JP2009268921A - Manufacturing method for absorbing body and absorbing body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent sandy touch or the like and unintentional deviation of absorbing characteristic in the case of using tow (a fiber bundle). <P>SOLUTION: This method for manufacturing an absorbing body includes: a polymer applying process of applying high absorptive polymer to the outer surface of a fiber aggregate 10 formed of tow made of fibers; and a polymer migration process of passing gas through the fiber aggregate 10 to which high absorptive polymer is applied to migrate the high absorptive polymer into the fiber aggregate 10 by the passing force of gas, wherein before the polymer migration process, the surface of the fiber aggregate 10 to which the high absorptive polymer has been applied is covered with a sheet 13, and in the polymer migration process, suction is performed from the surface on the opposite side to the surface covered with the sheet 13 in the fiber aggregate 10 to thereby migrate the high absorptive polymer into the fiber aggregate 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an absorbent body used for body fluid absorbent articles such as paper diapers and sanitary napkins, and a method for producing the absorbent body.

  Conventionally, an absorbent body used for a body fluid absorbent article has been formed by stacking short pulp fibers and superabsorbent polymer particles on a stacking drum, and then packaging them with an absorbent sheet such as crepe paper. On the other hand, in recent years, it has been proposed to use a tow (fiber bundle) composed of fibers as an absorbent body instead of a short fiber stack (see, for example, Patent Document 1).

  However, as shown in FIG. 15, the absorbent body 120 using the conventional tow has only the high-absorbent polymer 122 dispersed on the band-like tow 125 and then wrapped with the sheet 123 coated with the bead. Therefore, most of the superabsorbent polymer 122 is not held by the tow 125 or the sheet 123 and can move freely, and it has a crisp feel and an unintentional bias in absorption characteristics such as absorption amount occurs. There was a problem such as.

JP 2001-524399 A

  Thus, the main problem of the present invention is to eliminate the above-mentioned problems.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A polymer application step for applying a superabsorbent polymer to the outer surface of the fiber assembly made of tows composed of fibers;
A polymer moving step of passing a gas through the fiber assembly to which the superabsorbent polymer has been applied, and moving the superabsorbent polymer into the fiber assembly by the passing force of the gas;
Have
Prior to the polymer transfer step, a sheet is put on the surface of the fiber assembly to which the superabsorbent polymer has been applied,
In the polymer moving step, the superabsorbent polymer is moved into the fiber assembly by performing suction from the opposite side of the surface of the fiber assembly that covers the sheet.
The absorber manufacturing method characterized by the above-mentioned.

(Function and effect)
In the present invention, since the superabsorbent polymer can be moved into the fiber assembly by using the gas passing force, more superabsorbent polymer is contained in the fiber assembly as compared with the conventional method in which only the dispersion is performed. To be held well. Therefore, a crisp feel can be reduced. In addition, unintentional biases in the absorption characteristics such as the absorption amount are less likely to occur, in other words, the absorption characteristics can be made in an intended form, for example, uniform or non-uniform.

  In particular, when the sheet is arranged on one side of the fiber assembly and suction is performed from the opposite side, the suction force acting on the superabsorbent polymer increases, and the superabsorbent polymer can be moved more efficiently. become able to.

<Invention of Claim 2>
While applying an adhesive to the fiber assembly before applying the superabsorbent polymer,
The absorbent body manufacturing method according to claim 1, wherein an adhesive is applied to a surface of the sheet on the fiber assembly side before covering the sheet.

(Function and effect)
The superabsorbent polymer can be adhered to the fiber assembly and the sheet, and a crisp feel and an unintentional bias in the absorption characteristics can be more effectively prevented.

<Invention of Claim 3>
The absorber manufacturing method of Claim 2 which apply | coats an adhesive agent to the fiber assembly after moving the said superabsorbent polymer in a fiber assembly.

(Function and effect)
The superabsorbent polymer can be adhered to the fiber assembly while being moved as desired by suction. Therefore, it is possible to more effectively prevent a crisp feel and an unintended bias in the absorption characteristics.

<Invention of Claim 4>
The absorber according to claim 2 or 3, wherein, in the polymer moving step, the gas passage force acts on the intermediate portion in the width direction or the intermediate portion in the longitudinal direction of the fiber assembly stronger or longer than the other portions. Production method.

