JPH0459547A - Winding method for film - Google Patents

Abstract

PURPOSE:To perform winding of a flat PET film having surface coarseness (RA) of 10X10<-3>mu or less without the generation of wrinkles, such as surface wrinkles, by setting a contact pressure per one meter in the width of a film to 70kg or more by using a rubber roll, comprising a hollow body having a core of carbon fibers, as touch roll. CONSTITUTION:A film having surface coarseness (Ra) of 10X10<-3>mu or less is wound around a product roll brought into pressure contact with the film by means of a touch roll. In this case, a rubber roll comprising a hollow body having a core of carbon fibers is used as the touch roll, and a contact pressure per one meter in the width of a film is set to 70 kg or more.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for winding a film. The present invention relates to an improved film winding method for winding a film so that wrinkles such as surface wrinkles do not occur.

[Conventional technology]

For example, biaxially oriented polyester film (hereinafter simply P
ET film) is produced by longitudinally stretching with a roll stretching machine and laterally stretching with a stenter, and is wound up into a product roll and shipped.

Winding of the PET film onto a product roll is performed while applying pressure using a touch roll (contact roll).

The touch roll is used to restrict entrained air from entering the PET film layer wound into a product roll, and to prevent wrinkles from forming in the PET film due to degassing of the intruding air. - For boat fishing, the core material is a rubber roll made of a hollow aluminum body, and is used by being pressed against the product roll by a cylinder.

Incidentally, in recent years, in applications of PET films for magnetic recording media, flat PET films with a surface roughness (Ra) of 10×1 O-Sμ or less have been required.

[Problem to be solved by the invention]

Winding up a flat PET film as described above is extremely difficult, and when using a conventional touch roll, the amount of entrained air can be reduced unless the winding speed of the PET film is reduced to, for example, 170 m/min and productivity is sacrificed. It is impossible to wind up without preventing intrusion.

An object of the present invention is to provide an improved film winding method for winding a flat PET film having a surface roughness (Ra) of 10x10-3μ or less so that wrinkles such as surface wrinkles do not occur. In particular, 200 m/
This makes it possible to maintain a winding speed of min.

[Means to solve the problem]

In order to achieve the above object, the present inventor has conducted various studies and found that the above object can be easily achieved if a touch roll made of a specific core material is used as a touch roll under specific contact pressure conditions. This led to the completion of the present invention.

That is, the gist of the present invention is that the surface roughness (Ra) is 10×
In a film winding method in which a film of 10-3μ or less is wound around a product roll that is pressed by a touch roll, a rubber roll whose core material is a hollow body of carbon fiber is used as the touch roll. The present invention relates to a film winding method characterized in that the contact force is 70 kg or more.

The present invention will be explained in detail below.

In the film winding method of the present invention, the target film is a film with a surface roughness (Ra) of 10×10 −3 μm or less, and for boat fishing, a PET film is targeted.

PET film is produced by extruding a polyester resin into a sheet using a melt extruder, cooling and solidifying it to form an amorphous sheet, and stretching the sheet vertically and horizontally using a roll stretching machine and a tenter, according to a known method.

The PET film is wound directly from a stenter or wound onto a raw roll, then slit to an appropriate width and wound onto a product roll.

The method of the present invention uses a rubber roll whose core material is a hollow body of carbon fiber as a touch roll, and the gist of the method is to wind up the film using a product roll with a contact force of 70 kg or more per 1 m of film width. .

Rubber-wrapped rolls consisting of hollow bodies of carbon fibers have recently been developed and are known per se, but their use as touch rolls in film winding is not known. Moreover, conventionally, improvements to the above-mentioned touch rolls have been limited to the hardness of the surface rubber and its covering structure (for example, crown structure).
In particular, with regard to the winding of flat films with Ra of 10 x 10-3μ or less, the film winding speed was increased to 200 m/min by improving the core material of the touch roll and specifying the contact pressure conditions. There is no example of a film winding method that prevents entrained air from entering while maintaining the same.

In the present invention, the surface rubber of the touch roll is not particularly limited as long as the core material is a hollow body of carbon fiber, but it is usually a rubber having a hardness of 50 to 900, for example,
Various rubbers such as Hypalon, chloroprene, urethane, NBR, silicone, etc. can be used. The surface rubber layer is 2 to 20 mm from the core carbon fiber hollow body.
It is provided with a thickness of .

Further, in the present invention, it is necessary that the contact force of the touch roll with respect to the product roll be 70 kg or more per 1 m of film width. The contact force of the touch roll is adjusted by cylinders arranged to engage with bearings on both sides of the roll.

According to the present invention, a relatively large contact force is applied as described above, but since a touch roll with a specific structure is used, the amount of deflection due to the bending of the touch roll (the gap between the film and the touch roll) ) is significantly smaller (
For example, 0.04 mm or less).

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Note that the surface roughness (Ra) of the film was measured by the following method.

The center line average roughness Ra (μm) is defined as the surface roughness, and ■
It was determined as follows using a surface roughness measuring machine (SE-3F) manufactured by Koita Research Institute. That is, a part with a reference length L (2.5 mm) is extracted from the film cross-sectional curve in the direction of its center line, and the roughness curve y=f is created with the center line of this extracted part as the X axis and the vertical magnification direction as the y axis. When expressed as (x), the value given by the following formula is expressed in [μm]. The centerline average roughness was determined by determining 10 cross-sectional curves from the surface of the sample film, and was expressed as the average value of the centerline average roughness of the sampled portions determined from these cross-sectional curves. In addition, the tip radius of the stylus is 2
μm, load is 30mg, cutoff value is 0.08
mm.

Covered with a thickness of 5 mm, diameter 13 cm, length 130C
A roll of 1.5 m was used, and the contact pressure was 70 kg.

The winding speed of the film was changed and the maximum winding speed at which surface wrinkles did not occur was determined to be 250 m/min.

The film was wound in the same manner as above, except for changing the type of core material and surface rubber, and the maximum winding speed at which surface wrinkles did not occur was determined, and the results are shown in the table below along with the above results.
Shown in 1.

Example 1 A polyethylene terephthalate film (thickness: 7.0 μm) with an Ra of 8×10 −8 μm wound on a raw roll was cut into 1 m wide pieces using a slitter and then wound onto a product roll.

As a touch roll, Hypalon with a hardness of 70° is placed in a hollow carbon fiber body (thickness 20 mm). [Effects of the Invention] According to the method of the present invention explained above, Ra
The industrial value of the present invention is significant, as an industrially advantageous method for winding flat films of 3μ or less is provided.

Claims (1)

[Claims] (1) In a film winding method in which a film with a surface roughness (Ra) of 10 x 10^-^3μ or less is wound onto a product roll that is pressed by a touch roll, the core material of the touch roll is carbon fiber. A method for winding a film, characterized in that a rubber roll made of a hollow body is used, and the contact force is set to 70 kg or more per 1 m of film width.