Imaging and Evaluation of Droplet Generation Technologies for Pigment Based Inks

Abstract

In this paper, we present the results of our work on the jetting characteristics for both drop on demand (DOD) and continuous ink jet technologies for a variety of ink formulations. Dye and pigmented solvent and water based inks have been evaluated and conclusions are drawn based on critical ink parameters and printer configurations. We use the soluble dye based inks which have been widely used as our starting fluids and use this results as a basis to compare pigment dispersions in different vehicles. We compare the jetting characteristics and the effect of pigment dispersions on jetting characteristics and show how the jetting characteristics for pigment dispersions compare with those of solutions under “similar” conditions. Differences between the various formulations are illustrated and used to establish empirical methods for “tuning” ink and printer operating parameters to achieve desired jetting characteristics and print quality. It will be shown that by controlling these parameters, we can formulate appropriate pigment based inks to effectively work with ink jet printheads. We also study the effect of parameters like ink temperature on drop formation and printability.