A Dynamic Study of the Effect of Cationic Starch Molecular Weight and Charge on Filler and Fines Flocculation, Deflocculation, and Reflocculation
Date of Award
Master of Science
Chemical and Paper Engineering
Dr. Raymond L. James
Dr. John F. Bobalek
Masters Thesis-Open Access
A modified laboratory instrument was used to dynamically monitor the flocculation of fines and filler under various shear conditions on the "seconds" basis. A three-way factorial design and ANOVA were used to evaluate the significance of cationio starch molecular weight and charge in affecting fines and filler flocculation, deflocculation, and reflocculation. The reduction of molecular weight under high shear was suggested by the results. Both main effects and interaction effects of charge and molecular weight were important in determining flocculation. Charge was the only significant factor for the reflocculation process. Molecular weight was more important than charge in imparting shear resistance to the flocs. The linear behavior of the deflocculation curves was found to be associated with starches which promoted high shear-resistant flocs. Compression and shielding effects were used to interpret the phenomena. Molecular weight and charge were significant for the initial rate of deflocculation under 1100 rpm. The amount of flocculation and the amount of flocs retained in the deflocculation process were found to be the most important factors to determine polymer utility in the wet end.
Ching, Bob Shian-Hou, "A Dynamic Study of the Effect of Cationic Starch Molecular Weight and Charge on Filler and Fines Flocculation, Deflocculation, and Reflocculation" (1986). Masters Theses. 1301.