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:
Sep. 27, 1994
Filed:
Dec. 20, 1993
Applicant:
Inventor:
Xuan T Nguyen, Montreal, CA;
Assignee:
Domtar, Inc., Montreal, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ;
U.S. Cl.
CPC ...
162-6 ; 162-8 ; 162 65 ;
Abstract
Waste cellulosic paper products, for example, old corrugated container are recycled employing oxygen delignification in the presence of an alkaline material to produce a recycled pulp of lower kappa number, while maintaining adequate strength in the pulp. The recycling process preferably employs an acid pretreatment in combination with the oxygen delignification, and exposure of the waste product to the alkaline material is preferably controlled so that at any point in the delignification the waste product is exposed to not more than 50%, by dry weight, of the alkaline material based on the weight of residual lignin in the waste paper product.