Shrinkage effect of photopolymerization in mask exposing and laser scanning stereolithography

The aims of this paper are to present a numerical method in simulating the shrinkage effect and to analyze the deformation of the laser scanning and mask exposing system. A simulation code based on the dynamic finite element method is developed to analyze the shrinkage effect of polymerization and optimize the fabrication parameters including the scanning path, exposure time and shape effect. In experimental study, a fan blade is fabricated by using a laser scanning stereolithography and reconstructed the surface of fabricated blade for comparing the deformation with simulation prediction. Furthermore, a 2.5D model with sharp and rounded corners is fabricated by using mask exposing stereolithography. It was found that the sharp corner shrinks faster than rounded corner numerically and experimentally. Consequently, the experimental validations show that the developed code can analyze the deformation in laser scanning and mask exposing stereolithography. It can be further applied in optimizing the scan path and exposure time for eliminating shrinkage effect.