The separation between printed part and vat floor in constrained surface vat photopolymerization (VP) is a crucial issue, which limits the printability on different materials and the overall printing speed. This study aims to characterize the separation behavior of a photo-curable PDMS resin with hydrogel vat film in comparison to a convention baseline of commercial acrylate-based resin with PTFE film. A DLP printer is modified with an in-situ force measuring capability. 8 test cases with unique combinations of three factors (film, resin, and separation speed) are developed. The results found that all three factors influence the separation. A faster speed leads to a higher separation force but generally shorter separation distance. Hydrogel film demonstrates lower separation force and shorter separation distance than PTFE film. Photocurable PDMS resin shows lower separation force but longer separation distance than commercial acrylate-based resin. Moreover, the analyzed results also indicate all factors are significant, and have a general trend regardless of other factors.
