3D-printing of highly translucent ORMOCER®-based resin using light absorber for high dimensional accuracy

Additive manufacturing, more specifically digital light processing as a form of vat photopolymerization, has attracted great interest and plays an important role in many different applications. However, it becomes complicated when complex parts with overhangs and/or pores are printed, especially if the part has to be transparent. The aim of this study is to improve the dimensional accuracy in z-direction of highly translucent 3D-printed parts. Therefore, ORMOCER® resin-based materials containing different light absorbers are developed to control the penetration depth of incident light and thereby increase the resolution in z-direction. Penetration tests are conducted and show that, in the presence of light absorbers, the curing depth can be adjusted while maintaining a high translucency of the printed part. Furthermore, a model part is developed to quantify the overpolymerization in z-direction and the influence of the absorber. Additionally, properties that are important for future applications, for example in the dental sector, such as mechanical properties and biocompatibility, are investigated yielding promising results. Finally, a complex filigree 3D-grid structure is fabricated applying the resin-based absorber material.