JP2012055744A - Method for manufacturing absorbent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that there is a lack of integrity between filament assemblies and fear of separating later or producing displacement when forming an absorbent using a plurality of filament assemblies, and achieve improvement of strength and stickness.SOLUTION: When forming the filament assembly by opening a tow 52X and manufacturing the absorbent 56 using the filament assembly, a plurality of tows 52X having different properties and a nonwoven fabric 57 formed only by entanglement with the fibers not being mutually bonded are passed through a single passage in the state of being vertically piled up by inserting the nonwoven fabric 57 into between the tows 52X, and compression air is blown into the passage, when opening. While the plurality of tows 52X are collectively opened, the volume of the nonwoven fabric 57 is increased by the magnification of the fiber interval. The filaments of adjoining tows 52X and the fibers of the nonwoven fabric 57 are mutually entangled, and the integrated filament assembly is formed. The problem is thus solved.

Description

  The present invention relates to a method for producing an absorbent body using tow.

  Absorbent articles such as infant and adult tape-type and pants-type disposable diapers and sanitary napkins are used between the top sheet on the use side, the back sheet that prevents permeation of body fluids on the back side, and between these sheets. The basic element is an absorption element that receives and holds excreted body fluid that has permeated through the top sheet.

  For this basic element, an exterior sheet made of, for example, a non-woven fabric is provided on the back side of the back sheet, and a form for improving the touch when a plastic sheet is used as the back sheet, a form for forming so-called barrier cuffs on both sides of the product, etc. In order to improve the fit around the waist and the abdomen, a form for imparting elastic stretchability is appropriately added.

  As an absorbent element that receives and holds the body fluid that has passed through the top sheet on the use surface side, conventionally, a fiber stack of pulp staple fibers is generally used. It is also known to use superabsorbent polymer particles (hereinafter also referred to as “SAP”) to increase the amount of absorption in body fluids.

  In addition to the case where the SAP is dispersed on the piled fiber of short pulp fibers, there are cases where the SAP of the short pulp fibers is dispersed and held (Patent Document 1).

  On the other hand, in recent years, as shown in JP-T-2002-524399 (WO99 / 27879: Patent Document 2) and JP-T-2004-500165 (US Patent No. 6,646,180: Patent Document 3), It has been proposed to be used as an absorbent element.

  JP-T-2004-500165 discloses an absorbent element mainly composed of SAP and added with a filament assembly. This absorbent element is a laminate comprising an absorbent layer between about 50 to 95% by weight of SAP and about 5 to 50% by weight of a water-insoluble hydrophilic polymer such as starch and fibers, provided between an upper layer and a lower layer. This is a structure, which is folded into a C-shaped cross section and a channel is formed in the center. JP-T-2004-500165 discloses the use of filaments as examples of fibers.

JP 2004-65300 A Special Table 2002-524399 (WO99 / 27879) JP-T 2004-500165 (US Pat. No. 6,646,180)

However, when forming a filament aggregate obtained by opening the tow, the fiber assembly has a large number of performances such as basis weight, thickness, elasticity, density, rigidity, etc., which change at a time. It was impossible to design these performances individually and freely. As a result, even in the absorbent body, certain performances such as weight per unit area, thickness, elasticity, density, and rigidity cannot be designed individually and freely.
On the other hand, when an absorbent body is formed using a plurality of filament aggregate parts formed by tow opening, the opened state of each filament aggregate part differs depending on the part of the absorbent body. Or tow with different properties can be used for each filament assembly part, so that it has constant performance such as weight per unit, thickness, elasticity, density, rigidity, etc. It becomes possible to design freely. In particular, by adopting a structure in which a plurality of filament aggregate portions are accumulated in the thickness direction of the article, the performance in each part in the thickness direction of the article can be freely designed. Further, by adopting a structure in which a plurality of filament aggregate parts are arranged in parallel in the width direction of the article, the performance in each part in the width direction of the article can be freely designed.

In this case, when producing a composite absorbent element using a plurality of tows as raw materials, after opening the plurality of tows individually, the resulting filament assembly is composited by lamination or the like to form a single composite absorbent element. It is simple. However, what is obtained in this manner has poor integrity between the filament aggregates, and there is a risk of separation or deviation later.
Therefore, the main problem of the present invention is to solve this problem.

  The present invention that has solved the above problems is as follows.

<Invention of Claim 1>
It is a method of opening a tow to form a filament assembly, and manufacturing an absorber using this filament assembly,
During the opening, a plurality of tows having different properties and non-woven fabrics which are not bonded to each other and are formed only by entanglement are stacked in a single passage with the nonwoven fabrics sandwiched between the tows. Compressed air is blown into the passage while passing through and the plurality of tows are spread together, and the bulk of the nonwoven fabric is increased by increasing the fiber spacing, so that the adjacent tow filaments and the nonwoven fabric fibers are entangled with each other. A method for manufacturing an absorbent body, characterized in that an integral filament assembly is formed.

(Function and effect)
In this case, not only a plurality of tows, but also the nonwoven fabric increases in volume due to the expansion of the fiber interval, the adjacent tow filaments and the nonwoven fabric fibers are entangled with each other, and an integral filament aggregate is formed. Therefore, according to the present invention, it is possible to easily produce a tightly integrated filament assembly while maintaining the continuity of the filaments using a plurality of tows as raw materials without adding a special process. Become.
In addition, when the nonwoven fabric is sandwiched between the overlapping filament aggregate parts in this way, the strength and stiffness can be improved by the nonwoven fabric. In addition, when the superabsorbent polymer particles are held in the filament aggregate part so as to be movable, the non-woven fabric can block the movement of the superabsorbent polymer particles, and can be high when the outer surface of the product is touched by hand. It becomes possible to reduce a crisp and uncomfortable feeling caused by the unevenness of the absorbent polymer particles.

<Invention of Claim 2>
The absorbent body manufacturing method according to claim 1, wherein after forming the integral filament aggregate, superabsorbent polymer particles are dispersed and supplied onto the integral filament aggregate.

<Invention of Claim 3>
The absorber manufacturing method according to claim 1 or 2, wherein at least one of the basis weight, thickness, elasticity, density, and rigidity of the plurality of filament aggregate portions is different.

(Function and effect)
By manufacturing as described in this section, it is possible to manufacture absorbent bodies that are partially different in at least one of basis weight, thickness, elasticity, density, and rigidity.

  As described above, according to the present invention, when manufacturing an absorbent body using a filament aggregate obtained by opening a tow, a certain performance such as basis weight, thickness, elasticity, density, and rigidity can be freely designed. Advantages such as being able to do so are brought about.

It is a perspective view of a pants-type disposable diaper. It is an expanded state top view of a pants type disposable diaper. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. It is sectional drawing equivalent to the 3-3 line of another example. It is sectional drawing equivalent to the 3-3 line of another example. It is sectional drawing equivalent to the 3-3 line of a modification. It is sectional drawing equivalent to the 3-3 line of another example. It is an expanded state top view of a tape type disposable diaper. It is IX-IX sectional drawing of FIG. It is a schematic diagram which shows the example of manufacturing facilities of a pants-type paper diaper. It is a principal part schematic diagram of FIG. It is a schematic diagram of a widening apparatus. It is XIII-XIII sectional drawing of FIG. It is a schematic diagram of a fiber-spreading apparatus. It is a schematic diagram which shows the example of manufacturing facilities of another pants-type paper diaper. It is a principal part schematic diagram of FIG. It is a schematic diagram of a fiber-spreading apparatus. It is a principal part schematic diagram which shows the 2nd form of a fiber opening process. It is a principal part schematic diagram which shows the 3rd form of a fiber opening process. It is a principal part schematic diagram which shows the 3rd form of a fiber opening process. It is a schematic diagram of an air injection nozzle. It is a schematic diagram of the example of a superabsorbent polymer particle dispersion | distribution means. It is a schematic diagram of another superabsorbent polymer particle dispersion form. It is a schematic diagram of another superabsorbent polymer particle dispersion form. It is a schematic diagram which shows another example of manufacturing equipment. It is a schematic diagram which shows the example of manufacturing equipment of a tape-type disposable paper diaper. It is a schematic diagram which shows the example of manufacturing equipment of a tape-type disposable paper diaper.

