Evaluation of Bond Strength in Multi-Material Specimens Using a Consumer-Grade LCD 3D Printer

Additive Manufacturing (AM) is currently widely used as a means of production and processing. Among the techniques, stereolithography 3D printers (3DP) are highly accurate and versatile, making them popular for personal use. While many personal 3D printers with multi-material printing capabilities have appeared on the market, stereolithography printers for personal use have yet to appear. Therefore, assuming the realization of a low-cost, versatile 3D printer with this functionality, we verified whether the resins currently available for personal use are suitable for this functionality by conducting printing, secondary curing, and tensile tests. The printing results showed that all test specimens were printed with an exposure time of 8 s or more. The tensile test results indicated that the test specimens produced by multi-material printing exhibited tensile strength comparable to that of single-material specimens (90% to 114% of the weak material standard). Additionally, it was confirmed that strength manipulation and post-processing are possible with multi-material printing using the same printing parameters. These findings demonstrate that multi-material printing using conventional commercially available resins is sufficiently practical in terms of strength. The use of existing resins and low-cost photopolymerization-based 3D printers contributes to the realization of low-cost yet high-precision AM technology.