JP2001198975A - Method and device for correcting shape of film or the like, device for molding film equipped with the device, and rewinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for correcting the shape of film or the like by which the number of rejects in terms of shape is reduced and the quality is upgraded and a correcting device as well as a device for molding the film quipped with the correcting device, and a rewinding device. SOLUTION: A layered film 19 formed of two or more layers or the like is continuously heated in a shape adjusting section 15, preferably at a heating temperature above the second highest softening temperature level of the constituent layers and thereafter, is cooled down to the softening temperature level or lower of all the constituent layers. Thus the shape of the film 19 or the like is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to improve the quality of products such as films and to stabilize the sheet passing property by reducing warpage and shape defects of films and sheets (hereinafter collectively referred to as films and the like). The present invention relates to a method and an apparatus for correcting a shape of a film or the like, and a forming apparatus and a rewinding apparatus for a film or the like including the apparatus.

[0002]

2. Description of the Related Art Conventionally, as a method of correcting the shape of a film or the like, a method of winding the film or the like around a small-diameter roll to correct the shape of the film or the like, and a method of correcting the shape of the film or the like based on a difference in roll peripheral speed. is there.

[0003]

However, all of the above-mentioned methods are based on the balance of internal stress, and there is a problem in performing a stable correction. That is, in the method of winding a film or the like around a small-diameter roll, the amount of warpage can be reduced, but it is difficult to perform a stable correction.
Also in the method based on the difference in roll peripheral speed, it has been difficult to perform a stable correction due to an error in the roll peripheral speed detector. Further, in the latter case, as other problems in the equipment, a high-precision measuring device is required, and it is necessary to consider the temperature characteristics, the detection error, and the like of the measuring device. The present invention has been made in view of such circumstances, and solves the problems of the above-described method of correcting the shape of a film or the like, reduces shape defects of the film or the like, and improves the quality of the film or the like. It is an object to provide a correction method and device.

[0004]

In order to achieve the above-mentioned object, a method for correcting the shape of a film or the like according to the first aspect of the present invention is described below.
A film or the like having a layer structure of at least one layer is continuously heated at a heating temperature equal to or higher than the softening temperature of at least one of the constituent layers in the shape adjustment section, and then cooled to a temperature equal to or lower than the softening temperature of all the constituent layers. By doing so, the shape of the film or the like is modified. In addition, the method for correcting the shape of a film or the like according to the second invention is as follows.
A film or the like having a layer structure of two or more layers is continuously heated at a heating temperature equal to or higher than the second highest softening temperature among the softening temperatures of the constituent layers in the shape adjustment section, and thereafter, equal to or lower than the softening temperature of all the constituent layers. The shape of the film or the like is corrected by cooling to a temperature of the above. The cooling at this time may be natural cooling.

As described above, in a film or the like having a layer structure of two or more layers, by heating at least the softening temperature of at least one of the constituent layers, all the layers having a softening temperature lower than the softening temperature are softened. Then, the residual stress on the surface between the layers is released, and then the temperature is cooled to the softening temperature or lower of all the constituent materials, whereby the residual stress can be reduced. Accordingly, shape defects due to internal stress can be reduced. Further, preferably, by heating at a temperature higher than the second highest softening temperature, at least all layers except the layer having the highest softening temperature are softened, the residual stress on the surface between the layers is released, and thereafter, the softening temperature of all constituent materials is lower than the softening temperature. By cooling to below, residual stress can be reduced, shape defects due to internal stress can be reduced, and energy can be saved by suppressing the heating temperature.

A third aspect of the present invention is a method of correcting a shape of a film or the like in a shape adjusting section, wherein the shape of the film or the like is corrected under a low tension while maintaining a desired shape. As described above, by correcting the film or the like under low tension, the generation of residual stress when the tension is released can be further reduced. At the same time, by correcting the shape while maintaining the target shape, the shape can be made closer to the shape when no external force acts. Therefore, it is possible to correct a film or the like to a state closer to a desired shape.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for correcting the shape of a film or the like according to the present invention will be specifically described with reference to the embodiments shown in the accompanying drawings.

First, with reference to FIG. 1, the configuration of a device 10 for correcting a shape of a film or the like according to the present invention will be specifically described.
As illustrated, a shape adjustment section 15 is formed between the entrance bridle 12 and the exit bridle 14.
Then, in the shape adjustment section 15, from the upstream side to the downstream side, the heating fluid tank 1 as an example of the film heating means is provided.
6 and a film cooling section 18 composed of a pair of cooling rolls 17 as an example of a film cooling means.
Here, the heating fluid tank 16 is provided with a film 19 described later.
Is heated to a predetermined heating temperature or higher, and is filled with a heating fluid (for example, hot water) heated by the steam heat exchanger 20. In addition. A reversing roll 21 for reversing the film 19 is provided in the heating fluid tank 16. Further, a tension adjusting motor 22 for applying a low tension to the film 19 conveyed in the shape adjusting section 15 is connected to the output side bridle 14 in an interlocking manner.

Next, a method of correcting the shape of a film or the like using the above-described device 10 for correcting a shape of a film or the like will be described. The film 19 having two or more layers (for example, PBT: PET) that has been continuously conveyed horizontally to the entrance bridle 12 passes through the entrance bridle 12,
It is conveyed while bending downward under low tension, and is immersed in the heating fluid in the heating fluid tank 16, so that it is uniformly heated to the second highest softening temperature among the softening temperatures of the plurality of layers. Is done. Then, after being turned upside down by the reversing roll 21, it is conveyed upward and reaches the film cooling unit 18. Then, the film cooling unit 18
After the film 19 is cooled by the cooling roll 17 that forms the film 19, the film 19 is conveyed toward the outgoing bridle 14.

