ABSTRACT
Cohesion parameters for pigments, fillers, and fibers can often be evaluated by observation of the suspension and/or sedimentation behavior of particulate matter in different liquids. These characterizations are based on relatively stronger adsorption by some of the liquids compared with others. Those liquids with stronger interaction can suspend finer fractions of solids indefinitely or retard sedimentation, compared with the other liquids. Data should be interpreted by accounting for differences in the densities and viscosities of the test liquids, such that a relative sedimentation rate can be used for comparisons. The absolute sedimentation rates are generally not of primary interest. Data from such evaluations can be computer-processed to assign Hansen cohesion parameters (HSP) to the material in question. Cohesion parameter data are given for some newer pigments, fillers, and a carbon fiber to demonstrate the principles.
