JP4414363B2 - Method for manufacturing absorbent article - Google Patents

Description

  The present invention relates to an absorbent article for bodily fluids, for example, a method for producing disposable absorbent articles such as disposable diapers and sanitary napkins. In particular, the present invention provides a method suitable for manufacturing a disposable diaper of a pants type or a tape type (including a surface fastening tape).

  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. And an absorption element that receives and holds the excreted body fluid that has permeated through the top sheet.

  For this basic element, an exterior sheet made of, for example, non-woven fabric is provided on the back side of the back sheet, and a form that improves the touch when a plastic sheet is used as the back sheet, so-called barrier cuffs are formed on both sides of the product. In order to improve the fit around the waist and the abdomen, such as the form, a form that imparts 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 SAP is sprayed on the short fiber stack, there are cases where SAP is dispersed and held in the short fiber fiber (Patent Document 1).

  On the other hand, in Special Tables 2002-524399 (WO99 / 27879: Patent Document 2) and Special Tables 2004-500165 (US Pat. No. 6,646,180: Patent Document 3), continuous fibers are used as absorbent elements. It is disclosed.

  On the other hand, the aggregate of filaments is easy to break, so that the shape of the tissue is maintained, and when the SAP particles are included in the absorber or provided below the absorber, the tissue paper ( Wrapping with crepe paper) is required.

In this case, the aggregate of filaments is continuous in the longitudinal direction. Therefore, it is difficult to take a pile form that is put into a mold having a predetermined shape like a short pulp fiber. Therefore, it was a problem how to manufacture the absorbent element.
JP 2004-65300 A Special Table 2002-524399 (WO99 / 27879) 2004-500165 (US Pat. No. 6,646,180)

  Then, the 1st subject of this invention is manufacturing the absorbent article which has an absorbent element provided with the absorber which is excellent in the absorption characteristic of a bodily fluid, and has a comparatively high intensity | strength (koshi). Another object is to produce an absorbent element having a good shape by suitably combining an assembly of filaments continuous in the longitudinal direction and superabsorbent polymer particles.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A method for producing an absorbent article comprising an absorbent element that receives and holds body fluid that has passed through a top sheet on the use surface side,
From the upstream side of the manufacturing process,
The opening process of opening the tow into an assembly of filaments,
Spraying superabsorbent polymer particles on the aggregate of filaments;
A process of continuously wrapping a continuous body of absorbent bodies having an assembly of filaments and superabsorbent polymer particles with a covering sheet;
A step of individually dividing the continuous body of the absorbent body and the covering sheet to obtain an individual absorbent element, and a step of commercializing in combination with other materials while intermittently feeding the individual absorbent element,
The has, and
The step of spraying the superabsorbent polymer particles supplies the aggregate of filaments opened through the opening process onto the covering sheet, and the superabsorbent polymer particles are weighted from the filament aggregate. Projecting by applying an external force to the falling force due to intrusion of the superabsorbent polymer particles into the assembly of the filaments,
The manufacturing method of the absorbent article characterized by the above-mentioned.

(Function and effect)
The absorbent body of the present invention uses an aggregate of filaments obtained by opening a tow. Generally, tow is available as a tow compact called a bale. For example, it is compressed as a band having a width of 20 to 80 mm. As the absorbent body of the absorbent article, a bulky one is desirable. Therefore, the tow is used as an aggregate of opened filaments.
In this invention, the continuous body of the absorber which has the aggregate | assembly of the filament which opened the tow is wrapped with a covering sheet. Therefore, the shape can be maintained by wrapping an assembly of filaments, which are easily broken, with a covering sheet.
Further, instead of the tow stage, superabsorbent polymer particles are mixed into the aggregate of filaments obtained by opening the tow by spraying or the like. As a result, the superabsorbent polymer particles can easily enter the aggregate of filaments. As a result, the body fluid that has penetrated into the absorbent body can be effectively absorbed by the superabsorbent polymer particles.
Since the continuous body of the absorbent body having the aggregate of filaments and the superabsorbent polymer particles is continuously wrapped by the covering sheet, scattering of the superabsorbent polymer particles can be prevented in the production stage and the product stage.
In this invention, after dividing | segmenting the said continuous body of the said absorber and the said covering sheet separately and obtaining an individual absorption element, the form combined with another raw material is taken, sending an individual absorption element intermittently. Therefore, in the case of the length of an absorptive product, a pants type, or a tape type disposable diaper, an absorptive element can be located in the middle of the length of an absorptive main part. By fixing so that the front and back of the absorbent element may be wrapped with another material, it is possible to prevent the highly absorbent polymer particles in the absorbent element from being scattered at the manufacturing stage and the product stage.
Finally, it can be commercialized by combining other materials with other materials.

