Date of Award


Degree Name

Bachelor of Science


Pulp and Paper Technology

First Advisor

Dr. R. A. Diehm


Because beating is the most fundamental, but highly important, process in the paper industry, some of the changes in fiber structure that occur during beating have been investigated. A literature survey is also presented concerning a number of related investigations of fiber structure.

The experimental results indicate that fibrillation begins very shortly after the beating process is started. As beating progresses, the primary cell wall is removed, and the specific area of the fiber increases greatly when the watery medium encounters the secondary lamella area of the fiber. Continued beating shows that the action is a mechanical one, in that the fibers become bruised, brushed and cut into shorter lengths. The mechanical agitation of the Valley Beater unraveled the small fibrils that are wrapped spirally around the fiber. Prolonged beating eventually detached the fibrils and destroyed fiber structure entirely. After five hours beating, all that remained was a mass of fibrils that readily formed a mat on the slide made for microscopic study. These results compare favorably with published data.

The investigation did not prove that mucilage formed after extensive beating is amorphous. It appears as though the mucilage consists of fibrils and micro-fibrils, yet, equipment limitations prevented further work along these lines.