JP2007106508A - Conveyance device and conveyance method for thermoplastic resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently obtain tensile force reduction of a film being conveyed without causing defects such as scratch and wrinkle on the film during conveyance of the film. <P>SOLUTION: In this conveyance device for the thermoplastic resin film, thickness of air of a conveyance roll and the film is controlled by charging the roll and the film by a distance measuring device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transport apparatus and a transport method for producing a thermoplastic resin film having excellent surface characteristics and excellent productivity, which is free from surface defects such as scratches, particularly productivity of a thermoplastic resin film.

When winding up the thermoplastic resin film, it is necessary to control the film tension during film conveyance and during winding so that defects such as scratches and winding deviation do not occur on the film surface. For that purpose, it is necessary to cut the tension generated at the time of winding by the transport roll on the upstream side of the winder, and it is known to use a contact pressure roll, a grooved rubber roll, a suction roll, etc. as the means. . (For example, Patent Document 1 and Patent Document 2)
In addition, a method is known in which a charge is applied to the film or the transport roll to improve the adhesion between the transport roll and increase the friction between the transport roll and the film to cut the tension. (For example, Patent Document 3)
JP 62-167154 A JP-A-63-247251 JP 2000-218690 A

  However, when the rolls of Patent Documents 1 and 2 are used, there is a problem that the pressure contact roll and the grooved rubber roll tend to cause scratches on the film surface because dust adheres to the roll surface and is easily fixed. In addition, there is no generation of scratches on the suction roll, but there is a problem that the shape of the roll surface is transferred to the film.

  Further, in the method of Patent Document 3, since the amount of charge to be applied is not controlled, when the charge is large and the adhesion force is too strong, defects such as wrinkles occur on the film. On the other hand, if the film is too weak, the tension cut force of the transport film is insufficient, and the film wound or wound on the film surface may cause winding deviation. Therefore, it has been difficult to put a tension cut by applying a charge into practical use.

  The present invention employs the following means in order to solve such problems. In other words, the thermoplastic resin film conveyance device of the present invention is a conveyance device that conveys a thermoplastic resin film with a conveyance roll, and the thickness of the air layer between the conveyance roll and the thermoplastic resin film is 0.5 to 6.5 μm. It is a thermoplastic resin film conveyance device to be controlled. Moreover, the conveyance method of the thermoplastic resin film of this invention is a conveyance method using the said conveying apparatus.

  According to the thermoplastic resin film transport apparatus and transport method of the present invention, (I) the film surface is less scratched during film transport. (II) No shape transfer to the film on the roll surface that occurs during film conveyance. (III) The wound shape of the film wound up by the winding device becomes good. (IV) It is no longer necessary to use a material such as a rubber roll whose surface changes over time, such as a rubber roll, and periodic roll replacement is unnecessary. As a result, a high-quality film can be provided and productivity is improved.

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

  Although the resin plastic resin film in this invention is not specifically limited, If a typical example is given, they will be a polyethylene terephthalate, a polyethylene-2, 6-naphthalate, a polypropylene, nylon-6, polyphenyline sulfide, etc. Hereinafter, a thermoplastic resin film is simply expressed as a film.

  When a conventional film is transported using a transport roll, the thickness of the air layer between the film and the transport roll (hereinafter referred to as air thickness) is generally affected by the film transport speed, transport roll diameter, film tension, and film width. . When the air thickness is 8 μm on average, the gripping force between the transport roll and the film is almost lost, that is, the tension cutting force between the transport roll and the film is insufficient, the film meandering occurs irregularly, and the film edge cut Frequent tears occur in the club. Moreover, the end face of the wound film becomes uneven, and productivity is lowered. Further, when the air thickness is eliminated by a nip roll or static electricity and the film is transported in close contact with the transport roll, wrinkles are generated on the film, and in this case, productivity is lowered. In order to prevent these, it is optimal to always control the air thickness between the transport roll and the film to 0.5 to 6.5 μm.

