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:
Nov. 03, 1998
Filed:
Sep. 18, 1996
David W Park, Puyallup, WA (US);
Frank R Hunter, Bellevue, WA (US);
Weyerhaeuser Company, Tacoma, WA (US);
Abstract
The invention is a method of enhancing the strength of paper products, particularly the dry strength, without adversely affecting repulpability. It is also directed to the resulting products. It is particularly applicable but not limited to products with significant amounts of secondary fiber in the furnish. Preferably, about 10-30% of the fiber is separated from the furnish at some point prior to sheeting. This is treated with a cationic wet strength resin which is allowed to bond to the fiber. Cationic polyamide-epichlorohydrin resins are particularly useful. The treated fiber is them mixed with the untreated balance of the fiber at some point before the paper machine. Screnning fines on repulping do not normally exceed 2-3%.