Aspects of Aqueous Pigment Ink Formulation : Latency, Dynamic Surface Tension, and Pigment Volume Concentration

Abstract

Inkjet ink formulation can be challenging as the ink has to meet two seemingly contradictory requirements : it has to remain stable and not dry out during storage and while in the printhead nozzles prior to jetting, while at the same time it has to dry rapidly to form a durable coating once the ink droplets reach the substrate. In addition, the formulation has to meet the fluidic requirements to jet from thousands of extremely small nozzles repeatedly and reliably at high jetting frequencies. In this paper aspects of each of these three areas are considered : methods for controlling ink drop latency in open nozzles, fluidic physical property requirements for reliable jetting and the importance of the pigment volume ratio in determining final ink properties on non-porous or slightly porous substrates.