Maximum Percent of Post-Consumer Recycled Polypropylene in an Interior Hard Trim Panel

Abstract

This study examines the influences PCR PP has on mechanical properties, aesthetics, CO2 footprint, and the effects from aging. The purpose of the project is to aid Volvo Cars in updating their material composition of hard trim interior panels by recommending a suitable percentage of PCR PP to use. The investigated materials have been 30% PIR PP, 30% PCR PP, 40% PCR PP, 50% PCR PP, 60% PCR PP, and 70% PCR PP with the same amount of additives. To understand this influence, methods such as aging, tensile testing, impact testing, differential scanning calorimetry, perceived quality assessment, and CO2 footprint calculations were performed. The findings indicate that the mechanical properties are strongly limited by the impact strength, which decreases with the amount of PCR PP. This limits the recommendation for Volvo Cars to 30% PCR PP to be used. Regarding appearance, the perceived quality assessment shows that a switch to the highest material studied, 70% PCR PP, is possible. The tests performed present that aging for 500h and 1000h affects the crystallinity, resulting in varied outcomes for the studied mechanical properties. The CO2 footprint overall decreases with the amount of PCR PP content. Although, between 30% PIR PP and 30% PCR PP there is an increase in the CO2 footprint. Further studies should explore the effects on the full components instead of material samples, along with additional tests of the same kind as those conducted to further strengthen the results.