JP5197086B2 - Absorber fiber stacking device and absorber - Google Patents

Description

  The present invention relates to an absorbent stacking device. In particular, the present invention relates to a fiber stacking apparatus that can form an absorbent body that can be stably lowered in weight, and an absorbent body manufactured by the fiber stacking apparatus.

  Absorbents for absorbing urine, feces, menstrual blood, etc. are used for absorbent articles such as disposable diapers, sanitary napkins, and panty liners. Has been. Such an absorber manufacturing apparatus generally has a rotating drum, a vacuum suction section in the rotating drum, and a pile of pulverized pulp placed on an air flow and disposed on the outer peripheral surface of the rotating drum. 2. Description of the Related Art A fiber stacking apparatus including a supply unit that supplies a cavity is known (Patent Document 1). A suction hole communicating with the vacuum suction portion is provided on the bottom surface of the fiber stacking cavity. The fiber stacking cavity having such a configuration circulates between the supply means and the vacuum suction unit, and at that time, the pulverized pulp is stacked in the interior thereof. The absorbent body stacked inside the cavity is separated from the supply means and the vacuum suction unit, and transferred to the conveyor (Patent Document 1).

  In order to adjust the amount of accumulated fiber of the absorbent body constituting the absorbent article, an apparatus (Patent Document 2) that adjusts by arranging a non-breathable part by providing a sealant at the bottom of the cavity, or a accumulated fiber cavity The three-dimensional shape forming part is mounted on the bottom of the stacking cavity so that the porous body at the bottom is three-dimensional or convex toward the cavity opening side, and after excess powder is stacked, the excess amount An apparatus (Patent Document 1) that removes a granular material with a roll for scraping is known.

JP-A-60-236646 JP-A-5-200062

However, in the fiber stacking device of Patent Document 1, the state of the fiber stack and the shape of the fiber stack are disturbed at the time of scraping off, and the amount of fiber stack is not stable. In the part, the absorbency is reduced, and the possibility of causing external leakage increases. In the fiber stacking apparatus of Patent Document 2, if the sealing agent deteriorates and falls off the support, a desired absorber cannot be formed, and the dropped sealing agent becomes a foreign substance, causing a problem during use. In addition, as described above, there has been no known effective method for stably adjusting the amount of accumulated fibers in the absorbent body constituting the absorbent article.
Therefore, an object of the present invention is to provide a fiber stacking apparatus that can form an absorbent body that can be stably lowered in weight.

  As a result of intensive studies in view of such circumstances, the present inventors have a perforated region and a non-porous region as a stacked fiber support that forms the absorber, and the non-porous region is an absorber-forming region. It was found that an absorbent body of an absorbent article that can be stably reduced in weight can be formed by using a support disposed so as to be surrounded by the perforated region in the peripheral region of the present invention, and completed the present invention .

That is, (1) The present invention has a rotating drum provided with means for sucking on the inner surface side, and a plurality of stacking fiber supports disposed on the outer peripheral surface of the rotating drum. The absorbent body forming apparatus for forming the absorbent body by stacking the granular material supplied to the absorbent body forming area of the stacking support body, wherein the absorbent body forming area includes a perforated area and And a non-porous region, and the non-porous region is disposed in a peripheral region of the absorbent body forming region so as to be surrounded by the perforated region.
(2) The present invention provides the fiber stacking apparatus according to (1), wherein the non-porous region is disposed at a position of 5 mm to 15 mm from the outer edge of the absorbent body forming region.
(3) The present invention provides the fiber stacking apparatus according to (1) or (2), in which an interval between two adjacent non-porous regions is 5 mm to 20 mm.
(4) The fiber stacking apparatus according to any one of (1) to (3), wherein the fiber stacking support body further includes an absorbent body-forming concave portion with respect to an outer peripheral surface of the rotating drum. provide.
(5) The present invention provides the fiber stacking apparatus according to any one of (1) to (4), wherein the perforated region is formed by etching.
(6) The present invention further includes a low porosity area having a lower porosity than the perforated area so that the non-porous area is surrounded and at least a part thereof is in contact with the perforated area. The fiber stacking apparatus according to any one of (1) to (5) is provided.
(7) The present invention provides the fiber stacking apparatus according to any one of (1) to (6), wherein the thickness of the fiber stack support is uniform.
(8) The present invention is an absorbent body having regions in which the basis weights of the powder particles are different from each other, and a high basis weight region having a high basis weight is disposed in the central region of the absorber, compared to a high basis weight region. Provided is the absorbent body, wherein a low basis weight region having a low basis weight is arranged in a peripheral region of the absorbent body so as to be surrounded by a high basis weight region.
(9) The absorbent body according to (8), wherein the basis weight of the high basis weight region is 250 g / m ² or less and the basis weight of the low basis weight region is 1.5 times or more. provide.
(10) The present invention provides the absorbent body according to (8) or (9), wherein the low basis weight region is disposed at a position of 5 mm to 15 mm from the outer edge of the absorbent body.
(11) The present invention provides the absorbent body according to any one of (8) to (10), wherein an interval between two adjacent low basis weight regions is 5 mm to 20 mm.
(12) The present invention is such that an area having a basis weight between the basis weight of the high basis weight area and the basis weight of the low basis weight area surrounds the low basis weight area, and at least a part thereof. The absorber according to any one of (8) to (11), further disposed so as to be in contact with the high basis weight region.

