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.

Date of Patent:
Aug. 06, 1991

Filed:

Oct. 17, 1990
Applicant:
Inventors:

Richard Burley, Derby, GB;

Lucjan S Slota, Coventry, GB;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08B / ; D21C / ;
U.S. Cl.
CPC ...
162-9 ; 162 23 ; 1621576 ; 162207 ; 536 69 ; 536 70 ;
Abstract

Cellulosic sheet material is processed in preparation for esterification for example acetylation to produce cellulose acetate, by treating the sheet material with water and then feeding the wetted material into a machine that simultaneously shreds and dries the material. The conditions in the machine are carefully controlled (outlet temperature not in excess of 110.degree. C. and moisture content 4-15% by weight) to ensure that the cellulosic material does not become deactivated towards esterification. The method enables low alpha content cellulosic material supplied in the form of high density sheet to be acetylated to produce high quality cellulose acetate flake.


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