JP2009112347A - Absorbent manufacturing method and manufacturing apparatus - Google Patents

Abstract

An object of the present invention is to provide a method and an apparatus for manufacturing an absorbent body that can be uniformly dispersed in a water-absorbing polymer in a direction (CD) perpendicular to the flow direction (MD) during production of the absorbent body.
In the method for producing an absorbent body of the present invention, a water-absorbing polymer 51 is introduced into a flow of air flowing in a duct 3 via a polymer supply pipe 5 and is carried on the air flow. Is a method of manufacturing an absorbent body comprising a step of depositing the polymer in a predetermined shape, and the water-absorbing polymer 51 in the polymer supply pipe 5 is accelerated by jetting compressed air, and the accelerated water-absorbing polymer is supplied to the polymer. A method for producing an absorbent body, wherein a water-absorbing polymer dispersed by collision is introduced into the air flow by colliding with a dispersion plate 53 provided on the tip of the tube 5 or an extension line of the polymer supply tube 5.
[Selection] Figure 1

Description

  The present invention relates to an absorbent body manufacturing method and manufacturing apparatus.

As absorbent bodies for absorbent articles such as sanitary napkins, panty liners, and disposable diapers, those containing water-absorbing polymers in addition to fiber materials such as pulp fibers are widely used.
In the production of an absorbent body containing a water-absorbing polymer, the water-absorbing polymer is uniformly dispersed in a direction perpendicular to the flow direction (MD) at the time of producing the absorbent body (CD, hereinafter also referred to as “absorber width direction”). Is often required.

  Known techniques for dispersing the water-absorbing polymer in the width direction of the absorbent body include a method using a supply pipe with a widened tip, and a method of arranging a plurality of supply pipes in parallel (both refer to Patent Document 1). Yes.

JP 2006-115999 A

  However, even when a supply pipe having a wide tip is used, the water-absorbing polymer is often not sufficiently dispersed in the supply pipe. Moreover, the method of arranging a plurality of supply pipes in parallel cannot form a uniform dispersed state because a portion having a high spray density of the water-absorbing polymer is formed by the number of supply pipes.

  Accordingly, an object of the present invention is to provide an absorbent body manufacturing method and manufacturing apparatus that can uniformly disperse a water-absorbing polymer in a direction (CD) perpendicular to the flow direction (MD) during manufacture of the absorbent body. It is in.

  The present invention provides an absorbent body comprising a step of introducing a water-absorbing polymer into an air flow flowing in a duct via a polymer supply pipe and depositing the water-absorbing polymer carried on the air flow in a predetermined shape. In the method, the water-absorbing polymer in the polymer supply pipe is accelerated by jetting compressed air, and the accelerated water-absorbing polymer is provided on a distal end portion of the polymer supply pipe or an extension line of the polymer supply pipe. The object is achieved by providing a method for producing an absorbent body, in which a water-absorbing polymer that collides with a dispersion plate and is dispersed by the collision is introduced into the air flow.

  The present invention provides an absorbent body comprising a rotating drum having a deposition portion on an outer peripheral surface, and a duct for supplying a fiber material and a water-absorbing polymer on the outer peripheral surface of the rotating drum on an air flow generated inside. An apparatus, wherein the duct is provided with a polymer supply pipe for introducing the water-absorbing polymer into the duct, and the polymer supply pipe is configured to inject compressed air into the polymer supply pipe. Provided is an absorbent manufacturing apparatus having a mouth, and having a dispersion plate that impinges the water-absorbing polymer accelerated by the compressed air on the tip of the polymer supply pipe or an extension of the polymer supply pipe Thus, the object is achieved.

