The use of high shear dispersion in investment casting foundries is growing in popularity due to the belief that this method will reduce both the amount of time required to make a slurry and the cream-in time as compared to prop mixers or rotating tanks. However, without properly setting up the high shear dispersion process, variability in shell properties can be experienced.

Optimal dispersion guidelines for high shear dispersers have been outlined by Morehouse-Cowles in the Modern Dispersion Technology – A Primer in Dispersers handbook including dispersion speeds, blade size and height. Using this information and a study of dispersion time and slurry properties, it is possible to produce a consistent slurry. Deviation from the guidelines or incomplete slurry mixing can result in varying slurry characteristics.