Method for forming ultra-microapertures in thin termoplastic film materials and products formed thereby.

摘要

The invention is directed toward a method for forming a generally uniform pattern of ultra-microapertures in a thermoplastic film (14). The method includes the steps of: (a) forming (38) a generally uniform pattern of microapertures in a thermoplastic film; and (b) heating (76) the microapertured film in an unconstrained condition to a temperature where the microapertures shrink to ultra-microaperture size.