Abstract: Apparatus for improving the adhesion or pinning of an extruded polymer film to a moving quenching member, by maintaining in the absence of corona discharge, the quenching member at an electrical potential differing from the potential of the extrusion die, the magnitude of said potential being sufficient to increase the adherence of the film to the quenching member.

Abstract: The adhesion or pinning of an extruded film forming polymer to a moving quenching member is improved, in the absence of corona discharge, by maintaining the quenching member at an electrical potential while the extrusion die is grounded, one magnitude of said potential being sufficient to increase the adherence of the film to the quenching member.

Abstract: A method for the production of biaxially molecularly oriented polymeric film, wherein the flatness of the film is improved by subjecting the film preferably immediately after its heat-setting to a longitudinal tension that is at least three times higher than the normal film transport tension in the production process. Preferably, said higher longitudinal tension is at least 100 kp/sq.cm. The film may be subjected also between its longitudinal stretching and its heat-setting to said at least three times higher longitudinal tension. The temperature of the film during said treatment at increased longitudinal tension is between room temperature and the second order transition temperature of the film.