(Function and effect)
As described above, when a portion having a relatively strong gas passing force and a weak portion are provided, or a portion having a relatively long action time is provided, a movement amount of the superabsorbent polymer in the fiber assembly is relatively increased. Resulting in higher and lower portions, resulting in higher and lower density portions of the superabsorbent polymer in the fiber assembly. Therefore, the intended bias can be given to the absorption characteristics such as the absorption speed of the absorber.

<Invention of Claim 5>
An absorbent body produced by the method for producing an absorbent body according to claim 2 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and the sheet surrounding them.
The superabsorbent polymer is fixed by the adhesive between the fiber aggregate and the sheet on only one of the upper and lower sides of the fiber aggregate, and the superabsorbent polymer is contained in the fiber aggregate. An absorbent body characterized by being held.

(Function and effect)
By configuring in this way, most of the superabsorbent polymer is adhered, so that the superabsorbent polymer is difficult to move, and a crisp feel and an unintentional bias in absorption characteristics can be effectively prevented. .

<Invention of Claim 6>
An absorbent body produced by the method for producing an absorbent body according to claim 3 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and the sheet surrounding them.
The superabsorbent polymer is fixed by the adhesive between the fiber aggregate and the sheet on both upper and lower sides of the fiber aggregate, and the superabsorbent polymer is held in the fiber aggregate. An absorber characterized by that.

(Function and effect)
By configuring in this way, the superabsorbent polymer is adhered, so that the superabsorbent polymer is difficult to move, and it is possible to effectively prevent a crisp feel and unintentional bias in the absorption characteristics.

<Invention of Claim 7>
An absorbent body produced by the absorbent body production method according to claim 4 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and a sheet that wraps these.
The absorbent body characterized in that the amount of the superabsorbent polymer in the intermediate portion in the width direction or the intermediate portion in the longitudinal direction of the fiber assembly is larger than the amount of the superabsorbent polymer in other portions.

(Function and effect)
In this way, by providing a portion having a relatively large amount and a portion having a relatively high amount of the superabsorbent polymer, an intended bias can be given to the absorption characteristics of the absorber.

  In particular, when the amount of the superabsorbent polymer in the intermediate portion in the width direction of the fiber assembly is larger than the amount of the superabsorbent polymer in both sides in the width direction of the fiber assembly, when used for a body fluid absorbent article, A large amount of absorption can be ensured in a portion to which more body fluid is supplied.

  According to the present invention, there is an advantage that a crisp feel can be reduced, or an unintended bias in absorption characteristics such as an absorption amount hardly occurs.

It is the schematic which shows the manufacturing flow of a fiber assembly. It is the schematic which shows the manufacture flow of an absorber. It is a longitudinal section showing a 1st form of an absorber roughly. It is a longitudinal section showing a 1st form of an absorber roughly. It is a longitudinal section showing a 1st form of an absorber roughly. It is a longitudinal section showing a 1st form of an absorber roughly. It is a longitudinal section showing a 1st form of an absorber roughly. It is a longitudinal section showing a 1st form of an absorber roughly. It is a top view which shows the 2nd form of an absorber roughly. It is a longitudinal cross-sectional view which shows the 2nd form of an absorber roughly. It is a top view which shows the 2nd form of an absorber roughly. It is a longitudinal cross-sectional view which shows the 3rd form of an absorber roughly. It is a top view which shows roughly the 4th form of an absorber. It is the schematic which shows the various forms of an absorber. It is a longitudinal cross-sectional view which shows the conventional absorber schematically.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
<Composition of fiber assembly>
The fiber assembly used in the present invention is composed of tows (fiber bundles) composed of fibers. Examples of tow fibers include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.). In particular, cellulose esters and cellulose are 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 a spun fiber. The shape and size of cellulose is a continuous fiber that can be regarded as a substantially infinite length and has a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and a particle diameter of about several microns (for example, 1 to 100 μm). Can be selected from various sizes up to a fine powder. Cellulose may be fibrillated, such as beaten pulp.

  Examples of cellulose esters 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 polycaprolactone Cellulose ester derivatives such as 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.

  The tow constituent fiber 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 tow constituent fibers can be, for example, about 1 to 16 denier, preferably 1 to 10 denier, and more preferably about 2 to 8 denier. The tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. 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 tow constituting fiber is not particularly limited, and may be any one of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good. The tow constituting fibers are used in the form of tows (fiber bundles) formed by bundling, for example, about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. can do. The fiber bundle is preferably formed by bundling about 3,000 to 1,000,000 continuous fibers.

