Patent ID: 6183856
Filing Date: 2001-02-06
Classification: B32B,Y10T

Abstract:
An opaque, oriented polymeric film structure comprising a film consisting essentially of a thermoplastic polymeric matrix material, which film has a first surface and a second surface, the film having a plurality of voids, at least some of the voids not containing a void-initiating particle and at least some of the voids being interconnected with an adjacent void in the polymeric matrix material, the number of voids not containing a void-initiating particle being sufficient to impart a significant degree of opacity in the film structure, wherein said film is made by a process comprising melting and extruding said thermoplastic polymeric matrix material into a sheet, cooling said sheet to form an amorphous polymeric matrix material in which crystallization is initiated but not completed, and orienting the cooled sheet in at least one direction.