The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 18, 2022
Filed:
May. 15, 2018
Applicant:
Andritz Oy, Helsinki, FI;
Inventors:
Assignee:
Andritz Oy, Helsinki, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C 3/02 (2006.01); D21C 3/22 (2006.01); D21C 3/00 (2006.01); D21C 3/24 (2006.01); D21H 11/02 (2006.01);
U.S. Cl.
CPC ...
D21C 3/022 (2013.01); D21C 3/003 (2013.01); D21C 3/222 (2013.01); D21C 3/24 (2013.01); D21H 11/02 (2013.01);
Abstract
A method of producing chemical pulp including at least the following steps: a) wood chips or other comminuted ligno-cellulosic fibrous material is treated with a polysulfide-containing cooking liquor in an impregnation stage at a temperature of 90-145° C., and b) slurry of fibrous material from step a) is heated into cooking temperature and cooked for producing pulp having a desired kappa number. After step a) mercaptide ions are added into the slurry of fibrous material and the fibrous material is treated at cooking temperature in step b).