Forming a fine jet in inkjet printing

The formation of fine jets during the piezoelectric drop-on-demand inkjet printing has been investigated using ultra-high-speed video imaging. The speed of the jet can exceed 80 m/s, which is much higher than the general drop velocity during inkjet printing. The diameters of the thinnest jets are of the order of a few microns. The generation of such fine jets has been studied over a wide range of viscosities, using 7 different concentrations of water-glycerin solutions. This jetting is associated with the collapse of an air-pocket which is sucked into the nozzle during the printing. This occurs for longer expansion times for the piezo-element. We have characterized the relationship between the speed of the fine-jet and other parameters like the diameter of the jet and the physical properties of the liquid.