  According to the manufacturing method and manufacturing apparatus of the absorbent body of the present invention, it is possible to uniformly disperse the water-absorbing polymer in the direction (CD) orthogonal to the flow direction (MD) during the manufacture of the absorbent body.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
As shown in FIG. 1, an absorbent body manufacturing apparatus 1 according to an embodiment of the present invention includes a rotary drum 2 having a plurality of accumulation recesses 21 (deposition portions) formed at predetermined intervals on an outer peripheral surface, and a rotating drum 2. A duct 3 having one end portion covering a part of the outer peripheral surface of the drum 2 is provided. The duct 3 supplies the fiber material 42 and the water-absorbing polymer 51 in a scattered state on the outer peripheral surface of the rotating drum 2 while being placed on the air flow generated inside.

  The rotating drum 2 has a cylindrical shape and is driven to rotate in the direction of arrow A in FIG. On the outer peripheral surface of the rotating drum 2, accumulation concave portions 21, 21,... Having a shape corresponding to the shape to be imparted to the fibrous material and the water-absorbing polymer deposit are formed. The rotary drum 2 is connected to an intake fan (not shown), and is configured such that the partitioned spaces B and C in the rotary drum can be maintained at a negative pressure by driving the intake fan. A large number of pores (not shown) are formed in the bottom surface of each collecting recess 21, and each collecting recess 21 passes over the spaces B and C maintained at negative pressure. Meanwhile, the pores at the bottom of each accumulation recess 21 function as suction holes.

In addition, suction from the bottom surface of the accumulation recess 21 located on the space B causes an air flow that flows toward the outer peripheral surface of the rotary drum 2 in the duct 3.
In the vicinity of the end of the duct 3 opposite to the rotating drum 2 side, a fiber material supply device 4 that pulverizes a sheet-like absorbent material 41 such as a pulp sheet and supplies it as a fiber material 42 into the duct 3. Is provided. The fiber material 42 is conveyed toward the outer peripheral surface of the rotating drum 2 along with the air flow generated in the duct by the driving of the intake fan. In FIG. 1, the code | symbol 43 is a grinder.

The duct 3 has a cylindrical shape with a rectangular cross section having an upper wall 31, a lower wall 32, and left and right side walls (not shown), and between the rotating drum 2 and the introduction portion 44 of the fiber material 42 in the duct 3. A polymer supply pipe 5 for introducing the water-absorbing polymer 51 into the duct 3 is provided on the upper wall 31.
As shown in FIGS. 2 and 3, the polymer supply pipe 5 is a dispersion plate that collides a compressed air injection port 52 that injects compressed air into the polymer supply pipe 5 and a water-absorbing polymer 51 accelerated by the compressed air. 53 and a polymer inlet 54 for introducing the water-absorbing polymer 51 after colliding with the dispersion plate 53 into the duct 3.

  As shown in FIG. 2, the polymer supply pipe 5 is mainly composed of a cylindrical main body 50 having a circular cross section, and an injection port (compressed air injection port) 52 of the injection nozzle 55 is formed on the inner peripheral surface of the cylindrical main body 50. Is open. The cross section of the polymer supply pipe is preferably circular so as not to cause stagnation with respect to the flow of the polymer powder. The injection nozzle 55 is connected through a connecting pipe 56 to a compressed air tank (not shown) provided with a solenoid valve. The injection of compressed air can be controlled by controlling the opening and closing of the solenoid valve. A compressor is connected to the compressed air tank so that the pressure in the tank is always maintained within a predetermined range. The dispersion plate 53 has an elliptical shape that matches the shape of the end portion produced by cutting the cylindrical body 50 obliquely. The dispersion plate 53 is fixed to the distal end portion of the cylindrical main body 50. The dispersion plate 53 is provided so as to be inclined with respect to the central axis L of the cylindrical main body 50, and is provided substantially parallel to the upper wall 31 of the duct 3. The polymer inlet 54 is formed by providing a notch in the vicinity of the tip of the cylindrical main body 50.

The diameter of the polymer supply pipe 5 is preferably 10 to 100 mm, the diameter of the compressed air injection port 52 is preferably 3 to 30 mm, and the supply pressure of the compressed air depends on the diameter of the compressed air injection port. 5 MPa is preferred.

