JPH0153383B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a nonwoven fabric manufacturing apparatus for manufacturing a nonwoven fabric from a thermoplastic plastic film. This is an apparatus for manufacturing a reticulated nonwoven fabric formed by the following steps.

(Prior Art) When manufacturing a reticulated nonwoven fabric made of thermoplastic plastic, conventionally, a uniaxially stretched film was used, as shown in Japanese Patent Publication No. 45-10778, Japanese Patent Publication No. 47-2786, etc. It is formed into a split fiber shape or a narrow tape shape using the split fiber method, and the split fibers or narrow tape are arranged in the vertical direction with a predetermined width to form a vertical web, and the same split fibers or narrow tape are A reticulated nonwoven fabric was obtained by arranging them horizontally on a vertical web while cutting them into lengths corresponding to the width of the web, and then bonding and laminating them with a binder.

(Problems to be Solved by the Invention) However, it is extremely difficult to arrange such split fibers or narrow tapes at a uniform density in the vertical and horizontal directions. If the split fibers or narrow tapes are not uniformly arranged, the resulting product will be non-uniform. Therefore, when producing a reticulated nonwoven fabric by the method described above, a complicated device is required to uniformly arrange the split fibers or narrow tapes.

In addition, it is difficult to produce nonwoven fabric continuously and at high speed because it is necessary to repeatedly feed a horizontal web onto the vertical web in a direction perpendicular to the feeding direction and then cut the horizontal web. .

The present invention has been made in view of such problems, and its purpose is to
To enable continuous high-speed production of uniform reticulated nonwoven fabric.

(Means for Solving the Problems) In order to achieve this object, the present invention provides a pair of film feeding devices that feed continuous strips of an unstretched film that becomes a vertical web and an unstretched film that becomes a horizontal web. A longitudinal splitting device is used to form regular longitudinal slits in the unstretched strip-shaped film fed from one film feeding device, and the unstretched film with the longitudinal slits formed therein is vertically stretched by a longitudinal stretching device. A horizontal splitting device forms regular lateral slits on the unstretched film strip fed from the other film supply device, and the unstretched film with the lateral slits formed is The film is stretched in the lateral direction using a lateral stretching device.
Then, these stretched film strips are stacked by a laminating device provided at the rear end of the transverse stretching device so that the directions of the strips match each other, and are laminated by heat-pressing. .

(Function) With this configuration, when the unstretched film in which longitudinal slits are formed is stretched in the longitudinal direction, the slit-forming portion becomes constricted, the slit opens, and the unstretched film is uniaxially stretched. The result is a longitudinally stretched film equivalent to a large number of narrow tapes arranged at regular intervals in the longitudinal direction. Similarly, an unstretched film with slits formed in the lateral direction can be stretched in the lateral direction to have a lateral width equivalent to that of a large number of uniaxially stretched narrow tapes lined up at regular intervals in the lateral direction. It becomes a stretched film. These stretched films are then stacked one on top of the other while maintaining tension in the vertical or horizontal direction. Therefore, a reticulated nonwoven fabric with uniform vertical and horizontal meshes can be obtained.

(Example) Hereinafter, an example of the present invention will be described using the drawings.

The figure is a system diagram showing an embodiment of a reticulated nonwoven fabric manufacturing apparatus according to the present invention.

As is clear from the figure, this reticulated nonwoven fabric manufacturing apparatus is comprised of a plurality of devices arranged in upper and lower stages.

A film forming machine 1 is provided on the upper stage.
This film forming machine 1 includes a pair of kneading extruders 2,
The molten plastic extruded from die 2'
This is a two-layer molding machine that molds two layers of laminated film by the extruders 2 and 2', and different plastic raw materials are supplied to each extruder 2 and 2' from raw material supply devices 4 and 4', respectively. . One raw material is
It is a film material that becomes a plastic film layer that exhibits stretching strength, and the other raw material is said to become a polymer layer that exhibits adhesive properties when heated. The material for the polymer layer is selected so that the heating temperature for exhibiting its adhesive properties is within a range that does not impair the stretching strength of the plastic film layer. Moreover, the thickness of the polymer layer is made to be 3 to 15 μm after stretching.

The die 3 is arranged so that when the molded film 5 is fed in the horizontal direction, the polymer layer thereof is on the lower surface side. The width of the unstretched film 5 to be formed is equal to the width required after stretching.

The formed film 5 is guided to a casting device 6 of the film forming machine 1, cooled and solidified, and then fed in a horizontal direction. Therefore, in this embodiment, the film forming machine 1 constitutes a film feeding device that feeds the unstretched film 5 in a continuous strip.

Next to the casting device 6 is a vertical splitting device 7.
is provided. This vertical split device 7 is
For example, a large number of blades that are discontinuous in the circumferential direction are provided on the outer peripheral surface of the roll in parallel at regular intervals in the axial direction. Therefore, in the unstretched film strip 5 introduced into the vertical splitting device 7, a large number of vertical cuts, that is, slits, are formed intermittently and regularly at small intervals in the horizontal direction. Ru.