Hereinafter, an embodiment of the present invention will be described in detail with reference to a disposable diaper and its manufacturing equipment.
<Examples of pants-type disposable diapers>
FIG. 1 shows an example of a pants-type disposable diaper. The pants-type disposable diaper 10 includes an exterior sheet 12 on the outer surface (back surface) side and an absorbent main body 20 on the inner surface (front surface) side, and the absorbent main body 20 is fixed to the exterior sheet 12. The absorptive main body 20 is a portion that receives and absorbs and retains body fluids such as urine and loose stool (menstrual blood in a sanitary napkin described later). The exterior sheet 12 is a part for mounting on the wearer.

  The exterior sheet 12 has, for example, an hourglass shape as shown in the figure, and both sides are constricted, and this is a part into which a wearer's leg is put. The absorptive main body 20 can take any shape, but is rectangular in the illustrated form.

  As shown in FIG. 2, the exterior sheet 12 is folded back and forth after the absorbent main body 20 is installed and fixed at a predetermined position, and joined regions 12A on both sides of the front body 12F and the back body 12B of the exterior sheet 12. Are joined by heat fusion or the like. Thereby, a pants-type disposable diaper having a structure shown in FIG. 1 and having a waist opening WO and a pair of leg openings LO is obtained.

  An intermediate width in the longitudinal direction of the absorbent main body 20 shown in the drawing (that is, the vertical direction in FIG. 2, which is also the front-rear direction of the product) is shorter than the width connecting the constricted portions of the exterior sheet 12. This width relationship may be reversed or the same width.

  The exterior sheet 12 is preferably composed of two sheets of water-repellent nonwoven fabric, for example, and an elastic elastic member is interposed between these sheets, and a form that fits the wearer by the contraction force is desirable. As the elastic elastic member, thread rubber or elastic foam band can be used, but it is desirable to use a large number of thread rubbers. In the illustrated embodiment, the rubber threads 12C, 12C,... Are provided continuously in the width direction in the waist region W, provided only on both sides in the lower waist region U, and not provided in the crotch region L. Since the rubber threads 12C, 12C,... Are provided in both the waist region W and the lower waist region U, even if the shrinkage force of the rubber thread 12C itself is weak, the rubber waist 12C hits the wearer in the lower waist region U as a whole. The product fits well to the wearer.

(Absorbent body)
As shown in FIG. 3, the absorbent main body 20 of the embodiment includes a top sheet 30 made of, for example, a nonwoven fabric that allows body fluid to permeate, an intermediate sheet (second sheet) 40, and an absorbent element 50. A body fluid impermeable sheet (also called a back sheet) 70 made of a plastic sheet or the like is provided on the back side of the absorbent body 56. The exterior sheet 12 is provided on the back side of the body fluid impermeable sheet 70. Further, barrier cuffs 60, 60 are provided on both sides.

(Top sheet)
The top sheet 30 has a property of transmitting body fluid. Accordingly, the material of the top sheet 30 is sufficient if it exhibits this body fluid permeability, and examples thereof include a porous or non-porous nonwoven fabric and a porous plastic sheet. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. Examples include synthetic fibers such as polyethylene and polypropylene such as olefins, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers in which two or more of these are used. can do. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, and a needle punch method. For example, the spun lace method is a preferable processing method for obtaining flexibility and drapeability, and the thermal bond method is for obtaining bulkiness and softness.

  The top sheet 30 may be composed of a single sheet or a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

(Intermediate sheet)
In order to quickly transfer the body fluid that has permeated through the top sheet 30 to the absorbent body, an intermediate sheet 40 that is generally referred to as a “second sheet” that has a higher body fluid permeation rate than the top sheet 30 can be provided. This intermediate sheet not only improves the absorption performance by the absorbent body by quickly transferring the body fluid to the absorbent body, but also prevents the “reversal” phenomenon of the absorbed body fluid from the absorbent body, and the top sheet 30 is always dried. State.

  Examples of the intermediate sheet 40 include the same materials as the top sheet 30, spunlace, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric and a spunbond nonwoven fabric are preferable.

  The intermediate sheet (second sheet) 40 is interposed between the top sheet 30 and the covering sheet 58. As shown in FIG. 5, a configuration in which the intermediate sheet (second sheet) 40 is not provided can also be used.

  The intermediate sheet 40 in the illustrated form is disposed in the center shorter than the width of the absorber 56, but may be provided over the entire width. The length of the intermediate sheet 40 in the longitudinal direction may be the same as the length of the absorbent body 56 or may be within a short length range centered on the region that receives the body fluid. A typical material for the intermediate sheet 40 is a nonwoven fabric having excellent body fluid permeability.

(Absorption element)
The absorbent element 50 includes an absorbent body 56 having an aggregate of filaments 52, 52... And a superabsorbent polymer particles 54, 54... And a covering sheet 58 that wraps at least the back and side surfaces of the absorbent body 56. And have. Further, a holding sheet 80 is provided between the absorbent body 56 and the rear surface side portion (lower portion) of the covering sheet 58.

(Absorber)
The absorbent body 56 is formed by an assembly of filaments (substantially continuous long fibers) formed by opening the tow, and is characteristically a plurality of filament assembly portions formed from separate tows. 52A and 52B.

  In the absorbent body 56 of the present invention, the arrangement and number of filament aggregate portions are not limited. Therefore, as shown in FIG. 3, the filament assembly portions 52A and 52B are arranged in two layers on the top and bottom in the thickness direction of the article, and the number of laminations is three layers 52A, 52C and 52B as shown in FIG. As shown in FIG. 7, three filament assembly portions 52D, 52E, and 52F are arranged side by side in the width direction of the article, or in a surface direction orthogonal to the thickness direction, such as a longitudinal direction and an oblique direction, although not shown. A plurality of filament aggregate portions can be arranged side by side. Moreover, lamination | stacking and juxtaposition can also be combined.

  The widths of the filament assembly portions 52A and 52B may be the same, but when the plurality of filament assembly portions 52A and 52B are stacked, the widths of the filament assembly portions 52A and 52B are increased as necessary. You can also make them different. For example, in the case of a two-layer structure as shown in FIG. 3 and the like, although not shown, the width of the upper layer 52A can be made narrower than the width of the lower layer 52B.

  The plurality of filament aggregate portions 52A and 52B can have different opening states with respect to at least two tows.

  Further, a plurality of the same type of tows may be used as the raw material of each filament assembly portion 52A, 52B, but it is preferable to use a plurality of types of tows having different properties, for example, different materials, different finenesses, cross sections Those having different shapes, those having different degrees of acetylation, those having different hydrophilicity, and the like can be used. When a plurality of types of tows having different properties are used, it is preferable to select the type of tow according to the site in the absorber 56. More specifically, in the form shown in FIG. 3, the lower layer portion 52B is formed of a filament having excellent liquid holding performance, for example, a filament having a fineness of about 1 to 3 dtex, and the upper layer portion 52A is thicker than the lower layer portion 53B and has liquid diffusion performance. It is one preferable form that it is composed of a filament excellent in, for example, a filament having a fineness of 4 to 6 dtex. In this case, the liquid supplied from the top sheet 30 side diffuses over a wide range in the upper layer portion 52A, and is then absorbed and held by the lower layer portion 52B.

  Further, the plurality of filament aggregate portions 52A and 52B can be made different in at least one of basis weight, thickness, elasticity, density, and rigidity by making the spread state and the type different.

  Adjacent filament assembly portions 52A, 52B may simply be overlaid or arranged as shown in the enlarged portion of FIG. 3, and one portion 52A as shown in the enlarged portion of FIG. The filament 52a may be integrated with the filament 52b of the other portion 52B. In this case, the filaments 52a and 52b are intertwined and integrated in the vicinity of the boundary portion between the portions 52A and 52B, and a clear boundary does not occur. Further, the adjacent filament assembly portions 52A and 52B can be joined together by a joining means such as a hot melt adhesive or heat seal. When a hot melt adhesive is used, if the adhesive is concentratedly applied to the seams of the adjacent filament assembly portions 52A and 52B, the liquid in the excretory part is blocked by the seams, so that the liquid along the extending direction of the seams. The spread of

As shown in FIG. 6, it is also a preferred form to sandwich a nonwoven fabric 57 between adjacent filament assembly portions 52A and 52B. The code | symbol 57f represents the nonwoven fabric fiber. In this case, the nonwoven fabric 57 preferably has higher rigidity than the filament aggregate portions 52A and 52B. Specifically, it is preferable that the fineness of the constituent fiber 57f is about 2.0 to 6.0 dtex, the basis weight is about 15 to 50 g / m ² , and the thickness is about 0.2 to 2.0 mm. Although the kind of the nonwoven fabric 57 is not particularly limited, the fibers are not bonded to each other like the spunlace nonwoven fabric because they are easily integrated with the filament assembly portions 52A and 52B due to the entanglement of the fibers, and are formed only by entanglement. Are preferred.

