Regardless of their specific characterization as Styrene Block Copolymer Compounds (TPS), thermoplastic polyolefins (TPO), vulcanisates (TPV) or polyurethanes (TPU), thermoplastic elastomers (TPE) are not recycled in separate material streams. As ‘soft’ components in multi-material packaging products, their share is rather small compared to that of ‘hard’ plastics such as polypropylene or high-density polyethylene (HDPE).
In response to concerns regarding the co-recyclability of TPE together with PP or HDPE, KRAIBURG TPE started a project together with Institut cyclos-HTP to investigate the compatibility of selected TPS in polyolefin recycling streams and their potential impact in the process on the resulting post-consumer recycle (PCR).
The tests focused on classical TPS formulations with densities of <0.95 g/cm³ as used in typical multi-material packaging applications with PP and HDPE. The density limitation ensures that any components with higher densities would be removed from the main material stream and could not enter the next process step. In addition, the test program was engineered to extend to a wide range of further TPE, as required.