rear emboss 8f. A rear-end independent emboss 11 having a substantially inverted umbrella shape is formed.

[0059] According to the various embossments 8 to 11 formed as described above, the following effects can be obtained.

[0060] First, in the formation region of the first bulge-shaped emboss 8c, the intermediate arc-shaped emboss 8d, and the second bulge-shaped emboss 8e, as shown in detail in FIG. The embossed embosses 8c and 8e are formed by the embossed lines that bulge outward and the napkin width direction is a flexible shaft (folded line). Since the intermediate arc-shaped emboss 8d is an area where the emboss curve is reversed, the distortion-suppressing force of each bulge-shaped emboss 8c and 8e is released, so the line X-X in the napkin width direction can be relatively allowed. Bending force as a flexible shaft S

1 1

It is.

On the other hand, when the napkin 1 is attached to the shorts 30 as shown in FIG. 14, in the region of the reduced shape emboss 8b and the first bulge shape emboss 8c, the inward direction from the thigh The compressive force compresses the absorbent body 4 in the width direction, and at the same time, the force is transmitted by the emboss 8 formed along the longitudinal direction of the napkin, and the front side and the rear side On the sides, the acting forces Fl and F2 are applied inward. Further, when the crotch portion of the shorts 30 is pulled up to the body side, the napkin 1 receives a pressing force that presses against the crotch portion along the longitudinal center line Y—Y.

[0062] By receiving the acting force as described above, in the Z region, a first raised portion R is formed at the first bulge-shaped embossed 8c portion corresponding to the blood outlet, and this raised portion R

1 1 can absorb menstrual blood and the like by adhering to the vicinity of the blood drainage. Further, the second bulge-shaped embossed 8e portion corresponding to the perineum from the vaginal opening to the vicinity of the anus on the rear side is connected to the second via an intermediate arc-shaped embossed 8d on which an XX flexible shaft is formed. Ridge of R

1 1 2 formed, this bulge R can not be absorbed near the blood drainage due to close contact with the perineum

2

Thus, it is possible to reliably absorb the menstrual blood, etc., and to prevent leakage of the body fluid to the rear side.

That is, as shown in FIG. 10 (B), the intermediate arc-shaped embossed 8d region is free from distortion in the bulging direction, and has a first position positioned before and after the X-X flexible shaft. Swollen

1 1

Raised portions R and R are formed in the protruding shape embossed 8c region and the second bulging shaped embossed 8e region so that two peaks are connected, and the raised portion R is in close contact with the blood drainage area. Shi

1 2 1

The protruding part R is in close contact with the perineal area, so that it is possible to reliably prevent transmission of menstrual blood and the like.

2

I can do it. Note that the raised portion R is proportional to the formation scale of the bulge-shaped emboss 8e, It is formed smaller than the raised portion.

[0064] On the other hand, in the rear-side embossed 8f region, the second rear-side embossed 10 is formed in addition to the rear-side embossed 8f along the longitudinal direction of the napkin 1 on both sides of the middle-high portion 6, respectively. , Because these four embossments each form a flexible shaft,

twenty two

The sagability is improved and the fit to the valley of the hip is increased.

[0065] Further, the third bulge-shaped boss 8g formed at a position closer to the rear side of the rear side emboss 8f has a transverse line X_X, X-X corresponding to the inflection point position. Break

3 3 4 4

In addition to being easy to bend, since the distortion in the vertical line Y_Y direction of the napkin is divided at each inflection point position, it fits in the hip valley so that the area ζ rises

2

[0066] On the other hand, the substantially umbrella-shaped front end independent emboss 9 formed at the foremost end of the napkin 1 is formed on the rear side so that the front end of the napkin 1 can be easily bent by using this as a flexible shaft. In addition, the rear-end independent emboss 11 of the substantially reverse umbrella shape serves as a flexible shaft to make the left and right second wing-shaped flaps W, W easy to bend.