  Since the entanglement between fibers is weak, a binder having an action of adhering or fusing the contact portions of the fibers can be used mainly for the purpose of maintaining the shape. Examples of binders include triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate ester plasticizers, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force when melted and solidified, and includes a water-insoluble or hardly water-soluble resin and a water-soluble resin. 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.

<Method for producing fiber assembly>
The fiber assembly of the present invention made of tow can be produced by a known method, and if necessary, it can be opened in a band shape so as to have a desired size and bulk. The opening width of the tow is arbitrary, and can be, for example, about 100 to 2000 mm, preferably about 150 to 1500 mm. Opening the tow is preferable because the movement of the superabsorbent polymer described later becomes easier. Moreover, the density of an absorber can be adjusted by adjusting the degree of tow opening.

  As a method for opening a tow, for example, a method in which a tow is passed over a plurality of opening rolls and the width of the tow is gradually expanded as the tow progresses, and tension (elongation) and relaxation of the tow ( (Shrinkage) can be repeated, and a method of widening and opening using compressed air can be used.

  FIG. 1 is a schematic diagram showing an example of a fiber opening facility. In this example, the tow 1 serving as a raw fabric is sequentially fed out, and in the process of conveying, the widening means 2 using compressed air and a plurality of spread nip rolls 3, 4, and 5 whose peripheral speed is faster as the roll on the downstream side is combined. After passing through the opened portion and widened / opened, the fiber is passed through the binder addition box 6 to which a binder is added (for example, the box is filled with a mist of triacetin), and the fibers are made of tow having a desired width and density. It is formed as an aggregate 10.

<Method for producing absorber>
Next, an example of an absorber manufacturing facility using the fiber assembly obtained as described above will be described. FIG. 2 shows an example of manufacturing equipment, in which a continuous belt-like fiber assembly 10 made of tows having a desired width and density is supplied. For this reason, this absorber manufacturing line can be directly connected to the above-mentioned fiber assembly line, and the manufactured fiber assembly 10 can be directly fed into the absorber manufacturing line.

  The supplied fiber assembly 10 is first passed through a polymer spraying box 11, and after the superabsorbent polymer is sprayed on the upper surface thereof, it is fed into the suction drum 12. The suction drum 12 has an intake hole in the outer peripheral wall, and is configured to be sucked by a suction pump (not shown) from the inside over a predetermined range in the circumferential direction (a range substantially in the left half in the illustrated example). The fiber assembly 10 on which the polymer is dispersed is guided by the suction drum 12 while being in contact with the outer peripheral surface. In this process, suction is performed from the suction hole of the suction drum 12 so that the atmosphere passes from the superabsorbent polymer imparting side through the fiber assembly 10 to the opposite side. The polymer is moved into the fiber assembly 10.

  As the superabsorbent polymer, a polymer that absorbs and retains bodily fluids, for example, ten times or more of its own weight can be used. Examples include starch-based, cellulose-based and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, cross-linked sodium carboxymethyl cellulose and acrylic acid. A (salt) polymer or the like can be used. As the shape of the superabsorbent polymer, a commonly used granular material is suitable, but other shapes can also be used.

The amount (weight per unit area) of the superabsorbent polymer can be appropriately determined according to the amount of absorption required for the use of the absorber. Thus can not be said sweepingly, typically 0.03 g / cm ² or less, particularly preferably be a 0.01~0.025g / cm ^2.

  In a particularly preferred form, after the superabsorbent polymer is sprayed on the fiber assembly 10, the sheet 13 is further covered thereon. In this case, in the suction drum 12, suction is performed from the side surface opposite to the surface of the fiber assembly on which the sheet 13 is covered. In this way, when the sheet 13 is covered prior to suction, a stronger suction force acts on the high-absorbent polymer than when nothing is covered, and the high-absorbent polymer is efficiently gathered into the fiber assembly. It can be moved and dispersed inside the body 10. As the sheet 13, a liquid permeable sheet such as a crepe paper, a nonwoven fabric, a perforated sheet, or a liquid impermeable sheet such as a polyethylene film can be used. In particular, an absorbent sheet such as crepe paper is preferably used.

