Pigment Characterization in the Printing Ink and Coatings Industry
Particle size measurement is a collection of very old and very modern analytical techniques. It originated thousands of years ago with sieving as a method of characterizing the efficiency of crushing operations. Since this beginning, many methods of making this determination have evolved.2 During this evolution, the test procedures have become quicker, easier and more repeatable. This has led to ever wider adaptation of these methods, even to the point of on-line measurements.3 These developments have paralleled many of those in the printing ink and coatings industries. This has resulted in their adoption in this important industrial application.
Particle size measurement is unique among analytical techniques, and it has earned the separate classification as one of several physical test methods. In more straightforward analytical tests, a number, such as weight percent sulfur4 in a sample, is determined. This result is a direct determination of the sulfur contamination level of a hydrocarbon sample, for example. It is a well-understood number and can be used by regulatory agencies for enforcement.5 The data from physical tests on the other hand are more indirect and require additional determinations to become relevant.6 This critical difference requires a great deal of additional work and data interpretation.