Date of Award
Bachelor of Science
Paper Science and Engineering
Dr. David K. Peterson
Recyclable fines and filler contribute to approximately one half the primary sludge stream, and is often disposed of instead of utilized to its fullest potential. With successful recovery of the fines and filler from the primary sludge, less raw material will be needed in the production of paper. This will decrease the cost of virgin material and the cost of disposing the sludge, while at the same time decreasing the volume of waste sent to landfills. Primary sludge was collected from a local paper mill and stored at the facilities of Western Michigan University. Solids and ash testing was done on the sludge in order to obtain background knowledge of the sample. Fiber length was performed using the Clark Classifier. Fines and filler material was separated from the primary sludge by means of a laboratory scale sidehill screen implementing a continuous process. After screening, fiber classification and ash tests were performed on both the accepts and the rejects collected. At this point handsheets were made at varying levels of recovered fines and filler material to determine the effects that increased addition levels had on the strength and optical properties of the handsheets. The tests used to evaluate the handsheets were brightness, tear Index, tensile Index, and zero-span tensile.
Results showed that recovered fines and filler material can be added up to 10% addition level without significantly affecting the strength and optical properties.
Schultz, Daniel D., "Utilization of Paper Mill Primary Sludge" (1993). Paper Engineering Senior Theses. 490.