Date of Award
Bachelor of Science
Pulp and Paper Technology
Dr. Alfred H. Nadelman
Dr. John Schulz
Four Bench-type laboratory coaters were compared as to their pattern formation which influences the printability of the coated sheet.
The four Bench-type laboratory coaters used were Wire Wound Doctor Rods, Bird Film Applicators, Bench Trailing Blade Coater and the Martinson Coater.
A constant solids content coating color was used which consisted of 100 parts coating clay and 18 parts casein. A record of the viscosity of the coating slip was kept.
The coated sheets were evaluated by visual inspection, and photomicrographs were taken of the most characteristic patterns. Coat weight, reproducibility and smoothness values were also determined.
It was found that before supercalendering Bird Film Applicators gave the least pattern followed by Wire Wound Doctor Rods, Martinson Coater and Bench Type Trailing Blade Coater.
After supercalendering the patterns produced by all four devices looked similar. This was verified by the smoothness values, which all fell in the same range.
Longton, Clare L., "Pigment Coating of Paper in the Laboratory a Comparison of Several Methods" (1961). Paper Engineering Senior Theses. 368.