Characterization of an FDM-3D Printed Moldcore in a Thermoforming Process Using Taguchi in Conjunction with Lumped-Capacitance Method

Fused deposition modeling (FDM) is categorized in additive technology where prototypes and functional components are fabricated with no limitation of shape complexity and shorter part development time. However, besides its great advantages, its layer-by-layer fabrication has a weakness of poor surface roughness, and its plastic materials have low thermal conductivity. While there have been a lot of studies of the surface roughness in FDM, it is still required to solve the thermal problem that prevents FDM from being applied in manufacturing processes incorporating heating, such as thermoforming. In this paper, a new post-processing method for FDM-3D printed moldcore is experimentally investigated for surface finish improvement and heat absorption reduction to broaden the application scope of FDM. The Taguchi method in conjunction with a lumped-capacitance model is used in respect of multi-input and single-output (MISO). The results show that a chemical treatment using dimethylketone (acetone) improved the surface roughness while aluminum spray coating decreased heat absorption of the FDM’s samples using acrylonitrile–butadiene–styrene (ABS) filament. The dimensional variation during this process is also confirmed to be very small. This low-cost post-processing technique is found to be easily applied on both lab-scale and manufacturing scales, especially for low-volume production or prototype fabrication.