ORIENTED POLYMER COMPOSITION WITH A DEORIENTED SURFACE LAYER AND METHOD OF ITS MANUFACTURING

摘要

Prepare an oriented polymer composition that is cavitated, has cross sectional dimensions all at least three millimeters and at least one de-oriented surface layer having a thickness of at least 80 microns and at least 50 microns less than half the thickness of the oriented polymer composition, the de-oriented surface layer having a lower degree of polymer orientation than a 100 micron thick portion of the oriented polymer composition adjacent to and below the de-oriented surface layer by sufficiently heat treating a surface of a cavitated oriented polymer composition.