  Examples of the material of the filaments 52a and 52b include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.) and the like. Although it can be used, cellulose ester and cellulose are particularly preferable.

  As cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Regenerated cellulose such as rayon may be used, and the regenerated cellulose may be spun.

  Examples of cellulose esters that can be suitably used include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate. And cellulose ester derivatives such as polycaprolactone-grafted cellulose ester can be used. These cellulose esters can be used alone or in admixture of two or more. The viscosity average degree of polymerization of the cellulose ester is, for example, about 50 to 900, preferably about 200 to 800. The average substitution degree of the cellulose ester is, for example, about 1.5 to 3.0 (for example, 2 to 3).

  The average degree of polymerization of the cellulose ester can be, for example, 10 to 1000, preferably 50 to 900, more preferably about 200 to 800, and the average degree of substitution of the cellulose ester is, for example, about 1 to 3, preferably 1 to 1. 2.15, more preferably about 1.1 to 2.0. The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability.

  As the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms), particularly cellulose acetate is suitable. The degree of acetylation of cellulose acetate is often about 43 to 62%, but about 30 to 50% is particularly preferable because it is excellent in biodegradability. A particularly preferred cellulose ester is cellulose diacetate.

  The filaments 52a and 52b may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like.

  The fineness of the filaments 52a and 52b is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. The filaments 52a and 52b may be non-crimped fibers, but are preferably crimped fibers. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used. When crimped fibers are used, a bulky and light absorbent body can be produced, and a tow with high unity can be easily produced by entanglement between the fibers. The cross-sectional shape of the filaments 52a and 52b is not particularly limited, and may be any one of, for example, a circle, an ellipse, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. May be. For example, the filament is used in the form of a tow (fiber bundle) formed by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. . The fiber bundle is preferably formed by concentrating about 3,000 to 1,000,000 filaments.

  Tow is weakly entangled between filaments, so the contact part of the filament is bonded or fused to maintain the shape, prevent the migration of superabsorbent polymer particles, secure the stiffness of the absorber, and prevent urine diffusion. It is possible to use a binder or a hot-melt adhesive having the function of Examples of binders include ester plasticizers such as triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  Thermoplastic resins used as binders or hot-melt adhesives are resins that exhibit adhesive strength when melted and solidified, and include water-insoluble or poorly water-soluble resins and water-soluble resins. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or poorly water-soluble resins include polyethylene, polypropylene, ethylene-propylene copolymers, olefinic homo- or copolymers such as ethylene-vinyl acetate copolymers, polyvinyl acetate, polymethyl methacrylate, methacryl Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, optionally modified polyesters, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (eg, rosin esters), Hydrocarbon resin (eg terpene tree , Dicyclopentadiene resins, and petroleum resins), and hydrogenated hydrocarbon resins. One or two or more of these thermoplastic resins can be used.

  Examples of water-soluble resins include various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group, or a salt thereof. Vinyl water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxides, water-soluble polyesters, water-soluble polyamides, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents may be added to the thermoplastic resin.

Since tow can be produced by a known method, no detailed description will be given. Cellulose diacetate tow bales that can be suitably used in the absorbent element 50 are commercially available from Celanese, Daicel Chemical Industries, and the like. Cellulose diacetate tow bale has a density of about 0.5 g / cm ³ and a total weight of 400-600 kg.

  From this bale, the tow is peeled off and spread into a wide band so as to have a desired size and bulk. The opening width of the tow is arbitrary, and can be, for example, a width of 100 to 2000 mm, preferably about 100 to 300 mm of the width of the product absorber. Moreover, the density of an absorber can be adjusted by adjusting the opening state of the tow.

(Superabsorbent polymer particles)
Preferably, as shown in FIG. 3, superabsorbent polymer particles 54, 54. It is desirable that the superabsorbent polymer particles (SAP particles) are dispersed substantially in the entire thickness direction with respect to the aggregate of the filaments 52, 52. The state of being substantially dispersed throughout the thickness direction is conceptually shown as an enlarged view of the main part of FIG.

  If there is no SAP particle in the upper part, the lower part, and the middle part of the absorber 56, or if there is very little, it cannot be said that the "absorbed throughout the thickness direction". Therefore, “distributed in the entire thickness direction” means “distributed unevenly in the upper, lower, and / or middle portions of the aggregate of filaments, in addition to the form“ uniformly ”distributed in the entire thickness direction. However, it is still included in the form of being dispersed in the upper, lower and middle portions. Further, a form in which some SAP particles do not penetrate into the aggregate of the filaments 52, 52... Remain on the surface, and some SAP particles pass through the aggregate of the filaments 52, 52. The form on the sheet 58 and the form on the holding sheet 80 as shown in FIG. 6 are not excluded.

  When the superabsorbent polymer particles 54 are used, the type, the applied amount (including the case where the applied amount is zero), the dispersion mode, the density, and the like of the superabsorbent polymer particles 54 in the filament aggregate portions 52A and 52B are individually determined. It is possible to make them all the same, or to make the type and amount of the superabsorbent polymer particles 54 in any one of the filament aggregate portions 52A and 52B different from those of the other filament aggregate portions 52A and 52B. You can also In particular, one of the filament assembly part layers (particularly the lower layer 52B) contains a superabsorbent polymer and the other filament assembly part layer (particularly the upper layer 52A) does not contain a superabsorbent polymer. preferable.

  Here, the superabsorbent polymer particles mean “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used for this type of absorbent article can be used as they are, and those having a particle size of 100 to 1000 μm, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 60 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the body fluid supplied into the absorbent body returns to the outside of the absorbent body tends to occur.

  Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. Thereby, even if it is a case where it is set as a bulky absorber by using tow | toe, the sticky feeling after bodily fluid absorption can be suppressed effectively.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . By setting the basis weight of the polymer to 50 g / m ² or less, it is possible to prevent the lightening effect from becoming difficult to be exhibited by adopting an aggregate of filaments made of tow depending on the weight of the polymer. If it exceeds 350 g / m ² , not only the effect is saturated, but also the above-mentioned crisp and uncomfortable feeling is given due to excess of the superabsorbent polymer particles.

  If necessary, the superabsorbent polymer particles can adjust the spraying density or spraying amount in the plane direction of the absorber 56. For example, the body fluid excretion site can be applied in a larger amount than other sites. When gender differences are taken into account, men can increase the front spraying density (amount) and women can increase the center spraying density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorber 56 can also be provided.

  If necessary, a plurality of superabsorbent polymer particles having different particle size distributions can be prepared, and can be sequentially dispersed and projected in the thickness direction. For example, the superabsorbent polymer particle spraying means 90 is arranged at intervals in a plurality of lines, and after spraying and projecting a particle having a small particle size distribution, the particle having a large particle size distribution is sprayed and projected. Thus, it is possible to distribute a small particle size distribution on the lower side in the absorber 56 and a large particle size distribution on the upper side. This form is effective for allowing a particle having a small particle size distribution to penetrate deeply into an assembly of filaments.

  The ratio between the superabsorbent polymer particles and the aggregate of filaments determines the absorption characteristics. As a weight ratio in a planar area of 5 cm × 5 cm in the region directly receiving the body fluid in the absorbent body 56, it is desirable that the superabsorbent polymer particle / filament weight is 1 to 14, particularly 3 to 9.

  (Combination of other absorbent materials)

  As long as it has a plurality of filament assembly parts, other known absorbent materials, for example, short fiber absorbent materials formed by stacking short fibers such as pulp and airlaid and adding superabsorbent polymer particles as necessary Can be combined.

  (Absorber size / weight)

On the other hand, the size of the absorber 56 is preferably such that the planar projection area is 400 cm ² or more and the thickness is 1 to 10 mm, particularly 1 to 5 mm. When the size of the absorber is within this range, it is extremely advantageous to improve the resilience without increasing the weight, thickness and cost. The weight of the absorber is preferably 25 g or less, particularly 10 to 20 g. When the weight of the absorber is within this range, the advantage of not using a dedicated member becomes particularly remarkable.

  (Compressive properties of absorber)

  The compression resilience RC of the absorbent body 56 is preferably 40 to 60%, particularly 50 to 60%. Thereby, sufficient restoring property can be exhibited with the absorber itself.

