The Scientific Research and Experimental Development of customised inkjet fluids requires a fundamental understanding of the ink chemistry, the influence of individual components, and comprehension of complex principles of fluid dynamics involved in the journey of the inkjet fluid from the in-channel flow through the printhead nozzle to in-flight droplets and finally onto the substrate. In this journey, the inkjet fluid experiences extreme conditions, such as, low shear rates in the tank, medium, in the printhead channel, high shear rates during ejection from the nozzle, large elongation in-flight and finally, a high impact on landing onto the substrate. All aspects of ink bulk and dynamic properties under low and high shear, high frequency, high elongation and high impact must be considered to meet specific printhead and jetting conditions.
Adding to the complexity is the non-Newtonian (non-linear) behavior of these inkjet fluids. Ink vehicle (water, humectant, surfactant and biocide) are mainly Newtonian (linear), however, introduction of polymer (binder) and pigments (color) produces considerable deviations from the Newtonian behavior. In addition to inkjet fluid’s surface tension and viscosity, polymer’s viscoelasticity, intermittent pigment stability and dynamic surface tension also play a significant role in formulation.
Performance Testing Methodology
Single Channel Endurance
Multi Channel Endurance
Ink delivery and ink waste system