  As a method of controlling the air thickness between the transport roll and the film, for example, there is a method of slowing the transport speed, but the productivity is extremely deteriorated. As a method of controlling the air thickness without deteriorating the productivity, a method of applying static electricity as described above is preferable.

  The film thickness can be applied to a film having a thickness of about 3 to 700 μm. The average surface roughness of the film can be effectively applied to a film having few internal particles of 50 nm or less. The roll material of the transport roll for imparting electric charge is preferably a chrome plating roll or a ceramic roll having a surface roughness of 1.6 S or less so as not to give a defect such as a scratch to the film. Rubber rolls are also effective when possible even at relatively low grades.

  Moreover, although the conveyance speed of a film depends on conveyance conditions, such as the said film tension, at the time of low speed, it is in the range of the air thickness of this invention even if it does not provide static electricity in most cases. Therefore, in the present invention, it is preferable to use at a conveyance speed of 30 m / min or more.

  FIG. 1 shows an example of a thermoplastic resin film transport apparatus of the present invention. In FIG. 1, 1 is a film, 2 is a transport roll, and in the apparatus in which the film 1 being transported is transported by a transport roll 2 to a further downstream transport roll or winding device, the transport roll is charged with a charging device 3, A transport device having a ground 4 on the film side is the same as a known transport device.

  In the film transport apparatus as described above, the present invention measures the distance from the film surface by the distance measuring device 5, and calculates the air thickness L (μm) from the transport roll distance and the film thickness measured separately from the distance. . The output of the charging device 3 is controlled so that the air thickness L (μm) is always kept constant.

  In addition, as a method of making the air thickness L (μm) constant, there is a method of setting the charging device 3 on the film side and the conveying roll side to the ground 3 as shown in FIG. A similar effect can be obtained by attaching the measuring device 5 and controlling the air thickness L (μm). Further, in order to obtain a further charging effect, the ground is provided on one side in the above, but there is a method of charging opposite charges to both as shown in FIG.

  Although it is preferable to use a laser displacement meter capable of high resolution as the distance measuring device, a displacement meter using ultrasonic waves or the like may be used.

  In order to accurately measure the air thickness, it is natural to measure the deflection, deflection, and film thickness of the transport roll. For a specific method, the distance measurement device and the distance measurement device are used for the transport roll. There is a method in which one further is installed on the opposite side and the measurement results of the two are calculated while simultaneously measuring the deflection and deflection of the transport roll. The thickness of the film may be either before or after the present roll, but there is a method of calculating a thickness gauge in the same manner as in the deflection / runout of the roll.

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

    The film conveyance mode in each Example and Comparative Example was evaluated as follows.

(1) Film 皺 during transport 皺: No wrinkles ○: Minor wrinkles occasionally occur Δ: Minor wrinkles occur frequently ×: Wrinkles frequently occur.

(2) Tension cut property A: No film meandering O: Minor film meandering occasionally occurs: Minor meandering occurs frequently x: Occasionally large film meandering occurs.

(3) Scratches on the film surface ◎: No scratches occurred ○: Minor scratches (about 500 μm in length) occasionally occur Δ: Minor scratches (about 500 μm in length) occurred periodically ×: Frequent scratches Occurrence.

(4) Film tearing at the edge cut part ◎: Film running at the edge cut part is stable and no film tearing ○: Film running at the edge cut part is unstable but no film tearing Δ: Film tearing irregularly Occurrence ×: Frequent breakage.

(5) Disturbance of the film end surface ◎: No disturbance of the film end surface ○: Disturbance of 2 mm or less is occasionally generated on the film end surface Δ: Disturbance of 2 mm or more is occasionally generated on the film end surface ×: Disturbance of 2 mm or more is frequently observed on the film end surface To occur.

