Optimization of Vat-Polymerization binder formulation for 3D printing ceramic slurry using D-optimal mixture experimental design

The aim of the present study was to optimize a formulation of the vat-polymerization binder of 3D printing ceramic slurry using a D-optimal mixture experimental design. The selected methodology was based on an extreme vertices approach with 13 combinations, selecting three types of resin monomers (TMPTA, NPG2PODA, HDDA) and one type of plasticizer (TXIB) as independent variables, while mechanical properties (including tensile strength and elongation at break), volume shrinkage, viscosity, and curing depth were considered as response variables. The experimental data were analyzed to generate statistical models and response surfaces for analyzing the effects of component fractions on individual responses. Analysis of variance was performed. This method was applied to predict the optimal formulation. Based on the DoE results, the mixture of resins and plasticizer with an optimized composition ratio after curing showed better mechanical properties, lower volume shrinkage, lower viscosity, and an appropriate curing depth. Furthermore, a ceramic slurry containing 55 vol% Al2O3 was prepared to evaluate the printability of the optimized mixture. The relatively dense ceramic parts and smooth surface were successfully manufactured after de-binding and sintering. Our findings demonstrate the efficiency, reliability, and feasibility of the D-optimal mixture experimental design in modeling, predicting, and optimizing the formulation of the TMPTA/NPG2PODA/HDDA/TXIB composite. Overall, this study can be helpful in designing experiments and optimizing the vat-polymerization of 3D printing ceramic slurry.