Ink jet printing of alumina suspensions in liquid wax

This paper reports on our recent achievements, using a hot-melt ink system, towards the fabrication of ceramic bodies by controlled droplet deposition. Key factors for jetting were identified and the rheological behaviour of fairly concentrated particulate suspensions was optimised to match the window of print-head operation. As a demonstrator, several unfired objects containing 30 vol.% colloidal Al2O3 dispersed in paraffin were fabricated, using a three-dimensional inkjet plotter primarily developed for rapid prototyping. This platform is currently being improved to allow the fabrication of shapes with higher particulate contents. Preliminary studies using a 75 mum orifice diameter inkjet print-head have produced encouraging results

Direct inkjet deposition of ceramic green bodies:II - Jet behaviour and deposit formation

In order to successfully build three-dimensional shapes by hot-melt inkjet deposition it is essential to control the building block characteristics, i.e., the deposit geometry, dimensions and fine feature resolution. The deposit formation is mainly dependent on the material systems and their jetting behaviour. It is therefore crucial to understand how the jet formation is affected by the inks ' rheological properties and how to manipulate the jet-head driving parameters to achieve optimum deposition conditions. This paper reports our investigations with a model jet firing station, about the influence of driving parameters of hot-melt drop-on-demand print-heads (e.g., pulse shape and frequency) on the jet and deposit formation characteristics, for both unfilled and powder loaded vehicles. © 1999 Materials Research Society

Direct ink-jet deposition of ceramic green bodies: I - Formulation of build materials

A conventional rapid prototyping technology has been used to build prototypes using direct deposition through a drop-on-demand ink-jet printing system. Al2O3-filled waxes have been developed with viscosity values close to those of the materials used in commercial printing systems. Commercial dispersants based on stearic acid and sterylamine have been studied and stable ceramic suspensions with ceramic volume fractions in the range 20-40 volume% produced with suitable viscosity. A suspension of 20% Al2O3 in an alkane wax has been successfully printed

Direct ink-jet deposition of ceramic green bodies: I - Formulation of build materials

A conventional rapid prototyping technology has been used to build prototypes using direct deposition through a drop-on-demand ink-jet printing system. Al2O3-filled waxes have been developed with viscosity values close to those of the materials used in commercial printing systems. Commercial dispersants based on stearic acid and sterylamine have been studied and stable ceramic suspensions with ceramic volume fractions in the range 20-40 volume% produced with suitable viscosity. A suspension of 20% Al2O3 in an alkane wax has been successfully printed