Volume shrinkage and conversion rate of Al2O3 ceramic stereolithography suspension polymerised by ultraviolet light

Abstract

Abstract The volume shrinkage and conversion rate are important factors determining the defect generation and accuracy control of green parts in ceramic stereolithography. In this study, a specific laser reflection method with coverslips and real-time Fourier-transform infrared (RT-FTIR) spectroscopy were used to determine the effects of the double-bond concentration, monomer ratio, photoinitiator, and incident light intensity on the real-time volume shrinkage and conversion rate. A slurry with a lower double-bond concentration obtained by using a solvent exhibited a smaller shrinkage. The shrinkage law for pure resin wasn’t applicable owing to the ceramic particles. The mixing of ethoxylated pentaerythritol tetraacrylate (PPTTA) and 1,6-hexanediol diacrylate in suitable ratios promoted the conversion. In addition, the PPTTA could regulate the overall shrinkage. The photoinitiator had a small effect on the shrinkage. A high light intensity increased shrinkage significantly, while the conversion rate determined the shrinkage at a low light intensity.