Influence of post curing on the tensile properties in mask stereolithography

The oldest process of additive manufacturing is based on the crosslinking of liquid photopolymers using a light source, the socalled group Vat photopolymerization. This first procedure is called stereolithography (SLA), and more recently it has expanded to digital light processing (DLP), mask stereolithography (MSLA), continuous liquid interphase printing (CLIP) procedures that differ in the mode of illumination. The processes have many advantages, but one of the biggest disadvantages is the need for post curing after processing. The paper describes the MSLA procedure and the influence of the post curing time in the UV chamber on the tensile properties. The experiment plan was analyzed in the software Design Expert using analysis of variance. From the analysis it can be concluded that an increase in the post curing time leads to an increase in tensile strength of 53% and tensile modulus of 120%, but post curing reduces the elongation/strain by 64% and changes the color of the product.