Method and apparatus for generating foamed thermoplastic materials
CA 1189266 A · Owner: Maryland Cup Corporation · Inventors: Winstead, Thomas W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method and means are provided herein for entraining gas as a blowing agent in a thermoplastic melt to provide foamed thermoplastic extrudate. The method includes providing an extruded flowing mass of thermoplastic melt. The flow of the melt is constained into a tubular configuration over a finite distance. An annular sheet-like flow of gas is impinged under pressure on the tubular configuration of melt substantially transversely of the direction of flow thereof to entrain the gas in the melt. Subsequently the melt with entrained gas is returned to a flowing mass configuration where the flow rate and, temperature of the flowing mass with entrained gas is controlled to optimum values for …
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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 June 25, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 25, 2002.
- 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.