A Study of Starches at the Size Press

A literature research is presented concerning the five different starches which were used. Also covered were size presses and how they affect paper properties. BOD was also covered, and how starch has a tremendous effect on it. The literature research indicates there are few quantitative results in this area. The objective of the experimental work was to compare five different starches, applied at the size press, for physical and optical properties, and also BOD. The starches used were an ethylated, an oxidized, a cationic, a thermal-chemical and a thermal-chemical cationic. These five starches were applied at three solids levels and then tested. Looking at the experimental results on an overall basis, the thermal-chemical cationic seemed to have come out on top on just about every test. Most impressive were the BOD results for the thermal-chemical cationic at 7 percent solids. It showed a considerable difference in BOD levels when compared to the other starches at the same consumption level