An Investigation on Mechanical Properties of PLA Produced by 3D Printing as an Implant Material

Polylactic acid (PLA) is a thermoplastic polyester produced from lactic acid. It has become a popular material due to its economic cost and renewable resources. It is the most widely used filament material in 3D printing process. Its biocompatibility and biodegradability made it a perfect choice for medical implants. Its usage in 3D printing also provided flexibility in implant design and production. The aim of the study was to investigate the effect of printing parameters, namely layer height, print speed, infill and shell number, on the tensile and flexural properties of PLA test samples produced by 3D printing. Taguchi method was used to design the experiments. During the optimization of the parameters larger the better signal-to-noise ratio (S/N ratio) and analysis of variance (ANOVA) were used with the aid of Minitab 2019 software. The most effective first and second parameters for tensile loading were infill and number of shells and for bending they were number of shells and infill then followed by printing speed and layer height for both. The optimum parameters for tensile properties were obtained as 0.15 mm layer height, 60 mm/s print speed, 50 % infill and 5 lines of shell. For flexural properties they were 0.10 mm, 100 mm/s, 25% and 5 lines, respectively.