Process for extruding large oriented polymer shapes
CA 2044538 A1 · Owner: Courval, Gregory J. · Inventors: Courval, Gregory J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a solid state extrusion process a semi-crystalline polymer billet in a pressure chamber is forced through a die at the end of the chamber, with the polymer passing through the die at a temperature between 30°C below the alpha-crystalline temperature and the melting point of the polymer to form an oriented polymer profile. The pressure chamber is heated to about 0.50- 0.95 of the melting point of the polymer and the die is heated to about 0.65-1.2 of the melting point of the polymer, with the die preferably being heating to at least 5°C warmer than the billet. A haul off stress on the profile extruded from the die is maintained between at least 0.5 MPa and a maximum amount without plastic …
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 June 13, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 13, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 13, 2013.
- 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.