Process for extruding polymer shapes with smooth, unbroken surface
CA 2044536 A1 · Owner: Courval, Gregory J. · Inventors: Thomas, Dermot Richard Martin; Courval, Gregory J.; Allen, Steven Gregory
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A solid state extrusion process extrudes a semicrystalling polymer billet through a die at the end of a pressure chamber. The temperature of the die is controlled so that a thin surface layer of the polymer profile being extruded is melted to form a thin smooth, surface layer on the profile of reduced orientation and increased toughness and which is substantially free of surface imperfections. F501\A45039\mc
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.