In order to sufficiently exhibit the absorption effect of the superabsorbent polymer particles, it is desirable that the superabsorbent polymer particles enter the aggregate of filaments.
When the superabsorbent polymer particles are dispersed from above the filament aggregate, the filament aggregate is in a bulky state with many voids between the filaments. It penetrates well into the gap. In particular, instead of spraying the superabsorbent polymer particles only by gravity dropping, the superabsorbent polymer particles can be reliably sprayed into the aggregate of filaments by projecting with an external force. Therefore, for example, a form in which the superabsorbent polymer particles are dispersed substantially throughout the thickness in the aggregate of filaments is also possible.
In any case, according to the embodiment of the present invention, when the body fluid that has passed through the top sheet moves to the absorber, the body fluid quickly penetrates into many gaps between the filaments, and the superabsorbent polymer particles present in the gaps. Absorbs body fluids.
In addition, since the body fluid diffuses quickly in the orientation direction of the filament of the filament assembly, the body fluid can be absorbed in the entire planar direction of the absorber, and the absorption in the thickness direction described above can be achieved by the absorption of the body fluid by the highly absorbent polymer particles. Combined with the absorption in the plane direction, the amount of absorption increases.
As described above, one preferred form of the product produced by the method of the present invention is one in which superabsorbent polymer particles are dispersed substantially throughout the thickness direction with respect to the aggregate of filaments. This is because, in this embodiment, the body fluid absorbing ability by the superabsorbent polymer particles is exhibited over the entire thickness of the absorber.
If the superabsorbent polymer particles are unevenly distributed in the lower part of the absorber and the superabsorbent polymer particles are not present in the upper part, the body fluid that has moved to the absorber remains in the upper part of the absorber, When compressed by the wearer's movement, there is a large gap between the filaments, which causes a so-called “reversal” phenomenon in which body fluid easily escapes upward from the gap. Since the superabsorbent polymer particles are also present in the upper part by dispersing in the entire thickness direction, the body fluid is absorbed in the upper part of the absorber, confined in the gel, and absorbed even under pressure. Is difficult to release and prevents the “return” phenomenon.
A comparison with conventional absorbents in which superabsorbent polymer particles are uniformly dispersed in conventional pulp fibers (also called cotton-like pulp or fluff pulp) will be described. Absorbents mainly composed of pulp fibers have a slow absorption rate. And there is a limit to increasing the amount of absorption. This is because the short fibers are in a relatively tightly entangled state. Even if the superabsorbent polymer particles are uniformly dispersed in the pulp fiber, if the absorption capacity is exceeded at the upper part of the absorbent body, the body fluid does not move downward anymore and remains in the upper part of the absorbent body. "Phenomenon occurs. On the other hand, when the superabsorbent polymer particles are dispersed in many gaps between the filaments, the body fluid quickly moves downward or in the plane direction through the gaps between the filaments. Is absorbed.
When obtaining an absorbent body in which superabsorbent polymer particles have infiltrated into such an aggregate of filaments, even if the superabsorbent polymer particles are simply dispersed by gravity drop, the superabsorbent polymer particles in the filament aggregate Intrusion cannot be expected or the amount of intrusion is small.
However, according to the present invention, the superabsorbent polymer particles can be surely and invaded into the aggregate of filaments by projecting the superabsorbent polymer particles onto the aggregate of filaments by applying an external force.
Furthermore, according to the method of the present invention, by adjusting the external force applied to the superabsorbent polymer particles, the amount of the superabsorbent polymer particles penetrating into the aggregate of filaments can be adjusted. When the superabsorbent polymer particles are sprayed simply by gravity drop, the above penetration amount cannot be adjusted. According to the method of the present invention, the amount of the superabsorbent polymer particles entering the filament aggregate can be adjusted. As a result, as described above, the superabsorbent polymer particles are substantially in the thickness direction with respect to the filament aggregate. It can be dispersed throughout or unevenly distributed in the thickness direction. Therefore, the dispersion form of the superabsorbent polymer particles can be selected according to the characteristics required for the intended absorbent article.