According to the present invention, it is possible to arrange a low basis weight region surrounded by a high basis weight region in the peripheral region of the absorber, thereby making it possible to maintain the rigidity of the absorber, Use can be suppressed, and resource saving and cost reduction are possible.
In addition, by further arranging a region having a basis weight between the basis weight of the high basis weight region and the basis weight of the low basis weight region so as to surround the low basis weight region, the low basis weight region and the high basis weight are provided. The level difference between the regions can be reduced, the uncomfortable feeling when the absorbent article is mounted can be reduced, and the deformation due to the rigidity of the absorbent body can be reduced.

  Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited to those shown in the drawings. FIG. 1 is a schematic partial side view of a fiber stacking apparatus according to the present invention, and FIG. 2 is a perspective view of the rotary drum in FIG. FIG. 3 is a plan view showing one embodiment of the stacking fiber support according to the present invention, and a cross-sectional view thereof taken along the line A-A ′. (A)-(c) of FIG. 4 is a top view which shows one embodiment of the absorber of this invention. FIG. 5 is a cross-sectional view taken along the line A-A ′ of FIG. FIG. 6 is a plan view showing one embodiment of the absorbent body according to the present invention. FIG. 7 is a cross-sectional view taken along line A-A ′ of FIG. 6.

  As shown in FIG. 1, the absorbent fiber stacking apparatus 13 of the present invention places a pulverizer 1 for pulverizing an absorber constituent material and an pulverized absorber constituent material (powder particles 12) on an air stream. The conveying chamber 14, the rotating drum 2 having means for sucking on the inner surface side, the pile support 3 that receives the powder and forms the absorbent, and the formed absorbent is received by the conveyor 4. And means for passing. The formed absorber is released from the suction in the rotating drum 2 when transferred to the conveyor 4 and transferred onto the conveyor 4. As shown in FIG. 2, a plurality of stacked fiber supports 3 are arranged in a shape matching the outer peripheral curved surface of the rotary drum 2, and each stacked fiber support 3 forms one absorbent body. In the fiber stacking apparatus of the present invention, if necessary, supply means for supplying other additives such as a heat-sealing material, and a granular material laminated on the fiber stack support 3 are thermally melted and heated. Means for fusing may be provided.

FIG. 3: is a top view which shows one embodiment of the pile support body which concerns on this invention, and its AA 'sectional drawing.
The stacking fiber support 3 according to the present invention has a perforated region 5 and a non-porous region 6 in a region where an absorber is to be formed on the support (hereinafter referred to as “absorber forming region”). The non-porous region 6 is arranged in the peripheral region of the absorber forming region 15 so as to be surrounded by the perforated region 5. In the present specification, the “peripheral region” means a peripheral region of the absorbent body forming region 15 with respect to the central region of the absorbent body that comes into contact with the excretion part when the absorbent article is used. The outer shape of the absorbent body forming region 15 is the same shape as one absorbent body of the absorbent article, and may be any one of a bowl shape, an elliptical shape, a rectangular shape, and the like. When the absorbent article is, for example, a daytime sanitary napkin, the overall dimension of the outer shape of the absorbent body forming region is preferably 150 to 230 mm in the longitudinal direction and 50 to 90 mm in the short direction.

