Date of Award


Degree Name

Master of Science


Chemical and Paper Engineering

First Advisor

Dr. Raymond L. James

Second Advisor

Dr. John F. Bobalek

Access Setting

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.