Manufacture of paper and paper board
CA 2449897 A1 · Owner: Williams, Stephanie Caine · Inventors: Williams, Stephanie Caine; Chen, Gordon Cheng
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for making paper or paper board comprising forming an aqueous , cellulosic suspension adding a retention system to the cellulosic suspension draining the suspension on a screen to form a sheet and drying the sheet wherein the retention system comprises a swelling clay which has a TAPPI brightness of at least 70.
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 June 18, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 18, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 18, 2024.
- 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.