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 t erms of their ability to characterise oil-dispersed waxes used in printing inks: Photon Correlation Spectroscopy (PCS), light scattering and diffracti on, Scanning Electron Microscopy (SEM), and the National Printing Ink Resea rch Institute (NPIRI) grindometer. SEM as well as light scattering and diff raction techniques were found suitable for the compound waxes investigated. The importance of various physical parameters associated with the compound ing procedure, and their influence an the final particle sizes, were consid ered. These parameters included the cooling rate, in-crystallisation agitat ion, post-precipitation agitation, wax loading and crash-cool onset point.