Date of Award
Master of Science
Paper Engineering, Chemical Engineering and Imaging
Dr. Raja Aravamuthan
Dr. Brian Scheller
Dr. Ellsworth Shriver
Masters Thesis-Open Access
Changes in wet end of alkaline papermaking affect the size development as well as sizing loss. These changes include pH, alkalinity and type of filler used. Precipitated and ground varieties of carbonate fillers and the alkalinity associated with · them are believed to be the causes for the gradual sizing loss in alkaline papers due the accelerated hydrolysis reaction of sizing chemicals at higher alkalinity.
Precipitated and ground calcium carbonate fillers are used as fillers and compared to non carbonate filler such as kaolin clay for their response to size development and sizing loss at lower and higher alkalinity ranges over a period of 60 days. Two commercial sizing chemicals, alkyl ketene dimer (AKD) and alkenyl succinic anhydride (ASA) were evaluated for their response to the changes in wet end.
In general, the results show that the size loss with carbonate fillers is not as serious as projected in literature. The carbonate fillers lost approximately 15% of their initial size after 60 days. Ground calcium carbonate fillers are more resistant to size reversion than precipitated carbonate fillers. Kaolin clay developed more sizing with higher alkalinity, but lost 40% of initial sizing when used with ASA size.
Cherukuri, Suresh B., "The Effect of Wet End Operations on Sizing Loss in Alkaline Papers" (1996). Masters Theses. 5316.