Process for preparing cellulose pulp from lignocellulosic material while removing high molecular weight substances from the pulping liquor
CA 1264403 C · Owner: Nilsson, Nils Ove · Inventors: Nilsson, Nils Ove; Thorsell, Leif Urban Folke
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is provided for preparing cellulose pulp by delignification of lignocellulosic material which, comprises subjecting particulate lignocellulosic material in a pulping zone to the pulping action of a pulping liquor at a temperature at which pulping reactions leading to formation of cellulose pulp proceed, and substances having a molecular weight above about 3500, preferably above about 2000, and preferably above about 1500, are physically separated and removed from the lignocellulosic material and become dispersed in the pulping liquor; in the course of the pulping, withdrawing pulping liquor containing such dispersed substances, and removing such dispersed substances therefrom; and …
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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 January 16, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 16, 2007.
- 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.