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.

Date of Patent:
Apr. 24, 1984

Filed:

Dec. 03, 1981
Applicant:
Inventor:

Jonas A Lindahl, Domsjo, SE;

Assignee:

Mo och Domsjo Aktiebolag, Ornskoldsvik, SE;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21B / ;
U.S. Cl.
CPC ...
162 26 ; 162 28 ; 162 56 ; 162 72 ; 162 78 ; 162 87 ; 162 90 ;
Abstract

A process and apparatus are provided for the deresination and brightness improvement of cellulose pulp, by adjusting the pulp concentration to within the range from about 15 to about 35%; adding sufficient alkali to the pulp to bring the amount of alkali, calculated as NaOH, within the range from about 0.5 to about 17 g/kg of water accompanying the pulp; adding sufficient oxidizing bleaching agent to the pulp to bring the amount of oxidizing bleaching agent to within the range from about 0.2 to about 22 g/kg of water; subjecting the pulp to a mild, mechanical working in the bite of twin interdigitated rotating screws at an energy input of from 8 to 100 kWh per ton of pulp; removing and reacting the pulp with the added alkali and bleaching agent for from about 0.1 to about 5 hours; and then washing out dissolved resin from the pulp.


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