Process to increase the resistance to tearing of a heat-resettable material web
CA 2121748 C · Owner: Koppe, Heinz · Inventors: Vogel, Jurgen; Nicolai, Norbert; Koppe, Heinz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process to increase resistance to tearing in a heat-resettable material is described, followed by 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.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 20, 1994 and granted February 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 20, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.