<Invention of Claim 2 >
The step of spraying the superabsorbent polymer particles according to claim 1 from a direction to be used side at the stage of the product, on the aggregate of the filaments, in which the superabsorbent polymer particles projecting by adding an external force The manufacturing method of the absorbent article of description.

(Function and effect)
When the superabsorbent polymer particles are projected on the filament aggregate while accelerating from the direction of the use surface side in the product stage, the superabsorbent polymer is in the stage of commercialization and the stage until the consumer uses it. Since the gravitational force of the particles acts on the back surface side, the particles are more likely to enter the aggregate of filaments.
<Invention of Claim 3>
The method for producing an absorbent article according to claim 1 or 2, wherein centrifugal force is used as the external force and pressure air is not used.

<Invention of Claim 4 >
The continuous body of the absorbent body, the step of wrapping continuously by said covering sheet is, the one in which wrap with a holding sheet is interposed between the covering sheet and the filament assembly, according to claim 1 to 3 of A manufacturing method of an absorptive article given in any 1 paragraph .

(Function and effect)
The function of the holding sheet will be described in advance. That is, as a product to be obtained by the present invention, there are cases where superabsorbent polymer particles are included in the absorber, provided below the absorber, or both forms may be used together. When particles are included in the absorber, as described above, the filament aggregate has a large gap between the filaments, so that the SAP particles escape from the filament aggregate during the period from manufacture to use by the consumer. Tend to collect on the enveloping sheet.
However, in order to allow the body fluid to penetrate into the absorbent body, it is necessary to make the covering sheet (for example, tissue paper) thin, so when touching the back surface of the product, it is highly distributed in the lower part of the absorbent element. The unevenness of the polymer particle group gives a crisp and uncomfortable feeling and reduces the value of the product. On the other hand, if a holding sheet (which may be referred to as an “intervening sheet”) is provided, the holding sheet is stiff against the lower surface of the covering sheet, which reduces the jarring feeling when touching from the back of the product. It will not be generated.
Therefore, it is desirable to use a holding sheet. Therefore, when the holding sheet is wrapped as described above, a product in which the holding sheet is provided between the absorber and the covering sheet can be obtained.

<Invention of Claim 5 >
The step of spraying the superabsorbent polymer particles intermittently sprays the superabsorbent polymer particles to the aggregate of the filaments, and the step of obtaining the individual absorbent elements includes the step of spraying the superabsorbent polymer particles. The method for producing an absorbent article according to any one of claims 1 to 4, wherein the absorbent zone is divided by a cutter device between spray zones.

(Function and effect)
In the present invention, through the process of obtaining the individual absorbent elements divided individually suction absorbent body and the continuum of the covering sheet. A cutter device can be used to divide individually. However, when the superabsorbent polymer particles are continuously sprayed and projected onto the aggregate of filaments, the blade of the cutter device is worn out in a short time due to the presence of the superabsorbent polymer particles. Therefore, instead of continuously spraying and projecting the superabsorbent polymer particles, the superabsorbent polymer particles are intermittently sprayed and projected only in the zone Z (see FIG. 10) having a predetermined length. And if it cut | disconnects by the cutter apparatus between the dispersion | distribution zones of a super absorbent polymer particle, the abrasion of the blade of a cutter apparatus can be reduced.

<Invention of Claim 6 >
Step to achieve the commercialization, the absorbent element after combining with other materials, obtaining a separate absorbent body divided, and the step of combining the exterior material separate absorbent body, possess in this order And
The step of combining the individual absorbent main body with the exterior material is combined with the exterior material flowing along the line after turning the individual absorbent body 90 degrees,
The manufacturing method of the absorbent article of any one of Claims 1-5 .

  As described above, according to the present invention, it is possible to manufacture an absorbent article having an absorbent element including an absorbent body that is excellent in absorption characteristics of body fluid and has a soft and relatively high strength. In addition, an absorbent element having a good shape can be manufactured by suitably combining an assembly of filaments continuous in the longitudinal direction and superabsorbent polymer particles.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.
<Structure example of a pants-type disposable diaper>
FIG. 1 shows a structure example of a pants-type disposable diaper as an absorbent article to be manufactured according to the present invention. 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.

