Date of Award


Degree Name

Bachelor of Science


Pulp and Paper Technology


Turbidity has long been a problem to the paper industry. In the past, it has been mainly associated with secondary fiber mills, among others. However, with the recent increase in the price of virgin pulp, other mills are seriously considering secondary fiber as a substitute for virgin pulp. Therefore, turbidity may become a problem to a larger number of mills in the future. Turbidity arises when starch and a filler are sheared together in a system. It has been noted in the literature that hypochlorite-oxidized starch produces the greatest turbidity phenomenon.

This project assumed that the size of the starch polymer was largely responsible for this effect and attempted to reduce the chain length through enzymatic hydrolysis. Initial hypochlorite-oxidized starch-titanium dioxide turbidities of 2200 JTU were reduced to 40-80 JTU through the use of alpha and beta amylases.