  In order to fix the superabsorbent polymer to the fiber assembly 10, it is also preferable to apply an adhesive to the fiber assembly 10 before the superabsorbent polymer is applied. For this reason, as shown in the figure, the adhesive application device 14 can be disposed on the upstream side of the polymer spraying box 11. Although not shown, an adhesive is applied to the fiber assembly 10 after the application of the superabsorbent polymer and before the superabsorbent polymer is moved into the fiber assembly 10. It is also possible to apply an adhesive to the fiber assembly 10 during the period from exiting the box 11 to entering the suction drum 12.

  Moreover, when covering the sheet | seat 13, prior to covering the sheet | seat 13, it is also a preferable form to supply an adhesive agent to the surface used as the fiber assembly 10 side of the sheet | seat 13. FIG. For this reason, in the illustrated embodiment, an adhesive application device 15 is provided in the sheet supply path to the suction drum 12. When this form is adopted, the superabsorbent polymer exposed on the surface of the fiber assembly 10 is fixed to the sheet 13 via an adhesive, and the non-adherent superabsorbent polymer moves into the fiber assembly 10 by subsequent suction. Will come to be.

  Furthermore, it is also a preferable form to supply the adhesive to the fiber assembly 10 after suction, that is, after moving the superabsorbent polymer. For this reason, in the illustrated embodiment, an exposed side surface (the surface opposite to the sheet 13 side, the upper surface in the drawing) of the fiber assembly 10 on the downstream side of the suction drum 12 is provided. When this form is employed, the superabsorbent polymer that has moved to the side opposite to the polymer application side of the fiber assembly 10 among the applied superabsorbent polymer can be fixed to the fiber assembly 10. Further, when the exposed side surface of the fiber assembly 10 is covered with a separate sheet or both sides of the sheet 13 are wrapped around both ends of the fiber assembly 10 as described later, the exposed side surface of the fiber assembly 10 is exposed. The superabsorbent polymer that has moved to can be fixed to the sheet 13.

  Any one or a combination of two or more of these adhesives can be applied. As the adhesive, an adhesive made of a thermoplastic resin (specific examples are as described above) can be suitably used.

  Thus, the fiber assembly 10 to which the superabsorbent polymer has been applied is, for example, covered with a separate sheet, or wrapped around both sides of the sheet 13 with both ends of the fiber assembly 10 by a sailor as shown in the figure. After that, it is cut into a predetermined length to form individual absorbent bodies 17.

  On the other hand, the amount distribution of the superabsorbent polymer with respect to the fiber assembly 10, the density distribution of the superabsorbent polymer, and the fiber density distribution are preferably uniform for general purposes, but exhibit special absorption characteristics. For this purpose, it is also preferable to provide a relatively large portion / small portion, or a high portion / small portion depending on the purpose.

  Specifically, when applied to the illustrated embodiment, the polymer spraying box 11 can be provided with a relatively large portion and a small portion in the planar direction. In particular, in a body fluid absorbent article, it is often desired to increase the amount of absorption at the central portion in the width direction of the absorbent body. In this case, in the polymer spraying box 11, at the intermediate portion in the width direction of the fiber assembly 10. The superabsorbent polymer can be sprayed so that the amount of the superabsorbent polymer is larger than the amount of the superabsorbent polymer on both sides in the width direction of the fiber assembly 10. Further, in the polymer spraying box 11, the amount of the superabsorbent polymer in the longitudinal intermediate portion of the fiber assembly 10 (longitudinal intermediate portion of each absorber) is high before and after the longitudinal direction of the fiber assembly 10. The superabsorbent polymer can be sprayed so as to be greater than the amount of the absorbent polymer.

  Further, by providing a portion having a high suction force and a portion having a low suction force in the suction drum 12, a higher amount of superabsorbent polymer is positioned on the suction drum 12 side as the suction force is higher. The aggregate 10 can be provided with a relatively high density portion and a low density portion of the superabsorbent polymer. For example, by causing the suction force in the suction drum 12 to act stronger on the intermediate portion in the width direction of the fiber assembly 10 than on both sides in the width direction of the fiber assembly 10 (or to increase the suction time). As shown in FIG. 8 to be described later, the density of the superabsorbent polymer at the center portion in the width direction of the fiber assembly 10 can be made higher than the density of both side portions in the width direction. In such a structure, the absorption rate at the center portion in the width direction of the fiber assembly 10 is low, and the absorption rate at both side portions in the width direction is high. Therefore, when used in a body fluid absorbent article, the body fluid is the absorber. It becomes easy to spread throughout, that is, the diffusibility is improved.