  As shown in FIG. 3, the absorbent main body 20 according to 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. Further, barrier cuffs 60, 60 are provided on both sides.

  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.

  Typically, as shown in FIG. 3, a bodily fluid impermeable sheet 70 made of a plastic sheet or the like called a back sheet 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.

  Here, 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 irregularities of the superabsorbent polymer particles that have passed through the aggregate of filaments give a sense of incongruity when touched by a hand when used by a consumer. Therefore, a holding sheet 80 made of a nonwoven fabric or the like 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.

  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.

  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.

  As the covering sheet 58, tissue paper or non-woven fabric can be used. 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. If necessary, it may be sandwiched between two sheets of upper and lower layers or disposed only on the lower surface, but it is not desirable because it is difficult to prevent the movement of the superabsorbent polymer particles.

  As shown in FIG. 6, the holding sheet 80 may surround the side portion of the absorber 56. FIG. 6 also shows a case where the superabsorbent polymer particles are provided below the absorber 56, or the superabsorbent polymer particles contained in the absorber 56 are in a stage from manufacture to use by the consumer. The case where the filament 52 comes out of the aggregate and gathers on the holding sheet 80 is conceptually shown.

  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 an additional element.

  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.

  Although not shown, the constituent members of the absorbent main body 20 are fixed to each other by solid, bead or spiral application such as hot melt adhesive so as to be held in the shape shown in FIG. The same applies to the forms shown in FIGS.

<Details of absorbent elements>
The absorbent element of the embodiment includes an absorbent body 56. This absorbent body 56 has an aggregate of filaments 52, 52..., Opened tow and superabsorbent polymer particles 54, 54. Further, at least in the body fluid receiving region, the superabsorbent polymer particles (SAP particles) are dispersed substantially throughout the 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.

  On the other hand, the form in which some SAP particles remain on the surface of the filament aggregate without entering, and the form in which some SAP particles pass through the filament aggregate and are on the covering sheet 58 are also excluded. Is not to be done. If gel blocking is not considered, it may be unevenly distributed only in the upper part or only in the middle part, and if it is not considered in reverse, it may be unevenly distributed only in the intermediate part or only in the lower part.

  The production method of the present invention is also applicable to the case of obtaining an absorbent body having “the dispersion density of the superabsorbent polymer particles is large or small relative to the aggregate of filaments in at least one of the width direction, the longitudinal direction and the thickness direction of the product”. Applicable.

  The matter “the dispersion density of the superabsorbent polymer particles in the aggregate of filaments is large or small” includes various forms.

  This will be explained as follows. As shown in FIG. 20, with respect to the absorber 56, the width direction of the product is X, the longitudinal direction is Y, and the thickness direction is Z. The case where the density is made larger (higher) than other regions is defined as “close”. Further, the case where the superabsorbent polymer particles have the same dispersion density is defined as “uniform”.

  In Tables 2 to 4, the characteristic of each form is “the dispersion density of the superabsorbent polymer particles with respect to the filament aggregate is large or small in at least one of the width direction, the longitudinal direction and the thickness direction of the product”. The effect of was also shown. Of course, the conditions of the present invention can be used in combination.

  Thus, in all the width direction, longitudinal direction and thickness direction of the product, there is a specific effect as compared with the case where the dispersion density of the superabsorbent polymer particles with respect to the aggregate of filaments is uniform.

<Aggregate of filaments>
The aggregate of the filaments 52, 52,... Used in the present invention is obtained by opening a tow (fiber bundle) configured as a continuous fiber substantially regarded as a continuous fiber. 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.), and the like. In particular, cellulose esters and cellulose are preferable.

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

  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 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 is, for example, 1 to 16 dex, preferably 1 to 10 dex, and more preferably 1 to 5 dex. 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 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.

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

  However, the use of binder components that inhibit the entry of superabsorbent polymer particles should be avoided whenever possible. It is best not to use a binder component that inhibits penetration of the superabsorbent polymer particles.

Since tow can be produced by a known method, it will not be described in detail. Cellulose diacetate tow bales that can be suitably used in the present invention are commercially available from Celanese and Daicel Chemical Industries. 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 degree of tow opening.

