Design of experiment analysis on tensile properties of PLA samples produced by fused filament fabrication

The fused filament fabrication (FFF) is one of the most common forms of 3D printing with many hobbyists and as well as professional printers adopting this technology. With numerous printing parameters available for each print, having the knowledge to optimize the printing process to obtain a custom mechanical properties is clearly advantageous. This paper aims to analyze the elastic mechanical properties of PLA specimens manufactured through FFF process. To reduce experimental runs, the L-27 Taguchi orthogonal array was used to analyze the influence of seven parameters, (i) infill pattern, (ii) layer height, (iii) infill density, (iv) printing velocity, (v) raster orientation, (vi) outline overlap, and (vii) extruder temperature, and three interactions, (i) infill pattern/layer height, (ii) infill pattern/infill density and, (iii) layer height/infill density on both Young's modulus (E) and yield strength (Rp(0.2)). To remove any doubt about certain parameters, a two-level fractional factorial design with four factors (2(4-1)) was used to supplement Taguchi approach. Results show that the infill density, infill pattern, printing velocity, and printing orientation are the most influential parameters, whereas layer height, extruder temperature, and outline overlap have no significant influence on Young's modulus and Yield strength. We show that the analysis of interactions could play a leading role in optimization parameters by removing doubt concerning some parameters. This work could be further developed to propose a model to help designers to obtain either tailor-made or a robust mechanical property with minimum variation and uncertainty in product.