Analysis of the Ink-Stream Break-Up Phenomenon in Continuous Inkjet Printing

The ink-stream break-up phenomenon in continuous inkjet printers has been studied herein. A numerical model has been developed to reproduce and analyze the non-monotonic behavior of ink-stream break-up length (BUL) against the amplitude of piezo-actuator oscillation. That is, when the amplitude is increased, the BUL initially decreases to a local minimum point, then increases to a local maximum point, and finally decreases again. The developed model is split into two stages, first being the emergence of periodic "initial indentation" on ink stream caused by piezo-oscillation and the second being the growth of indentation. Finally, the calculated results of BUL against oscillation amplitude is compared with experimental data. We confirmed that the model well reproduces the characteristic of BUL and clarified the emergence mechanism of its local minimum and maximum points.