Improvements in or relating to welding
CA 2124448 A1 · Owner: Colman Products Limited · Inventors: Wallwork, Stephen Fred
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method of and apparatus for, welding , an element comprising paper to a thermoplastic material without , pre-treatment of the plastics material. In one described embodiment a laminate (12) comprising paper with a vapour permeable, liquid impermeable coating on one major surface was successfully, welded to a polypropylene material (15) some 1.5 mm thick the, uncoated surface of the laminate forming the interface with the polypropylene, by subjecting the interface to conditions between two ranges of parameters, a temperature of 185 ·C and a pressure of 460 kPa for a period of 10 seconds and a temperature of 220 ·C and a pressure of 460 kPa for a period of 5 …
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 November 25, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 2014.
- 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.