Furthermore, it is preferable that the compression energy WC of the absorbent body 56 is 4.0 to 10.0 gf · cm / cm ² , since it can be compressed compactly to the same level as before or during packaging.

  These compression characteristics can be adjusted by adjusting the filament density by opening or the like, selecting the filament material, selecting the type of binder such as a plasticizer, adjusting the degree of processing, or a combination thereof.

  Here, the compression energy (WC) is energy consumption when pressing the central part of the test piece (holding sheet) cut to a length of 200 mm and a width of 50 mm up to 50 g.

This compression energy can be measured with a handy compression tester (KES-G5, manufactured by Kato Tech). The measurement conditions for this tester are: SENS: 2, force meter type: 1 kg, SPEED RANGE: STD, DEF sensitivity: 20, pressurization area: 2 cm ² , capture interval: 0.1 (standard), STROKE SET: 5.0, upper limit load: 50 gf / cm ² .

  On the other hand, the compression resilience (RC) is a parameter representing the recoverability at the time of compression. Therefore, if the recoverability is good, the compression resilience increases. This compression resilience can be measured with a handy compression tester (KES-G5, manufactured by Kato Tech). The measurement conditions for this tester are the same as for the compression energy.

  (Enveloping sheet)

As the covering sheet 58, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, and the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used instead of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The basis weight is preferably 5 to 50 g / m ² , particularly 10 to 30 g / m ² .

  As shown in FIG. 3, the covering sheet 58 has a form of covering the entire layer of the aggregates of the filaments 52, 52... And the superabsorbent polymer particles 54, 54. It is also possible to cover only the back and side surfaces. Although not shown, only the upper and side surfaces of the absorbent body 56 are covered with crepe paper or nonwoven fabric, and the lower surface is covered with a body fluid-impermeable sheet such as polyethylene, and the upper surface of the absorbent body 56 is covered with crepe paper or nonwoven fabric. For example, the lower surface may be covered with a body fluid impermeable sheet such as polyethylene (each of these materials becomes a component of the covering sheet). If necessary, the aggregate of the filaments 52, 52, and the superabsorbent polymer particles 54, 54 ... may be sandwiched between two upper and lower sheets or arranged only on the lower surface. This is not a desirable form because it is difficult to prevent movement.

  (Holding sheet)

  The superabsorbent polymer particles 54 can be interposed between the holding sheet 80 and the absorbent body 56 by spraying or the like. The superabsorbent polymer particles 54 may pass through the aggregate of filaments 52 at the time of dispersion / projection onto the aggregate of filaments 52 or in the subsequent process or until the consumer uses it. The unevenness of the superabsorbent polymer particles that have passed through the filament aggregate gives a crisp and uncomfortable feeling when touched by a hand when used by a consumer. Therefore, a holding sheet 80 having a holding performance of the absorbent polymer is interposed between the absorbent body 56 and the covering sheet 58. The holding sheet 80 reinforces the stiffness that is not sufficient only by the covering sheet 58 such as tissue paper (crepe paper), and reduces or prevents a sense of incongruity when touched by the hand when the consumer uses it.

  In FIG. 6, when the superabsorbent polymer particles 54 are provided below the absorber 56, or when the superabsorbent polymer particles 54 contained in the absorber 56 are used from the manufacture to the consumer. In the stage, the case where the filament 52 is pulled out from the aggregate and collected on the holding sheet 80 is conceptually shown.

  The material of the holding sheet 80 is not particularly limited as long as it has a holding performance of the superabsorbent polymer particles 54. Specifically, for example, non-woven fabric, crimped pulp, low-absorbency cotton fiber (for example, non-degreased cotton fiber, degreased cotton fiber, rayon fiber treated with a water repellent or a hydrophobizing agent, etc.). ), Polyethylene fibers, polyester fibers, acrylic fibers, polypropylene fibers, silk, cotton, hemp, nylon, polyurethane, acetate fibers, airlaid (mixed with superabsorbent polymer particles) sheets, and the like.

If the holding sheet 80 and the nonwoven fabric, its holding sheet 80, the compression energy 0.01~10.00gfcm / cm ² based on KES test, preferably, at 0.01~1.00gfcm / cm ^2, and compressed The non-woven fabric has a resilience of 10 to 100%, preferably 70 to 100%.

  The reason for providing the holding sheet 80 is to hold, for example, the superabsorbent polymer particles 54 that have fallen down (dropped out) from the absorbent body 56 as described above. Therefore, since the superabsorbent polymer particles 54 that have come out come into contact with the user via the covering sheet 58 and the holding sheet 80, there is no possibility of being transmitted to the user as a sense of incongruity. In particular, the holding function is sufficiently exhibited when the nonwoven fabric has the above-described compression energy and compression resilience.

  Further, since the superabsorbent polymer particles 54 that have escaped are held by the holding sheet 80 and do not move on the covering sheet 58, there is no possibility of uneven distribution of absorption capacity. In particular, in order to prevent the superabsorbent polymer particles 54 from moving on the holding sheet 80, an adhesive hot melt adhesive or the like can be applied on the holding sheet 80 in advance. Alternatively, the upper surface of the holding sheet 80 (surface toward the use surface side) may be a rough surface to prevent the superabsorbent polymer particles 54 from moving on the holding sheet 80. Examples of the roughening or fluffing means for this purpose include a non-net surface that is not a net surface during the production of the nonwoven fabric, a marble process, a needle punch process, and a brushing process.

  Even if the holding sheet 80 is provided only below the absorber 56 as shown in FIG. 3 or the like, the holding sheet 80 passes through the side surface of the absorber 56 and extends up to the upper surface of the absorber 56 as shown in FIG. May be. It is also possible to use a plurality of holding sheets 80 in a stacked manner.

  The above example is an example in which the holding sheet 80 is provided between the absorbent body 56 and the back surface side portion of the covering sheet 58, but the holding sheet 80 may be on the back side from the covering sheet 58 (its form) In short, if the holding sheet 80 is provided on the back surface side with respect to the absorbent body 56, it is possible to reduce or not cause a crisp discomfort when touching from the back surface of the product.

(Body fluid impermeable sheet)
The body fluid impermeable sheet 70 simply means a sheet disposed on the back surface side of the absorber 56, and in the present embodiment, is a sheet in which the absorber 56 is interposed between the top sheet 30. Therefore, the material of the main body liquid impermeable sheet is not particularly limited. Specifically, for example, an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet or the like, a nonwoven fabric that substantially ensures liquid impermeability by interposing a waterproof film (in this case, A body fluid impermeable sheet is comprised with a waterproof film and a nonwoven fabric.) Etc. can be illustrated. Of course, in addition to this, materials having liquid impermeability and moisture permeability, which have been used and used in recent years from the viewpoint of preventing stuffiness, can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given.

  The body fluid impervious sheet 70 can be prevented from side leakage of body fluid by extending it to the use surface in a so-called forehead form (not shown). This is prevented by interposing a second body fluid impermeable sheet 72 between the double barrier sheets 64 forming 60. According to this embodiment, since the second body fluid impermeable sheet 72 extends until the barrier cuff 60 stands up, the body fluid diffused laterally through the top sheet 30 and the side of the soft stool between the barrier cuffs 60, 60 There is also an advantage that leakage can be prevented.

  (Barrier cuffs)

  Barrier cuffs 60, 60 provided on both sides of the product are provided to prevent urine and soft stool that travel laterally along the top sheet 30 and prevent side leakage. It is.

  The illustrated barrier cuff 60 is a doubled water-repellent non-woven sheet, and is formed so as to protrude from the back side of the absorbent body 56 to the lower side of the top sheet 30 and to protrude to the front side. Yes. In order to prevent urine moving in the lateral direction along the top sheet 30, in particular, the side part of the body fluid impermeable sheet 70 is inserted between the double nonwoven fabric sheets, and the barrier cuff 60 protruding from the surface side is provided. It extends halfway.

  The shape of the barrier cuff 60 itself can be designed as appropriate. However, in the example shown in the drawing, an elastic elastic member, for example, a rubber thread 62 is fixed to the tip and middle of the protruding portion of the barrier cuff 60 under stretch, The barrier cuff 60 stands up due to the contraction force in use. As shown in FIG. 3, the base side of the barrier cuff 60 is positioned so that the middle rubber thread 62 is positioned at the center side of the front rubber thread 62, 62 and fixed to the front and rear end portions of the top sheet 30. It rises diagonally toward the center side, and the tip part stands up diagonally outward from the intermediate part.

