Patent ID: 7517478

Claim:
A process for preparing a polyvinyl alcohol film, comprising the steps of: forming a polyvinyl alcohol film of 30 to 90 μm thickness from a solution of a polyvinyl alcohol resin, and rolling up said film around a cylindrical core made of a metallic material to form a film roll, wherein the surface hardness of the film roll is set to a Shore A hardness of 60 to 95, wherein said hardness is measured according to JIS K 6301 under conditions of 25° C. and 55% RH, and total thickness of the film on the core is no less than that of a 1,000 m of said polyvinyl alcohol film wound around the cylindrical core, and further wherein a guide roll is disposed in the vicinity of said cylindrical core and said film is rolled up around said cylindrical core by passing said film between said core and said guide roll in the state that a space between said core and said guide roll is maintained during the rolling up operation or in the state that said guide roll is in contact with said cylindrical core through the running film.