JP2007261013A - Apparatus for embossing thermoplastic film and method for forming embossed thermoplastic resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for embossing a thermoplastic resin film which is free from the production of a powder when the thermoplastic resin film is embossed and prevents the occurrence of a product defect by the powder and a method for forming the embossed thermoplastic resin film. <P>SOLUTION: In the thermoplastic film embossing apparatus for forming an uneven embossed pattern in a shape of a belt in the conveyance direction at the side edge of the thermoplastic resin film, an embossment belt pressing the thermoplastic film is provided, and the embossed pattern is formed on the surface of the embossment belt on the side of pressing the thermoplastic resin film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an embossing apparatus and an embossed thermoplastic resin film for preventing production of thermoplastic resin film, in particular, dust generated during embossing, and no surface defects of the thermoplastic resin film. It relates to a manufacturing method.

Various film molded products using thermoplastic resin as a raw material are known. Among them, polyester film, especially polyethylene terephthalate film, is superior in terms of mechanical properties, electrical properties, chemical resistance, dimensional stability, etc., so it is suitable for magnetic tapes, capacitors, packaging materials, plate making, electrical It is used as a base material in various fields such as insulating materials, beverage can lamination, and photographic film. The thermoplastic resin raw material is discharged from a die by, for example, a melt extrusion method, and is cooled and solidified by a drum or the like. Thereafter, the film is biaxially stretched at an appropriate temperature and stretch ratio, and wound into a roll with a winder. At the time of winding, the end surface of the film as an intermediate product may be displaced or wrinkles may occur on the film due to the air that is entrained, which may cause a winding form defect. Conventionally, as a countermeasure for these, there has been known a method of embossing a film side edge portion by an embossing ring having a large number of protrusions, and forming a film with irregularities on the film (for example, Patent Document 1, Patent Document). 2). In this post-process, there is a process of winding to the width and length required by the customer, that is, a slit process. In this process as well, there is a method of embossing on the side edge of the film and forming the film with irregularities and winding it. Are known.
JP 7-108603 A JP-A-9-124199

  However, when processing protrusions on a film using a conventional embossing ring, it is inevitable that the film will be scraped and powder will be generated, and the generated powder will be mixed during film winding and the winding shape will deteriorate. In many cases, the powder itself causes problems when the film is surface-treated in a later process. In order to eliminate these problems, a dust remover or the like is installed to remove the powder, but it is difficult to completely remove the powder, and further, the equipment cost and the operating cost increase the cost of the product.

The present invention employs the following means in order to solve such problems. That is, the embossing apparatus of the present invention is an embossing apparatus for forming an uneven embossed pattern along the transport direction in a strip shape on the side edge of a thermoplastic resin film, in which an embossing belt that presses the thermoplastic resin film is provided. An embossing apparatus for a thermoplastic resin film having an embossed pattern formed on the surface of the embossed belt on the side where the thermoplastic film is pressed against.
Further, the method for producing an embossed thermoplastic resin film according to the present invention is such that an embossed pattern of an embossed belt in which an uneven embossed pattern is formed on the belt surface is formed on a side edge portion of a traveling thermoplastic resin film. This is a method for producing an embossed thermoplastic resin film, in which a belt surface on the formed side is pressed and an embossed pattern is formed in a strip shape along the conveying direction.

  According to the thermoplastic resin film embossing apparatus and the embossed thermoplastic resin film manufacturing method of the present invention, no powder is generated from the film during embossing. (I) The local protrusion on the film surface is eliminated and the film is wound. Sometimes a good roll is obtained. (II) Omission of surface treatment due to powder during film surface treatment performed in the subsequent process is eliminated. These effects make it possible to provide a high-quality film and further improve productivity.

  Hereinafter, the present invention will be described based on examples.

  The thermoplastic resin film in the present invention is not particularly limited, and representative examples include polyethylene terephthalate, polyethylene-2, 6-naphthalate, polypropylene, nylon-6, polyphenylin sulfide and the like. Hereinafter, a thermoplastic resin film is simply expressed as a film.

  Conventionally, when embossing a film, it is common to contact the film between an embossing ring with a protrusion on the outer periphery of the ring and a rubber roll or a metal roll, and then transfer the protrusion on the embossing ring to the film. Met. However, as described above, this method inevitably generates powder from the film during embossing.

  The inventors of the present application have studied the cause of the generation of powder from the film in the conventional method, and in order to press the embossed ring with the protrusion on the surface of the circular ring against the film conveyed in a straight line, It was clarified that the film was scraped and powder was generated because the direction of the movement of the linear movement of the film was different from the rotational movement of the embossing ring when the protruding part of the ring was transferred to the film. In addition, when the embossing ring protrusion part is detached from the film recess from the film recess having the same shape as the embossing ring protrusion, the direction of movement is different as described above, so the film is scraped and powder is generated. I clarified that.

  Therefore, the inventors of the present invention have intensively studied a method for eliminating the generation of these powders. As a result, the embossed protrusions run linearly in the same direction and in the same direction as the film speed with respect to the linear motion of the film. When embossing is performed by pressing, and the emboss projection is released from the film, the method of pulling out the emboss projection while running straight in the same direction and in the same direction as the film speed is the most effective for shaving. Based on the idea that there is, the present invention has been achieved.