Example 1
Using the apparatus shown in FIG. 1, the film thickness of polyethylene terephthalate is 100 μm, the average surface roughness of the film is 45 nm, and a flat roll made of rubber or hard chrome plating with a surface of 1.2S is used as a transport roll. And the suction roll was not used. The film was wound under the conditions of a conveyance speed of 150 m / min and a film winding tension of 15 kg / m. The amount of static electricity applied was controlled so that the air thickness L at that time was 1 μm. About the dispersion | variation in the measurement result of a distance measuring device, it became a stable measurement result by making it the average of sampling interval 1 second and the frequency | count of sampling 30 times.

  At that time, the air thickness L between the film and the transport roll and the evaluation result of the wound film are as shown in the following table. When a rubber roll was used, satisfactory results were not obtained with respect to film scratches in the present invention, but in the case of a plating roll, the effects of the present invention could be fully exhibited.

(Example 2)
As a result of controlling the applied amount of static electricity so that the air thickness was 2 μm in Example 1, when a rubber roll was used, satisfactory results were not obtained for film scratches in the present invention, but in the case of a plating roll, As a result, the effects of the present invention can be fully exhibited.

(Example 3)
As a result of controlling the applied amount of static electricity so that the air thickness was 5 μm in Example 1, both the rubber roll and the plating roll were able to sufficiently satisfy the effects of the present invention.

(Comparative Example 1)
In Example 1, the air thickness was 0 μm, that is, the amount of static electricity applied was controlled so that the roll and the film were in close contact with each other. As a result, wrinkles occurred during film conveyance, and a film usable as a product could not be obtained.

(Comparative Example 2)
As a result of controlling the amount of static electricity applied so that the air thickness becomes 8 μm in Example 1, film tearing and disturbance of the film end due to insufficient tension cutting force occur, and it is difficult to obtain a film that can be used as a product. Met.

(Comparative Example 3)
As a result of controlling the amount of static electricity applied in Example 1 so that the air thickness becomes 12 μm, film breakage and disturbance of the film end due to insufficient tension cutting force occur as in Comparative Example 2, and the product can be used as a product. It was difficult to obtain a film.

(Comparative Example 4)
As a method for controlling the air thickness in Example 1, the transport speed, the transport roll diameter, and the film tension were changed, and the air thickness could be controlled within the range of the present invention, but the productivity was poor and impractical. It was. Further, an attempt was made to control the air thickness by installing a suction nozzle immediately before the film enters the transport roll, but it was difficult to put it to practical use because of the flapping of the film and fluctuations in the suction pressure. That is, the method of applying static electricity and controlling the air thickness according to the present invention was most preferred.

(Comparative Example 5)
As a result of controlling the amount of static electricity applied in Example 1 so that the film conveyance speed was 25 m / min, the conveyance roll surface roughness was 3.2 S, the film surface roughness was 60 nm, and the air thickness was 5 μm, the tension cut force As a result, the film was broken and the film edge was disturbed, and a film usable as a product could not be obtained.

An example of the conveyance apparatus of the thermoplastic resin film of this invention is shown. The other example of the conveying apparatus of the thermoplastic resin film of this invention is shown. The other example of the conveying apparatus of the thermoplastic resin film of this invention is shown.

Explanation of symbols

L Air thickness (distance between film and roll)
1 Film 2 Transport Roll 3 Charging Device 4 Earth 5 Distance Measuring Device

Claims (5)

  In the conveyance apparatus which conveys a thermoplastic resin film with a conveyance roll, the conveyance apparatus of the thermoplastic resin film which controls the thickness of the air layer between a conveyance roll and a thermoplastic resin film to 0.5-6.5 micrometers.   The thermoplastic resin film transport apparatus according to claim 1, wherein a charge is imparted to the transport roll or the thermoplastic resin film upstream of the transport roll.   The thermoplastic resin film according to claim 1 or 2, wherein the thermoplastic resin film is a plated or coated transport roll having a transport speed of 30 m / min or more and a surface roughness of 1.6 S or less. Transport device.   A thermoplastic resin film transport method using the thermoplastic resin film transport apparatus according to claim 1.   The method for conveying a thermoplastic resin film according to claim 5, wherein the average surface roughness of the thermoplastic resin film is 50 nm or less.

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