Process for producing thermoformable polypropylene films and sheets
CA 2017698 C · Owner: Breidt, Peter, Jr. · Inventors: Breidt, Peter, Jr.; Wagner, John Ralph Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Thermoformable polypropylene films and sheets and the process of producing same. The process comprises the steps of providing a polypropylene film or sheet, the film or sheet produced from a resin self from the group of homopolymers and copolymers of propylene and mixtures thereof and stretching the film or sheet in at least one direction to obtain a partial orientation of a degree effective to minimize sag during thermoforming. A process for thermoforming polypropylene is also provided.
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 May 29, 1990 and granted November 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 29, 2012.
- 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.