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

<Example of manufacturing method of pant-type absorbent article (pants-type paper diaper)>
Now, an example of the production method of the present invention for producing the above-described pant-type absorbent article will be described. The example shown in FIG.7 and FIG.8 is an example of manufacture 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. Subsequently, an assembly 52Z of filaments 52 in which the tow has been opened is supplied from above through a fiber-opening process described in detail later, and the assembly of filaments 52 from above is supplied by the superabsorbent polymer particle spraying means 90. The superabsorbent polymer particles 54 are dispersed over the entire thickness direction of the filament aggregate. Then, the wrapping sheet 58 wraps the absorbent element 50 by passing the sailor 92. 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 the state where the nonwoven fabric sheet is interposed in advance (not shown in FIG. 7), 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. 7 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.

  The opening from the bale 52X is performed, for example, in the form shown in FIG. That is, the toe 52Y is pulled out from the bail 52X, and is gradually widened through the widening device 120 and is guided to the thickening device 110 through the first nip 126A, the second nip 126B, and the third nip 126C. After the thickness is increased to a substantially final filament aggregate 52Z, the superabsorbent polymer particles 54 are sprayed and supplied by the superabsorbent polymer particle spraying means 90, and then to the sailor 92. It is sent. The tow is pulled out from the bale 52X by being pulled in by the first nip 126A (corresponding to a driving nip roll).

More specifically, 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.

  The nip pressure and the own weight of the free nip roll 124 may be determined as appropriate. However, in a normal case, the nip pressure is preferably less than 5 MPa, and the roll self-weight is preferably less than 10 kg per roll. Within this range, stabilization of the tension can be easily realized.

  Thus, the supply amount of the tow 52Y to the first nip 126A that controls the supply amount of the tow becomes stable, so that the size, weight, and quality of the absorbent body become stable.

  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.

  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.

  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.

  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, it is guided to the second spreader 110. As the second opening device 110, a device such as US Pat. No. 6,253,431 can be used, but the embodiment has the same structure as that disclosed in Japanese Patent Application Laid-Open No. 59-500292 (WO 83/03267). As shown schematically in FIG. 9, a venturi portion 110b is formed between the inlet 110A and the outlet 110B, and a compressed air blowing port 110a is provided on the inlet side. It has an air exhaust hole 110c. 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 enters from the inlet 110A by the ejector effect, and as a result, the tow 52Y is drawn and a forward force is applied. When the tow 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 expanded, so that the tow 52Y is mainly opened in the thickness direction. At that time, as shown in the lower part of FIG.

  The inventors of the present invention are that the opening is not sufficient with the second opening device 110 alone, and it is desirable to open the tow 52Y in advance for tension and relaxation with the first opening device. I found out. Therefore, it is desirable to employ a combination of the above-mentioned two spread forms.

In the present invention, as a superabsorbent polymer sprinkling means 90 for spraying the high-absorbent polymer particles with respect to aggregation of the filaments, not only its own weight by falling force of the superabsorbent polymer particles themselves, by applying an external force projection Means for applying (providing acceleration force) are employed . An example of this is shown in FIG. That is, a rotary drum 90b having a projection hole 90d in a casing 90a having an opening in the lower part is configured to rotate in the moving direction of the web (counterclockwise in FIG. 10), and a shutter drum 90c is provided therein. It is a thing. The projection unit 90A including these elements is connected to a hopper 90B (see FIG. 8), and a superabsorbent polymer particle spraying unit 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. In the state of FIG. 10, the fully opened state is shown. 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.

When the rotating drum 90b rotates with the casing 90a and the pre-positioned shutter drum 90c fixed without rotating, the superabsorbent polymer particles 54 fall through the projection holes 90d. Due to the rotation of the rotating drum 90b, a radial centrifugal force acts on the superabsorbent polymer particles 54, and an acceleration force (external force) greater than free fall acts on the superabsorbent polymer particles 54, It is sprayed and projected onto the aggregate of filaments 52 at a high speed. Therefore, the superabsorbent polymer particles 54 can penetrate deeply into the gaps between the filaments 52. In a method that relies only on the free fall of the superabsorbent polymer particles 54, the superabsorbent polymer particles are unevenly distributed mainly only in the upper part of the aggregate of filaments 52, and the superabsorbent polymer particles are substantially in the entire thickness direction with respect to the aggregate of filaments. It is difficult to disperse.

