Optimisation procedure for additive manufacturing processes based on mask image projection to improve Z accuracy and resolution

Mask image projection is an additive manufacturing (AM) technique used in photocurable materials which allows the simultaneous energy delivery in a whole area instead of a single spot. A common problem for this AM process is the uncontrolled penetration of light energy, which could cause a solidification of non-desired layers. In this paper, an optimization procedure is developed and presented in order to increase Z accuracy and resolution of printed parts through the control of the total accumulated dose and the photocuring conversion ratio of each spatial location of the manufacturing volume. Consequently, the uncontrolled monomer-to-polymer conversion of down-facing surfaces could be reduced. A finite element strategy is used in the optimisation procedure to obtain a full discretization of the whole manufacturing domain. Furthermore, experimental tests have been done to compare experimental results and numerical estimations. The results show that the use of the optimisation procedure increases the accuracy and resolution of printed parts along the manufacturing direction.