JPS5835135B2 - Heat treatment method for flexible strips based on synthetic resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for heat treating a flexible strip having a synthetic resin film as a base material, which can be scaled to a flexible strip with good flatness. A flexible strip is at least a synthetic resin film, such as a single layer of synthetic resin film, a composite film laminated with another synthetic resin film, or a composite film with an additional coated layer on these single layers or composite films. refers to the material that is the base material.

Generally, when heat-treating a flexible strip made of synthetic resin film, such as evaporated polyethylene terephthalate film, as shown in FIG. After the film is heated and softened while being conveyed in a zigzag manner by a plurality of metal rollers 21' in a heating section 2', it is subsequently conveyed in a zigzag manner by a plurality of metal rollers 31' in a cooling section 3' and transferred to a winding roller. A method of cooling and hardening to the extent that it does not cause damage to the rolled material has been used.

However, in such a method, as shown in FIG. 2, corrugated vertical wrinkles 11' and convex portions 12' occur on the film 1', and when the conveyance speed is further increased, the film 1' becomes metal. There were drawbacks such as the film 1' not coming into close contact with the roller 31', and small irregularities caused by uneven cooling occurring all over the film 1'.

Such drawbacks can be solved even if the distances between the plurality of metal rollers 21/ and between the plurality of metal rollers 31' are changed or the metal rollers 21' and 31' are placed in the heat treatment apparatus shown in FIG. A type of pneumatic support roller with air jet nozzles interspersed on the surface of a semi-cylindrical pipe (
It was not possible to sufficiently overcome this problem even by replacing the rollers 21" and 31" (hereinafter referred to as pneumatic rollers).

The object of the present invention is to find a method for heat treating a flexible strip based on a synthetic resin film that does not have the above-mentioned drawbacks.

When the present inventor heat-treats a flexible strip having a synthetic resin film as a base material, the flexible strip is heated at a temperature equal to or higher than the secondary transition point of the base material while being supported and conveyed by pneumatic pressure. a first step in which the flexible strip is softened by heating, and a second step in which, following the first step, the flexible strip is cooled and hardened at a temperature below the secondary transition point of the base material while being supported and conveyed by pneumatic pressure. It has been found that the above object can be achieved by carrying out the pneumatic conveyance in at least the second step while the flexible strip is completely bent.

That is, when a flexible band-shaped article having a synthetic resin film as a base material is subjected to a heat treatment including a heating and softening step and a cooling and hardening step while being supported and conveyed by air pressure, at least the cooling and hardening step is accompanied by a hardening process. By supporting and transporting the casing in a curved state without substantially straight transporting, the flexible strip does not suffer from defects such as unevenness or wrinkles and maintains flatness. It can be wrapped around a highly flexible strip.

An air jet nozzle of any shape is installed on the wall of the roller and guide pipe body used for such curved conveyance.
For example, the pipe wall is provided with circular holes or slit-like holes, and the curvature of the tube wall having the circular or slit-like air outlet holes depends on the type and thickness of the flexible strip. It can be made to any suitable size, generally the radius of curvature is 500m.
It is desirable to lower it by 1.

In addition, in order to support and curve a flexible strip using pneumatic pressure, one large-diameter pneumatic roller or a guide pipe may be used, but usually a plurality of relatively small-diameter rollers of 500 mm or less are used. In addition, it is convenient to arrange the rollers close to each other to convey the flexible strip, and in this case, the rollers are arranged so that the flexible strip is not conveyed in a straight line and is conveyed only in the curved portion. It is necessary.

Examples of the present invention will be described below with reference to FIGS. 4 to 6, but the embodiments of the present invention are not limited thereby.

FIG. 4 is a diagram showing an apparatus A according to an embodiment of the present invention.

Device A is a flexible strip 1 whose base material is a synthetic resin film.
It consists of a part 2 where it is heated and softened, and a part 3 where it is cooled and hardened.

Here, the flexible strip 1 introduced into the device A is a heating section in which a plurality of guide pneumatic pipes 21 are arranged in a staggered manner, each having air jet nozzles scattered on the wall of a semi-cylindrical pipe. 2, the base material is heated and softened to a temperature above the secondary transition point of the base material, and then a plurality of cylindrical pneumatic rollers of a type having air jet nozzles interspersed with the pipe walls of the plurality of cylindrical pipes are brought into close proximity. The flexible strip 1 is placed in a curved state and supported and conveyed through the cooling section 3, where it is cooled and hardened to a temperature below the secondary transition point of the base material. The flexible strip 1 is rolled up by a winding device.