  The superabsorbent polymer particles 54 may be continuously dispersed and projected on the aggregate of the filaments 52. However, as shown in FIG. 7, 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 dispersed and projected continuously, but intermittently dispersed 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.

Furthermore, the superabsorbent polymer sprinkling means 90, the high-absorbent polymer particles 54 that are sprayed onto the aggregate of full Iramento from below of the aggregate of the filaments may be aspirated.

Note that FIG. 11 is not a spraying means 90 for spraying the superabsorbent polymer particles by applying the external force (centrifugal force) described above instead of the vacuum roll 106 in FIG. 7 and FIG. the general purpose of the superabsorbent polymer sprinkling means in the form of dropping sex polymer particles due to its own weight, from the vacuum roll 106 upwards on the aggregate 52Z filament 52, that shows a comparative example to spray high-absorbent polymer particles 54 . 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.

<About superabsorbent polymer particles>
The term “superabsorbent polymer particles” in the present invention means to include “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 of the present invention, those having a water absorption rate of 40 seconds or less are suitably 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, in order to obtain the dispersion pattern of the superabsorbent polymer particles shown in Tables 2 to 4, the superabsorbent polymer particles can be adjusted in 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 spray density (amount), while women can increase the center spray 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.

<About materials used>
(Enveloping sheet)
As the covering sheet 58 used for the absorbent body 56, 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 in place 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 8 to ²⁰ g / m ² , particularly 10 to 15 g / m ² .

  The covering sheet in the above embodiment covers at least the back and side surfaces of the absorbent body 56. If necessary, only the top and side surfaces of the absorbent body 56 are covered with crepe paper or non-woven fabric, and the bottom surface is covered. A form covered with a body fluid impermeable sheet such as polyethylene, an upper surface of the absorbent body 56 covered with crepe paper or a nonwoven fabric, and a side surface and a lower surface covered with a body fluid impermeable sheet such as polyethylene may be used. It becomes a component of the sheet.

(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.

(Compression characteristics of aggregate of absorbers)
In the present invention, the compression resilience RC of the absorbent body 56 is 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 fiber density of the aggregate of filaments by opening or the like, selecting the fiber 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 when the fiber is compressed. 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.

(Top sheet)
In the present embodiment, 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 to the absorbent body, an intermediate sheet that is usually referred to as a “second sheet” and has a higher body fluid permeation rate than the top sheet can be provided. This intermediate sheet not only improves the absorption performance of the absorbent body by quickly transferring body fluid to the absorbent body, but also prevents the "reversing" phenomenon of the absorbed body fluid from the absorbent body, and the top sheet is always dry It can be.

  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.

(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 recess E by embossing in both the top sheet 30 and the intermediate sheet 40, the intermediate sheet 40 has a basis weight of 8 to 40 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 recess 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.

(Body fluid impermeable sheet)
In the present invention, the bodily fluid impermeable sheet simply means a sheet disposed on the back side of the absorber 56, and in the present embodiment, the sheet interposes the absorber 56 with the top sheet 30. ing. 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.

(Holding sheet)
In the present embodiment, the holding sheet 80 is used to eliminate or reduce a jerky discomfort. The material is not particularly limited as long as it has a retention property of the absorbent polymer. 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 fiber, polyester fiber, acrylic fiber, polypropylene fiber, silk, cotton, hemp, nylon, polyurethane, acetate fiber and the like.

However, when the holding sheet 80 and the nonwoven fabric, compression energy is 0.01~10.00gfcm / cm ² based on KES test, preferably, at 0.01~1.00gfcm / cm ^2, and the compression resilience 10 -100%, preferably 70-100% non-woven fabric.

  The reason for providing the holding sheet 80 is to hold, for example, the absorbent polymer that has fallen down (dropped out) from the absorbent body 56 as described above. Therefore, since the superabsorbent polymer particles that have slipped 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, when the nonwoven fabric has the above-described compression energy and compression resilience, the function as a holding sheet is sufficiently exhibited.

  Further, since the absorbent polymer that has slipped out is held by the holding sheet 60 and does not move on the covering sheet 58, there is no possibility of uneven absorption capacity. In particular, in order to prevent the superabsorbent polymer particles from moving on the holding sheet 80, a hot-melt adhesive having adhesiveness can be applied on the holding sheet 80 in advance. FIG. 8 shows an adhesive application device 104 for this purpose. Moreover, you may make it a superabsorbent polymer particle prevent a movement on the holding sheet 80 by making the upper surface (surface which goes to a use surface side) of the holding sheet 80 into a rough surface. 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.

