Modified process for preparing pulp for paper making
CA 2024935 A1 · Owner: Kokta, Bohuslav V. · Inventors: Kokta, Bohuslav V.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to an improved process preparing pulp suitable for papermaking, consisting of short time saturated steam cooking of chips impregnated with alkaline solutions of sulphites in the temperature range of 180 to 210°C instantaneous pressurizing the reactor with cool nitrogen after cooking to super atmospheric pressure from 25 to 50 atm followed by explosive decompression and fiber refining.
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 September 10, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 10, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 10, 2012.
- 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.