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:
Jul. 12, 1994
Filed:
Feb. 18, 1992
Jian E Jiang, Glens Falls, NY (US);
Brian F Greenwood, Glens Falls, NY (US);
Joseph R Phillips, Glens Falls, NY (US);
Kamyr, Inc., Glens Falls, NY (US);
Abstract
Kraft pulp is bleached to a brightness of about 90 CPPA or greater, without the use of chlorinated organic compounds that has commercially acceptable strength properties. During production of the kraft pulp it is subjected to extended delignification, by adding kraft white liquor to a first recirculation loop in the digester, and/or a second, wash, recirculation loop in the digester; or by conventional pulping followed by two oxygen stages, with washing between the stages. The extended delignification pulp is then subjected to ozone bleaching, with an ozone dosage of less than 1.0% (preferably less than about 0.5%). The ozone bleaching sequence may be a (ZE)P(ZE)P sequence.