Effect of post-processing treatments on completeness of cure and mechanical properties of FormLabs Clear and High-Temperature printed acrylic resin*

The effect of UV and thermal processing on the properties of a UV-curable polymer fabricated with 3D printing was studied. The polymers studied were proprietary methacrylate based resins (Formlabs) and samples were printed directly in test geometries. Uniaxial compression tests at room temperature were performed for Young’s modulus, Poisson’s ratio, and yield stress. Thermal tests using a Differential Scanning Calorimeter (DSC) described the glass transition temperature range, physical aging and (additional) high-temperature reactions of the samples. Post-processing consisted of either additional UV exposure time or high temperature "soak" time (or both). These indicated that post-processing has a pronounced effect on the mechanical and thermal properties. Both aspects of post-processing (UV and high-T soaks) increase the yield stress, the modulus and the glass transition. Combining high-T soaks with additional UV exposure is particularly effective.