The injection angle θ1 of compressed air into the polymer supply pipe 5 (in this embodiment, the intersection angle between the extension line L1 of the center line of the injection nozzle 55 and the center axis L of the cylindrical body 50, see FIG. 2) From the viewpoint of efficient acceleration of the water-absorbing polymer, it is preferably 10 to 75 degrees, particularly preferably 20 to 50 degrees. Moreover, it is preferable that the opening 54 does not exist on the extension line L1 of the center line of the injection nozzle 55.
Further, the angle θ2 formed by the central axis L of the polymer supply pipe 5 and the dispersion plate 53 (in this embodiment, the angle formed by the central axis L of the cylindrical main body 50 and the dispersion plate 53, see FIG. 2) is the water absorption. From the viewpoint of improving the dispersibility of the conductive polymer, it is preferably 100 to 170 degrees, particularly preferably 110 to 50 degrees.

The dispersion plate 53 in the present embodiment is provided directly fixed to the polymer supply pipe 5, but instead of this, the dispersion plate 53 is supported by a support extending from the upper wall, left and right side walls, etc. of the duct 3 ( It can also be provided at the tip of the polymer supply pipe 5 in a state where it is supported by (not shown).
In addition, as shown in FIG. 5, the dispersion plate 53 can be provided on the extension line of the polymer supply pipe 5 while being separated from the tip of the polymer supply pipe 5. In this case, the dispersion plate 53 can be supported by, for example, a support body (not shown) extending from the upper wall 31 and the left and right side walls of the duct 3.
The disposition position of the dispersion plate 53 depends on the supply amount of compressed air, but the distance h (see FIGS. 2 and 5) from the upper wall 31 of the duct 3 is 5 to 30 cm, particularly 5 to 20 cm. preferable.
When the dispersion plate 53 and the polymer supply pipe 5 are separated, the distance L3 between the dispersion plate 53 and the polymer supply pipe 5 (see FIG. 5, measured along the central axis L of the polymer supply pipe cylindrical main body 50). If the cross section of the polymer supply tube cylindrical body is circular, the ratio R / L3 to the circular diameter R of the same area is zero when the cross section of the polymer supply tube cylindrical body is non-circular (supply pipe) And a distance where the dispersion plate is in contact) to 1 is preferable.
The polymer inlet 54 has a left-right opening angle θ3 (see FIG. 3) of 100 to 360 degrees, particularly 150 to 180 degrees, with the intersection point between the center axis L of the cylindrical body 50 and the dispersion plate 53 as the center P. It is preferable that

  A funnel-shaped polymer introduction pipe 57 is connected to the other end of the cylindrical main body 50 of the polymer supply pipe 5, and a screw (not shown) is connected to an inverted conical polymer inlet 58 of the polymer introduction pipe 57. A water-absorbing polymer is introduced by a feeder or the like, and the introduced water-absorbing polymer is supplied into the duct 3 through the polymer introduction pipe 57 and the cylindrical main body 50 of the polymer supply pipe 5.

As the fiber material supplied into the duct, various materials conventionally used for absorbent bodies of absorbent articles such as sanitary napkins, panty liners, and disposable diapers can be used without particular limitation. For example, short fibers of cellulosic fibers such as pulp fibers, rayon fibers, and cotton fibers, and short fibers of synthetic fibers such as polyethylene are used. These fibers can be used alone or in combination of two or more.
The fiber material is preferably all or part of pulp fiber, and the ratio of pulp fiber in the fiber material is preferably 20 to 100% by mass, more preferably 80 to 100% by mass, and still more preferably. Is 100% by mass.

