JPH09182768A - Production method and device for banded fiber aggregate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase rigidity of an ear part to prevent it from being distorted and breaking by forming a fiber aggregate, then the ear part is pressed with a force stronger than that for a web body when manufacturing a banded fiber aggregate of an absorbing object such as a sanitary napkin in which a web body is provided with a pair of ear parts at a certain distance. SOLUTION: A laminating body 30 is a banded object in which a base paper 32, fiber assembly 34 and absorbing paper 36 are laminated, and the fiber aggregate 34 is made in such a manner that a web body 38 is provided with a pair of ear parts 40 at a certain distances. When pressing the laminating body 30 with a press roll unit from the top, the laminating body 30 is pressed by top and bottom rolls 42 and 44 with held between a vacuum conveyer 16 and a press belt 18. At that time, because of flexibility of the vacuum conveyer 16, it is deformed according to the surface shape of the bottom roll 44 when being pressed by the top roll 42, the base paper 32, web body 38 and absorbing paper 36 are not strongly pressed but the ear parts 40 is strongly pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a belt-shaped fiber assembly made of pulp or the like and an apparatus therefor. More specifically, the present invention relates to a disposable diaper or a sanitary napkin that is cut at a predetermined position. The present invention relates to a method and an apparatus for manufacturing a belt-shaped fiber assembly that is preferably used as an absorbent body of various absorbent articles and the like.

[0002]

2. Description of the Related Art In an apparatus for manufacturing absorbent articles such as disposable diapers and sanitary napkins, there are generally several transition parts. The crossover portion generally means a connecting portion between the conveyors and the mechanical device is discontinuous. When manufacturing an absorbent article using a manufacturing apparatus having such a crossover, the following disadvantages occur.

That is, the absorbent body used in the above absorbent article comprises a pulp web made of pulp fibers such as fluff pulp. And, in general, the pulp web contains:
An extending portion called a flap portion 220 as shown in FIG. 8 is provided so as to extend outward from both longitudinal edges of the main body 210 of the pulp web 200. Then, when manufacturing an absorbent article, the pulp web 200 is first manufactured as a strip-shaped continuous body 300 as shown in FIG. 9, and a portion corresponding to the flap portion 220 is as shown in FIG. The ears 320 are formed at a predetermined interval. Then, the strip-shaped continuous body is superposed on a mount having an absorbent paper such as tissue wrapped with a water-absorbent polymer and pulp, and is cut at a predetermined position to obtain an absorbent body having a laminated structure. . Furthermore, this absorber
In the subsequent step, the elastic rubber that is sandwiched by the continuous body of the top sheet and the back sheet and that is necessary for forming the gather is arranged between the top sheet and the back sheet. And finally, an absorbent article is obtained by cutting at a predetermined position.

Since the width of the mount is substantially equal to the width of the main body 210 of the pulp web 200, the ears 320 of the strip-shaped continuous body 300 are conveyed while protruding from the mount. Will be done.
That is, the ear portion 320 is not supported by the mount and is in a low density state (for example, about 0.02 g / cm ³ ) in which pulp fibers are loosely entangled. In the process in which the strip-shaped continuous body 300 of the pulp web passes through the crossover portion, the ear 320 is not supported by the mount as described above, so that vibration (impact) when passing through the crossover portion or It may be deformed by its own weight or may be broken in some cases.

In order to avoid the above inconvenience, for example, the following proposals (1) and (2) have been made. (1) When the strip-shaped continuous body 300 of the pulp web passes through the transition portion, compressed air is blown from below the transition portion to horizontally hold the ear portion 320 to be drooped. (2) A belt-shaped continuous body of a pulp web having a constant width that does not have the ears 320 is used, and a predetermined shape is obtained by trimming in a post process.

However, the method of the above proposal (1) has a drawback in that it is difficult to stably hold the ear portion 320 when the shape of the ear portion 320 is curved. Further, the method of the above-mentioned proposal (2) has a drawback that a trimming device is separately required, the manufacturing equipment becomes complicated, and a large number of parts cut by trimming occur, resulting in high manufacturing cost.

Therefore, an object of the present invention is to provide a method and apparatus for stably and simply manufacturing a belt-shaped fiber assembly having ears.

[0008]

In order to achieve the above object,
The inventors of the present invention have diligently studied, and control the compression force in the width direction of the pulp web, that is, the rigidity of the ear portion is increased by further compressing the ear portion to increase its density, and It was found that the ear can be prevented from being deformed or broken even when passing through.

The present invention has been made on the basis of the above-mentioned findings, and a pair of opposed ears extending outwardly from both side edges in the longitudinal direction of the web body are provided at predetermined intervals. A method for producing a strip-shaped fiber assembly comprising pulp fibers, which comprises compressing the ears more strongly than the web body after the formation of the fiber assembly, and a method for producing the strip-shaped fiber assembly. By doing so, the above object is achieved.

