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:
Aug. 30, 1977
Filed:
Feb. 17, 1976
Applicant:
Inventor:
David M Mackie, Vancouver, CA;
Assignee:
MacMillan Bloedel Limited, Vancouver, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 65 ; 162 72 ; 162 79 ; 162 81 ; 162 90 ;
Abstract
A method is described for increasing the yield of pulp obtained from an alkaline pulping process. A lignocellulosic material, such as wood chips, is first pretreated with an aqueous solution containing from 0.1 to 10% by weight of monoethanolamine, methylamine or dimethylamine and from 0.01 to 1% by weight of copper nitrate or nickel nitrate at elevated temperature and pressure in a closed vessel. This pretreated material is then subjected to conventional alkaline pulping, preferably soda or two-stage soda-oxygen pulping.