When the flexible strip 1 is heat-treated by the apparatus A having such a configuration, the flexible strip 1 is supported and conveyed under the curved shape by the plurality of rollers 31 that are supported and conveyed by air pressure. As a result of being cooled and hardened below the secondary transition point of the base material, the generation of irregularities and wrinkles on the flexible strip 1 is prevented, and even if they occur in the previous process, they are supported and conveyed under the curved shape. It is corrected during the process, and a flexible strip 1 with excellent flatness is finally obtained.

FIG. 5 is a diagram showing another embodiment of apparatus B based on the present invention.

Device B consists of a semi-cylindrical guide pneumatic pipe 23 that is vertically divided into two by a partition plate 23' into a heating section 21a and a cooling section 31a. The flexible strip 1 used as a base material, the air pressure and cooling part 31 having a temperature equal to or higher than the secondary transition point of the base material ejected from the heating part 21a.
A flexible strip 1 that is continuously supported and conveyed under the curved shape by air pressure having a temperature below the secondary transition point of the base material ejected from a, and as a result has excellent flatness without wrinkles or unevenness. It is something that can be obtained.

FIG. 6 is a diagram showing still another embodiment of the apparatus C based on the present invention.

The device C consists of a heating section provided with a plurality of pneumatic rollers 21b and a cooling section provided with a plurality of pneumatic rollers 31b, and all the rollers are provided close to each other.

Here, the flexible belt-like material having a synthetic resin film as a base material was introduced into the device C, and the pneumatic rollers 2 were placed close to each other.
While being supported and conveyed in a curved manner by the base material 1b, the base material is heated to a temperature higher than the secondary transition point of the base material to soften it, and is subsequently curved and supported and conveyed by a plurality of pneumatic rollers 31b provided close to each other. During this process, the base material is heated to a temperature above the secondary transition point F to be cured, and then rolled up using an external winding device.

In this way, all conveyance within the heat treatment apparatus C is carried out in a curved manner by pneumatic rollers placed close to each other, so that the flexible strip does not have wrinkles or irregularities, and has excellent flatness. You can wander around the sexual bands.

As described above, according to the present invention, since the flexible strip is conveyed in an open state and subjected to secondary transfer, it is possible to obtain a flexible strip with excellent flatness without wrinkles or irregularities. In addition, since the flexible strip is supported and conveyed using pneumatic rollers, even if heat treatment is performed at high temperatures and high speeds, unevenness due to uneven cooling does not occur on the surface of the flexible strip, unlike when supported and conveyed using conventional metal rollers. do not have.

[Brief explanation of drawings]

Figures 1 and 3 show the conventional heat treatment of flexible strips.
It is a figure showing ' and A〃. FIG. 2 is a diagram showing a flexible strip that has been heat-treated by the conventional processing apparatus A' shown in FIG. FIG. 4, FIG. 5, and FIG. 6 are diagrams showing heat treatment apparatuses A, B, and C according to embodiments of the present invention. In Fig. 4, 1 is a flexible strip made of synthetic resin film as a base material, 2 is a heating section of heat treatment device A, 3 is a cooling section of heat treatment device A, and 21 is used for heating section 2 of heating device A. A semi-cylindrical guide pneumatic pipe, 31 is a cylindrical pneumatic roller used in the cooling section 3 of heat treatment apparatus A, 23 in FIG. A partition plate that divides the semi-cylindrical guide pneumatic pipe 23 into a heating section and a cooling section, 21a and 31a are the heating section and cooling section of the semi-cylindrical guide pneumatic pipe of heating device B, and 21b and 31b in FIG. 6 are heating sections. The heating cylindrical pneumatic roller and the cooling cylindrical pneumatic roller of apparatus C are shown.

Claims (1)

[Claims] 1. A first step of softening a flexible band-like material having a synthetic resin film as a base material by heating it at a temperature equal to or higher than the secondary transition point of the base material while being supported and conveyed by air pressure; and the first step. followed by a second step of cooling and curing the flexible strip at a temperature below the secondary transition point of the base material while being supported and conveyed by pneumatic pressure; 1. A method for heat treating a flexible strip having a synthetic resin film as a base material, the method comprising supporting and conveying the flexible strip using pneumatic pressure in a curved state f.