Further, according to the present invention, as a device preferably used in the above method, a pair of opposed ears extending outwardly from both side edges in the longitudinal direction of the web body are provided at predetermined intervals. A pair of belts for sandwiching and transporting the fiber aggregate along the longitudinal direction thereof, and a large-diameter roll corresponding to the ears and the web. A pair of roll compression means comprising a stepped roll having a small diameter roll corresponding to the main body and a smooth roll, the roll compression means capable of compressing the fiber assembly from above and below the belt; The present invention provides an apparatus for producing a strip-shaped fiber assembly.

In the manufacturing method of the present invention, the ears of the fiber assembly are compressed more strongly than the web body. As a result, the density of the ears is higher than the density of the web body. That is, since the rigidity of the ears is higher than the rigidity of the web main body, it is prevented from being deformed or broken by vibration (impact) or its own weight when passing through the bridging part.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the drawings. Here, FIG. 1 is a schematic view of an apparatus preferably used in the manufacturing method of the present invention as viewed from the side, and FIG. 2 is a schematic view showing a state in which absorbent paper, a fiber assembly and a mount are laminated. 2 is a cross-sectional view taken along the line AA in FIG. 2, FIG. 4 is a cross-sectional view taken along the line BB in FIG. 2, FIG. 5 is a schematic view of the press roll unit as seen from the side, and FIG. FIG. 7 is a sectional view taken along line A, and FIG. 7 is a schematic view showing a preferable compressed state of the fiber assembly.

The apparatus 10 preferably used in the manufacturing method of the present invention shown in FIG. 1 is a stacking chamber 12, a stacking drum 14 located below the stacking chamber 12, and the stacking drum 14 and its lowermost portion. It has a vacuum conveyor 16 in contact with it, a press belt 18 that holds and conveys the fiber assembly together with the vacuum conveyor 16, and a press roll unit 20 that compresses the vacuum conveyor 16 and the press belt 18 from above and below. Also,
The traveling direction turnback portion 22 of the vacuum conveyor 16
Is adjacently provided with a conveyor 24 for conveying the fiber assembly to the next step.
A transfer section 26 exists between 6 and the transfer conveyor 24.

In the apparatus 10 shown in FIG. 1, pulp fibers such as fluff pulp are stacked on the stacking drum 14 from the stacking chamber 12. The surface of the stacking drum 14 is provided with a recess (not shown) for forming a continuous body of pulp web having a shape as shown in FIG. 2, that is, a band-shaped fiber aggregate. Pulp fibers are piled in the recess, and as a result, the continuous body is formed. As the pulp fiber, not only the above-mentioned fluff pulp but also the one usually used as the absorbent body of the absorbent article can be used without particular limitation.

The fiber stack drum 14 is rotating in the direction of the arrow shown in FIG. 1, and is in contact with a vacuum conveyor 16 made of a mesh belt having air permeability at its lowermost portion. The vacuum conveyor 16 is provided with a vacuum zone 28 therein and sucks the vacuum conveyor 16 from the outside. The strip-shaped fiber aggregate (not shown) formed and stacked by the stacking drum 14 is transferred onto the vacuum conveyor 16 at the lowermost part of the stacking drum 14.

When the fiber assembly is transferred, a strip-shaped backing sheet (not shown) in which a water-absorbent polymer and pulp are wrapped with absorbent paper such as tissue between the fiber assembly and the vacuum conveyor 16 is provided. ) Is inserted, and a band-shaped absorbent paper (not shown) such as a tissue is placed on the fiber assembly.
Are laminated. That is, a strip-shaped laminate having a three-layer structure of the mount, the fiber assembly and the absorbent paper is formed on the vacuum conveyor 16. The stacked body is conveyed while being held on the vacuum conveyor 16 by suction by the vacuum zone 28.

The laminated body will be described with reference to FIGS. 2 to 4. As described above, the laminated body 30 includes the mount 3
2. A belt-shaped member in which the fiber assembly 34 and the absorbent paper 36 are laminated in this order. The fiber assembly is
The web body 38 is a strip-shaped member provided with a pair of opposed ears 40 extending outwardly from both side edges in the longitudinal direction of the web body 38 at predetermined intervals, and is made of pulp fiber as described above. . As shown in FIGS. 2 to 4, the width of the fiber assembly 34 in the web body 38 portion is substantially the same as the width of the absorbent paper 36. Also, the ear 40
The width of the fiber assembly 34 in is larger than the widths of the mount 32 and the absorbent paper 36. That is,
The fiber assembly 34 is supported by the mount at the web body 38 portion thereof, but none of the ear portions 40 supports it.