  (Embossing)

You may form the recessed part E by embossing from the surface side of the top sheet 30 to the thickness direction. In this case, the embossed recess E is formed only on the top sheet 30, and the embossed recess E is formed on both the top sheet 30 and the intermediate sheet 40 as shown in FIG. A concave portion by embossing can be formed (not shown) so as to reach a part or substantially the entire thickness direction of the absorber 56 from the side. In order to form the recesses E by embossing on both the top sheet 30 and the intermediate sheet 40, the intermediate sheet 40 has a basis weight of 5 to 50 g / m ² , a thickness of 0.2 to 1.5 mm, and a top sheet. As for 30, it is desirable that the basis weight is in the range of 15 to 80 g / m ² and the thickness is in the range of 0.2 to 3.5 mm in that embossing can be sufficiently performed under the condition that liquid permeability is not impaired.

  Moreover, you may form the recessed part by embossing only in the intermediate sheet 40, without forming a recessed part in the top sheet 30, and also emboss only in the absorption element 56, without forming a recessed part in the top sheet 30 and the intermediate sheet 40. In addition, the embossed recess may be formed only in the absorbent body 58 without forming the recess in the top sheet 30, the intermediate sheet 40, and the covering sheet 58.

  The recess E has an effect of inducing and diffusing body fluid in the direction in which the recess E extends. Therefore, when the recesses E are substantially continuous in a groove shape (including the case where a plurality of recesses are arranged at intervals and form a single groove), the body fluid reaches the absorber before reaching the absorber. It becomes diffused along the recess E, so that a wider part of the absorber can be used for absorption. Therefore, the absorbent capacity of the entire product is increased, and the absorbent article is less likely to cause side leakage or reversal due to insufficient absorbent capacity.

  On the other hand, the absorber 56 made of tow is liable to be less rigid than a conventional pulp product, but it is preferable to form a recess by embossing in the absorber 56 because the rigidity can be increased. Although not shown, in order to increase the rigidity of the absorbent element 50, it is also a preferred form to form a concave portion by embossing in the thickness direction from the back surface side (the side opposite to the top sheet 30 side) of the absorbent body 56. In order to form the concave portion on the back surface side, embossing is integrally performed so as to reach the absorber 56 from the back surface side of the holding sheet 80, the covering sheet 58, the body fluid impermeable sheet 70 or the exterior sheet 12. Can do. Moreover, it is preferable to form such a concave portion on the back surface side together with the concave portion E on the front surface side, but it is also possible to form only the concave portion on the back surface side without forming the concave portion E on the front surface side. When the concave portions are provided on both the front and back sides, the shape of the concave portions may be common to the front and back sides, or may be different from each other.

  The embossed recess has the effect of inducing and diffusing body fluid in the extending direction. It also has the effect of increasing rigidity. Therefore, it is desirable to determine the shape of the embossed recess in consideration of these effects. For example, the recesses are substantially continuous in the shape of a groove (including the case where a plurality of recesses are arranged in a row and form a single groove), and the plurality of recesses are arranged in a dotted pattern at intervals. It may be. In addition, as the planar pattern, groove-shaped or dot-shaped concave portions are arranged in the longitudinal direction, the width direction, a lattice shape combining these, a zigzag shape (zigzag shape) reciprocating in the width direction, or irregularly arranged. Forms can be taken. Furthermore, appropriate forms such as a pin shape, a Mt. Fuji shape, and a bellows shape can be adopted.

  (Other)

  In addition, although not shown in figure, each structural member of the absorptive main body 20 is mutually fixed by appropriate application forms, such as solid, beads, or spiral application, such as a hot-melt adhesive.

  (Example of tape-type disposable diapers)

  8 and 9 show examples of tape-type disposable diapers. FIG. 9 is a view taken along the line IX-IX in FIG. 8, but the absorbent main body 20 is slightly exaggerated.

  The tape-type disposable diaper 10A has fastening pieces attached to both end portions on the back side of the diaper, has a hook element on a fastening surface of the fastening piece, and a back sheet constituting the back side of the diaper is laminated with a nonwoven fabric. The diaper is configured to be able to engage with a hook element of the fastening piece at an arbitrary position on the surface of the back sheet when the diaper is used as a body.

  The absorbent main body 20 has an absorbent body 56 interposed between the top sheet 30 and the body fluid impermeable sheet 70. The absorbent body 56 is entirely wrapped by a covering sheet 58 made of tissue paper, and has a rectangular shape in plan view. A holding sheet 80 is provided between the absorber 56 and the covering sheet 58.

  Further, an intermediate sheet 40 is interposed between the top sheet 30 and the absorber 56. The body fluid impermeable sheet 70 has a rectangular shape wider than the absorbent body 56, and a back sheet 12A made of an hourglass-shaped non-woven fabric is provided on the outer side thereof.

  The top sheet 30 has a rectangular shape wider than the absorbent body 56, extends slightly outward from the side edge of the absorbent body 56, and is fixed to the body fluid impermeable sheet 70 with a hot melt adhesive or the like.

  Barrier cuffs 60A projecting to the use surface side are formed on both sides of the diaper. The barrier cuffs 60A are formed of a barrier sheet 64 made of a nonwoven fabric substantially continuous in the width direction, and an elastic elastic member such as a thread rubber. And one or a plurality of leg rubber elastic members 62 as elastic elastic members for the leg periphery. 130 is a fastening piece by a hook-and-loop fastener.

  The inner surface of the barrier sheet 64 has a fixing start edge at a position separated from the side edge of the top sheet 30, and the outer portion in the width direction extends from the fixing start edge to the extending edge of the body fluid impermeable sheet 70. It is fixed by. The outer surface of the barrier sheet 64 is fixed to the back sheet 12A with a hot melt adhesive or the like on the lower surface thereof. Further, an elastic expansion / contraction member for gasket cuff, for example, thread rubber 66 is provided.

  The starting end of the inner surface of the barrier sheet 64 fixed to the body fluid impermeable sheet 70 forms an upstanding end of the barrier cuff 60A. Around the leg, the inside of the standing end is a free part that is not fixed to the product body, and this free part comes to stand by the contraction force of the rubber thread 62.

  In this example, by using a hook-and-loop fastener as the fastening piece 130, it can be mechanically fastened to the backsheet 12A. Therefore, a so-called target tape can be omitted, and a fastening position by the fastening piece 130 can be freely selected.

  The fastening piece 130 has a base portion of a fastening base material made of plastic, polylaminated nonwoven fabric, paper, or the like joined to the back sheet 12A, for example, with an adhesive, and has a hook element 130A on the tip side. The hook element 130A is bonded to the fastening substrate with an adhesive. The hook element 130A has a large number of engaging pieces on the outer surface side thereof. A temporary fixing adhesive portion 130B is provided on the tip side from the hook element 130A. At the end of the assembly of the product, the temporary fixing adhesive portion 130B is adhered to the barrier sheet 64, thereby preventing the fastening piece 130 from being peeled off at the front end side. At the time of use, it peels off against the adhesive force and brings the front end of the fastening piece 130 to the front body. The fastening base material is exposed at the tip side of the temporary fixing adhesive portion 130B, and is a tab portion.

  A target printing sheet 74 as a design sheet is provided on the inner surface side of the back sheet 12A on the opening side of the front body, and a design that serves as a guide for the position at which the hook element 130A of the fastening piece 130 is fastened is applied. Target printing is performed so that the target can be visually recognized through the back sheet 12A.

  When the diaper is mounted, the diaper is mounted on the body in the shape of a boat, and the contraction force of the rubber thread 62 acts. Therefore, the barrier cuff 60A stands up around the leg by the contraction force of the rubber thread 62.

  The space surrounded by the standing part forms a confined space for urine or soft stool. When urinating into this space, the urine is absorbed into the absorbent body 56 through the top sheet 30, and the rising part of the barrier cuff 60A becomes a barrier for the solid matter of soft stool, and the overpass is prevented. The In the unlikely event that urine leaks laterally over the standing distal side edge of the standing part, side leakage is prevented by the stop function by the flat contact part.

In this embodiment, it is desirable that the barrier sheet 64 forming each standing cuff is not liquid-permeable but substantially liquid-impervious (may be semi-liquid-permeable). Further, the surface sheet (nonwoven fabric laminate) of the present invention may have a property of repelling liquid by silicon treatment or the like. In any case, it is preferable that the barrier sheet 64 and the back sheet 12A are air permeable, and the barrier sheet 64 and the back sheet 12A are sheets having a water pressure resistance of 100 mmH ₂ O or more. Thereby, it becomes air permeable in the width direction side part of a product, and a wearer's stuffiness can be prevented.