The perforated region 5 has a hole penetrating from the front surface to the back surface of the pile support 3. The hole has a predetermined hole diameter. The pore diameter is determined by the length of the powder and the like, but is preferably in the range of 0.1 to 1.0 mm. If the pore diameter is less than 0.1 mm, the powder particles are likely to be clogged as the power required for suction increases, and if it exceeds 1.0 mm, the powder particles pass through the holes and the yield of the absorber is reduced. This is not preferable.
The holes are usually arranged in a staggered manner on the support with a pitch of 0.2 to 3.0 mm. The minimum width of the rib portion formed between the holes is usually 0.1 to 2.0 mm.
Perforation rate of the perforated region 5, that is, the ratio of the area of the perforated region 5 to the entire area of the absorber forming region 15 (opening rate (%)) ([(area of the perforated region) / (absorber formation) The area of the region)] × 100) is preferably 6 to 60%, particularly preferably 20 to 60%. If the open area ratio is less than 6%, the fiber-stacking efficiency is poor and the productivity is reduced, and if it exceeds 60%, the minimum width of the rib portion is too narrow and it is difficult to produce a perforated region in the fiber-fiber support 3. In addition, the rib portion of the support is easily broken, which is not preferable.

The thickness of the pile support 3 is preferably uniform, and is usually in the range of 0.05 to 5.0 mm. This is because when the thickness of the support is uniform, there is no unevenness in stacking, the absorbent body is stably peeled off from the stacking support during transport, and high reproducibility of the molded product is obtained.
The ratio of the maximum hole diameter to the thickness of the pile support 3 ((maximum hole diameter) / (thickness)) is preferably in the range of 0.02 to 10. If it is less than 0.02, the loss of the suction pressure becomes large, the productivity is lowered, and if it exceeds 10, the strength of the rib portion is lowered and the durability is lowered, which is not preferable.
A pore diameter, a hole area ratio, etc. are suitably selected by the component of a granular material, the thickness of the laminated granular material, etc.

  The non-porous region 6 may be a closed figure surrounded by the perforated region 5 such as a circle, an elliptical system, a rectangle, a square, or a star. The minimum width of the non-porous region 6 is 5 mm because the basis weight difference between the granular material 12 stacked in the non-porous region 6 and the granular material 12 stacked in the porous region 5 can be obtained. Is preferable, and 5 to 30 mm is particularly preferable. If it is less than 5 mm, the piles of the granular material also occur in the non-porous region 6 and the basis weight difference of the granular material disappears, which is not preferable. Moreover, when it exceeds 30 mm, since the area | region where the basic weight of a granular material becomes low becomes large and the rigidity of an absorber falls, it is unpreferable.

  The non-porous region 6 is disposed in the peripheral region of the absorber forming region 15. This is because the center part of the absorbent body comes into contact with the excretion part during use of the absorbent article, so it is necessary to increase the basis weight of the powder and increase the absorbency of the absorbent body. This is because the high absorbency is not required. Preferably, the non-porous region 6 is preferably disposed at a position of 5 mm to 15 mm from the outer edge of the absorbent body forming region 15. This is because if the distance from the outer edge is less than 5 mm, the pile shape may collapse. Moreover, the space | interval of two adjacent non-porous areas is preferable in the range of 5 mm-20 mm from the point which reduces the discomfort at the time of mounting | wearing of an absorbent article, and reduces the deformation | transformation by the rigidity of an absorber.

  The arrangement pattern of the non-porous region 6 is not particularly limited as long as it is in the peripheral region of the absorber forming region 15, for example, as shown in FIG. 3, or arranged in a staggered manner in the short direction of the absorber forming region 15, Or as shown to (a) of FIG. 4, you may arrange | position in the longitudinal direction of the absorber formation area 15 at 1 row. Alternatively, they may be arranged in a line in the short direction of the absorber formation region 15 ((b) in FIG. 4) or in the entire peripheral region of the absorber formation region 15 ((c) in FIG. 4). The area of the non-porous region 6 is 10% or more of the entire area of the absorber forming region 15. If it is less than 10%, the effect of reducing the fine particle volume is reduced, which is not preferable.

  As shown in FIG. 5, in the perforated region 5 of the stacking support 3, since the holes are formed on the opposite side from the surface of the stacking support 3, the powder particles are thickly laminated by the suction means. A “high basis weight region” can be formed. On the other hand, in the non-hole area | region 6, since the hole is not formed, it is difficult to laminate | stack a granular material. Therefore, the non-porous region 6 can form a “low basis weight region” compared to the perforated region 5. In the peripheral region of the excretion part where the prevention of deformation of the absorbent body is prioritized over the improvement of the excretion absorbability, when the basis weight is uniformly reduced, the rigidity is uniformly reduced. Since the absorbent body molded by the fiber stacking device has a structure in which the low basis weight region is surrounded by the high basis weight region in the peripheral region, the absorber is deformed due to the rigidity of the high basis weight region. Can be prevented.