  As the water-absorbing polymer, various polymers conventionally used for absorbent bodies of absorbent articles such as disposable diapers and sanitary napkins can be used without particular limitation. For example, starch-based, cellulose-based or synthetic polymer-based materials can be used. The water-absorbing polymer is usually in the form of particles. As the water-absorbing polymer, those having a liquid absorbency retention of 20 times or more of its own weight and a gelling property are preferable. For example, starch-acrylic acid (salt) graft copolymer, starch-acrylonitrile copolymer Preferred are a saponified compound, a crosslinked product of sodium carboxymethyl cellulose, an acrylic acid (salt) polymer, and the like. These water-absorbing polymers can be used alone or in combination of two or more.

As shown in FIG. 1, the manufacturing apparatus 1 according to the present embodiment includes a fiber material 42 and a water-absorbing polymer 51 that are transported in an airflow flowing in a duct 3 in a scattered state, and are used for accumulation located in a space B. After being accumulated in the accumulation recess 21 by suction from the bottom surface of the recess 21, the deposit 8 is conveyed to the lower end of the rotary drum 2 while being held in the accumulation recess 21 and rotated. At the lower end of the drum 2, the deposit 8 is configured to be released onto the first core wrap sheet 7 </ b> A on the vacuum conveyor 6. The vacuum conveyor 6 includes a breathable endless belt 61 and a vacuum box 62. After the first core wrap sheet 7A is supplied onto the endless belt 61, the fiber material and A deposit 8 of a water-absorbing polymer is placed, and the second core wrap sheet 7B is further supplied onto the deposit 8.
The mold release from the recess 21 for accumulation is performed by maintaining the space D partitioned in the rotary drum 2 at a positive pressure by a pressurizing means (not shown) and from the pores at the bottom of the recess 21 for accumulation. Air is blown out and sucked from the vacuum conveyor 6.

An embodiment of an absorber manufacturing method using the absorber manufacturing apparatus 1 described above, that is, an embodiment of the absorber manufacturing method of the present invention will be described.
In the manufacturing method of the absorbent body according to the present embodiment, the water-absorbing polymer 51 is introduced into the air flow flowing in the duct 3 through the polymer supply pipe 5, and the water-absorbing polymer 51 conveyed on the air flow is shaped into a predetermined shape. In which the water-absorbing polymer 51 in the polymer supply pipe 5 is accelerated by jetting compressed air, and the accelerated water-absorbing polymer 51 is added to the tip of the polymer supply pipe 5. After colliding with the dispersion plate 53 provided in the section, it is introduced into the duct 3.
In the present embodiment, compressed air is injected into the polymer supply pipe 5 to accelerate the water-absorbing polymer 51 in the polymer supply pipe 5.

The manufacturing method of this embodiment will be described in further detail.
In order to manufacture the absorber using the absorber manufacturing apparatus 1, the rotary drum 2 is rotated and the intake fan is operated to make the spaces B and C have a negative pressure. Further, the vacuum conveyor 6 is operated, and the supply mechanism for the first and second core wrap sheets 7A and 7B is also operated.
By the operation of the intake fan, a suction force is generated on the bottom surface portion of the accumulation recess 20 located on the space B, and an air flow that flows toward the outer peripheral surface of the rotary drum 2 is generated in the duct 3.

  When the fiber material supply device 4 is operated to supply the fiber material 42 into the duct 3, the fiber material 42 is in a scattered state and is carried on the air flow flowing through the duct 3, and the rotating drum. 2 is supplied toward the outer peripheral surface.

Further, the screw feeder or the like is operated, the water-absorbing polymer is introduced into the polymer inlet 58, and the compressed air is injected from the compressed air outlet 52.
The water-absorbing polymer introduced into the polymer introduction port 58 flows into the polymer supply pipe 5 by the air flow generated in the polymer introduction pipe 57 and the polymer supply pipe 5 mainly by the influence of the air flow generated in the duct and by its own weight. Led.
Then, compressed air is injected from the compressed air injection port 52 to the water-absorbing polymer in the polymer supply pipe 5, and the moving speed of the water-absorbing polymer rapidly increases, and has a high kinetic energy to the dispersion plate 53. collide. Then, the collided water-absorbing polymer is bounced back to the dispersion plate and scattered in various directions, and the scattered water-absorbing polymer is introduced into the duct 3 from the polymer inlet 54.

