Multivariate non-linear regression models for the relationship between the vat photopolymerization 3D printing process of alumina ceramics and the shrinkage rate of sintered bodies

This study integrates JMP-based response surface methodology with multivariate regression to optimise process parameters and predict shrinkage behaviour in vat photopolymerization-printed alumina ceramics. The analysis highlights that coating thickness is an important factor in shrinkage control, while the relative importance of linear, interaction, and quadratic contributions varies with shrinkage mode. Results showed that the shrinkage rate in the length direction was mainly associated with the linear terms of coating thickness and scraper movement speed, with an additional contribution from their interaction. The width-direction shrinkage was primarily affected by the linear term of laser power, together with the interaction between laser power and coating thickness. The inner-diameter shrinkage was mainly governed by the quadratic term of scraper speed and the interaction between laser power and scraper speed, indicating a pronounced non-linear response. The volumetric shrinkage was predominantly influenced by quadratic terms, especially those associated with coating thickness, laser power, and laser scanning speed.