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:
Feb. 04, 1992
Filed:
Aug. 23, 1990
Bengt Nilsson, Skoghall, SE;
Kamyr AB, Karlstad, SE;
Abstract
A refiner for producing mechanical pulp has greater spacing between bars of the refiner grinding elements than is conventional. The grooves between the bars have a sloping bottom, making an angle of about 1.degree.-30.degree. (preferably 5.degree.-20.degree.) with respect to a straight line between the bars. The width of the grooves is about 10-50 mm. The relative rotation of the refiner elements (whether disks, cylindrical, or conical) with respect to each other results in sequential refining: a moving tension field, with successive compressions before impacts, and expansions, achieving increased fiber flexibility, more fiber rolling motion, and less fiber cutting. Pulp produced has increased fiber flexibility yet maintains a high content of long fibers, and higher refiner capacity also ensues. Also, the refiner of the invention can be used to mix treatment chemicals --such as bleaching chemicals in liquid form--into kraft pulp at high consistency (e.g. about 30-55%).