Patent ID: 8101109
Filing Date: 2012-01-24
Classification: B29C,B29K

Abstract:
1. A solution casting process comprising a step of: casting a dope containing a polymer and solvent on a first surface of a casting band which moves, to form a cast film, said casting band circulating endlessly by at least two driving rolls between which the casting band extends; controlling temperatures of said casting band and said cast film by said at least two driving rolls at a temperature suitable for facilitating volatilization of the solvent; cooling to gel said cast film to a cooling temperature lower than 6 deg. C within a predetermined cooling region, disposed to start at a stripping point for said cast film, and to extend upstream therefrom with a length equal to or less than 25% of a length of said casting support band by use of a cooling roll which is different from said at least two driving rolls and contacts a second surface of said casting band that is reverse to said first surface, or a cooler for blowing cooling gas to said cast film; stripping said cast film from said casting band at said stripping point; drying said stripped cast film to produce a polymer film, wherein a dew point of a portion around said stripping point of said cast film is set equal to or less than 0 deg. C.