Reuse of ground tire rubber (GTR) as a filler of TPE matrix*

Used car tires are the type of waste that does not decompose naturally and is not recyclable in molten state. Despite many initiatives to reuse these materials on a global scale, a large part of used tires are still landfilled. The present work is an attempt to use ground powder of ground tire rubber (GTR) to filling the TPE-S thermoplastic elastomer matrix. The aim of this study was to obtain TPE-GTR compositions in standard thermoplastic processing machines. This study used rubber powder with a grain size of 0.2-0.4 mm, obtained by grinding process in a knife mill of own design. The GTR filler into the TPE matrix in the amount of 5 and 50 wt% was dosed. Specimens were produced by injection molding. The obtained molded parts were tested for tensile strength, Shore hardness and Schob elasticity. Influence of melt temperature on TPE-GTR molded parts properties was also examined. The addition of GTR to the matrix causes a significant decrease in elongation at break, while improving the stiffness, damping properties and hardness of the TPE-GTR composition. It was also found that the melting temperature above 200°C has negative effect on the properties of the TPE-GTR compounds