Date of Award
Bachelor of Science
Paper Science and Engineering
Dr. David Peterson
Deinking is of critical importance to the reuse of secondary fiber in the paper industry. As with all papermaking processes there is a definite concern on the final quality of the product and the waste that is generated. Waste problems are a growing concern and with tighter discharge limits there is a growing concern of how to deal with these problems. One solution to this problem is the idea of a closed cycle deinking process which reutilizes the wastewater stream for pulping and recovering of usable fiber which is otherwise lost to the system. As with everything there are problems that can occur when implementing a system such as this. The focus of this project is to determine if there is solids build up within the deinking and paper making loop and if there indeed is show these effects on the final paper by testing the whitewater and comparing those tests to the physical properties of the paper. From the results of the whitewater tests there does seem to be a buildup of suspended material within the system, but contrary to the initial belief the amount of dissolved material in the system actually decreased. Trends were also observed when comparing TSS and TDS to tensile and tear indexes. It seemed that both were affected by dissolved material and tensile was affected by suspended material both deal with bonding potential. It was also seen and will be explained in more detail that the optical properties of paper were not affected namely opacity and brightness but, scattering coefficient was slightly affected by the increase in suspended solids. The following parts of this report will go through the actual data and trends and will also go through the background and experimentation that was completed.
Warmbier, Chad H., "Deinking in a Closed Loop and the Effects of Solids on Paper Properties" (1996). Paper Engineering Senior Theses. 563.