JP5057708B2 - Absorbent manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to an absorber used for an absorbent article, and more particularly to a method and an apparatus for manufacturing an absorber comprising a liquid-absorbing open-cell foam.

  As a technique relating to the manufacture of an absorbent article using a liquid-absorbing open-cell foam, a technique described in Patent Document 1 below has been proposed. In this technique, a liquid-absorbing open-cell foam is continuously formed by extrusion.

Special table 2003-530149 gazette

  When manufacturing an absorbent body having a constant width, a manufacturing method by extrusion molding as described in Patent Document 1 is also preferable, but a shape in which the central portion in the length direction is constricted to fit the crotch or In the case of a middle-high form in which the central part is raised compared to the peripheral part, it cannot be produced by extrusion molding.

  Therefore, an object of this invention is to provide the manufacturing method and apparatus of an absorber which can manufacture suitably the absorber which comprises the open-cell foam of a desired form.

  The present invention is a method for manufacturing an absorbent body comprising a liquid-absorbing open-cell foam, wherein the raw material of the open-cell foam is supplied into a mold placed on the periphery of the rotary body, and the rotation The object is achieved by providing a method for producing an absorbent body in which the open cell foam is molded by foaming the raw material in the mold while rotating the body.

  The present invention also relates to an apparatus for manufacturing an absorbent body having a liquid-absorbing open-cell foam, a rotating body provided with a molding die having a recess disposed in a peripheral portion thereof, and the molding die. The object is achieved by providing a manufacturing apparatus for an absorbent body provided with a raw material supply means for supplying a raw material for the open-cell foam.

  According to the method and apparatus for producing an absorbent body of the present invention, an absorbent body having a desired form of open-cell foam can be suitably produced. The open-cell foam in the present invention refers to a foam in which internal bubbles are connected, and refers to a material that exhibits absorption performance when used as an absorber.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.
FIG. 1 schematically shows an embodiment of an absorbent body manufacturing apparatus (hereinafter also simply referred to as a manufacturing apparatus) according to the present invention.

  As shown in FIG. 1, the manufacturing apparatus 1 of the present embodiment includes a rotating body 3 in which a plurality of molds 2 each having a recess 21 are arranged in a circumferential portion and provided rotatably, and the mold 2 has a continuous liquid-absorbing property. The raw material supply means 4 for supplying the raw material of the cellular foam, the first sheet supply means 5 for supplying the first sheet 11, and the support for supporting the first sheet 11 so as to form the molding surface of the open-cell foam 1. Means 6; second sheet supply means 7 for supplying the second sheet 12 to the inner surface of the mold 2; and suction means 8 for adsorbing the second sheet 12 to the inner surface through a flow passage 23 of the mold 2 to be described later. And a conveying means 9 for conveying the absorbent body 10 removed from the mold 2.

  The recess 21 of the mold 2 has a molding surface 22 corresponding to the shape of the open-cell foam to be molded. In the present embodiment, as shown in FIG. 2, the molding surface 22 is formed such that an open-cell foam having a shape in which the central portion in the length direction is constricted and the central portion of the absorber is higher than the peripheral portion is formed. Is provided. The molding die 2 is provided with a flow passage 23 that opens at the molding surface 22.

  The rotating body 3 includes a rotating drum 31 in which a plurality of molds 2 can be installed on the periphery, and a drive source (not shown) that drives the rotating drum 31 to rotate. The rotating drum 31 has a double structure in which only the frame portion for fixing the molding die 2 rotates and the central portion does not rotate. The central portion has a flow passage 32 communicating with a suction pump of the suction means 8 described later. A partition wall 33 is provided for determining the suction force of the suction pump within a predetermined angle range.

  The raw material supply means 4 includes tanks 41 and 42 for storing foam constituents, a tank 43 for storing absorbent polymers, and a mixer 44 that mixes foam constituents and water-absorbing polymers into raw materials. And a nozzle 45 for injecting the raw material from the mixer 44 into the mold 2.

  The components of the foam consist of a thermoplastic polymer, which is the main component of the skeleton structure, a gas foaming agent for foaming, and a surfactant to make the foam surface after foaming hydrophilic, and in some cases fibers. The material can be used as a raw material.

  The first sheet supply means 5 includes a feeding device 51 that feeds the first sheet 11 from the original fabric.

  The first sheet support means 6 drives a roller group including a roller 61 arranged along the circular orbit of the surface of the mold 2, a belt 62 wound around the roller group, and the roller group. And a motor (not shown).

  The second sheet supply means 7 includes a feeding device 71 that feeds the second sheet 12 from the original fabric, and a roller 72 for feeding the second sheet 12 fed from the feeding device 71 in a predetermined path. .

  The suction means 8 includes a suction pump (not shown) that adsorbs the second sheet 12 to the molding surface 22 of the molding die 2 through the flow passage 23 and the flow passage 33 of the molding die 2.

