Date of Award


Degree Name

Bachelor of Science


It is the purpose of this thesis to attempt to evaluate the influence of fines on a alkyl ketene dimer (AKD) synthetic sizing agent and to study the role of fines on sizing.

It was found that the addition of fines lowered the degree of sizing in the sheet. Since there was more surface area available when fines were increased, more sizing agent was necessary in order to obtain the same level of sizing with a Hercules or Cobb Size Test. Since the amount of sizing agent was held constant, sizing decreased as a result of the addition of fines.

A sheet produced from longer fibers reacted with the sizing agent prior to the fines addition resulted in a lower degree of sizing than a sheet made from reacting the sizing agent with the fines first. It is believed that the unsized fines had a greater ability to block off the hydrophobic ends of the sized longer fibers and therefore decreased sizing efficiency.

In a sheet containing an insignificant amount of AKD, fines tended to increase sizing in the sheet. The Washburn equation predicts the rate of penetration since rate of penetration is proportional to pore size. By increasing the amount of fines the pore size of the sheet was decreased and therefore, rate of liquid penetration decreased.