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. 18, 1992
Filed:
Jan. 21, 1988
Applicant:
Inventor:
Raymond C Lachapelle, Kirkland, CA;
Assignee:
Canadian Liquid Air Limited, Quebec, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 60 ; 162 63 ; 162 78 ; 162 87 ; 162 88 ;
Abstract
A process for souring chemical or mechanical cellulosic pulp using carbon dioxide to obtain proper acidification of the pulp slurry. The souring is performed after a single or a multistage bleaching sequence ending with sodium hypochlorite, calcium hypochlorite or hydrogen peroxide or the like in a common process for the preparation of paper pulp. The use of CO.sub.2 permits bleaching to continue because CO.sub.2 does not destroy the bleaching residuals remaining from the single or last bleaching stages.