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Expired Canadian patentCanada

Process for production of cellular thermoplastic bodies

CA 1069662 A · Owner: Union Carbide Corporation · Inventors: Mulvaney, William P.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A process is provided for the production of a cellular thermoplastic body, wherein solid thermoplastic material is melted under pressure in an extruder, a gaseous blowing agent is injected into the molten thermoplastic material under pressure and said molten thermoplastic material and said gaseous blowing agent is passed to a zone of reduced pressure to effect the cellular expansion of said thermoplastic material by said gaseous blowing agent, and wherein said gaseous blowing agent is metered at sonic velocity at a point upstream of the injection of said gaseous blowing agent into said molten thermoplastic material.

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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

  • Granted January 15, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 15, 1997.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedJanuary 15, 1980
Term endedJanuary 15, 1997
Patent numberCA 1069662 A
Classification (IPC)B29C44/34 +1 more

Timeline

Timeline From CIPO dates

198119831985198719891991199319951997Patent grantedJan 15, 1980Term endedJan 15, 1997

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.