  Furthermore, since the fiber assembly 10 made of tow makes it easy for the liquid to flow along the continuous direction of the fibers, a special absorption characteristic is imparted by providing a relatively high part and a low part of the fiber density. Can do. Such a thing can be achieved by, for example, performing strong fiber opening partially at the time of manufacturing the fiber assembly 10 or partially using a plurality of tows bundled together. As a specific example, for example, as shown in FIG. 10 to be described later, the fiber density of the intermediate portion in the width direction of the fiber assembly 10 made of tow may be higher than the fiber density of both side portions in the width direction. This is a preferred form. In the fiber assembly 10 made of tow, the liquid easily flows along the continuous direction of the fibers, so that more liquid flows along the continuous direction of the fibers at the intermediate portion in the width direction of the fiber assembly 10.

<First form of absorber>
Next, the absorber will be described in detail. FIG. 3 shows a first form of the absorbent body. The absorbent body 20 includes a fiber assembly 21 made of tows composed of fibers, a superabsorbent polymer 22, and a sheet 23 that wraps them. The adhesive 24 is applied on the entire surface or substantially the entire surface of the sheet 23 where at least the superabsorbent polymer is provided. Note that “substantially the entire surface” means 80% of the portion where the superabsorbent polymer is provided.

  More specifically, in the form shown in FIG. 3, a layer made of the superabsorbent polymer 22 is provided on the inner surface of the sheet 23 via the adhesive 24, and the fiber assembly 21 is further provided thereon via the adhesive 25. Further, a sheet 23 is bonded onto the fiber assembly 21 via an adhesive. The sheet 23 in the illustrated example is configured to wrap the fiber assembly 21 and the superabsorbent polymer 22 by being folded back on both sides, but a form in which the sheet 23 is sandwiched between two upper and lower sheets can also be employed. As this sheet | seat 23, as above-mentioned, an absorptive sheet like a crepe paper is used suitably.

  In addition, on the entire surface or substantially the entire surface of the sheet 23 where at least the superabsorbent polymer is provided, a portion where the adhesive is applied and a portion which does not have a plurality of adhesives surrounded by the portion where the adhesive is applied are provided. It can also be configured to have a superabsorbent polymer adhered to the sheet 23 by a portion to which an adhesive is applied and a superabsorbent polymer present in a portion not having the adhesive.

  When the adhesive 24 is applied in a continuous surface, curtain coating or roll coating can be used. Moreover, when providing the part which apply | coated the adhesive agent and the part which does not have the some adhesive agent enclosed by the part which applied the adhesive agent, spiral application | coating can be used. As the adhesive 24, the aforementioned thermoplastic resin can be suitably used.

  In the present embodiment, most of the superabsorbent polymer 22 is adhered to the sheet 23 by the adhesive 24, or a part of the superabsorbent polymer 22 is adhered to the sheet 23 by the adhesive 24. Most of the superabsorbent polymer 22 is constrained in a closed space that does not have an adhesive surrounded by a portion to which the adhesive is applied. Further, part or all of the superabsorbent polymer 22 is bonded to the fiber assembly 21 with an adhesive 25. Therefore, it is possible to effectively prevent a crisp feel and an unintentional bias in absorption characteristics. In addition, the code | symbol 26 has shown the adhesive agent which adhere | attaches the sheet | seat 23 and the surface on the opposite side to the polymer side surface of the fiber assembly 21. FIG.

  4 to 8 show other applications. The form shown in FIG. 4 is different from the form shown in FIG. 3 in that the superabsorbent polymer 27 is also held in the fiber assembly 21. Such a form can be manufactured by the above-described manufacturing method. The form shown in FIG. 5 is different from the form shown in FIG. 3 in which the superabsorbent polymer 22 is provided only on one side (lower side) of the fiber assembly 21. 22 and 29 are different. In this case, the superabsorbent polymer 29 positioned on the upper side of the fiber assembly 21 can be bonded to the fiber assembly 21 with the adhesive 28. In the form shown in FIG. 6, the superabsorbent polymer 27 is held in the fiber assembly 21 in the form shown in FIG. 5 as in the form shown in FIG.

