Patent ID: 7892470

Claim:
A producing method for a polymer film comprising the steps of: forming a casting film by casting a dope containing a polymer and a solvent on a moving support; peeling said casting film containing said solvent from said support as a wet film; blowing air from an air blowing device onto each side edge portions of said wet film, said air blowing device being provided above said wet film, said air pressing against said each of said side edge portions to approximately flatten said side edge portions, an air outlet of said air blowing device being provided above said each of said side edge portions; transporting said wet film while approximately flattened side edge portions are being held by film holders; and said air blowing device has upper and lower outlets so as to reduce formation of a decompressed area over said wetting film and under said blowing device, wherein said upper and lower outlets are provided on the same side of the film to blow air on the same side of the film.