Experimental analysis of waveform effects on satellite and ligament behavior viain situmeasurement of the drop-on-demand drop formation curve and the instantaneous jetting speed curve

Abstract

In situ techniques to measure the drop-on-demand (DOD) drop formation curve and the instantaneous jetting speed curve are developed such that ligament behavior and satellite behavior of inkjet droplets can be analyzed effectively. It is known that the droplet jetting behavior differs by ink properties and the driving waveform voltage. In this study, to reduce possible droplet placement errors due to satellite drops or long ligaments during printing, waveform effects on drop formation are investigated based on the measured DOD drop formation curve and the instantaneous jetting speed curve. Experimental results show that a dwell time greater than the so-called efficient dwell time was effective in reducing placement errors due to satellite drops during the printing process.

Alginate microsphere fabrication using bipolar wave-based drop-on-demand jetting

“…12(b) illustrates an ideal scenario where the pressure waves are in phase. This can be achieved by carefully selecting the dwell time to start the positive pulse (dashed line) when the negative pulse wave (solid line) oscillates to a positive peak [32], making an enhanced positive pressure wave. Such an enhanced pressure wave better facilitates the droplet formation process at the orifice.…”

The role of wettability of nonideal nozzle plate: From drop‐on‐demand droplet jetting to impact on solid substrate

“…Castrej on-Pita et al 5 developed a large-scale droplet generator for on demand or continuous mode. In addition, the voltage waveform as an important factor could significantly influence the droplet formation dynamics 8 and droplet volume, 9 particularly for the droplet modulation with low viscosity. Dong et al 6 carried out experiments by an imaging system to analyze the main stages of DoD droplet formation.…”

“…Further, Jang et al 7 explored droplet formation process experimentally to investigate the influences of ink properties on the inkjet printability and quality of products. In addition, the voltage waveform as an important factor could significantly influence the droplet formation dynamics 8 and droplet volume, 9 particularly for the droplet modulation with low viscosity. 10 A comprehensive investigation including actuating waveform, ink property, and nozzle size was explored by Liou et al 11 with microflow visualization and computational fluid dynamics.…”

Drop-on-demand satellite-free drop formation for precision fluid delivery

“…In the continuous mode, the satellite droplets can be eliminated by applying a large perturbation upstream of the nozzle  frequently a sinusoidal wave, allowing control over amplitude and wavelength (Pimbley & Lee 1977)  or by excitation with combinations of harmonics (Chaudhary & Maxworthy 1980). In the case of DOD, finding the working conditions for the suppression of satellites for viscous fluids remains a trial-and-error process for the formation of both microlitre (Castrejón-Pita et al 2008, 2011Harris et al 2015) and picolitre drops (Wang et al 2012;Dong, Carr & Morris 2006;Kwon 2010). Castrejón-Pita et al (2015) fitted a nozzle with an iris to allow variation of the nozzle diameter in their L-drop generator in order to control the number of satellites.…”