Development of high solid content aqueous 3Y-TZP suspensions for direct inkjet printing using a thermal inkjet printer

An aqueous 3Y-TZP suspension with 24.2 vol.% solid content was developed for "Direct Inkjet Printing" (DIP). The printing unit was a common HP-DeskJet printer. The suspension was adjusted in terms of particle size, viscosity, and pH-value, so that it became compatible with the printing system. Therefore, suspensions of various compositions were prepared and printed two-dimensionally to analyze the influence of several organic additives on printability. The printouts were evaluated and typical printing errors were classified. The composition of the suspension was optimized and successive and error free single layers of 3Y-TZP were printed. The suspension was examined and characterized in terms of particle size and distribution, composition, viscosity, surface tension, pH-value, vapour pressure, and the Ohnesorge number. A printed 3Y-TZP layer of 12 μm thickness was sintered to full density.