  The other points, for example, the material used for each part, etc. are the same as in the case of the above-described pants-type paper diaper, and therefore the description is omitted.

<Example of how to make disposable diapers>
Next, a manufacturing example of the above-described paper diaper will be described.
(In the case of pants-type diapers)
The example shown in FIG.10 and FIG.11 has shown the manufacturing equipment example of the pants-type disposable diaper shown in FIG.1, FIG.2 and FIG.6.

  The covering sheet 58 is supplied to the line from the upstream side, and then the holding sheet 80 is supplied. In order to prevent the movement of the superabsorbent polymer particles to be supplied later, a hot melt adhesive or the like having adhesiveness can be applied to the holding sheet 80 in advance. FIG. 11 shows an adhesive application device 104 for this purpose.

  Subsequently, a filament aggregate 52Z formed by opening the tow (details will be described later) is supplied from above, and the superabsorbent polymer particles 54 are sprayed thereon by the superabsorbent polymer particle spraying means 90. Supplied. Thereafter, the wrapping sheet 58 is wrapped by passing the sailor 92, and the absorbent element 50 is obtained. Next, it is divided in the line direction by the cutter device 94 to obtain individual absorbent elements 50.

  Furthermore, since the intermediate sheet (second sheet) 40 has a structure shorter than the entire length of the absorbent element 50 in the embodiment, the intermediate sheet (second sheet) is supplied intermittently.

  Subsequently, the components of the barrier cuff 60 and the top sheet 30 are supplied from above, and the body fluid impermeable sheet 70 is supplied from below. Here, in the supply line of the barrier sheet 64 constituting the barrier cuff 60, the thread rubber 62 is stretched between the two nonwoven fabrics and the second bodily fluid impermeable sheet 72 is fixed in advance by an apparatus (not shown). Supply is made in a state and is supplied to the main line together with the top sheet 30. The components of the barrier cuff 60, the top sheet 30 and the body fluid impermeable sheet 70 supplied to the main line are folded into a shape shown in FIG.

  At the end of the line of the absorbent main body 20, the rectangular absorbent main body 20 having a longitudinal direction along the line is obtained by cutting with the cutter device 98. The obtained absorbent main body 20 is turned 90 degrees by the turning device 100 so that the longitudinal direction of the absorbent main body 20 is orthogonal to the line.

  On the other hand, in the line of the exterior sheet 12, the thread rubber 12C flows in a state where the nonwoven fabric sheet is interposed in advance (not shown in FIG. 10), and a cutter is used to form a leg-surrounding portion. (Not shown) is cut into an oval shape, and when reaching the combination station 102, an absorbent main body 20 that has been rotated is installed between the cut-out portions, and is fixed by a hot melt adhesive or the like. Combined with the sheet 12. Then, it is folded up and down with the horizontal line in FIG. 10 as a boundary, and the joining regions 12A on both sides of the front body 12F and the back body 12B of the exterior sheet 12 are joined by heat fusion or the like. Thereafter, the product is divided in the line direction (the dividing means is not shown) to obtain individual products.

(First form of opening process)
The opening process can be performed by a line having a form (reference form) shown in FIG. 11, for example. That is, according to the number of filament aggregate parts provided in a single absorbent body (two in the illustrated example), the opening lines L1 and L2 are individually provided, and the tows 52Y are individually opened by the lines L1 and L2. The filament aggregates 52Z are respectively formed by fibering, and the plurality of filament aggregates 52Z are arranged in a predetermined arrangement (in the illustrated example, the upper and lower layers are arranged, but they can be arranged in parallel in the CD direction or they can be combined). After the assembly, the superabsorbent polymer particles 54 are sprinkled and supplied by the superabsorbent polymer particle spraying means 90 and then sent to the sailor 92. These filament aggregates 52Z become the filament aggregate portions 52A and 52B in the above-described absorber 56, respectively.

  The tows 52Y of the lines L1 and L2 may be the same, or the types such as the fineness may be different. Further, the degree of opening in each of the lines L1 and L2 can be set individually and can be set to the same level, but can also be made different. Then, at least one of the basis weight, thickness, elasticity, density, and rigidity of the obtained filament aggregate 52Z (filament aggregate portions 52A and 52B) can be made different.

  More specifically, in each fiber opening line L1, L2, the toe 52Y is pulled out from the bail 52X, and the first nip 126A, the second nip 126B, And through the third nip 126C, it is guided to the thickening device 110.

  The tow is pulled out from the bale 52X by being pulled in by the first nip 126A (corresponding to a driving nip roll). Characteristically, the tow 52Y pulled out from the bail 52X is subjected to a first nip through a nip of a free nip roll 124 composed of a pair of nip rolls configured to rotate freely after the angle is changed by the turn portion 122. It is drawn in by 126A. In such a configuration, the transfer resistance of the free nip roll 124 (determined according to the nip pressure and the roll weight) functions as a brake that suppresses the pull-in speed of the tow 52Y, and the tension after the free nip roll 124 becomes stable. This is because the rotation of the free nip roll 124 occurs only when the tow passes. As a result, the size, weight and quality of the absorber are stabilized.

  The nip pressure and the own weight of the free nip roll 124 may be determined as appropriate. In normal cases, the nip pressure is preferably more than 0 MPa and less than 10 MPa, and the roll weight is more than 0 kg and less than 10 kg per roll. Is preferred. Within this range, stabilization of the tension can be easily realized.

  The tow 52Y pulled out from the bale 52X is between the bale 52X and the free nip roll 124, between the free nip roll 124 and the first nip 126A, between the first nip 126A and the second nip 126B, and second. The widening device 120 provided between the nip 126B and the third nip 126C respectively widens in steps to a desired width. At this time, it can also be enlarged in the thickness direction.

  12 and 13 show an example 120 of a widening device. The widening device 120 includes a rectangular tube passage 120A having a predetermined width X through which the tow 52Y passes, and a compressed air jet outlet 120B formed on a surface along the width direction on the inner surface of the passage 120A. The tow 52Y to be introduced is widened to the full width of the passage by the force of compressed air. The height of the passage is equal to or greater than the thickness of the tow 52Y to be introduced. When the thickness of the passage is higher than the thickness of the tow 52Y, the tow 52Y is also expanded in the thickness direction.

  As shown in FIG. 13, the jet outlet 120 </ b> B is symmetrical with respect to the center in the width direction of the passage 120 </ b> A, and has a dogleg shape (or V-shape) positioned downstream in the toe passage direction toward the center in the width direction of the passage 120 </ b> A. Shape) is a slit.

  When the tow enters the passage 120A in a state where air is ejected from the slit 120B, the tow 52Y has a width so as to receive the force of the compressed air in a balanced manner even if the entry position is deviated from the center in the width direction. The tow 52Y is naturally guided to the center in the width direction of the passage 120A. That is, the introduction position of the toe 52Y can be centered using compressed air for widening. Further, in this embodiment, since the tow 52Y is guided in a non-contact manner, there is an advantage that damage and collapse of the tow are less likely to occur compared to the case where the tow 52Y is guided by contact. Further, the widening device 120 having such a centering function exhibits not only the centering in the widening but also the function of correcting the transfer position.

  When performing the centering using the compressed air as described above, the shape of the slit is not limited to the square shape, the line is symmetrical with respect to the center in the width direction of the passage 120A, and the toe passing direction is directed toward the center in the width direction of the passage 120A. As long as the conditions located on the downstream side are satisfied, it may be formed in a curved shape, an arc shape, or the like.

  On the other hand, tension is applied between the first nip 126A and the second nip 126B so as to apply tension to the tow 52Y, and conversely, the second nip 126B and the third nip 126C are relaxed. In addition, the peripheral speed of each nip roll is set. As a result, tension is applied to the tow 52Y between the first nip 126A and the second nip 126B, so that the entanglement between the filaments is forcibly removed to some extent, and the separation of the filaments is promoted. With the separation, the toe 52Y is widened by the widening device 120, so that the tow 52Y can be further uniformly widened. Further, the tow 52Y is widened by the widening device 120 while the tow 52Y is relaxed between the second nip 126B and the third nip 126C, so that the toe 52Y can be further uniformly widened. The opened state in this part can be changed mainly by changing the tension.