As shown in FIG. 2, the laminated body 30 conveyed on the vacuum conveyor 16 is placed on the vacuum conveyor 16 over the entire width thereof.
Therefore, the ears 40 of the fiber assembly are not supported by the mount, but are supported by the vacuum conveyor 16, so that they are deformed or broken while being transported on the vacuum conveyor 16. There is nothing to do.

The laminated body 30 conveyed on the vacuum conveyor 16 is inserted between the vacuum conveyor 16 and the press belt 18 and further conveyed forward. That is, the laminated body 30 including the fiber assembly 34
Is the vacuum conveyor 16 and the press belt 1
It is sandwiched and conveyed between a pair of belts consisting of 8 and. The width of the press belt 18 is substantially the same as the width of the vacuum conveyor 16. As mentioned above,
The vacuum conveyor 16 is a mesh belt having air permeability, and the press belt 18 may be either a flat belt having no air permeability or a mesh belt having air permeability. As described above, at least one of the pair of belts that holds and conveys the laminated body 30 including the fiber assembly 34 has air permeability, so that the air inside the laminated body 30 is removed to the outside by compression. In this case, the change of the laminate 30 can be prevented, which is preferable.

The laminate 30 sandwiched and conveyed by the pair of belts is further forwarded and reaches the press roll unit 20 as a roll compression means. The press roll unit will be described with reference to FIGS.

As shown in FIGS. 5 and 6, the press roll unit 20 is composed of a pair of upper and lower rolls 42 and 44. Here, the upper roll 42 is a smooth roll. On the other hand, the lower roll 44 includes a large-diameter roll 46 corresponding to the ears and a small-diameter roll 4 corresponding to the web body.
8 is a stepped roll. 5 and 6
The lower roll 44 shown in is a stepped roll in which a small-diameter roll is arranged between two large-diameter rolls 46 and two large-diameter rolls 46 and a small-diameter roll 48 are integrated. In this case, one of the upper roll 42 and the lower roll 44 is movable in the vertical direction, and the rolls are openable and closable.

The material of the upper roll 42 and the lower roll 44 is not particularly limited, but it is preferable that the surface of at least one roll has elasticity. The elasticity of the surface of the roll is preferable because the selvage portion 40 can be stably compressed even when the fiber assembly 34 has a distribution of thickness and weight. In the press roll unit 20 shown in FIGS. 5 and 6, the surface of the lower roll 44 is composed of the elastic member 50. As the elastic member 50, for example, a rubber material or a plastic material can be used.

The press roll unit 20 will be described in more detail. As shown in FIGS.
2 compresses the laminated body 30 including the fiber assembly 34 from above via the press belt 18. on the other hand,
The lower roll 44 compresses the laminated body 30 including the fiber assembly from below via the vacuum conveyor 16.

The laminate 30 including the fiber assembly 34
The compression of the laminate will be described with reference to FIG.
0 is compressed by the upper and lower rolls 42 and 44 while being sandwiched between the vacuum conveyor 16 and the press belt 18. In this case, since the vacuum conveyor 16 is a mesh belt and has flexibility as described above, it is deformed along the surface shape of the lower roll by being pressed by the upper roll 42 through the laminated body 30. Therefore, the laminate (that is, the mount 32, the web main body 38 of the fiber assembly 34, and the absorbent paper 36) inserted between the small-diameter roll 48 of the lower rolls 44 and the upper roll 42 is It is not compressed so strongly. On the other hand, a portion of the lower roll 44 that is inserted between the large-diameter roll 46 and the upper roll 42, that is, the ear portion 40 of the fiber assembly 34 is strongly compressed. As a result, the fiber assembly 34
Of these, the ears 40 are compressed more strongly than the web body 38. Therefore, since the density of the compressed ear portion 40 is increased and the rigidity thereof is increased, the deformation and the breakage of the compressed ear portion 40 are prevented even when passing through the transition portion.

As described above, the rigidity of the ear portion 40 is increased, so that the ear portion 40 can stably pass through the transition portion.

Further, in the present invention, as shown in FIG. 7, in the fiber assembly 34, the ears 40 and both side portions 52 in the longitudinal direction of the web body 38 are located at the center of the web body 38 in the longitudinal direction. It is more preferable that the compression is stronger than that near the portion 54. By compressing the fiber assembly 34 in this way, the compressed portion becomes a continuous strip shape, so that the rigidity of the ear portion 40 is further enhanced and the ear portion 40 is further increased.
The deformation and breakage of is further prevented. In this case, the width W in which the web body 38 is compressed is preferably 15 to 20 mm inward from the side edge in the longitudinal direction in order to obtain sufficient rigidity.

