Film formation method capable of preventing fluctuation of ribbon

摘要

A film is formed by casting a ribbon (1) on a support (3) from a flow cast die (2) while pulling said ribbon (3) toward said support (1) by providing a decompression area. The decompression area is divided into a middle portion, a left portion and a right portion. Degrees of decompression in these three portions satisfy the following formulae: <DF>0 < (PC-PL) x 100/PC < 15; </DF> <DF>0 < (PC-PR) x 100/PC < 15; </DF> <DF>PL-PR x 100/0.5(PL+PR) < 10; </DF> wherein PC is a degree of decompression in said middle portion, PL a degree of decompression in said left portion, and PR a degree of decompression in said right portion. The film obtained by the above method is suitable for a polarizing plate protection film, which is used for a liquid crystal display device. <IMAGE>