摘要 |
Cellulose triacetate film is produced by a solution casting process. Dope, which includes cellulose triacetate and mixed solvent with methyl acetate, is cast on a rotary drum in a form of bead by use of a flow casting die, to form gel film. When a self-supporting characteristic of the gel film becomes higher than one limit value, the gel film is stripped from the rotary drum by use of a stripping roller, to obtain the cellulose triacetate film. During the casting step, a surface of the rotary drum is cooled at -10° C. or lower. |