Statistical modelling and optimization of mechanical properties for PLA and PLA/Wood FDM materials

Abstract

This investigation examines the results of two variable parameters during the fused deposition modeling (FDM) 3D printing process of conventional polylactic acid (PLA) and organic biocompatible compound material with wood (PLA/W; coconut flour), on ultimate tensile strength, UTS (MPa) and modulus of elasticity E (MPa). The parameter optimization is based on a customized response surface (RSM) design and uses an L9 orthogonal array. The control variables investigated were nozzle temperature (NT, oC) and layer thickness (LT, mm), whilst regression models for UTS and E of both materials, i.e., PLA and PLA/W, were constructed to correlate the control parameters. Proper analysis was preceded based on response surface analysis through contour plots. The regression models were further useded as objective functions to maximize UTS and E (MPa) for both filament materials by applying the grey-wolf optimization genetic algorithm (GWO).