  Further, the form shown in FIG. 7 is a form in which the adhesive 25 and the superabsorbent polymer layer 22 in the form shown in FIG. 4 are omitted, and the superabsorbent polymer 27 is held only in the fiber assembly 21. This form can be manufactured by the manufacturing method described above. Furthermore, the form shown in FIG. 8 is a layer 21 </ b> B in which only the fiber aggregate (not holding the superabsorbent polymer 27) is separately provided on the fiber aggregate 21 holding the superabsorbent polymer 27 in the form shown in FIG. 7. The fiber assembly 21 holding the superabsorbent polymer 27 and the fiber assembly-only layer 21B are bonded with an adhesive 26B.

  In addition, when these absorbent bodies are used for a body fluid absorbent article, either of them may be used as a body fluid receiving side. In particular, in the embodiment shown in FIGS. 3 and 5, the fiber assembly side is a body fluid receiving side. It is preferable to use it.

<Second form of absorber>
Next, FIG.9 and FIG.10 has shown the 2nd form of the absorber. The absorbent body 30 includes a fiber assembly made of tows composed of fibers and a core portion 31 having a superabsorbent polymer, and a sheet 32 that wraps the core portion 31. A relatively large part and a small part are provided. Some of this amount is indicated by the density of dots in the figure. By comprising in this way, the absorption characteristic of the absorber 30, especially the amount of absorption can be given intentional bias.

  Such a form can be achieved, for example, by providing a portion with a large amount and a small portion with a large amount of polymer spray in the above-described production method.

  In particular, as in the illustrated example, it is preferable that the amount of the superabsorbent polymer in the intermediate portion 30C in the width direction of the fiber assembly is larger than the amount of the superabsorbent polymer in the both side portions 30S in the longitudinal direction of the fiber assembly. It is. In this case, when the body fluid absorbent article (in the illustrated example, the disposable diaper DP) is used in the width direction, a large amount of absorption in the width direction intermediate portion 30C to which more body fluid is supplied can be secured.

  Further, as shown in FIG. 11, it is also preferable that the amount of the superabsorbent polymer in the longitudinal intermediate portion 30M of the fiber assembly is larger than the amount of the superabsorbent polymer in the longitudinal direction 30E before and after the fiber assembly. It is.

  In this embodiment, the superabsorbent polymer may be held in the fiber assembly, held on the surface of the fiber assembly, or both. Furthermore, the superabsorbent polymer may be held only partially on the surface of the fiber assembly, and may be held entirely in the fiber assembly.

<Third form of absorber>
Next, FIG. 12 has shown the 3rd form of the absorber. The absorbent body 40 includes a fiber assembly made of tows composed of fibers and a core portion 41 containing a superabsorbent polymer, and a sheet 42 that wraps these cores. The absorbent polymer has a relatively high density portion and a low density portion. This density level is indicated by gradation in the figure. As described above, if a portion having a relatively high density and a portion having a low density of the superabsorbent polymer in the fiber assembly is provided, it is possible to intentionally bias the absorption characteristics, particularly the absorption rate.

  Such high and low density of the superabsorbent polymer can be achieved by the above-described production method. In this case, in the superabsorbent polymer, the portion where the suction force is strong or long acts, a larger amount of the polymer moves to the suction side, and the density becomes higher.

  In particular, as in the illustrated example, it is preferable that the density of the superabsorbent polymer in the intermediate portion 40C in the width direction is higher than the density of the superabsorbent polymer in both side portions 40S in the width direction. In this case, the absorption speed of the intermediate portion 40C in the width direction is slow, and the absorption characteristics of the both side portions 40S in the width direction are fast. Therefore, when the body fluid absorbent article is used with the width direction aligned, a large amount of body fluid is supplied to the longitudinal direction intermediate portion of the width direction intermediate portion 40C and diffuses well from there to the surroundings, so a wider area is used for absorption. As well as being able to do so, the so-called side leakage is prevented because the absorption speed at both side portions 40S in the width direction is high.

