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:
Apr. 07, 2015
Filed:
Jan. 30, 2013
Gatien Faucher, Saint Etienne, FR;
Rene Hund, Villars, FR;
Gatien Faucher, Saint Etienne, FR;
Rene Hund, Villars, FR;
S.P.C.M. SA, , FR;
Abstract
A method for manufacturing a sheet of paper and/or board having improved retention and drainage properties is provided, according to which, before the formation of the sheet and/or board, at least two retention aids are added to the fibrous suspension. These two retention aids are a main retention aid corresponding to a (co)polymer having a cationic charge density above 2 meq/g, obtained by the Hofmann degradation reaction, and a secondary retention aid corresponding to a water-soluble or water-swellable polymer having an anionic charge density above 0.1 meq/g. The main retention aid is introduced into the fibrous suspension in a proportion of 100 to 800 g/t of dry pulp, and the secondary retention aid is introduced into the fibrous suspension in a proportion of 50 to 800 g/t of dry pulp and has an intrinsic viscosity IV above 3 dl/g.