  In this way, the water-absorbing polymer 51 accelerated by the jet of compressed air collides with the dispersion plate and then introduced into the duct, so that the water-absorbing polymer 51 has the duct 3 as shown in FIG. It is in a state of being widely dispersed in the inner width direction (Y direction), and is deposited in the accumulation concave portion 21 together with the fiber material 42 while maintaining the dispersed state. FIG. 4B shows the dispersion state of the water-absorbing polymer 51 when the water-absorbing polymer 51 is introduced into the duct 3 in the same manner except that the compressed air is not injected.

The deposit 8 of the fiber material 21 and the water-absorbing polymer 51 in the accumulation recess 21 is conveyed to the lower end of the rotary drum 2 and accumulated as a deposit 8 formed into a shape corresponding to the shape of the accumulation recess 21. The mold is released from the recess 21 for use.
Then, the deposit 8 released from the accumulation recess 21 is disposed between the first and second core wrap sheets 7A and 7B to form a continuous body 9 of the absorber. The continuous body 9 of the absorbent body is transported to a subsequent process by a known transporting means, and is cut by a known cutting means to become an absorbent body 9 used for each absorbent article.

  According to the manufacturing apparatus and the manufacturing method of the present embodiment, as described above, the water-absorbing polymer is accelerated by jetting compressed air, collides with the dispersion plate, and then introduced into the duct, whereby the water-absorbing polymer is ducted. 3 can be dispersed widely and uniformly in the width direction (Y direction), and thereby efficiently produce the absorbent body 9 uniformly dispersed in the direction perpendicular to the flow direction (MD) during the production of the absorbent body. can do.

As mentioned above, although each embodiment of the manufacturing method and manufacturing apparatus of the absorber of this invention was described, this invention is not restrict | limited to said each embodiment, It can change suitably.
For example, in the above-described embodiment, the upper and lower surfaces of the fibrous material and water-absorbing polymer deposit 8 released from the accumulation recess 21 are covered with the first and second core wrap sheets 7A and 7B. Alternatively, an absorber in which the upper and lower surfaces of the deposit 8 are covered with a single core wrap sheet may be manufactured, and an absorber that does not cover one or both of the upper and lower surfaces of the deposit 8 may be manufactured. It may be manufactured.

The accumulation recess 21 may be formed on the outer peripheral surface of the rotary drum 2 as a groove-like recess that is continuous in the circumferential direction.
In the method and apparatus of the present invention, a water-absorbing polymer or a fiber material may be deposited on the non-concave deposition portion. For example, a suction force is applied only to a certain region on the outer peripheral surface of a mesh conveyor having no concave portion formed on the surface facing the duct or a concave portion formed on the outer peripheral surface, and the water absorbent polymer is applied only to the predetermined region. Or a fiber material may be deposited. In this case, the portion where the suction force is applied is the deposition portion.

  The polymer supply pipe 5 may be provided with a cylindrical main body having a non-circular cross section perpendicular to the central axis L instead of the cylindrical main body 50 having a circular cross section. For example, a cross-sectional shape perpendicular to the central axis may include an oval, square, rectangular, trapezoidal, rhombus, triangular, or other cylindrical body. Further, the compressed air injection port 52 can be provided in a state of protruding into the cylindrical main body 50. The shape of the dispersion plate 53 can also be a shape other than an ellipse. The injection nozzle 55 can also be provided in a portion other than the inverted truncated cone portion of the polymer introduction tube 57.

  In addition, as shown in FIG. 6, the polymer supply pipe 5 is provided with a branch portion 59 that communicates with the flow path 50 a of the water-absorbing polymer 51 but does not allow the polymer to pass therethrough, and jets of compressed air provided in the branch portion 59 The water-absorbing polymer 51 supplied from a position downstream of the injection port 52 (on the polymer introduction port 54 side) may be accelerated by the compressed air injected from the port 52. In this case, although not shown in the figure, in order to introduce the water-absorbing polymer 51 against the pressure of the compressed air, a device including a polymer pushing means and a valve is provided.

