Mechanical and tribological characterization of 3D printed-cryogenically treated thermoplastic polyurethane

Abstract

In knee replacement surgery, the longevity of implants, particularly the plastic spacer between the femur and tibial metallic component, has profound implications. Traditionally, Ultra-High Molecular Weight Polyethylene (UHMWPE) has been the material of choice, yet its susceptibility to rapid wear necessitates the exploration of alternatives. Among these, Thermoplastic Polyurethane (TPU) is a promising candidate. This study delves into the transformative impact of deep cryogenic treatment (DCT) on the tribological, mechanical, and surface attributes of Fused Deposition Modeling (FDM) - produced TPU.Key findings unveil a substantial enhancement in the wear performance of DCT-treated TPU compared to its untreated counterpart. Moreover, extrusion temperature (ET) and print speed (PS) emerge as pivotal parameters, with optimal outcomes observed at 250 °C and 15 mm/s, signifying their paramount importance. In contrast, layer thickness (LT) and raster orientation (RO) exhibit less influence on tribological properties. Furthermore, a notable transformation in surface characteristics is evident, with untreated TPU presenting a smoother profile than treated TPU.This research underscores the potential of deep cryogenic treatment to augment the tribological and mechanical properties of TPU, rendering it a compelling prospect for orthopedic implants. These findings contribute significantly to the ongoing endeavor to enhance implant materials and their durability in biomedical applications.