THERMOPLASTIC RESIN FILM EXCELLENT IN THICKNESS UNIFORMITY AND PRODUCTION THEREOF

摘要

PURPOSE: To obtain a thermoplastic resin film not having thickness irregularity having a peculiar cycle and extremely high in thickness uniformity by separating the thickness irregularity of the film by the generation cause thereof to eliminate the same. CONSTITUTION: A thermoplastic resin film excellent in thickness uniformity is characterized by that the thickness irregularity in the longitudinal direction of the film is 5% or less and the ratio Pw1/PwT of the spectrum intensity sum Pw1 in a wavenumber of 0.015-0.45 (1/m) when the waveform of the thickness irregularity is subjected to Fourier analysis to the spectrum intensity sum Pw T in a total wavenumber and is 0.2 or less.