A longitudinal stretching device 8 is provided next to the longitudinal splitting device 7. This longitudinal stretching device 8 is a roll-type stretching device consisting of a large number of rolls whose rotational speed increases from the front to the rear. While the film 5 passes through this longitudinal stretching device 8, it is heated to a required temperature, and the film 5 is heated to a required temperature in the longitudinal direction. It is designed to be stretched at a certain magnification.

The longitudinally stretched film 5 stretched by the longitudinally stretched device 8 is then guided downward while remaining in a tensioned state.

On the other hand, another film forming machine 9 is provided at the lower stage of the manufacturing apparatus. This film molding machine 9 is also a two-layer molding machine similar to the upper film molding machine 1, and different plastic raw materials are supplied from a pair of raw material supply devices 10, 10' to a pair of kneading extruders 11, 11', respectively. Each extruder 11,1
The molten plastic extruded from die 1'
2 to form a two-layer laminated film. The laminated film is also said to be composed of a plastic film layer that exhibits stretching strength and a polymer layer that exhibits adhesive properties when heated.

In this case, the die 12 is arranged so that when the formed film 13 is fed in the horizontal direction, the polymer layer is on the upper surface side. Further, the formed film 13 is guided to a casting device 14 of the film forming machine 9, cooled and solidified, and then sent in a horizontal direction. Therefore, in this embodiment, the film forming machine 9 constitutes another film feeding device that feeds the unstretched film 13 in a continuous strip.

The width of the stretched film 13 to be formed is determined by taking into consideration the width required after stretching in the lateral direction and the stretching ratio. In addition, the thickness of the polymer layer is 3 after stretching.
The thickness is determined to be ~15μ.

A horizontal splitting device 15 is provided next to the casting device 14. This horizontal split device 1
5, for example, has a large number of blades arranged intermittently in the axial direction on the outer peripheral surface of the roll and arranged in parallel at regular intervals in the circumferential direction. In that case, no blades should be provided at either end of the roll. Therefore, the stretched film strip 13 guided to the horizontal splitting device 15 has a large number of horizontal cuts, or slits, placed at small intervals in the vertical direction on its surface except for both ends in the axial direction. It is formed intermittently and regularly.

Next to the vertical splitting device 15, a horizontal stretching device 1 is installed.
6 is provided. This transverse stretching device 16 is a tenter type stretching device using clips, and while the film 13 passes through this transverse stretching device 16,
It is heated to a required temperature and stretched in the transverse direction at a required magnification.

This lateral stretching device 16 is equipped with a number of clips greater than the number of clips forming the length required for lateral stretching, and a laminating device 17 is provided at the rear end of the tenter. This laminating device 17 is used for the longitudinally stretched film 5 sent from the upper longitudinally stretched device 8.
a heating device 18 for heating the film 13 that has been horizontally stretched by the horizontal stretching device 16; and a heating device 19 that heats the film 13 that has been horizontally stretched by the horizontal stretching device 16; It consists of a crimping device 20 for crimping. Note that the heating device 19 for heating the horizontally stretched film 13 may be a heating device for horizontally stretching as it is. This laminating device 17
In this case, the films 5 and 13 are fed at the same traveling speed so that their strip directions are the same. The width of the longitudinally stretched film 5 is set to be such that it can fit between the clips of the tenter, so that the longitudinally stretched film 5 is maintained in tension in the longitudinal direction, and the horizontally stretched film 13 is maintained in a tensioned state in the transverse direction. These are stacked while being held.

A reticulated nonwoven fabric 2 formed by laminating the longitudinally stretched film 5 and the laterally stretched film 13 in this manner.
1 is adapted to be wound up by a winding device 22.

Next, the operation of the reticulated nonwoven fabric manufacturing apparatus configured as described above will be explained.

2 formed by the upper film forming machine 1
The layered film 5 is fed horizontally with its polymer layer facing downward. After a large number of longitudinal slits are cut in the entire surface by the longitudinal splitting device 7, the strip is stretched in the longitudinal direction by the longitudinal stretching device 8. When the film 5 is stretched longitudinally, the space between the slits of the film 5 becomes constricted and the slits open.
Therefore, the film 5 has a state in which a large number of uniaxially stretched narrow tapes are arranged in the longitudinal direction.
Moreover, since the slits are provided intermittently and regularly, the film 5 is in a state equivalent to that of narrow tapes arranged correctly on a predetermined axis. The film 5 thus longitudinally stretched is then sent to the lower stage side.

On the other hand, the two-layer film 13 formed by the lower laminated film 9 is fed in the horizontal direction with its polymer layer facing upward. and,
After a large number of lateral slits are cut in the entire surface except for both ends by the lateral splitting device 15, the slit is stretched in the lateral direction by the lateral stretching device 16. When the film 13 is stretched laterally, the space between the slits of the film 13 becomes constricted and the slits open. Therefore, the film 13 has a state in which a large number of uniaxially stretched narrow tapes are arranged in the horizontal direction. Furthermore, since the slits are disposed intermittently and regularly, the film 13 is in a state equivalent to that of a regular array of narrow tapes of a predetermined length.

