Date of Award


Degree Name

Bachelor of Science


Pulp and Paper Technology

First Advisor

Dr. S. Kukolich


Alkaline sizing has many inherrent advantages over conventional sizing with rosin and alum. The presence of alum alone in the papermaking system can be a detrimental factor to some characteristics of the process and the final sheet. By sizing under alkaline conditions not only is alum eliminated from the system but also a superior grade of sizing is achieved.

For the sizing of softwoods with Aquapel, an alkyl ketene dimer, it was found desirable to size in the pH range 8.0 to 8.3 and Canadian Standard Freeness 500 to 530. The kraft softwood was found slightly more susceptible to alkaline sizing reactions than the sulfite softwood. Significant effects of pH were observed on the rate of development of reaction between the sizing agent and the fiber and on the extent of reaction.