B B

[0067] By the way, in the napkin 1, the blood drainage position is a force that is generally determined as the corresponding position of the wing flaps W and W positions. For example, as shown in FIG. Various embosses 8 to 11 may be formed so as to be relatively shifted downward so that the region corresponds to the wing flaps W and W.

[Other Examples]

(1) To make the napkin 1 bend easily at the flexible shaft XX position formed between the first bulge-shaped embossed 8c region and the second bulge-shaped embossed 8e region,

1 1

You may make it provide the auxiliary | assistant embossing along a substantially width direction. Fig. 12 (A) shows an example in which an arcuate emboss 14 oriented in the width direction is formed at the center in the width direction as the auxiliary emboss, and Fig. 12 (B) shows the width direction so as to connect the embosses on both sides. This is an example in which arc-shaped emboss 15 is formed on the surface.

(2) In the above embodiment, the second rear embossing 10 and 10 are formed independently. However, as shown in FIG. 12 (C), the second rear embossing 10 and 10 and the rear The end independent emboss 11 may be continuous to form a substantially U-shaped continuous emboss 16. (3) Further, as shown in FIG. 13, the region including the blood drainage region, the region Y including the perineum corresponding portion, and the region Y including the third bulge-shaped emboss 8g are small on the surface of the middle high portion 6.

twenty three

It is desirable to improve the absorbability of menstrual blood etc. by forming a large number of hollow dodd embosses 18. 18. In the example in the figure, the position adjacent to the flexible axis X-X and the third

1 1

For each of the bulge-shaped embossed 8g portions, arc-shaped embosses 14 and 17 oriented in the width direction are formed at the center in the width direction.

(4) In the above embodiment, emboss 8 has a pair of left and right emboss lines joined at the front end and rear end of the napkin to form a closed shape as a whole, but the pair of left and right emboss lines are connected to the front end and Z Or you may form in the aspect which is not couple | bonded at a rear-end part.

Example

[0069] Absorber samples with various synthetic fiber mixing ratios in the upper-layer absorber 4A were prepared, and an absorption rate test and a liquid permeability test were performed. The upper absorbent body 4A was made of PE / PET core-sheath composite fiber that had been subjected to a hydrophilic treatment, and the lower absorbent body 4B was made of an absorbent layer made of pulp fibers and a superabsorbent resin without containing synthetic fibers.

[0070] The absorption rate test assumes that a person with a large amount of menstrual blood has been wearing a napkin for 1 hour, and placed 3.5 cc artificial menstrual blood on the liquid-permeable top sheet surface every 8.5 minutes. The absorption rate was defined as the absorption rate at the seventh absorption time (time until 3.5 cc of artificial menstrual blood was absorbed). In the liquid permeability test, weigh the upper and lower absorbers, drop 3.5cc of artificial menstrual blood on the upper absorber, and leave it for 5 minutes, then upper and lower absorbers. Was measured again and calculated from the amount of artificial menstrual blood that had penetrated into the lower layer absorber. The test results are shown in Table 1 below and in Figure 15.

[0071] [Table 1] Synthetic fiber mixing rate (%) Absorption rate (S) Liquid permeability (%)

0 14. 02 77. 50

10 12. 58 80. 07

30 20. 70 88. 71

50 23. 41 89. 05 [0072] As shown in FIG. 15, in order to prevent leaks reliably after a person with particularly high menstrual blood volume wears a napkin for 1 hour, the liquid permeability is 85% or more and the absorption rate is 25 seconds or less. Therefore, it has been found that the mixing ratio of the synthetic fiber is 20 to 80%, preferably 40 to 60%.

Brief Description of Drawings

FIG. 1 is a development view of the sanitary napkin 1 of the present invention.

[Fig. 2] This is a cross-sectional view (a view taken along line II-II in Fig. 1).

[Fig. 3] A cross-sectional view thereof (a view taken along line III-III in Fig. 1).

