| 摘要 |
PROBLEM TO BE SOLVED: To reduce the shrinkage of a film even under high temperature storage and processing a thermoplastic resin into a film-like form with a calendar roll and cooling it to a specified temperature level with cooling rolls and further, taking up the cooled film with a takeup device at a specific ratio of speeds between the final cooling roll and the takeup device. SOLUTION: A thermoplastic resin of polyvinyl chloride is formed into a film with a calendar roll, then the temperature of a raw film between a final cooling roll and a takeup device is sufficiently cooled so that the temperature is 50 deg.C or less, and the film is taken up at a takeup device speed ratio of 1.02-1.07. When the speed ratio between the final cooling roll and the takeup device falls within this range, a distortion contained in the film is lessened. In the cooling rolls, it is desirable that the raw film be quenched. that is, quenching the raw film enables a high strength film to be available. Consequently, the film does not develop creases even during a long time of storage following its width joining fabrication and also the degree of shrinkage of the film can be diminished. |
