Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering

First Advisor

Dr. David K. Peterson


Recoverable fiver is a major component of paper mill primary sludge, and it is often landfilled instead of utilized to its potential. With successful recovery of fiber from sludge, less raw materials will have to be purchased and a lesser volume will be landfilled, thus decreasing landfill disposal costs.

Primary sludge from a local paper mill was collected and stored at Western Michigan University. Solids and ash testing was done first to get background knowledge of the sludge. Fiber length was then determined using the Clark Classifier. Fiber recovery was accomplished by using a laboratory scale sidehill screen. After screening, the Clark Classifier was again used to determine fiber length distribution. Handsheets were then made at varying levels of recovered fiber to determine the maximum amount of recovered fiber that can be added before strength properties decrease.

Results showed that recovered fiber can be added up to 10% to 12% recovered fiber without affecting brightness before a drop off in strength occurs. In light of current environmental awareness, this is a significant finding.

Recommendations for future work include a pilot machine trial and more involved handsheet project to gain more knowledge of the effect of recovered fiber on sheet properties.