PRODUCTION OF BIAXIALLY STRETCHED POLYAMIDE FILM

摘要

PROBLEM TO BE SOLVED: To produce a biaxially stretched polyamide film excellent in dimension al stability and reduced in thickness irregularity. SOLUTION: A simultaneous biaxial stretching machine wherein a stretching process is divided into first and second stretching zones is used and the stretching temps. of the respective stretching zones are set to temp. ranges represented by formula; first stretching zone temp. (T1): 50<=T1( deg.C)<=70, second stretching zone temp. (T2): 100<=T2( deg.C)<=120 and the dividing position of the first and second stretching zones is provided at a position so as to set percent of stretch (areal ratio) at 300-500%.