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:
Jan. 12, 1988
Filed:
Dec. 30, 1985
Applicant:
Inventors:
Leonard E Lowrie, Rainier, OR (US);
William L Duncan, Tacoma, WA (US);
Assignee:
Weyerhaeuser Company, Tacoma, WA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D21C / ; D21B / ; D21B / ;
U.S. Cl.
CPC ...
162 78 ; 162 24 ; 162 28 ; 162 26 ; 162 71 ;
Abstract
A two-stage pulp refining system in which the fibrous material from the first stage refiner is in contact with an alkaline bleaching solution between refining stages at a temperature of 32.degree.-96.degree. C. and at a consistency of 15-25% on an oven dry basis. The material is then diluted and then pressed to a consistency of at least 20% and passes through the second stage refiner.