Examination of adhesive force and the model’s dimension in continuous and conventional printing using the oxygen inhibition effect

Abstract

In constrained surface vat photopolymerization, the adhesive force between the formed layer of the model and the bottom of the resin container restricts the printing capability. This research investigates the adhesive forces in digital light processing (DLP) and continuous digital light processing (CDLP), focusing on how the oxygen inhibition effect, resin container membrane, and model geometries affect these forces. This study tested four distinct resin vats, with particular attention given to oxygen-permeable vats, to evaluate their role in reducing adhesive forces. A permeable vat that reduced the separation force by 52% using the oxygen inhibition layer was assessed for continuous printing. The influence of model geometry on the adhesive force in DLP and CDLP was evaluated using a permeable vat. Moreover, an inverse relationship was identified between resin absorbance and both curing depth and printing speed. It was observed that as the model’s cross-sectional area increased, so did the adhesion force in continuous printing. These findings prove that continuous printing can achieve faster build times in CDLP than in DLP, with a maximum speed of 288 mm/h.