  In a more preferred form, one roller of the second nip 126B is formed with a large number of continuous grooves in the circumferential direction at small intervals in the longitudinal direction. This groove has a function of accelerating tow breaking by allowing the filament to enter into a large number of grooves. Further, in this case, in order to enhance the effect of the groove, the holding angle of the toe 52Y (the rotation direction angle of the toe contact portion) in one grooved roller of the second nip 126B is increased, and the tow 52Y and the grooved roller are Increasing the contact area is also a preferred form. Specifically, the angle formed by the tow 52Y upstream of the second nip 126B and the tow 52Y downstream, that is, the direction change angle by the grooved roller is less than 180 degrees, particularly an acute angle (smaller than 90 degrees). It is preferable to configure. The opening state also changes by adopting the grooved roller.

  In addition, the first nip 126A, the second nip 126B, and the third nip 126C may have different combinations of roll diameters, but in that case, the tension applied to the tow 52Y between the rolls due to the difference in peripheral speed, Since the contact resistance between the roll and the tow 52Y and the like may be non-uniform in the toe width direction, it is preferable that all of them be configured in common.

  Next, the tow 52 </ b> Y that has passed through the third nip 126 </ b> C is guided to the thickening device 110. The thickening device 110 has a structure similar to that disclosed in, for example, Japanese Patent Application Laid-Open No. 59-500392 (WO 83/03267), and schematically shows an inlet 110A and an outlet 110B as shown in FIG. A venturi section 110b is formed between the venturi section 110b, a compressed air inlet 110a on the inlet side, and an air exhaust hole 110c in the venturi section 110b. In plan view, it has a substantially rectangular shape and is flat in a direction penetrating the paper surface of FIG.

  When the compressed air is blown from the blowing port 110a, air is introduced from the inlet 110A by the ejector effect, and as a result, each tow 52Y is drawn into the passage and given a forward force. Each toe 52Y is exhausted from the air exhaust hole 110c at a position past the venturi part 110b, and the space of the venturi part 110b is enlarged, so that the bulk of the toe 52Y mainly increases in the thickness direction, The thickness is increased. In addition, widening is possible as shown in the lower part of FIG. Also in this thickening device 110, the spread state can be changed mainly by changing the passage size, the amount of compressed air, the air distribution in the width direction, and the like.

(Second form of opening process)
15 and 16 show an example of a production line (reference form) suitable for forming the absorber structure shown in FIG. That is, supply lines L1 and L2 are individually provided in accordance with the number of tows to be combined (two in the illustrated example), and a plurality of tows 52Y supplied from the lines L1 and L2 are collectively introduced into the thickening device 110. The first embodiment is basically the same as the first embodiment except that an integral filament aggregate 52Z is formed. In the illustrated example, a plurality of tows 52Y are stacked one above the other, but they can be arranged in the CD direction or a combination thereof.

  More specifically, the tows 52Y that have passed through the third nip 126C of each of the lines L1 and L2 are collectively introduced into the thickening device 110 in a desired mutual arrangement such as being stacked vertically. When the compressed air is blown from the blowing port 110a, air is introduced from the inlet 110A by the ejector effect, and as a result, each tow 52Y is drawn into the passage and given a forward force. When each toe 52Y reaches the venturi portion 110b, the air is exhausted from the air exhaust hole 110c, and the space of the venturi portion 110b is enlarged, so that the bulk of the toe 52Y is mainly thick as shown in FIG. The direction increases and the thickness is expanded. In addition, widening is possible by making the width | variety of a channel | path wider than the width | variety of the toe 52Y introduced. At this time, as the distance between the filaments 52 and 52 in each toe 52Y increases and the bulk increases, the filaments 52 and 52 of the adjacent tows are entangled with each other to form an integral filament aggregate 52Z. Is done.

  The plurality of tows 52Y supplied from the lines L1 and L2 may pass through the passage of the thickening device 110 as they are. However, as shown in FIG. 18, the plurality of tows 52Y are gathered on the entrance side of the passage. When the adjacent tow 52Y is pressed between the single nip rolls 126D and the adjacent tows 52Y are pressed together, a plurality of tows 52Y can be gathered in advance, and the introduction into the passage becomes smooth and the filaments of the adjacent tows 52Y This is preferable because it becomes easier to entangle.

(Third form of the opening process)
As shown in FIG. 6, when a nonwoven fabric is sandwiched between adjacent filament assembly portions 52A and 52B, as shown in FIG. 19, in the second embodiment, a plurality of tows 52Y supplied from the lines L1 and L2 are used. Are collectively introduced into the thickening device 110, the nonwoven fabric 57 fed from a roll (not shown) is supplied and sandwiched between the tows 52Y (embodiment of the present invention). In this case, not only the plurality of tows 52Y but also the nonwoven fabric 57 increases in volume due to the expansion of the fiber interval, the filaments of the adjacent tows 52Y and the fibers of the nonwoven fabric 57 are entangled with each other, and an integral filament aggregate 52Z is formed. It is formed. As shown in FIG. 20, also in the first embodiment, the non-woven fabric fed out from a roll (not shown) when assembling a plurality of filament aggregates 52Z individually opened and formed in each line L1, L2 into a predetermined arrangement 57 can be supplied and sandwiched between the filament aggregates 52Z (reference form).

(Fourth form of opening process)
FIG. 21 shows a fourth form (reference form). That is, in this embodiment, as described in the first embodiment, a plurality of filament aggregates 52Z that are individually opened in the respective lines L1 and L2 are assembled and arranged as described in the second embodiment. It introduces into the thickening apparatus 110, and integrates it by blowing a compressed air in a channel | path, letting the several filament aggregate 52Z pass in a single channel | path.

(Super absorbent polymer particle spraying means)
As the means 90 for dispersing the superabsorbent polymer particles to the filament aggregate 52Z, it is preferable to disperse the superabsorbent polymer particles in substantially the entire thickness direction of the filament aggregate 52Z. As such a superabsorbent polymer particle spraying means 90, a means for giving an acceleration force as well as a dropping force due to the weight of the superabsorbent polymer particle itself is desirable. An example of this is shown in FIG. In other words, a rotary drum 90b having a projection hole 90d in a casing 90a having an opening in the lower portion is configured to rotate in the moving direction of the web (counterclockwise in FIG. 22), and a shutter drum 90c is provided therein. It is a thing. The projection unit 90A including these elements is connected to the hopper 90B (see FIG. 11), and the superabsorbent polymer particle spraying means 90 is configured.

  The superabsorbent polymer particles 54 from the hopper 90B are configured to be supplied into the rotary drum 90b. Here, the opening position of the shutter drum 90c is adjusted in advance with respect to the opening position of the casing 90a. The state shown in FIG. 22 shows a fully open state that is completely coincident. Further, the projection holes 90d of the rotary drum 90b are divided into four groups in the circumferential direction as shown in the drawing as a group divided in the circumferential direction. Therefore, in the process shown in the drawing, four sheets of paper diapers are rotated. In contrast, superabsorbent polymer particles are dispersed and projected.

  The superabsorbent polymer particles 54 may be continuously dispersed and projected onto the aggregate of the filaments 52. However, as shown in FIG. 10, the absorbent element 50 is divided in the line direction by the cutter device 94, and individually. When the absorbent element 50 is used, the blade of the cutter device 94 is worn out in a short time due to the presence of the superabsorbent polymer particles 54. Therefore, it is desirable that the superabsorbent polymer particles 54 are not sprayed and projected continuously, but intermittently sprayed and projected only in the zone Z as shown in FIG.

  For this reason, as described above, the projection holes 90d of the rotary drum 90b are formed as a group divided in the circumferential direction, in the figure, divided into four groups in the circumferential direction, thereby forming the superabsorbent polymer particles 54. Is intermittently scattered and projected only in the zone Z. As a result, the zone Z can be divided between the zones Z by the cutter device 94, and wear of the blade of the cutter device 94 can be suppressed.

  The amount of the superabsorbent polymer particles sprayed can be adjusted mainly by adjusting the opening diameter of the projection hole 90d and the position of the opening of the shutter drum 90c with respect to the opening position of the casing 90a. The position should be followed. Moreover, the dispersion pattern of the superabsorbent polymer particles can be adjusted by the arrangement of the divided projection holes 90d.

  On the other hand, if necessary, the superabsorbent polymer particles 54 are dispersed and projected onto the aggregate of the filaments 52 together with the pressure air, so that the superabsorbent polymer particles are substantially entirely in the thickness direction with respect to the aggregate of filaments. It is also possible to disperse them. However, it is not recommended because the superabsorbent polymer particles dispersed and projected on the aggregate of filaments 52 are scattered by the pressure air and scattered outside the predetermined region.

