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. 22, 2008
Filed:
Jan. 18, 2002
Applicants:
Jeffrey S. Tolan, Ottawa, CA;
Corina Popovici, Ottawa, CA;
Luc Thibault, Casselman, CA;
Inventors:
Assignee:
Iogen Bio-Products Corporation, Ontario, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C 3/18 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method of bleaching chemical pulp with xylanase after chemical bleaching is provided. The method comprises the steps of exposing chemical pulp to a chlorine dioxide bleaching stage to produce a partially bleached pulp, treating the partially bleached pulp with a xylanase in an enzyme treatment stage at a pH of about 3 to about 8, then carrying out an alkaline extraction of the pulp. The pulp bleaching method of the present invention may be performed in a pulp mill as part of a complex pulp bleaching process.