| 摘要 |
PROBLEM TO BE SOLVED: To provides a film suppressed in the occurrence of cramping wrinkles and curling, and thus having excellent surface properties. SOLUTION: A dope 12 is cast on a rotary drum 22 from a casting die 21. A self-supporting gel film 25 on the rotary drum 22 is peeled off to obtain a soft film 27. The cramping wrinkles and curling of the soft film is suppressed by setting the longitudinal elastic modulus of the soft film 27 to 450,000 Pa or more and feeding the soft film through a delivery part 30. The curling of the soft film is corrected by nip rollers. The cramping wrinkles of the soft film are corrected by applying a stretching force to the soft film 27 in the feed direction of the soft film. Thereafter, thus obtained is fed to a tenter type dryer 50. The soft film 27 is dried in the tenter type dryer 50 and a drying chamber 51 to be taken up as a film 28 by a winder 54. COPYRIGHT: (C)2007,JPO&INPIT |