The basis weight of the high basis weight region is preferably 250 g / m ² or less, more preferably about 140 to about 180 g / m ² , and particularly preferably about 160 g / m ² . If the basis weight exceeds 250 g / m ² , fiber piles occur from the periphery of the non-porous region 6 to the center of the non-porous region 6, and there is no basis weight difference between the perforated region 5 and the non-porous region 6. It is not preferable. The basis weight of the low basis weight region is preferably about 50 to about 90 g / m ² , and particularly preferably about 75 g / m ² . The basis weight of the high basis weight region is preferably 1.5 times or more the basis weight of the low basis weight region.

  Further, in another embodiment of the stacking fiber support 3 according to the present invention, in addition to the perforated region 5 and the non-porous region 6, a low porosity area is further provided so as to surround the non-porous region 6. It may be done. Here, the perforated region having a hole area ratio of 6 to 60% is compared with the high hole area region having a relatively high hole area within the range of the hole area ratio and the high hole area region. In order to prevent deformation of the absorber, at least a part of the low porosity area must be in contact with the high porosity area. is there. The width of the low porosity area is usually 2 to 30 mm, preferably 5 to 20 mm.

FIG. 6 is a plan view of one embodiment of the absorbent body according to the present invention having a low porosity area, and FIG. In the present embodiment, the absorber forming area 15 is further provided with a low porosity area 11 surrounding the non-porous area 6.
In the present embodiment, the basis weight of the powder particles that are stacked on the stacking support 3 increases in the order of the non-porous region 6, the low porosity region 11, and the high porosity region 10. A gentle basis weight distribution is generated in the direction from the open area 11 to the non-porous area 6. Therefore, the level | step difference between the non-porous area | region 6 and the high aperture ratio area | region 10 can be reduced, the discomfort at the time of mounting | wearing of an absorbent article can be reduced, and the deformation | transformation by the rigidity of an absorber can also be reduced.

  There are two or more low porosity areas, and they may be provided in the same circle. By providing two or more types of low-aperture areas around the non-porous area 6, further reduction in the level difference between the non-porous area 6 and the high-aperture area 10, and a sense of incongruity when the absorbent article is mounted And reduction of deformation due to the rigidity of the absorber. In that case, these low porosity areas are different from each other, and the low porosity area having the lowest aperture ratio around the non-porous area 6 is further reduced to the low porosity area. It is preferable to arrange | position so that the low porosity area | region which has a higher porosity may surround the circumference | surroundings.

  The granular material used in the present invention is usually a mixture of pulverized pulp obtained by pulverizing sheet-like wood pulp and a superabsorbent polymer. Instead of wood pulp, for example, artificial cellulose fibers such as chemical pulp, cellulose fibers, rayon and acetate can be used. Examples of the superabsorbent polymer include starch-based, acrylic acid-based, and amino acid-based particulate or fibrous polymers. You may further add the heat sealing | fusion material for carrying out heat fusion of a granular material to this granular material. Examples of the heat fusion agent include particulate or fibrous thermoplastic resins such as polyethylene, polyethylene copolymer, polypropylene, polypropylene copolymer, polyethylene terephthalate, and polyethylene terephthalate copolymer.

  The method for producing a stacking fiber support 3 according to the present invention includes a non-porous region 6 and a perforated region 5, and the perforated region and the non-porous region have a predetermined size and are disposed at predetermined positions. Although it is not particularly limited as long as it is a method capable of forming a support, it can be preferably produced by subjecting a metal or resin plate to chemical processing such as etching or physical processing such as punching (special feature). No. 2005-288960). Specifically, the metal plate is covered with a chemical-resistant protective resin film, and the metal plate in a portion not covered with the film is corroded with a corrosive agent to form a hole, which is manufactured by etching. Is preferred.

