Investigations of influence of infill pattern on tensile strength of 3D-printed poly lactic acid and Polyethylene Terephthalate Glycol material using Design of Experiments

Abstract

Polylactic Acid(PLA) and Polyethylene Terephthalate Glycol(PET-G) material fabricated with Fused Filament Fabrication(FFF) method in 3D printing has been recognized as one of the important material in artificial tissue/bone engineering applications and adaptors of lower limb prosthesis due to its low cost and less weight. The effect of infill-pattern, infill-density, layer height and speed of the nozzle with 3D printed PLA and PET-G samples on tensile strength was carried out using Design of Experiments. PLA and PET-G samples were fabricated with Fused Filament Fabrication (FFF) method in 3D-printing process and tested using Tensile Testing Machine (UTM) for optimization of process parameters. Experiments were designed using taguchi L9 orthogonal array with five process parameters and three levels to find optimum process parameters of 3D printed samples. Confirmation experiments were conducted with optimum process parameters for both PLA and PET-G samples to compare predicted results of taguchi. The predicted results and confirmation test results reveals that both predicted taguchi results and confirmation test results were within the confident level. The taguchi analysis results evident that the layer height was the main factor affecting tensile strength of PLA samples and infill pattern was the influencing factor affecting on the tensile strength of PET-G material.