Selection of Printing Parameters of a Thermoplastic Elastomer Processed through Material Extrusion

Abstract

Three-dimensional printing technologies are growing additive manufacturing techniques in both the industrial and private sectors. Due to the large number of possible applications for parts built through this technique and the higher standards required for the final products, the need to study new materials increases as a means of delivering innovation into the sector. This paper aims to characterize a polyamide thermoplastic elastomer (polyether block amide) used in the material extrusion technique. Polyether block amide is a material that, among others, could have applications in the field of biomechanics thanks to the combination of high flexibility and relatively high strength. In order to study the behavior of the material after its processing, two controlled printing parameters (layer height and infill density) are related with the resulting mechanical properties measured through tensile testing. A factorial design of experiments is applied to conduct the experimental executing. Once all specimens are printed and tested, an analysis of variance test is processed to analyze the statistical influence of the considered parameters on the material behavior. Consequently, the recommended values for three-dimensional printing of the material are determined in order to obtain the best tensile mechanical properties. The results obtained demonstrate that the Young's modulus can be increased by using a fill density of 75% and a layer height of 0.3 mm. However, regarding the yield strength, there is not a big difference between 50% and 75% infill between layer heights of 0.25 and 0.3 mm.