ENVIRONMENTAL STRESS CRACKING RESISTANCE (ESCR) OF RECYCLED PP (RPP) FROM AND FOR YOGURT CUPS
Recycling of plastic packaging waste is a promising approach towards a circular economy due to the high amount used and the short application time. This paper uses the concept of environmental stress cracking resistance (ESCR) to investigate the fatigue behavior of recycled yogurt cup materials. As test environments air and oil where chosen, where the latter imitates the fatty structure of yogurt. Therefore, four fractions of manually sorted post-consumer polypropylene yogurt cup waste was shredded to flakes and washed with different temperatures and media. Additionally, one of these fractions was blended with varying amounts of virgin pipe material. Furthermore, the reference material, which is currently used for yogurt cups was tested for comparison. Various influences of the fatigue tests were detected, which are a more pronounced influence of oil than of air, especially for recyclates but also for virgin materials and a significant improvement of the recyclates which were blended with a pipe grade material.