Optimization of FDM 3D Printing Process Parameters of Biodegradable Poly Lactic Acid Polymeric Samples

In this study, the mechanical properties of poly lactic acid samples produced by FDM 3D printing technique were investigated. The 3D printing process parameters were optimized using design of experiment (DOE) Taguchi approach for achieving the optimum mechanical performance. In this regard, infill percentage (at three levels of 30, 50, and 70%), raster angle (at three states of 0/90, -30/30, and -45/45 degree), and layer thickness (at three levels of 200, 250, and 300 µm) were considered as process parameters for optimization procedure. Their effects on density (as porosity degree), impact strength (as mechanical property), and specific impact strength (the impact strength to density ratio) were investigated. Analysis of variance (ANOVA) was utilized to find the most effective processing parameters. The findings revealed that the infill percentage was the most effective parameter on the density and the impact strength. The density and the impact strength were reduced with the decrease of the infill percentage. These decrements were in a way that their ratio, specific impact strength, was almost constant. The layer thickness had the most influence on the specific impact strength. The specific impact strength was improved by reducing the layer thickness due to the raster entanglement. The optimum conditions to achieve the highest mechanical performance were the raster angle of 30/-30 degree and the layer thickness of 200 µ. The optimum infill percentage depended on the application.