An experimental study of drop-on-demand drop formation

The dynamics of drop-on-demand (DOD) drop formation have been studied experimentally using an imaging system with an interframe time of 1μs and a spatial resolution of 0.81μm∕pixel. Using a piezoelectrical actuated inkjet printhead with the nozzle orifice diameter of 53μm, experiments were conducted over a range of viscosities (1.0–5.0cP) and surface tensions (35–73mN∕m). The effects of the driving signal, which controls the piezoelectric transducer that produces the pressure pulse to drive the liquid from the reservoir through the orifice, have been examined along with those of liquid properties. The main stages of DOD drop formation, including ejection and stretching of liquid, pinch-off of liquid thread from the nozzle exit, contraction of liquid thread, breakup of liquid thread into primary drop and satellites, and recombination of primary drop and satellites, are analyzed based on the experimental results. The breakup time of liquid threads was found to be dependent mainly on the capillary time based...