  In FIG. 6, the holding sheet 80 is provided only below the absorbent body 56, but the holding sheet 80 may be wound up and extended to the upper surface of the absorbent body 56 through the side surface of the absorbent body 56. It is also possible to use a plurality of holding sheets 80 in a stacked manner.

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

<Tape type absorbent article (tape type disposable diaper) structure example>
The absorbent article produced according to the present invention includes a tape-type absorbent article.
The example of a tape type disposable diaper is demonstrated referring FIG.13 and FIG.14. FIG. 14 is a view taken along the line 14-14 in FIG. 13, 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.

  A specific example will be described. Between the top sheet 30 and a liquid-impervious sheet that is substantially impermeable to liquid, for example, a liquid-impermeable sheet 70 that is completely impermeable to liquid, such as polyethylene, an absorbent body 56 is provided. Intervened. 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 liquid-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 outside 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 liquid-impermeable sheet 70 by 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 end 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 end to the extending edge of the liquid-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 liquid-impermeable sheet 70 forms an upright 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 absorbent element 50 is the same as in the case of the above-described pants-type absorbent article, and an absorbent body 56 having an aggregate of filaments 52, 52... And high-absorbent polymer particles 54, 54. And a covering sheet 58 that wraps the absorber 56. 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. Here, the superabsorbent polymer particles 54 may be interposed between the holding sheet 80 and the absorbent body 56 by spraying or the like. The function of the holding sheet 80 is the same as that of the above-described pants-type absorbent article.

  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. If necessary, a form without using the intermediate sheet 40 as shown in FIG. 16 may be used.

  As the covering sheet 58, tissue paper or non-woven fabric can be used. As shown in FIG. 14, the covering sheet 58 has a form in which the aggregate of the filaments 52, 52... And the superabsorbent polymer particles 54, 54. It is also possible to cover only the back and side surfaces. If necessary, it may be sandwiched between two sheets of upper and lower layers or disposed only on the lower surface, but it is not desirable because it is difficult to prevent the movement of the superabsorbent polymer particles.

  The holding sheet 80 may surround the side portion of the absorber 56. Further, FIG. 17 shows a case where the superabsorbent polymer particles are provided below the absorber 56 or the superabsorbent polymer particles contained in the absorber 56 are used at the stage from manufacture to use by the consumer. The case where the filament 52 comes out of the aggregate and gathers on the holding sheet 80 is conceptually shown.

  Although not shown, the constituent members are fixed to each other by solid, bead or spiral application such as hot melt adhesive so as to be held in the shape shown in the drawing.

<Example of manufacturing method of tape-type absorbent article (tape-type paper diaper)>
The example of the manufacturing method of this invention for manufacturing said tape-type paper diaper is demonstrated.
The example shown in FIG.18 and FIG.19 is an example of a manufacturing method of the tape-type disposable diaper shown in FIG.13 and FIG.14.
Explaining this, the covering sheet 58 is supplied to the line from the upstream side, and then the holding sheet 80 is supplied. Subsequently, an assembly 52Z of filaments 52 in which the tow has been opened is supplied from above by going through the same opening process as the method for manufacturing the above-described pants-type absorbent article (therefore, redundant description is omitted), The superabsorbent polymer particle spraying means 90 projects and sprays onto the aggregate 52Z of filaments 52 from above, and the superabsorbent polymer particles 54 are mixed and dispersed in the aggregate of filaments (superabsorbent polymer particles). Mixing step). Then, the sailor 92 is passed to enclose the absorbent element 50 with the encapsulating sheet 58 (step of continuously encapsulating the absorbent body with the encapsulating sheet). Next, it is divided in the line direction by the cutter device 94 to obtain individual absorbent elements 50 (step of obtaining individual absorbent elements).

  Furthermore, the process of combining with other materials will be described. Since the intermediate sheet (second sheet) 40 has a structure that is short with respect to the entire length of the absorbent element 50 in the embodiment, it is supplied intermittently, After the second body fluid impermeable sheet 72 is supplied from the side, the side portion is folded by the sailor 94, then the top sheet 30 is supplied from above, and the body fluid impermeable sheet 70 is supplied from below, A 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, a semi-finished product comprising an absorbent body including an absorbent element combined with other materials is cut by a cutter device 98 to obtain a product.

