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:
Jun. 02, 1981

Filed:

Jul. 25, 1979
Applicant:
Inventors:

Ake O Sandstrom, Taby, SE;

Bo G Falk, Jarfalla, SE;

H S Bystedt, Daderyd, SE;

Assignee:

Defibrator AB, Stockholm, SE;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21B / ;
U.S. Cl.
CPC ...
162 26 ; 162 28 ; 162 78 ;
Abstract

Method of producing peroxide bleached pulp from fibrous lignocellulose materials which are subjected to a defibration step in a grinding space defined between a pair of discs which rotate relative to one another within a steam pressurized grinding housing. The pulp material is fed into the central portion or 'eye' of the grinding space by a screw conveyor which rotates in a bore communicating with the grinding housing to form a steam-tight plug to prevent blow-back of pressurized steam from the grinding housing. The steam-tight plug, upon entry into the central portion of the grinding space, is broken up into fiber bundles which are accelerated radially outwards in the grinding space by the centrifugal force while being subjected to progressively increasing defibrating action. A peroxide-containing bleaching solution is introduced into the grinding space so as to react with the separated fibers of the pulp material during the defibrating action.


Find Patent Forward Citations

Loading…