| 摘要 |
PROBLEM TO BE SOLVED: To obtain a film roll without black streaks extended in a circumferential direction when a band in which a welded part extended in a longitudinal direction is at the side is used as a casting support.SOLUTION: A circular band 33 in which a center part 33c and a side part 33s are integrated by a welded part 33w is used as a casting support. The band 33 is circulated by rotation of a drum 34 and runs in the longitudinal direction (A direction). Casting is performed from the casting die 38 so that a casting film 39 is formed on the center part 33c and the side part 33s of the band 33. Subtle compulsory meandering is performed by a BEP controller 54 that holds an edge position of the band 33 constant so that the band 33 at the casting position is oscillated in the width direction at a constant frequency. An upper region of the welded part being part of the casting film 39 on the welded part 33w also has a slightly meandered shape due to the subtle compulsory meandering. When the film is rewound, the upper region of the welded part is rewound in the meandered shape, thus black streaks are eliminated. |
