Film winding device and method for making optical film employing the same

Abstract

The invention provides a film winding device and a method for making an optical film employing the same. The film winding device (10) winds the movable film (12) upon the winding shaft to form a roller-surrounding object (28), which carries out coiling suspension bearing over the film with the surface pressure above the regulation. Moreover, a triangular-shaped space part (36) is formed by taking the winding starting point as the peak between the coiling suspension bearing film surface and the surface of the roller-surrounding object. The triangular-shaped space part (36) is equipped with an attracting mouth (32) which absorbs the air inside the space part with over-regulated absorbing pressure. Under this condition, the film is wound, suspend, and supported to a support roller (30) in the manner that the surface pressure of the coiling suspension film surface is greater than the absorbing pressure of the absorbing mouth. Moreover, with the changes of the winding diameter of the roller-surrounding object, a moving mechanism is utilized to make the support roller and the absorbing mouth move simultaneously.

Description

technical field [0001] The present invention relates to a film winding device and an optical film manufacturing method using the same, and particularly relates to a winding technique after manufacturing a base film for an optical film. Background technique [0002] For example, optical films such as polarizing plate protective films for liquid crystal display devices, optical compensation films produced through coating and drying of base films, and antireflection films require high planar performance. [0003] A base film such as cellulose triacetate (TAC) is usually formed by a solution film-forming method, and the formed base film is wound by a winding device. Therefore, winding misalignment during winding, winding wrinkles, scratches (including micro-scratches of about 50 μ to 100 μ), deformation of the film end (commonly known as the ear) (knurled portion dented or stretched) ) and other winding failures will become a major problem in quality. [0004] Winding failure ...

AI Technical Summary

Problems solved by technology

[0014] However, conventional film winding devices are not sufficient as winding devices for optical films requiring high planar performance.

[0015] That is, although the winding device of Patent Document 1 is provided with a low-friction resin protruding portion at the tip of the suction nozzle, when the suction pressure of the suction nozzle is increased, the vibration of the film becomes larger, and the occurrence of scratches cannot be prevented.

If the suction pressure is lowered, although the vibration of the film is reduced, the desired winding firmness cannot be obtained

In recent years, as described above, as the width of the optical film increases, the air volume of the associated wind increases, and a suction pressure of 200 Pa or more is required. However, in the winding device of Patent Document 1, when the suction pressure is 200 Pa or more, Increased jitter

[0016] In addition, although the winding device of Patent Document 2 can prevent the vibration of the film, since the pressing roller is in contact with the film surface, it cannot prevent scratches and scratches caused by slipping and the like.

Furthermore, in the case of a wide-width film, it is necessary to form the pressing roll into a crown roll (crown roller), which is prone to wrinkle

[0017] In addition, since the winding device of Patent Document 3 can completely press the winding point in a non-contact manner, it can prevent the occurrence of scratches and scratches as in Patent Documents 1 and 2, but requires high wind pressure, and the cost of blower equipment is very high. high cost

In addition, there are problems such as scattering of surrounding waste materials and generating noise due to wind pressure

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