That is, in the present embodiment, the film 19 having a layer structure of two or more layers is formed into a shape adjustment section which is a region to which a low correction tension generated at a speed ratio between the entrance bridle 12 and the exit bridle 14 is applied. 15 and heated by the heating fluid to a temperature equal to or higher than the second highest softening temperature, and then cooled by the cooling roll 17 and, if necessary, further cooled by the pinch roll 13 in the outlet bridle 14. It passes through the bridle 14 to release from the correction tension. Further, the cooling of the film 19 starts after the film 19 comes out of the heating fluid,
The cooling roll 17 completely lowers the temperature to the softening temperature or lower.

As described above, in the present embodiment, the heating and cooling of the film 19 can be performed under low tension in the target temperature range, so that the shape of the film 19 at the time of cooling can be made constant. Film 19 having more than two layers
Can be modified. Further, in this embodiment, the film 19 is heated with a liquid (warm water) and the film 19 is cooled with the cooling roll 17, but in the present invention, the heating method and the cooling method of the film 19 are not limited to these. It is needless to say that the present invention is not limited to this method, and other heating methods and cooling methods can be used.

FIG. 2 shows a modification of the above-described method for correcting the shape of a film or the like. As shown in the figure, in the present modification, a cutter 23 for cutting to a target width is provided downstream of the outlet bridle 14. Further, a shape measuring device 24 is further provided on the downstream side, and based on the detected value, the tension adjusting motor 22 is driven to precisely control the low tension of the film 19 conveyed in the tension shape adjusting section 15. The temperature of the film 19 can be precisely controlled by driving the flow control valve 25 to increase or decrease the amount of heating by the steam heat exchanger 20.

FIG. 3 shows an embodiment in which the shape correcting device 10 for a film or the like described above is incorporated in a forming device 30 for a film or the like. In the present embodiment, the film forming apparatus 30 is configured such that the film 19 having two or more layers extruded from the T die 31 is deformed by the stretching apparatus 32,
After passing through the shape correcting device 10 such as a film, the width and thickness of the product are managed by the thickness meter 33 and the edge trimmer 34,
The take-up reel 35 is configured to take up the work. At this time, even if the shape of the film 19 is deteriorated by the stretching device 32, the shape defect can be reduced by the shape correcting device 10 such as a film.

FIG. 4 shows a test performed by the present inventors.
The degree of relaxation of the curl generated in the film by stretching is indicated by the state of the stress caused by the heating temperature and the tension on the film having a layer structure of two or more layers. Two types of two-layer films were used as the films subjected to the test. As is apparent from FIG. 4, in order to reduce the curl diameter to 100 mm or less, the shape may be corrected with a heating temperature of 60 ° C. or more and a low stress of about 9.0 (N / mm ² ) or less. You can see that.

[0015]

According to the method and apparatus for correcting the shape of a film or the like of the present invention, the shape of a film can be stably corrected at a low cost with simple equipment, and the quality of a product film can be improved. Further, in a film forming apparatus or the like, abnormalities of the film or the like at the time of passing the sheet can be reduced, and the sheet passing property of the film or the like can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a device for correcting a shape of a film or the like according to an embodiment of the present invention.

FIG. 2 is a perspective view of a device for correcting a shape of a film or the like according to a modification of the embodiment of the present invention.

FIG. 3 is an overall configuration explanatory view showing the overall configuration of a film or other forming apparatus incorporating the film or other shape correcting device.

FIG. 4 is a graph showing a relationship between a heating temperature of a film or the like, tension, and curl.

[Explanation of symbols]

 10: Shape correction device for films etc., 12: Inlet bridle, 14: Outlet bridle, 15: Shape adjustment section, 16: Heated fluid tank 17: Cooling roll, 18: Film cooling unit, 19: Film 20: Steam heat Exchanger, 21: reversing roll, 22: tension adjusting motor, 23: cutter, 24: shape measuring device, 25: flow control valve, 30: film and other forming device, 31: T die, 32: stretching device, 33: Thickness gauge, 34: Edge trimmer, 35: Take-up reel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Hironaka 1302 Higashitoyoi, Kudamatsu City, Yamaguchi Prefecture Toyo Kohan Co., Ltd. (72) Inventor Tsutomu Akito 1302 HigashiToyoi, Kudamatsu City, Yamaguchi Prefecture Toyo Kohan Co., Ltd. F-term in the Kudamatsu factory (reference) 4F209 AC03 AG01 AG03 AM35 NA11 NB02 NG02 NG05 NH06 NK10

Claims (6)

[Claims] 1. A film having a layer structure of two or more layers,
In the shape adjustment section, the shape of the film or the like is corrected by continuously heating at a heating temperature equal to or higher than the softening temperature of at least one of the constituent layers, and then cooling to a temperature equal to or lower than the softening temperature of all the constituent layers. A method for correcting the shape of a film or the like, characterized in that: 2. A film having a layer structure of two or more layers,
In the shape adjustment section, the heating is continuously performed at a heating temperature equal to or higher than the second highest softening temperature among the softening temperatures of the constituent layers, and then, the film is cooled to a temperature equal to or lower than the softening temperature of all constituent layers. A shape correcting method for a film or the like, wherein the shape is corrected. 3. The shape of a film or the like according to claim 1 or 2, wherein the shape of the film or the like in the shape adjustment section is corrected under a low tension while maintaining a desired shape. How to fix. 4. A shape correcting apparatus used in the shape correcting method for a film or the like according to claim 1. 5. An apparatus for forming a film or the like, comprising the apparatus for correcting a shape according to claim 4. 6. A rewinding device for a film or the like, comprising the shape correcting device according to claim 4.