Extruding polystyrene foam with variation of mass distribution
CA 1054764 A · Owner: Mobil Oil Corporation · Inventors: Luthra, Vinod K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A thermoplastic foamed resin extruding operation is described which uses an inner die lip machined to vary the width of the die annulus or opening so that varying thicknesses or mass concentrations of preselected desired width will be formed in the extruded resin sheet obtained therefrom. The mass concentration variations in the extruded sheet are coordinated with a downstream thermoforming operation involving deep and shallow draw forming or different sheet fabrications such as folding scoring, cutting, etc.
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
- Granted May 22, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 22, 1996.
- 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.