P‐86: Prediction of Droplet Behavior in Piezoelectric Inkjet Printing Based on Waveguide Theory

Abstract

In the present study, we numerically investigate the effect of sub‐pulse addition on the applied voltage waveform on the high‐speed jetting procedure of drop‐on‐demand inkjet printing. The concept of a waveguide was adopted to model the reflective and interference properties of sound waves in complex geometrical layout of the pump structure partially surrounded by the piezoelectric actuator. We proposed a nonlinear model in which the mass is concentrated in points by dividing the fluid column and the connecting duct inside the pump section into equal‐sized volumetric elements. A three‐dimensional finite volume numerical simulation was performed for the solution of the Navier‐Stokes equation based on the volume‐of‐fluid method for tracing the fluid interface. The negative part of the bipolar waveform acts as a suction‐removal residual pressure, suppressing the satellite, while the positive voltage repels the meniscus and separates the liquid from the meniscus. The present method based on waveguide theory was successfully applied to evaluate the effect of multi‐step waveform voltage in terms of maximum velocity, size, satellite generation, ligament length.