Water-soluble sacrificial 3D printed molds for fast prototyping in ceramic injection molding

Fabrication of steel molds is a major expense (time and cost) in ceramic injection molding research and development. 3D printed resin molds for fast prototyping are therefore highly attractive and have gained increasing attention. This paper reports strategies to use sacrificial molds 3D printed by fused deposition modeling (FDM) from PVA or digital light processing (DLP) from water soluble resin. Usage of sacrificial molds allows injection molding of complex geometries, which are not accessible for simple two-part molds. Ceramic heating elements in diverse geometries were injection molded using a composite feedstock containing MoSi2, Al2O3 and feldspar. More parts with various geometries were produced from Al2O3 feedstock. A comparison revealed that DLP printed molds are better suited for parts with very small structural features due to the higher resolution of the DLP process as compared to FDM. Finally, ceramic heaters were fabricated using two-component ceramic injection molding and successfully tested.