Date of Award
Bachelor of Science
Pulp and Paper Technology
The degree of dispersion of pigment has been claimed to be an important variable in the determination of sheet properties such as smoothness and gloss. The degree of dispersion of a pigment can be related to relative sediment volume (RSV) by comparison of the solid and void volumes of a clay slip. One school of thought suggests that there is a relation between RSV and coated sheet properties; this relation being, as RSV decreases, smoothness and gloss increase. It was decided that an attempt to relate RSV (degree of dispersion) to optical properties of coated paper could be valuable. Because it was difficult to measure RSV of a coating color using the centrifuge method, it was assumed that if a constant amount of adhesive was used in each of the clay slurries with different RSVs, the relative RSVs of the coating color would remain constant. The theoretical RSVs of the respective coatings were plotted against the optical properties of the coated paper. No correlation was found between RSV and smoothness, gloss, brightness, or opacity, although it was found that as the percent electrolyte added was increased, the gloss increased.
Chalfin, James A., "The Effect of Relative Sediment Volume on Sheet Properties of Coated Paper" (1967). Paper Engineering Senior Theses. 73.