FIG. 4 is a cross-sectional view showing a laminated structure (part 1) of upper layer absorber 4A and lower layer absorber 4B.

FIG. 5 is a cross-sectional view showing a laminated structure (No. 2) of upper layer absorber 4A and lower layer absorber 4B.

FIG. 6 is a longitudinal sectional view showing an absorbent body manufacturing apparatus 30.

FIG. 7 is a plan view of relevant parts showing an example of the shape change of the casing 30.

FIG. 8 is a side view showing a shape change example of the casing 30.

FIG. 9 is an explanatory diagram of embosses 8 to 11.

[Fig. 10] (A) is an enlarged view of the main part, and (B) is a view taken along line BB.

FIG. 11 is a development view of the sanitary napkin 1 in which the positions of the embosses 8 to 11 are shifted downward.

[FIG. 12] (A) to (C) are diagrams showing modifications of embossing.

FIG. 13 is a development view showing another emboss formation mode.

FIG. 14 is a perspective view showing a mounted state of the napkin.

FIG. 15 is a graph showing test results in Examples.

FIG. 16 is a cross-sectional view showing a conventional absorber laminated structure.

Explanation of symbols

[0074] 1 ... sanitary napkin, 2 ... liquid-impervious backsheet, 3 ... liquid-permeable topsheet, 4 ... absorbent, 4A ... upper absorbent, 4B ... lower absorbent, 5 ... crepe paper, 6 ... Middle high part, 7 ... Side nonwoven fabric, 8 ... Emboss, 8a ... Front end emboss, 8b ... Reduced shape emboss, 8c ... First bulge shape emboss, 8d ... Intermediate arc boss, 8e ... Second bulge shape Embossing, 8f ... Rear side embossing, 8g ... Third bulging shape embossing, 9 ... Front end independent embossing, 10 ... Second rear side embossing, 11 ... Rear end independent embossing, BS ... Solid gather, W ... Wing flap , W ... buttocks side wing-like flap, 14 ... pulp fiber sheet, 15 ... bale-like synthetic fiber,

B

30 ... Absorber manufacturing device, 31 ... First defibrator, 32 ... First feeding path, 33 ... Feeding fan, 34 ... Metering feeder, 35 ... Second feeding path, 36 ... Feeding fan, 37 ... Damper for feeding amount adjustment, 38 ... Second defibrator, 38b ... Damper for introduction of air, 39 ... Supply casing, 40 ...-Stacker, 41 ... Transfer drum, 42 ... Rotating drum for stacking, 42a … Absorbing molding recesses, 43 ··-suction chamber, 44… polymer inlet

Claims

The scope of the claims

[1] In an absorbent article in which an absorbent body is interposed between a liquid-permeable top sheet and a back sheet, and the absorbent body has a laminated structure of an upper layer absorbent body and a lower layer absorbent body,

The upper layer absorber and the lower layer absorber are laminated without using an adhesive, and embossing is given from the upper surface and / or outer periphery of the upper layer absorber toward the lower layer absorber. Absorbent article.

[2] The absorbent article according to claim 1, wherein the body fluid permeability of the upper-layer absorbent body is 85% or more.

[3] The 7th absorption rate when absorbing 5 cc of artificial menstrual blood 7 times every 8.5 minutes on the surface of the liquid-permeable top sheet is 25 seconds or less. Absorbent article according to crab.

[4] Any one of claims 1 to 3, wherein the upper layer absorber and the lower layer absorber are surrounded by crepe paper, and an opening is formed in the crepe paper at least on the lower surface of the upper layer absorber and / or the upper surface of the lower layer absorber. Absorbent article according to crab.

5. The absorbent article according to any one of claims 1 to 3, wherein the upper layer absorber and the lower layer absorber are surrounded by crepe paper in a state where the upper layer absorber and the lower layer absorber are laminated.