Date of Award
Bachelor of Science
Pulp and Paper Technology
Dr. Stephen Kukolich
Comercial bleached soft wood sulfite pulp was used. The pulp was refined in a Standard Valley Beater to a Canadian Standard freeness of 428. This pulp was preserved and used to make all of the handsheets, on a Noble and Wood handsheet mold.
The Titanium dioxide added to the handsheets was prepared in three different ways: simple dispersion, dispersion of the Titanium dioxide along with cationic substances, and addition of the dispersed Titanium dioxide and the cationic substance to the pulp without previous co-dispersion. The optical properties of the sheets were measured and the Titanium dioxide in the sheets was found by an ash analysis. The scattering coefficient of the Titanium dioxide in the sheets was then determined with the Judd chart of the Kubelka-Munk equation. The percents of retention were also determined.
The results also indicate that there are optimum percent levels of cationic polyamide (PA) based on the weight of Titanium dioxide. At one percent level the method of co-dispersion can produce a three dollar per ton of five percent Titanium dioxide paper savings. The savings over using un-treated Titanium dioxide is about six dollars per ton on a run of paper which was five percent un-treated Titanium dioxide.
Hartman, Neil A., "The Effects of Cationically Charged Titanium Dioxide on Particle Dispersion in the Sheet of Paper" (1969). Paper Engineering Senior Theses. 253.