Heat-Treatment and Water Immersion Effect on the Mechanical Properties and Joint Strength of 3D-Printed Polylactic Acid Parts

This paper investigates the effect of short-time water immersion (WI) and heat-treatment (HT) post-processes on the mechanical properties and joint strength of printed polylactic acid (PLA) parts with various raster angles. Using these post-processing methods to enhance the joint strength of printed PLA parts could be deemed as the novelty and the contribution of the current study. The WI and HT of the tensile test specimens and the adherends of the bonded joints were carried out at 21 degrees C and 90 degrees C, respectively. Depending on the raster angle, the tensile strength of the heat-treated specimens was about 11%-43% higher than that of the untreated specimens. Interestingly, it was found that WI had a more significant effect on the strength of printed parts than HT. In the case of WI, the tensile strength was increased by about 27%-57% as compared to the untreated specimens. Joint tests revealed that HT and WI exerted a similar positive effect on the strength of the joints. The findings highlighted that short-time WI is at least as effective as HT in increasing the tensile and joint strengths of 3D-printed PLA parts.