Oil-dispersed waxes for printing inks. Part I: Techniques for characterising particles and effect of cooling rate on particles

Four different techniques for determining particle size were evaluated in terms of their ability to characterise oil-dispersed waxes used in printing inks: Photon Correlation Spectroscopy (PCS), light scattering and diffraction, Scanning Electron Microscopy (SEM), and the National Printing Ink Research Institute (NPIRI) grindometer. SEM as well as light scattering and diffraction techniques were found suitable for the compound waxes investigated. The importance of various physical parameters associated with the compounding procedure, and their influence an the final particle sizes, were considered. These parameters included the cooling rate, in-crystallisation agitation, post-precipitation agitation, wax loading and crash-cool onset point.