Dynamics of Ink Jet Printing

(1) Ink droplet formation and physical properties of jet ink

Abstract

The process of ink droplet formation in ink jet printing is observed by the microimage-monitoring system synchronized with a printer head driver. Effects of viscosity and surface tension of jet ink on size and velocity of ink droplet were mainly investigated. The physical properties of jet ink were adjusted with the addition of polye (thylene glycol) and isopropyl alcohol. With increasing viscosity and decreasing surface tension, the velocity of an ink droplet decreased, and the size was also slightly decreased. These phenomena can be analyzed with Reynolds number.
Sphericity of an ink droplet decreased with increasing viscosity. Satellite formation and its merger into the main ink droplet are of particular interest, but the relations between the satellite and physical properties of jet ink were not so clear. From a viewpoint of printability, jet inks with higher Reynolds number, higher surface tension, and lower viscosity are recommended