  Further, together with or instead of the superabsorbent polymer particle spraying means 90, the superabsorbent polymer particles 54 sprayed on the filament aggregate may be sucked from below the filament aggregate.

  Further, as shown in FIG. 23, the rotating roll of FIG. 10 is replaced with a vacuum roll 106, and not the spraying means 90 for spraying the superabsorbent polymer particles by applying the centrifugal component described above, but simply the superabsorbent polymer particles. The superabsorbent polymer particles 54 can also be sprayed onto the aggregate 52Z of the filaments 52 from above the vacuum roll 106 by the general-purpose superabsorbent polymer particle spraying means 90 of the type that drops the water by its own weight. In this case, since the superabsorbent polymer particles enter the aggregate of the filaments 52 by the suction force of the vacuum roll 106, the superabsorbent polymer particles are dispersed below the absorber 56 in the product stage. FIG. 24 shows a case where the rotating roll in the example of FIG.

  The aggregate 52Z of filaments 52 is transferred to the holding sheet 80 (on the covering sheet 58 when the holding sheet is omitted) arranged on the covering sheet 58 in the rolling roll or vacuum roll 106, and then the sailor It is wrapped by the covering sheet 58 by passing through 92.

  On the other hand, when the superabsorbent polymer particles 54 are included in the filament aggregate 52Z, as shown in FIG. 11 and FIG. 23, after the plurality of filament aggregates 52Z are assembled and arranged, they are integrally superabsorbed. 25, as shown in FIG. 25, a superabsorbent polymer particle spraying means 90 is provided for each line L1 and L2 individually, and the superabsorbent polymer is individually separately provided for each filament aggregate 52Z. After supplying the particles, they can be assembled. Although not shown, the superabsorbent polymer particle spraying means 90 is provided in one of the lines, but the superabsorbent polymer particle spraying means 90 is not provided in the other line, and the filament assembly including the superabsorbent polymer particles. After forming the body 52Z and the filament aggregate 52Z that does not include the body 52Z, these can also be arranged together. Moreover, although not shown in figure, the superabsorbency after individual arrangement | positioning of each filament assembly 52Z as shown in FIG. It can also be combined with an integral supply of polymer.

  When individual supply of the superabsorbent polymer to each filament aggregate 52Z is performed, the type of superabsorbent polymer particles in each filament aggregate 52Z, the applied amount (including when the applied amount is zero), the dispersion mode, the density, etc. They can be determined individually and can be all the same, or the type and amount of superabsorbent polymer particles in any filament aggregate 52Z can be different from those of the other filament aggregates 52Z.

  In any of the above forms, the aggregate 52Z of the filaments 52 is placed on the holding sheet 80 disposed on the covering sheet 58 in the rolling roll or vacuum roll 106 (when the holding sheet is omitted, the covering sheet 58 is omitted). After being transferred to (above), it is wrapped by the covering sheet 58 by passing it through the sailor 92. Therefore, when the final adjustment of the aggregate 52Z of the filaments 52 is performed, after the formation of the filament aggregate 52Z, before the wrapping by the sailer 92, in the case of the illustrated embodiment, the sailer 92 immediately before or after the transition. It is desirable to carry out before.

  For example, during the transition, the aggregate 52Z of the filaments 52 is slightly crushed by the transition force and the tensile force of the line, and the feeling of fluff is reduced due to the reduction in raising. However, in order to ensure the transfer, it is necessary to apply the transfer force as necessary and sufficient. Therefore, it is a preferable mode that the air injection nozzle 127 is provided immediately after the roll or vacuum roll 106, for example, and air is blown onto the upper surface of the aggregate 52Z of the filaments 52. Thereby, the entanglement of the fibers becomes strong and the integrity of the filament aggregate 52Z is improved. The direction and angle of the air injection nozzle 127 can be freely set and adjusted according to the purpose. Further, in order to blow air uniformly in the width direction, it is preferable to provide a plurality of outlets 127x at predetermined intervals in the width direction as shown in the plan view of FIG. In this case, the air can be distributed and supplied from the common air supply pipe 127s to each outlet 127x.

  As another final adjustment, for example, an air injection nozzle 128 that injects air only to both ends of the aggregate 52Z of the filaments 52 can be provided immediately before the sailor 92, for example. Thereby, only the both ends of the aggregate | assembly 52Z of the filament 52 can be widened, the shape of an absorber can be prepared, and the intertwining of the fibers in an edge part also becomes strong. The air injection nozzle 128 can be applied in combination with or in place of the air injection nozzle 127 described above. The widening by the air injection nozzle 128 is not limited to simple width, for example, in order to ensure that the polymer migration-preventing adhesive applied by the adhesive application device 104 does not protrude from the end of the assembly 52Z and is hidden as appropriate. Can be done for the purpose. The direction and angle of the air injection nozzle 128 for widening can be freely set and adjusted according to the purpose. Further, as shown in the plan view of FIG. 21B, the widening nozzle 128 has a pair of outlets 128x spaced in the width direction according to the width of the aggregate 52Z of filaments 52, A configuration may be adopted in which air is distributed and supplied from the common air supply pipe 128s to each outlet 128x.

(Example of tape-type disposable diapers)
FIG. 26 shows an example of a method for manufacturing the tape-type disposable diaper shown in FIGS. 8 and 9, and this example employs the opening process of the first embodiment described above. Moreover, FIG. 27 employs the opening process of the second embodiment. In either case, the supply of the intermediate sheet (second sheet) 40 is the same as in the case of the pants type. After the intermediate sheet 40 is intermittently supplied, the top sheet 30 is supplied from above, and the body fluid impermeable sheet 70 is supplied from below, and then the barrier sheet 64 constituting the barrier cuff 60 is supplied. In the supply line of the barrier sheet 64, supply is performed in a state where the thread rubber 62 is fixed under stretch between two nonwoven fabrics in advance by a device (not shown). At the end of the line, the semi-finished product with the absorbent main body is divided by the cutter device 98 to obtain the product 10.

  The present invention is suitable for absorbent articles such as paper diapers, sanitary napkins, incontinence pads, and absorbent pads used in combination with diaper covers.

  DESCRIPTION OF SYMBOLS 10 ... Pants type disposable diaper, 10A ... Tape type disposable diaper, 12 ... Exterior sheet, 12A ... Back sheet, 20 ... Absorbent main body, 30 ... Top sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 52 ... Filament, 52X ... Veil, 52Y ... Toe, 52Z ... Aggregation of filaments, 54 ... Superabsorbent polymer particles, 56 ... Absorber, 57 ... Nonwoven fabric, 58 ... Cover sheet, 60, 60A ... Barrier cuff, 64 ... Barrier sheet, 70 ... body fluid impermeable sheet, 72 ... second body fluid impermeable sheet, 80 ... holding sheet, 90 ... superabsorbent polymer particle spraying means, 90A ... projection unit, 90a ... casing, 90b ... rotating drum, 90c ... shutter drum , 92 ... Sailor, 94 ... Cutter device, 98 ... Cutter device, 100 ... Turning device, 102 ... Combination station DESCRIPTION OF SYMBOLS 104 ... Adhesive coating device, 110 ... Composite fiber opening device, 110a ... Pressure air blowing port, 110b ... Venturi section, 120 ... Widening device, 124 ... Free nip roll, 126A ... First nip, 126B ... Second nip, 126C ... 3rd nip, 130 ... Fastening piece, E ... Recess, Z ... Superabsorbent polymer particle spray zone.

Claims (3)

It is a method of opening a tow to form a filament assembly, and manufacturing an absorber using this filament assembly,
During the opening, a plurality of tows having different properties and non-woven fabrics which are not bonded to each other and are formed only by entanglement are stacked in a single passage with the nonwoven fabrics sandwiched between the tows. Compressed air is blown into the passage while passing through and the plurality of tows are spread together, and the bulk of the nonwoven fabric is increased by increasing the fiber spacing, so that the adjacent tow filaments and the nonwoven fabric fibers are entangled with each other. A method for manufacturing an absorbent body, characterized in that an integral filament assembly is formed.   The absorbent body manufacturing method according to claim 1, wherein after forming the integral filament aggregate, superabsorbent polymer particles are dispersed and supplied onto the integral filament aggregate.   The absorber manufacturing method according to claim 1 or 2, wherein at least one of the basis weight, thickness, elasticity, density, and rigidity of the plurality of filament aggregate portions is different.

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