The Effects of Fillers on the Deinkability of Printed Paper

This report covers the effect of fillers on the deinkability of a printed sheet of paper. Paper was produced with varying amounts of titanium dioxide and clay retained as fillers. This paper was then cut into 8½ X 11 inch sheets. The top half of each sheet was printed and cut away from the bottom unprinted half. Both of these portions were repulped by identical methods and brightness measurements were made from this recycled pulp. Differences in these brightnesses were ploted against percent ash in the sheet. It was found that at low levels of addition the filler increases the deinkability and at higher levels it decreases the deinkability of the paper. It was also found that there were only small differences between the effects of titanium dioxide and clay