A method of heat treating polyester film.

摘要

This invention relates to a method for minimizing low temperature shrinkage of an axially-oriented heat set polyester film which includes heating the polyester film by employing impinging heated gas at a temperature of 140 DEG to 180 DEG C for a time period between 15 and 3 seconds as defined by the area in Figure 1,delineated by points A, B, C and D under tension of less than 2.413 x 10<6> pascal. The film is kept out of contact with any surface during the heat treatment.