Investigation of the part deformation in stereolithography

Taking the part deformation in SL process as the objective of study, principles are analyzed in detail. Some new concepts such as shrinkage force and surface-distributed loads are proposed according to the resin shrinkage while curing and the adhesive characteristics between adjacent layers. The time-varied stiffness is presented based on the change of part structure during layer increase. Hence, the nature of part deformation in SL process is exposed. The experiment results are consistent with the theoretical analysis. Therefore, a new hatching pattern called separate area scanning is proposed, which can improve the part accuracy by reducing the deformation.