Date of Award
Bachelor of Science
Paper Science and Engineering
This thesis involves a study of the reaction of coating pigment slurries to ultrasonic vibrations during drying on a sheet of paper. The coating was done with a Meyer Rod and immediately transferred to the surface of a loudspeaker apparatus until dry. Several different coating formulations were used and evaluated with and without ultrasonic agitation. These coatings include combinations of #2 clay, delaminated clay, titanium dioxide, calcium carbonate, and polystyrene plastic pigment. Frequencies of 25,000 Hz and 42,000 Hz were used as well as the control group which was not treated. The amplitude was the highest attainable with the frequency generator alone. A proposal of this thesis is that the orientation and void volume of the pigment/binder slurry will be affected by the agitation, as well as increased binder migration. Several properties of the sheet were analyzed and compared to theoretical responses.
The coated sheets were evaluated for coat weight, gloss, smoothness, K & N ink test, brightness, and opacity. The gloss and smoothness tests showed the largest responses. A binder migration toward the surface upon ultrasonic treatment showed a decrease in gloss. Smoothness increased due to increased parallel orientation of the pigments to the sheet.
Husted, Craig N., "Effects of Ultrasonic Vibration on a Coating Slurry as It Dries on the Sheet" (1983). Paper Engineering Senior Theses. 210.