An experimental analysis of the influence of the ink properties on the drop formation for direct thermal inkjet printing of high solid content aqueous 3Y-TZP suspensions

Direct inkjet printing (DIP) of ceramics as a novel solid freeform fabrication (SFF) method has been subjected to extensive research in the recent years. The studies have focused either on the simulation of the drop ejection or the production of demonstration objects. The aim of this study was to close the gap between the simulation results and product oriented studies. 3Y-TZP inks of 24 vol.% solid content were prepared and characterized in terms of physical properties as well as dimensionless quantities (Re, We, Ca, and Oh). The drop volume and velocity were estimated by considering a constant ejection pressure but varying physical properties of the ejected inks. A thermal inkjet printer was used to eject arrays of single drops as well as three-dimensional 3Y-TZP demonstration objects. The drop arrays were analyzed to determine the relation between the ink properties and the drop formation. The demonstration object was sintered close to the full density.