The conveying means 9 is constituted by a belt conveyor 92 in which a suction box 91 is installed. The suction force of the suction box 91 is applied to the absorbent body 10 that has been molded, and the absorbent body 10 is removed from the mold 2. Transport. In order to stabilize the demolding, air may be sent from the inside of the rotary drum 31 to the flow passage 23.
In FIG. 1, the absorber 10 is temporarily fixed to the belt conveyor 92 by a suction force, and the first sheet 11 side is a flat surface. It is a curved shape close to the shape of the outer peripheral surface, and when used in an absorbent article, it becomes easy to follow the curved shape in the front-rear direction (abdomen-dorsal direction) of the body.

  Next, an embodiment of a manufacturing method of an absorber of the present invention is described based on a manufacturing method by manufacturing device 1 of the above-mentioned embodiment.

  First, before the manufacturing apparatus 1 is activated and the raw material is supplied to the mold 2, the second sheet supply means 7 causes the second sheet supply means 7 to apply the second sheet feeding means 7 to the molding surface 22 rotating with the rotation of the rotary drum 32. A sheet 12 is supplied. Then, the second sheet 12 is adsorbed to the molding surface 22 by the suction pump. As the 2nd sheet | seat 12, the paper, the nonwoven fabric, etc. which are conventionally used for the absorber are used.

  Since the second sheet 12 must conform to the shape of the inner surface of the rotary drum 32, (1) the first sheet 11 is used in a width corresponding to the middle-high part, and (2) a material that is easily stretched (for example, a nonwoven fabric). It is possible to easily form the middle and high portions where the central portion is raised by using materials and methods such as (3) embossing after application of the first sheet 11.

  Next, the raw material is supplied from the nozzle 45 of the raw material supply means 4 to the recess 21 of the mold 22. The raw material is prepared by mixing the constituents of the foam stored in the storage tanks 41 and 42 and the absorbent polymer stored in the tank 43 with the mixer 44. Moreover, the absorbent polymer conventionally used for the absorbent article is used for the absorbent polymer.

  The thermoplastic polymer is preferably a polyolefin such as polyethylene or polypropylene, but polyurethane can also be used.

  As the gas blowing agent, a gas such as carbon dioxide, helium or nitrogen can be used, and a mixture of water and air can also be used.

  The surfactant is preferably a semi-compatible material that has good compatibility with the resin and gradually precipitates on the resin surface after the resin is cooled. Specifically, the surfactant is used in JP-A-3-185167. The surfactant is preferred.

  The fiber material only needs to have a melting point higher than that of the thermoplastic polymer, but the hydrophilic material is preferably pulp or rayon, and the thermoplastic fiber material is preferably polyester having a melting point of 30 ° C. or higher. When this fiber material is blended, the capillary diameter can be reduced, so that the liquid absorbency can be increased. In addition, as a characteristic of the material used, the use of a hydrophilic material allows the foam to be liquid-absorbing without a surfactant, and the thermoplastic fiber material has a skeleton structure (even at a high expansion ratio). Effects such as being stable can be obtained.

  Next, the first sheet 11 is supplied by the first sheet supply means 5 so as to close the mold 2 supplied with the raw material, and further, the first sheet 11 is pressed against the mold 2 by the first sheet support means 6. Then, a part of the molding surface of the open cell foam 13 is formed by the first sheet 11.

  For the first sheet 11, a polypropylene nonwoven fabric or a liquid-impermeable polyethylene film can be used.

  And while rotating the rotating body 3, the said raw material is foamed within the shaping | molding die 2, and the open-cell foam 13 is shape | molded. In the present embodiment, the process of foaming the raw material and stabilizing the foam is completed during the movement of the mold 2 accompanying the rotation of the rotating body 3. In order to obtain stable foaming, the molding die 2 is in the range of 40 to 90 ° C., preferably in the range of 50 to 70 ° C. when the foaming raw material is injected. Adjust. By manufacturing in this way, when the foam comes into contact with the rotating body 3 (second sheet), it is possible to prevent solidification before foaming is sufficiently performed on the contacted surface. The foaming rate is 50% or more, preferably 100 to 500%. When the foaming ratio is such, the obtained absorbent body does not become too hard, and the stability of the shape (particularly during use) is also improved.

  A plurality of rollers 61 are used, the foam can be prevented from excessively jumping out to the first sheet 11 side, and the first sheet side 11 can be cooled earlier than the second sheet 12 side. For this reason, the first sheet 11 side is less foamed than the second sheet side 12 or the foam is compressed.

  In order to remove or destroy (hereinafter referred to as open cell formation) each foamed film of the foam when foaming is sufficiently performed, the roller 61 or another roller (not shown) is used. In the case of using the roller 61, the protrusion during foaming is performed and then compressed and shaped in an overheated state at 80 to 120 ° C. (depending on the thermoplastic polymer used). Another roller is preferable from the viewpoint of easy adjustment.

