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:
Jun. 02, 1981
Filed:
Oct. 26, 1979
Applicant:
Inventor:
Birger Dahl, Valaskjold, NO;
Assignee:
Borregaard Industries Limited, Sarpsborg, NO;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D06M / ;
U.S. Cl.
CPC ...
8125 ; 536 56 ; 536 60 ;
Abstract
The disadvantages stemming from a high content of hemicellulose in recirculated sodium hydroxide solutions used for the mercerization of cellulose in the preparation of viscose are reduced or eliminated by subjecting at least a part of the spent sodium hydroxide solution to an ultrafiltration process to remove part or all of the hemicellulose therein. The filtered sodium hydroxide liquor is supplied with make-up sodium hydroxide and is returned to the mercerization step.