Much of the information herein has been condensed from reports of research sponsored by TAPPI and conducted by Dr. Sheldon Kurath and his co-workers at the University of Wisconsin-Oshkosh. References to published papers on this work are listed in the last section of this summary. A complete set of progress reports is on file at TAPPI headquarters.
At the time this work was initiated, flow properties of coatings usually were determined using one of several types of commercially available viscometers (see TAPPI Suggested Method T 648 "Viscosity of Coating Clay Slurry"). These viscometers were not capable of testing coating colors at the high shear rates encountered in modern paper coating machines. A need for an instrument to characterize coating formulations at shear rates near and above 10 6 s -1 was recognized by Dr. Kurath. His development of a high-pressure capillary jet viscometer (1) and subsequent TAPPI support of studies of coating formulations at very high shear rates (2-4) has served to demonstrate the utility of the instrument.
