Plastics sacks
CA 1086271 A · Owner: Imperial Chemical Industries Limited · Inventors: Pickells, Thomas W.; Lack, Donald C.; Lawes, Norman E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multiwall sack comprising an outer wall of microperforated plastics film and an inner wall of flexible air-, permeable sheet of foamed themoplastic material. The sack is particularly useful in the packaging of powders because it allows air entrained with said powders during filling to escape through its walls during or subsequent filling.
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 September 23, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 23, 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.
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.