Ink-jet printing of wax-based alumina suspensions

Suspensions of fine alumina powder in a paraffin wax have been successfully formulated with viscosity values sufficiently low to allow ink-jet printin g using a commercial printer. A commercial-grade paraffin wax, with stearyl amine and a polyester, were used as the dispersant system. Suspensions with powder loadings up to 40 vol% were passed through the ink-jet printer head . Unfired ceramic bodies with a feature size of < 100 mum have been success fully fabricated with waxes that had a powder loading of 30 vol%. The influ ence of suspension fluid properties on the ink-jet printing process has bee n studied, and the importance of the acoustic resonance within the ink-jet printing apparatus has been demonstrated.