METHOD OF ENHANCING STRENGTH OF PAPER PRODUCTS AND THE RESULTING PRODUCTS

• Main Authors: HUNTER FRANK R, PARK DAVID W
• Format: Patent
• Language: English
• Published: 26.06.2000
• Edition: 7
• Subjects: IMPREGNATING OR COATING OF PAPER; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; TEXTILES; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G

PURPOSE: The present invention describes a method by which PAE resins and other types of paper making additives normally used for imparting wet strength may be used for increasing dry strength and other properties of papers without adversely affecting repulp-ability. CONSTITUTION: The invention is a method of enhancing the strength of paper products, particularly the dry strength, without adversely affecting repulp-ability. 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. Screening fines on repulping do not normally exceed 2-3%.