  In addition, instead of depositing the water-absorbing polymer into the air flow that conveys the fiber material and depositing the mixed fiber material and the water-absorbing polymer in the concave portion for accumulation (deposition portion), accumulation is performed. The fiber material may be deposited in the concave portion (deposition portion), and then the water-absorbing polymer conveyed by the air flow not containing the fiber material may be deposited on the deposited fiber material.

It is a schematic diagram which shows one Embodiment of the manufacturing apparatus of the absorber of this invention. It is a figure which shows the detail of the polymer supply pipe | tube in the manufacturing apparatus of the absorber shown in FIG. 1, FIG. 2 (a) is a vertical sectional view along the flow direction of the air flow in a duct, FIG.2 (b) is a polymer supply. It is the perspective view which looked at the pipe | tube from the upper side of the downstream of the flow direction of an airflow. It is a perspective view which shows the state which looked at the front-end | tip part vicinity of the polymer supply pipe | tube in the manufacturing apparatus of the absorber shown in FIG. 1 from the polymer inlet side. 4A and 4B are explanatory diagrams showing the operational effects of the present invention. FIG. 4A shows a dispersion mode of the water-absorbing polymer when compressed air is injected, and FIG. 4B shows water absorption when compressed air is not injected. It is a figure which shows the dispersion | distribution aspect of a conductive polymer. It is a figure (figure 2 equivalent figure) which shows other embodiment of the manufacturing apparatus of the absorber of this invention. It is a figure (FIG. 2 equivalent figure) which shows other embodiment of the manufacturing apparatus of the absorber of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorber manufacturing apparatus 2 Rotating drum 21 Accumulation recess (deposition part)
DESCRIPTION OF SYMBOLS 3 Duct 4 Fiber material supply apparatus 41 Sheet-form absorber raw material 42 Fiber material 5 Polymer supply pipe 51 Water-absorbing polymer 52 Compressed air injection port 53 Dispersion plate 54 Polymer introduction port 55 Injection nozzle 56 Connection pipe 57 Polymer introduction tube 6 Vacuum conveyor 7A, 7B First and second core wrap sheets 8 Deposits of fiber material and water-absorbing polymer 9 Absorber 9A Absorber continuum

Claims (4)

A method for producing an absorbent body comprising a step of introducing a water-absorbing polymer into a flow of air flowing in a duct via a polymer supply pipe and depositing the water-absorbing polymer carried on the air flow in a predetermined shape. ,
The water-absorbing polymer in the polymer supply pipe is accelerated by jetting compressed air, and the accelerated water-absorbing polymer is made to collide with a dispersion plate provided on the tip of the polymer supply pipe or an extension line of the polymer supply pipe. A method for producing an absorbent body, wherein a water-absorbing polymer dispersed by collision is introduced into the air stream.   The manufacturing method of the absorber of Claim 1 in which the airflow which flows through the said duct contains the fiber material. An apparatus for manufacturing an absorbent body, comprising: a rotating drum having a deposition portion on an outer peripheral surface; and a duct for supplying a fiber material and a water-absorbing polymer on an air flow generated inside the rotating drum on the outer peripheral surface of the rotating drum. ,
The duct is provided with a polymer supply pipe for introducing the water-absorbing polymer into the duct, and the polymer supply pipe has a compressed air injection port for injecting compressed air into the polymer supply pipe. And
The absorber manufacturing apparatus which has a dispersion | distribution plate which collides the water absorbing polymer accelerated with the said compressed air on the front-end | tip part of the said polymer supply pipe, or the extension line of this polymer supply pipe.   The absorber manufacturing apparatus according to claim 3, wherein an angle θ <b> 2 formed by a central axis L of the polymer supply pipe and the dispersion plate is 100 to 170 degrees.

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