Patent ID: 6159412
Filing Date: 2000-12-12
Classification: B29C,B29K

Abstract:
A process for the production of a final thermotropic liquid crystalline polymer film, comprising, feeding a first film of a molten thermotropic liquid crystalline polymer to a pair of rollers which have a gap between them which is approximately equal to a thickness of said first film, and passing said first molten thermotropic liquid crystalline polymer film through said gap to form said final thermotropic liquid crystalline polymer film, wherein:said rollers oscillate relative to one another and parallel to their rotational axes at a frequency of about 20 to about 200 Hz as said first film passes through said gap;one of said rollers being at such a temperature that said thermotropic liquid crystalline polymer freezes against said roller as said first film Passes through said gap;the other roller of said rollers being at a such a temperature that a rolling bank of molten thermotropic liquid crystalline polymer is formed on said other roller as said first film passes through said gap;both surfaces of said final film are essentially solid as said final film exits said gap; andsaid temperatures and said frequency are such that said thermotropic liquid crystalline polymer is oriented in the transverse direction by transverse shear on said thermotropic liquid crystalline polymer imparted by the oscillation of said rollers as said first film passes through said gap.