Pulping process
CA 2094819 C · Owner: Swift, Lawrence K. · Inventors: Mera, Fernando E.; Swift, Lawrence K.; Andrews, Ethan K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A pulp preparation process in which pulp treatment is expanded to include in-digester treatments (Figures 7 8, 9) previously, performed outside of the digester (12) in discrete process equipment. Specifically a manner for in-digester bleaching is disclosed preferably using non-chlorine containing bleaching reagents.
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 October 7, 1991 and granted February 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 7, 2013.
- 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.