  Here, the steps up to the step of obtaining the individual absorbent elements can take the same form as in the above-described method for producing the pant-type absorbent article.

  The production method of the present invention can naturally be applied to the production of absorbent pads used in combination with sanitary napkins, incontinence pads, diaper covers, etc., but the method in that case would be easily guessed by those skilled in the art. The description is omitted.

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 a schematic diagram which shows the example of a manufacturing method of a pants-type disposable diaper. It is the principal part schematic diagram. It is a schematic diagram of a fiber-spreading apparatus. 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 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 the center 14-14 sectional view taken on the line. FIG. 14 is a cross-sectional view taken along line 14-14 of another example. FIG. 14 is a cross sectional view taken along line 14-14 of another example. FIG. 14 is a cross-sectional view corresponding to an arrow line 14-14 of a modified example. It is a schematic diagram which shows the example of a manufacturing method of a tape-type disposable diaper. It is the principal part schematic diagram. It is explanatory drawing of the direction of an absorber.

  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, 58 ... Cover sheet, 60, 60A ... Barrier cuff, 64 ... Barrier sheet, 70 ... Impermeable to body fluid , 72 ... second body fluid impermeable sheet, 80 ... holding sheet, 90 ... superabsorbent polymer particle spraying means, 90A ... projection section, 90a ... casing, 90b ... rotary drum, 90c ... shutter drum, 92 ... sailor 94 ... Cutter device 98 ... Cutter device 100 ... Turning device 102 ... Combination station 104 ... Viscosity Agent application device 110 ... second fiber opening device 110a ... pressure air blowing port 110b ... venturi section 124 ... pretension roll 126A ... first nip 126B ... second nip 126C ... third nip 130 ... Fastening piece, E ... recess, Z ... superabsorbent polymer particle distribution zone.

Claims (6)

A method for producing an absorbent article comprising an absorbent element that receives and holds body fluid that has passed through a top sheet on the use surface side,
From the upstream side of the manufacturing process,
The opening process of opening the tow into an assembly of filaments,
Spraying superabsorbent polymer particles on the aggregate of filaments;
A process of continuously wrapping a continuous body of absorbent bodies having an assembly of filaments and superabsorbent polymer particles with a covering sheet;
A step of individually dividing the continuous body of the absorbent body and the covering sheet to obtain an individual absorbent element, and a step of commercializing in combination with other materials while intermittently feeding the individual absorbent element,
The has, and
The step of spraying the superabsorbent polymer particles supplies the aggregate of filaments opened through the opening process onto the covering sheet, and the superabsorbent polymer particles are weighted from the filament aggregate. Projecting by applying an external force to the falling force due to intrusion of the superabsorbent polymer particles into the assembly of the filaments,
The manufacturing method of the absorbent article characterized by the above-mentioned. The step of spraying the superabsorbent polymer particles according to claim 1 from a direction to be used side at the stage of the product, on the aggregate of the filaments, in which the superabsorbent polymer particles projecting by adding an external force The manufacturing method of the absorbent article of description. The manufacturing method of the absorbent article of Claim 1 or 2 which uses a centrifugal force as said external force and does not use pressurized air. The continuous body of the absorbent body, the step of wrapping continuously by said covering sheet is, the one in which wrap with a holding sheet is interposed between the covering sheet and the filament assembly, according to claim 1 to 3 of A manufacturing method of an absorptive article given in any 1 paragraph . The step of spraying the superabsorbent polymer particles intermittently sprays the superabsorbent polymer particles to the aggregate of the filaments, and the step of obtaining the individual absorbent elements includes the step of spraying the superabsorbent polymer particles. The method for producing an absorbent article according to any one of claims 1 to 4, wherein the absorbent zone is divided by a cutter device between spray zones. Step to achieve the commercialization, the absorbent element after combining with other materials, obtaining a separate absorbent body divided, and the step of combining the exterior material separate absorbent body, possess in this order And
The step of combining the individual absorbent main body with the exterior material is combined with the exterior material flowing along the line after turning the individual absorbent body 90 degrees,
The manufacturing method of the absorbent article of any one of Claims 1-5 .

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