  FIG. 1 shows an example of an embossing apparatus for thermoplastic film according to the present invention. In FIG. 1, 1 is a film, 2 is an emboss belt, 3 is a backup roll, and 4 is a nip roll. A contact roll is applied to the film 1 by the backup roll 3 and the nip roll 4 installed on the opposite side of the embossing surface of the embossing belt 2 traveling at the same speed as the film 1 being conveyed, and a recess is processed in the film. The entrance angle θ1 between the film 1 and the embossed belt 2 is preferably 0.5 to 3 degrees, and similarly the advance angle θ2 is preferably 0.5 to 3 degrees. If either or both of the approach angle and the advance angle exceed 3 degrees, the film may be scraped off during embossing to generate powder. In addition, the approach angle and the advance angle should be close if they are close to 0 degrees, but in order to keep the embossed belt and the film in close contact from a separated state and away from the close state, the approach angle and advance The angle is preferably 0.5 degrees or more.

  Since the emboss belt has a large mechanical loss, there are a method of forcibly driving it so as to be at the same speed as the film, and a method of replenishing torque only for the mechanical loss, but any method may be used as long as the film and the emboss belt are at the same speed. For a film having sufficient strength, the embossing belt is driven by the film, so that it is not particularly necessary to drive the embossing belt.

  The material of the embossed belt is preferably a steel belt, and there is a method of forming the protruding portion on the belt surface by electric discharge machining, but the material, the shape of the protrusion, the manufacturing method, etc. are not particularly limited. In addition, as a countermeasure against wear on the protruding portion of the embossed belt, it is preferable to apply to the embossed belt of the present invention also the hardening treatment such as plating and quenching which is also applied to the conventional embossing ring.

Example 1
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  In the apparatus shown in FIG. 1, a steel belt having protrusions was used as an emboss belt, a metal roll was used as a backup roll, and a rubber roll was used as a nip roll. The polyethylene terephthalate film was wound up under the conditions of a film thickness of 300 μm and a film conveying speed of 50 m / min. At that time, the approach angle between the film and the embossed belt was set to 0.5 degrees, the advanced angle was set to 0.5 degrees, and the film was embossed. Although the powder was sampled on the surface of the film being transported after embossing with an adhesive roll for 30 minutes, there was no adhesion of the powder.

(Example 2)
In Example 1, the entry angle between the film and the embossed belt was 0.5 degrees, the advance angle was 3 degrees, and the film was embossed. As a result of sampling the surface of the film being transported for 30 minutes with an adhesive roll after embossing, a small amount of powder was generated, but it was much smaller than the amount of conventional embossing generated. In addition, since the amount of generated powder was very small, it was impossible to evaluate quantitatively.

(Example 3)
In Example 1, the entrance angle between the film and the embossed belt was set to 3 degrees, the advance angle was set to 3 degrees, and the surface of the film being transported after embossing was sampled for 30 minutes with an adhesive roll. Compared to the amount of embossing generated using a conventional dust remover, the amount was very small.

(Comparative Example 1)
In Example 1, the entry angle between the film and the embossed belt was 5 degrees, the advance angle was 5 degrees, and the film was embossed. As a result of sampling the surface of the film being transported after the embossing with an adhesive roll for 30 minutes, the generation of the powder was comparable to the generation amount of the embossing ring.

(Comparative Example 2)
In Example 1, the entrance angle between the film and the embossed belt was 5 degrees, the advance angle was 3 degrees, and the film was embossed. As a result of sampling the surface of the film being conveyed after the embossing with an adhesive roll for 30 minutes, the generation of the powder was slightly smaller than the amount of the embossing generated.

(Comparative Example 3)
In Example 1, the entry angle between the film and the embossed belt was 3 degrees, the advance angle was 5 degrees, and the film was embossed. As a result of sampling the surface of the film being conveyed after the embossing with an adhesive roll for 30 minutes, the generation of the powder was slightly smaller than the amount of the embossing generated.

An example of the embossing apparatus of the thermoplastic resin film of this invention is shown.

Explanation of symbols

1 Film 2 Embossed Belt 3 Backup Roll 4 Nip Roll θ1 Entrance Angle between Film and Embossed Belt θ2 Advancement Angle between Film and Embossed Belt

Claims (6)

  In an embossing apparatus for forming an uneven embossed pattern along the conveying direction in a strip shape on the side edge of a thermoplastic resin film, it has an embossed belt that presses the thermoplastic resin film and presses the thermoplastic film An embossing device for thermoplastic resin film, with an embossed pattern formed on the surface of the embossed belt.   The embossing apparatus for a thermoplastic resin film according to claim 1, wherein the embossing belt is disposed so that an approach angle between the thermoplastic resin film and the embossing belt is 0.5 degrees or more and 3 degrees or less.   The embossing apparatus for a thermoplastic resin film according to claim 1 or 2, wherein the embossing belt is disposed so that an advancing angle between the thermoplastic resin film and the embossing belt is 0.5 degrees or more and 3 degrees or less.   The belt surface on the side where the embossed pattern of the embossed belt formed on the belt surface is pressed against the side edge of the traveling thermoplastic resin film, and the embossed pattern is banded along the transport direction. A method for producing an embossed thermoplastic resin film to be formed.   The method for producing an embossed thermoplastic resin film according to claim 4, wherein an approach angle between the thermoplastic resin film and the embossed belt is 0.5 degrees or more and 3 degrees or less.   The method for producing an embossed thermoplastic resin film according to claim 4 or 5, wherein an advancing angle between the thermoplastic resin film and the embossed belt is 0.5 degrees or more and 3 degrees or less.

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