Optimizing the separation process for improved zirconia molding through liquid crystal display 3D printing

Mask stereolithography 3D printing for zirconia ceramics has attracted increasing attention in the industrial manufacturing due to their advantages of complex shapes, precisely controlled internal structures and fine surface effects. However, high refractive index and expensive equipment cost have always affected its development. Herein, we combine liquid crystal display (LCD) light curing 3D printing with zirconia molding, which is free from environmental and price limitations. In the conventional method of operation, the cured layer is bonded to the bottom and cannot be manufactured. We put forward a strategy for optimizing separation process and investigate the mechanism of the separation process in depth for high-quality zirconia ceramics LCD 3D printing. The results show that the controlled adjustment of the surface free energy can achieve a great reduction in the separation force, which enabled the successful printing of zirconia ceramics based on LCD. The effect of physical properties of the separation membrane on the separation process was studied and the solid content and 3D printing parameters of ceramic paste were optimized. When the solid content is 72.5 wt%, high quality zirconia ceramic parts with flexural strength of 255 MPa and relative density of 98.1 % can be obtained. This work provides new ideas for the convenient customization of zirconia ceramics in many fields.