Another roller is preferably a roller having a width substantially the same as or narrower than the concave portion 21 of the rotating body 31 because it is preferable that a part of the roller enters the concave portion 21. It is more preferable that the portion is formed and that a needle-like object or protrusion having a diameter of about 2 to 5 mm at the base is provided.
A press roller may be arranged in a subsequent process after the conveying means 9 so that each foamed film may be removed or destroyed.

  Then, the suction force of the suction box 91 of the transport means 9 is applied to the absorbent body 10 in which the molding of the open-cell foam 13 has been completed, the absorbent body 10 is removed from the mold 2 and transported to the next process by the belt conveyor 92. To do.

  As described above, according to the manufacturing apparatus 1 and the manufacturing method of the present embodiment, the absorbent body 10 in which the open-cell foam 13 having a desired shape is wrapped with the first and second sheets 11 and 12 is preferably manufactured. can do. In this embodiment, since the first cell support means 6 molds the open-cell foam 13 in a state where the first sheet 11 constituting a part of the molding surface is supported, the open-cell foam 13 The bulge from the mold 2 can be prevented and the open cell foam 13 can be wrapped with the first sheet 11. Furthermore, since the open cell foam 13 is wrapped with the first and second sheets 11 and 12, the mold can be easily removed from the mold 2. Further, since the foam does not directly contact the mold 2, the mold 2 is not easily soiled and maintenance is easy.

The present invention is not limited to the embodiment.
The present invention is preferably molded while covering the open-cell foam with the first and second sheets as in the above embodiment, but can be molded without using one of the first or second sheets. .

  According to the method and apparatus for producing an absorbent body of the present invention, an absorbent body comprising an open-cell foam having a desired shape can be suitably produced. The present invention can be applied to the production of open-cell foams used for other than absorbent bodies, as well as absorbent bodies used for absorbent articles such as sanitary napkins, incontinence pads, and disposable diapers.

It is a figure which shows typically one Embodiment of the manufacturing apparatus of the absorber of this invention. It is a perspective view which shows typically the shaping | molding die in one Embodiment of the manufacturing apparatus of the absorber of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorber manufacturing apparatus 2 Mold 21 Recess 22 Molding surface 3 Rotating body 4 Raw material supply means 5 First sheet supply means 6 First sheet support means 7 Second sheet supply means 8 Suction means 9 Conveyance means 10 Absorber 11 First 1 sheet 12 2nd sheet 13 Open-cell foam

Claims (7)

A method for producing an absorbent comprising a liquid-absorbing open-cell foam,
The raw material of the open-cell foam is supplied into a mold having a concave surface corresponding to the shape of the open-cell foam to be molded, which is arranged in a plurality around the periphery of the rotating drum , and then the raw material is supplied. In addition, the first sheet is supplied so as to close the mold, and the belt wound around a roller group disposed along a circular path on the circumferential surface of the rotating drum on which the mold is disposed is used. While pressing the first sheet against the mold and rotating the rotating drum , the raw material is foamed in the mold to form the open-cell foam, and the open-cell foam is molded with the first sheet. The manufacturing method of the absorber which forms a part of surface . Before supplying the raw material to the molding die, the second sheet is supplied to the molding surface of the molding die, and the second sheet is adsorbed to the inner surface through a flow passage provided in the inner surface of the concave portion of the molding die. The method for producing an absorbent body according to claim 1, wherein the open-cell foam is formed by interposing the second sheet between the mold and the raw material. After forming the foam by foaming the raw material in the mold, the foam has the same or narrow width as the concave portion of the mold, and is disposed on the peripheral surface of the rotating drum separately from the roller group The said open-cell foam is shape | molded by squeezing the said foam formed in the said shaping | molding die using the roller of a heating state, removing or destroying each foam film | membrane of this foam. 2. A method for producing the absorber according to 2. An absorbent manufacturing apparatus comprising a liquid-absorbing open-cell foam,
A rotating drum provided rotatably with a plurality of molds having inner surfaces of recesses corresponding to the shape of the open-cell foam to be molded;
Raw material supply means for supplying the raw material of the open-cell foam to the mold ,
First sheet supply means for supplying a first sheet to the periphery of the rotating drum;
A belt wound around a group of rollers arranged on a circumferential surface of the rotating drum on which the molding die is arranged, and forming a molding surface of the open cell foam together with the molding die; As described above, an absorbent body manufacturing apparatus comprising a supporting means for supporting the first sheet with the belt . The absorber manufacturing apparatus according to claim 4, further comprising a second sheet supply unit that supplies a second sheet to the molding surface of the mold. The absorbent body manufacturing apparatus according to claim 5 , wherein the molding die is provided with a flow passage that opens at the molding surface, and includes suction means for adsorbing the second sheet to the inner surface through the flow passage. . 7. The apparatus according to claim 4, further comprising a heated roller disposed on a peripheral surface of the rotating drum, separately from the roller group, having the same width as or narrower than the concave portion of the mold. An absorbent body manufacturing apparatus according to claim 1.

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