As shown in FIG. 1, the fiber assembly 34 compressed by the press roll unit 20 passes through the transition section 26, and is transferred to the post-process which is usually performed in the production of the absorbent article by the conveyor 24. Be transferred. In this case, since the ears 40 of the fiber assembly 34 are compressed as described above and have high rigidity,
Even when the fiber assembly 34 passes through the transition part 26,
The ear 40 is prevented from being deformed or broken. In addition, as the above-mentioned post-process, generally, the above-mentioned strip-shaped laminate 3 is used.
Cutting 0 into predetermined absorbers at predetermined positions,
While arranging the backsheet continuum under the absorber,
Step of applying elastic rubber for forming waist gathers and leg gathers on the back sheet, arranging a continuous body of the top sheet so as to cover the absorber, and joining the top sheet and the back sheet Steps, and steps of cutting the joint portion between the top sheet and the back sheet into individual absorbent articles and the like are included.

It is particularly effective that the manufacturing method of the present invention is applied before the strip-shaped fiber aggregate formed in a predetermined shape passes through the crossover portion of the conveyor. However,
The manufacturing method of the present invention is not only applied to such cases, but also applied to other steps in manufacturing the absorbent article as necessary.

The present invention has been described above based on its preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made. For example,
In the lower roll 44, the large-diameter roll 46 and the small-diameter roll 48 may be formed as separate bodies instead of being integrated. Also,
The fiber assembly 34 includes the mount 32 and the absorbent paper 3
6 does not have to be compressed together, and the fiber assembly 34 alone may be compressed. In the above press roll unit, the upper roll may be a stepped roll and the lower roll may be a smooth roll. The fiber assembly 34 may be formed by other means instead of the fiber stacking drum 14.

[0030]

According to the present invention, when a fiber assembly having ears is manufactured, the ears are further compressed to increase the density thereof, so that the rigidity of the ears is increased and the fiber assembly is crossed. Even when passing through the portion, the ear portion is prevented from being deformed or broken.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an apparatus preferably used in the manufacturing method of the present invention.

FIG. 2 is a schematic diagram showing a state in which an absorbent paper, a fiber assembly and a mount are laminated.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a schematic view of the press roll unit as viewed from the side.

6 is a cross-sectional view taken along the line AA in FIG.

FIG. 7 is a schematic view showing a preferable compressed state of the fiber assembly.

FIG. 8 is a schematic diagram showing a pulp web used in an absorbent article.

FIG. 9 is a schematic view showing a state in which pulp webs are continuously formed.

[Explanation of symbols]

 12 stacking chamber 14 stacking drum 16 vacuum conveyor 18 press belt 22 press roll unit 24 transport conveyor 26 crossing section 28 vacuum zone 30 laminate 32 mount 34 fiber aggregate 36 absorbent paper 38 web body 40 ear 42 upper roll 44 lower Roll 46 Large-diameter roll 48 Small-diameter roll 50 Elastic member 52 Side edge in the longitudinal direction of the web body 54 Central portion in the longitudinal direction of the web body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area A61F 13/18 307G

Claims (6)

[Claims] 1. A method for producing a strip-shaped fiber assembly made of pulp fibers, in which a pair of opposed ears extending outward from both side edges in the longitudinal direction of the web body are provided at predetermined intervals. In the method for producing a strip-shaped fiber assembly, the ears are compressed more strongly than the web body after the fiber assembly is formed. 2. A step provided with a large-diameter roll corresponding to the ears and a small-diameter roll corresponding to the web body, for conveying the fiber assembly by sandwiching it between a pair of belts along the longitudinal direction thereof. The method for producing a fiber assembly according to claim 1, wherein the fiber assembly is compressed from above and below the belt by a pair of roll compression means composed of a roll and a smooth roll. 3. The method for producing a fiber assembly according to claim 1, wherein the ears and both side portions in the longitudinal direction of the web body are compressed more strongly than in the vicinity of the central portion in the longitudinal direction of the web body. 4. An apparatus for producing a strip-shaped fiber assembly made of pulp fibers, in which a pair of opposed ears extending outwardly from both side edges in the longitudinal direction of the web body are provided at predetermined intervals. A pair of belts for sandwiching and transporting the fiber assembly along its longitudinal direction; and a stepped roll having a large diameter roll corresponding to the ears and a small diameter roll corresponding to the web body. An apparatus for producing a belt-shaped fiber assembly, comprising a pair of roll compression means composed of smooth rolls, the roll compression means capable of compressing the fiber assembly from above and below the belt. 5. The apparatus for producing a fiber assembly according to claim 4, wherein the large diameter roll and the small diameter roll are integrated. 6. The fiber assembly manufacturing apparatus according to claim 4, wherein at least one of the pair of belts has air permeability.