<Fourth form of absorber>
Next, FIG. 13 has shown the 4th form of the absorber. The absorbent body 50 has a fiber assembly made of tows composed of fibers, a superabsorbent polymer, and a sheet that wraps them. Characteristically, the fiber density in the fiber assembly is relatively A high part and a low part are provided. This level of density is indicated by the density of the lines in the figure. A fiber assembly made of tow has a property of diffusing liquid along the continuous direction of the fiber, and this tendency becomes more prominent as the density increases. Therefore, the intended bias can be given to the absorption characteristics of the absorbent body 50 by providing a relatively high fiber density portion and a low fiber density portion in the fiber assembly.

  As described above, such high and low fiber density can be achieved by, for example, performing strong fiber opening partially at the time of manufacturing the fiber assembly, or by partially using a plurality of tows.

  In particular, as in the illustrated example, it is a preferred embodiment that the fiber density of the intermediate portion 50C in the width direction of the fiber assembly is higher than the fiber density of both side portions 50S in the width direction of the fiber assembly. In this case, since the diffusibility of the body fluid in the width direction intermediate portion 50C is higher than the diffusibility of the body fluid in the width direction both side portions 50S, more body fluid is supplied when the body fluid absorbent article is used in the width direction. The body fluid can be easily diffused in the intermediate portion 50C in the width direction, so that a larger area can be used for absorption, and so-called side leakage is effectively prevented because the body fluid is difficult to diffuse in the both side portions 50S in the width direction. The

<Application example to body fluid absorbent article>
FIG. 14 shows an application example of the above-described absorber to the disposable diaper DP and sanitary napkin NP. As shown in FIGS. 14 (a) and 14 (b), the absorbent body 60 is preferably provided so that the fiber continuous direction of the tow is along the longitudinal direction (front-rear direction) of the article, but FIGS. 14 (c) and 14 (d). As shown in Fig. 4, the tow fiber continuous direction can be provided along the width direction of the article.

  The present invention is suitable for absorbents of body fluid absorbent articles such as paper diapers and sanitary napkins and the production thereof, but can be applied to other uses within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Fiber assembly, 11 ... Polymer dispersion | distribution box, 12 ... Suction drum, 13 ... Sheet, 14-16 ... Adhesive application apparatus, 17 ... Absorber.

Claims (7)

A polymer application step for applying a superabsorbent polymer to the outer surface of the fiber assembly made of tows composed of fibers;
A polymer moving step of passing a gas through the fiber assembly to which the superabsorbent polymer has been applied, and moving the superabsorbent polymer into the fiber assembly by the passing force of the gas;
Have
Prior to the polymer transfer step, a sheet is put on the surface of the fiber assembly to which the superabsorbent polymer has been applied,
In the polymer moving step, the superabsorbent polymer is moved into the fiber assembly by performing suction from the opposite side of the surface of the fiber assembly that covers the sheet.
The absorber manufacturing method characterized by the above-mentioned. While applying an adhesive to the fiber assembly before applying the superabsorbent polymer,
The absorbent body manufacturing method according to claim 1, wherein an adhesive is applied to a surface of the sheet on the fiber assembly side before covering the sheet.   The absorber manufacturing method of Claim 2 which apply | coats an adhesive agent to the fiber assembly after moving the said superabsorbent polymer in a fiber assembly.   The absorber according to claim 2 or 3, wherein, in the polymer moving step, the gas passage force acts on the intermediate portion in the width direction or the intermediate portion in the longitudinal direction of the fiber assembly stronger or longer than the other portions. Production method. An absorbent body produced by the method for producing an absorbent body according to claim 2 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and the sheet surrounding them.
The superabsorbent polymer is fixed by the adhesive between the fiber aggregate and the sheet on only one of the upper and lower sides of the fiber aggregate, and the superabsorbent polymer is contained in the fiber aggregate. An absorbent body characterized by being held. An absorbent body produced by the method for producing an absorbent body according to claim 3 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and the sheet surrounding them.
The superabsorbent polymer is fixed by the adhesive between the fiber aggregate and the sheet on both upper and lower sides of the fiber aggregate, and the superabsorbent polymer is held in the fiber aggregate. An absorber characterized by that. An absorbent body produced by the absorbent body production method according to claim 4 and comprising at least a fiber assembly composed of tows composed of fibers, a superabsorbent polymer, and a sheet that wraps these.
The absorbent body characterized in that the amount of the superabsorbent polymer in the intermediate portion in the width direction or the intermediate portion in the longitudinal direction of the fiber assembly is larger than the amount of the superabsorbent polymer in other portions.

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