Mechanical characterization of thermoplastic elastomers based on olefin processed through material extrusion

Thermoplastic elastomeric materials are processable through 3D printing. These materials demonstrate excellent mechanical properties, along with good flexibility. A better understanding of the creation of bonds between the filaments of these copolymers is still needed. When extruded, these materials have shown to have a different behavior compared to commonly known thermoplastic materials. The methodology, hereby presented, relies on the tensile tests of 3D-printed samples of two thermoplastic elastomers based on olefin: TPO 90A and TPO 96A. In order to study the effect of printing parameters on the mechanical behavior of the samples, these have been manufactured following a full factorial design of experiments. Statistical influences were evaluated with an analysis of variance. Layer height and fill density were the variable parameters. Eventually, these two parameters were shown to have a significant effect on the mechanical properties studied (Young’s modulus and yield strength). Once all the results were analyzed, the presented methodology was applied to another set of specimens. These had been manufactured with a different printer and with the same material but colored. The analysis of variance showed that, although the mechanical properties were affected by the color pigments, the trends of this analysis and the recommended manufacturing values did not vary. The results showed that when working with thermoplastic elastomers and in order to maximize Young’s modulus and yield strength, a 0.3-mm layer height and a 75% fill density should be selected.