Abstract:
This research focused on studying the recycling of ultra-high molecular weight polyethylene affecting mechanical and tribological properties. Pure ultra-high molecular weight polyethylene powder produced in Thailand was used in this study as an initial material. The particle size and morphology of ultra-high molecular weight polyethylene powder were examined through hot extrusion process with a closed die which was an important process in the study. Three cycles of heating were performed to study mechanical and tribological properties under the closed die with the pressure of 5 MPa and the inside temperature at 140oC for 180 minutes. A cooling process using a cooling press was applied to reduce the temperature after the hot extrusion. The results showed that when the ultra-high molecular weight polyethylene was heated for 3 cycles, the Yield Stress, the Tensile Strength, the Elongation at Break, the impact and the melting point decreased. In addition, the coefficient of friction slightly increased, the density decreased, and the wear rate decreased. Based on the examination of the surface using a surface roughness tester revealed that there were no significant differences in scratch marks when compared to the wear surface of pure ultra-high molecular weight polyethylene. The study showed that there is a need to reinforce the particles to improve the efficiency of mechanical and tribological properties of ultra-high molecular weight polyethylene. Furthermore, mechanical, thermal, chemical and tribological properties shall be tested again.