Potential use of Rigid 10K in VPP-UVL additive-manufactured mold inserts for injection molding of plastic parts: Opportunities and challenges

In recent years, additive manufacturing (AM) has gained increasing attention for its integration with injection molding (IM), specifically through the production of mold inserts. In the case of mold inserts produced by vat photopolymerization (VPP), this integration is limited by the thermal-insulating nature and anisotropic shrinkage of photocurable resins. This study presents a comprehensive evaluation of Rigid 10 K, a photocurable resin glass-filled (55–75 wt%), assessing its suitability for hybrid IM. The work includes thermal, rheological, chemical, and morphological analyses, besides examining the effects of print orientation on mechanical properties, dimensional accuracy, and shrinkage. ANOVA results confirmed that print orientation is critical for mechanical properties such as flexural modulus, tensile stress, and strain (p < 0.001), whereas its influence on flexural stress was moderate (p = 0.03), and Young’s Modulus was unaffected (p = 0.45). Z-orientation maximized structural integrity, increasing tensile strength by 29.4 % and reducing the shrinkage by 30.4–52.0 % compared to flat orientations. Numerical IM simulations revealed heat accumulation and associated defects in parts molded with the Rigid 10 K insert. In physical trials, the insert withstood 50 injection cycles without catastrophic failure. This study establishes design-oriented guidelines for improving insert longevity and provides a framework for the integration of highly filled VPP resins in IM applications.