  The conventional general fiber stack support is formed of a fibrous knitting made of metal or the like. Therefore, in order to form a non-porous region, a plurality of supports or a block-shaped non-ventilated structure is used. It was necessary to arrange the functional parts on the pile support. Therefore, depending on how the supports are stacked and the arrangement of the blocks, the air flow is disturbed on the support, and the lamination is not stable at the shadowed portion of the blocks. On the other hand, the stacking fiber support 3 according to the present invention has the perforated region 5 and the non-porous region 6 formed on a single support by etching, so that the stacking fiber support 3 and the absorption support 3 are absorbed. No step is generated between the body and the fiber stacking process and the transferability to the conveyor 4 is stabilized.

  A production example (FIG. 3) of the pile support 3 is shown below. A 0.3 mm thick stainless steel plate (SUS304) is etched by a conventional method, and has a circular hole with a diameter of 0.3 mm. The hole is formed in a staggered pattern of 60 degrees at a pitch of 0.5 mm. A support having a minimum width of 0.2 mm, an opening ratio of 32.6%, and a ratio of the maximum diameter of the holes to the thickness of the pile support was 1.0. Further, the ratio of the area of the non-porous region to the entire area of the absorber forming region was 24.6%.

  In such a piled fiber support 3 that has been subjected to etching processing, in order to increase the basis weight of the granular material in the central region of the absorbent body in particular, in the perforated region that will be the central region of the absorbent body forming region Further, an absorbent body forming recess may be further formed.

FIG. 1 is a schematic partial side view of the fiber stacking apparatus of the present invention. FIG. 2 is a perspective view of the rotary drum in FIG. 1 and the fiber stacking support disposed on the drum. FIG. 3 is a plan view showing one embodiment of the stacking fiber support according to the present invention, and a cross-sectional view thereof taken along the line A-A ′. (A)-(c) of FIG. 4 is a top view which shows one embodiment of the absorber of this invention. FIG. 5 is a cross-sectional view taken along the line A-A ′ of FIG. FIG. 6 is a plan view showing one embodiment of the absorbent body of the present invention. FIG. 7 is a cross-sectional view taken along line A-A ′ of FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crusher 2 Rotating drum 3 Stacking support 4 Conveying conveyor 5 Perforated area 6 Nonporous area 7 Absorbent body 8 Sheet pulp 9 Frame 10 High porosity area 11 Low porosity area 12 Powder and granules 13 Stacking fiber Device 14 Chamber 15 Absorber formation region

Claims (7)

A rotating drum provided with means for sucking on the inner surface side, and a plurality of fiber stacking supports disposed on the outer peripheral surface of the rotating drum, and the granular material supplied into the chamber by the suction means An absorbent stacking device for forming an absorbent by stacking on an absorbent body forming region of a stacking support,
The absorber-forming region has a perforated region and a non-porous region, and the non-porous region is disposed so as to be surrounded by the perforated region in a peripheral region of the absorber-forming region ,
The non-porous region is disposed at a position of 5 mm to 15 mm from the outer edge of the absorber forming region,
The interval between two adjacent non-porous regions is 5 mm to 20 mm,
The stacking support further has a recess for forming an absorber with respect to the outer peripheral surface of the rotating drum,
The perforated region is formed by etching,
A low porosity area having a lower porosity than the perforated area is further disposed so as to surround the non-porous area and so that at least a part thereof is in contact with the perforated area;
The fiber stacking apparatus, wherein the fiber stacking support has a perforated region and a non-porous region formed on a single support by etching . The fiber stacking apparatus according to claim 1 , wherein the thickness of the fiber stack support is uniform. An absorbent body manufactured by the fiber stacking apparatus according to claim 1, the center of the absorbent body have a different area basis weight of the granular material, the high basis weight regions having a basis weight higher absorber The said absorber arrange | positioned so that the low basic weight area | region which is arrange | positioned at an area | region and whose basic weight is low compared with a high basic weight area | region may be enclosed in the peripheral area | region of an absorber. The absorbent body according to claim 3 , wherein the basis weight of the high basis weight region is 250 g / m ² or less and 1.5 times or more the basis weight of the low basis weight region. The absorber according to claim 3 or 4 , wherein the low basis weight region is disposed at a position of 5 mm to 15 mm from an outer edge of the absorber. The absorber according to any one of claims 3 to 5 , wherein an interval between two adjacent low basis weight regions is 5 mm to 20 mm. A region having a basis weight between the basis weight of the high basis weight region and the basis weight of the low basis weight region surrounds the low basis weight region, and at least a part thereof is in the high basis weight region. It is further arranged in contact, absorbent body according to any one of claims 3-6.

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