The longitudinally stretched film 5 sent from the upper stage and the laterally stretched film 13 formed at the lower stage are heated by heating devices 18 and 19 of the laminating device 17 provided at the rear end of the horizontal stretching device 16, respectively. The layer is heated to a temperature at which it becomes adhesive. Then, in the laminating device 17, each film 5,
13 are made to run at the same speed and have their band directions coincident with each other, and are crimped together by a crimping device 20. At this time, each film 5, 1
No. 3 is stacked so that both of the polymer layers form the laminated inner surfaces, so that they are firmly adhered by the polymer layers. In this way, the reticulated nonwoven fabric 21
is formed. Moreover, since the lamination is carried out while maintaining the tensioned state of each film 5, 13 after stretching, the lamination is performed while maintaining the state in which the meshes are uniformly formed at the same density during stretching. ,
The nonwoven fabric 21 obtained by the lamination also has a uniform network density.

Furthermore, by providing the laminating device 17 in the horizontal stretching device 16, the horizontally stretched film 13 is sent to the laminating device 17 while maintaining the heated state for horizontal stretching. Thermal energy for this can be reduced.

In the above embodiment, both the longitudinally stretched film 5 and the transversely stretched film 13 are formed as two-layer films, but only one film 5 or 13 is formed as a two-layer film. You can also make it so. Alternatively, both of the films 5 and 13 may be made into one layer, and an adhesive layer may be applied to the inner surface of the laminated film in the laminating device 17 or the like.

Further, in the above embodiment, the nonwoven fabric manufacturing apparatus has the film forming machines 1 and 9 for forming the respective films 5 and 13, but it is also possible to use preformed films. In that case, the wound unstretched film may be continuously supplied to the vertical splitting device 7 and the horizontal splitting device 15 by a film feeding device such as a roll.

(Effects of the Invention) As is clear from the above description, according to the present invention, after forming regular longitudinal slits in one unstretched film, the slits are stretched in the longitudinal direction, and the other unstretched film is stretched in the longitudinal direction. After forming horizontal slits in the stretched film, the slits are stretched in the horizontal direction, so that a narrow tape consisting of a large number of uniaxially stretched films can be stretched to a predetermined width in the vertical direction with a uniform density. This results in two types of tapes: one in which the tapes are arranged in the same way, and the other in which similar narrow tapes of a predetermined length are arranged at a uniform density in the lateral direction. Since these tapes are laminated on each other while being maintained in the stretched state, each narrow tape is not disturbed, and a reticulated nonwoven fabric having a uniform density can be reliably and easily obtained.

Moreover, since the formation of slits, stretching, and lamination can be performed continuously while the film is running at a constant speed using a splitting device, a stretching device, and a laminating device, respectively, the reticulated nonwoven fabric can be manufactured continuously and at high speed.

[Brief explanation of drawings]

The figure is a system diagram showing an embodiment of a reticulated nonwoven fabric manufacturing apparatus according to the present invention. 1...Film forming machine (film feeding device),
2, 2'...Kneading extruder, 3...Die, 5...Film, 6...Casting device, 7...Vertical splitting device, 8...Longitudinal stretching device, 9...Film forming machine (film feeding device) ), 11, 11'...Kneading extruder, 12...Die, 13...Film, 14...
...Cast device, 15...Horizontal split device, 1
6... Lateral stretching device, 17... Laminating device, 18,1
9...Heating device, 20...Crimping device, 21...Reticulated nonwoven fabric.

Claims (1)

[Scope of Claims] 1. A pair of film feeding devices that feed two sheets of unstretched film in the form of continuous strips, and a small interval in the lateral direction between the unstretched strips of film fed from one of the film feeding devices. a longitudinal splitting device that forms a large number of regular longitudinal slits by the longitudinal splitting device; a longitudinal stretching device that longitudinally stretches an unstretched film on which longitudinal slits have been formed by the longitudinal splitting device; and the other of the film feeding devices. A horizontal splitting device forms a large number of regular horizontal slits at small intervals in the longitudinal direction on the unstretched film strip fed from the film. A transverse stretching device that stretches in the transverse direction, and a transversely stretched strip-shaped film that is provided at the rear end of the interior of the transverse stretching device and is stretched in the transverse direction by the transverse stretching device and held in a state of tension in the transverse direction. An apparatus for producing a reticulated nonwoven fabric, comprising: a laminating apparatus for stacking longitudinally stretched strip films sent from the longitudinal stretching apparatus so that their strip directions match each other and bonding them under heat. 2. Each of the film supply devices comprises a film forming machine, and at least one of the film forming machines is a two-layer forming machine that forms a polymer layer that exhibits adhesive properties when heated on one side of the film. An apparatus for producing a reticulated nonwoven fabric according to claim 1.