Abstract: A process to increase resistance to tearing in a heat-resettable material involves extruding a polymer of a specified crosslinking density to produce a plastic web. After cooling the plastic web is heated by creating a temperature decreasing towards its core and stretched at core temperature below crystalline melting temperature of partially crystalline and crystalline polymers resulting in a distribution of orientation over the full section of the plastic web. Resistance to tearing will be essentially increased in this manner based on a simple, low-cost production process.
Type:
Grant
Filed:
April 22, 1994
Date of Patent:
January 2, 1996
Assignee:
Stewing Nachrichtentechnik GmbH & Co.
Inventors:
Norbert Nicolai, Heinz Koppe, Thomas Schwabe, Jurgen Vogel