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:
Aug. 12, 1997
Filed:
Apr. 28, 1995
Applicant:
Inventor:
Omar F Ali, Morrisville, PA (US);
Assignee:
Union Camp Holding, Inc., Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 65 ; 162 78 ;
Abstract
The present invention relates to a Kraft pulp bleaching stage which is to be carried out after conventional bleaching stages to high brightness. It has been discovered that ambient-temperature bleaching with inorganic peroxy acid salts, such as peroxymonosulfates, at this point can provide substantial increases in pulp brightness without significant decreases in pulp viscosity. Peroxy acid bleaching according to the present invention is carried out at ambient temperature and no greater than about 40.degree. C. and at an initial pH that is slightly alkaline and preferably about 7.25.