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:
May. 22, 1984
Filed:
Jul. 19, 1982
Applicant:
Inventors:
Bjorn H Fritzvold, Hosle, NO;
Nicolai Soteland, Oslo, NO;
Assignee:
Myrens Verksted A/S, Oslo, NO;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ;
U.S. Cl.
CPC ...
162 65 ; 162 78 ;
Abstract
In a method for bleaching oxygen delignified cellulose-containing pulp such as sulphate, sodium and sulphite pulps with ozone and peroxide, the ozone treatment takes place at two stages, the alkaline solution which is added subsequent to the ozone treatment includes peroxide and complex formers, and 55 to 85% of the total amount of chemicals is added at the first stage.