A comparative evaluation of compression moulded and fused deposition modelling 3D printed thermoplastic polyurethane

Additive manufacturing, also known as 3D printing, is transforming the industry and becoming more common every day due to its considerable time saving and lower costs, compared to the established conventional manufacturing methods. The mechanical strength of 3D printed products is affected by the parameters of the 3D printing process. Thermoplastic Polyurethane (TPU) is a type of elastomer, capable of being used on any fused deposition modelling (FDM) 3D printer. A series of TPU test pieces with different infill density and patterns were produced using a FDM printer. The influence of infill parameters on the 3D part’s mechanical properties has been evaluated. Five patterns with a range of infill densities were compared in this study. The tensile properties of the printed specimens were influenced by the infill density, whereas the infill pattern used in this study has marginal effects. The grid pattern with 100% infill density showed the highest tensile strength, with a value of 4.43 MPa. The results were compared with specimens, which were prepared through conventional compression moulding. The dynamic mechanical thermal analysis (DMTA) and load–deflection analysis (LDA) tests showed that specimens with 100% infill density may not be significantly affected by different infill patterns selected in this study under low strain testing conditions.