Feasibility analysis of the substitution of natural rubber by 3D printed TPU for shock absorption applications

The manufacture of customized natural rubber products, traditionally processed by compression molding, requires molds and tooling produced by machining, which are costly and require long manufacturing times. Therefore, there is a need to explore technological alternatives to reduce lead times and production costs, but without compromising the mechanical and functional properties characteristic of natural rubber components. One possible solution is the implementation of additive manufacturing technologies using flexible thermoplastic materials that can mimic the characteristics of natural rubber for shock absorption applications. In this context, thermoplastic polyurethane (TPU) presents itself as a promising option. The TPU 95 and D70 formulations are selected for the study, which are of interest in the case of the fabrication of an elastic buffer for occasional impact damping of railway components. Since the properties of TPU vary depending on the printing conditions, a study of how different printing parameters affect different properties of the material is carried out. This type of elastic buffer is characterized by complying with a certain damping curve. This damping curve is simulated with the compression test, obtaining that the compression modulus at 10% (0.53 − 0.52) and 20% (1.12–1.14) deformation have very similar values for both materials.