The purpose of this paper is to develop a novel post-processing technique of fused deposition modeling (FDM) parts to improve surface roughness and reduce heat absorption and for high-temperature application in thermoforming process.
The current technique consists of chemical treatment, drying and aluminum coating. First, surface morphology was investigated using FDM specimens with a flat surface. The heat absorption characteristic was also analyzed by Taguchi-based design of experiment and modified lump-capacity model. In addition, dimensional accuracy and uniformity were investigated under high-temperature conditions, which were similar to a typical thermoforming process, with specimens having concave and convex grooves.
It was verified that the proposed post-processing technique could efficiently improve surface quality of FDM parts with the arithmetic average surface roughness of 2.06 µm. In addition, the coated aluminum layer was found to reflect the heat radiation, resulting into a sufficient reduction of heat absorption. From the investigation of dimensional accuracy and uniformity, it was found that the current technique produced maximum change of 0.11 mm and uniform thickness of an aluminum layer within 0.07 mm.
The present study establishes a novel post-processing technique, enabling to treat the surface of FDM parts for high-temperature applications. It provides a simple way of using typical FDM parts for a thermoforming process as the mold cores. Furthermore, it can be used in other rapid tooling technologies, consequently widening the application areas of FDM.
