Process for the injection moulding of multi-layered articles
CA 1318098 C · Owner: Du Pont Canada Inc. · Inventors: White, George; King, David Campbell; Lillis, Rupert Martin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An injection moulding process for the manufacture of multi-layered articles, especially articles having barrier properties, is disclosed. The process comprises clamping a thermoplastic film over the cavity of a mould of an injection moulding process, the film being capable of being stretched. The film is then stretched within the mould by inserting the core of the mould, preferably using a core in which a central part enters the mould and partially stretches the film prior to the remainder of the core entering the mould. The mould is then closed, excess film is trimmed off and polymer is injected into the mould cavity. The resultant article is a multi-layered injection moulded article …
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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 May 25, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 25, 2010.
- 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.