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:
Dec. 25, 1990
Filed:
Jul. 17, 1989
Applicant:
Inventors:
Assignee:
Eka Nobel AB, Surte, SE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21H / ; D21H / ;
U.S. Cl.
CPC ...
1621683 ; 1621816 ; 162183 ;
Abstract
In a process for making paper from an aqueous paper pulp, especially a pulp containing bleached/unbleached mechanical pulps or unbleached chemical pulps, a combination of chemicals is added for improving drainage and retention. As drainage-and retention-improving aids are added a cationic polyacrylamide and a sol of colloidal inorganic particles having at least one surface layer of aluminium silicate or aluminum-modified silicic acid.