In addition to price/performance aspects, parameters such as sustainability and resource efficiency are increasingly decisive for the marketability of certain materials. Both global initiatives such as the circular economy approach and current national legislation (Verpackungsgesetzt / Packaging Act) now call for an increase in recycling rates and the use of high-quality recyclates in new products. However, contaminated plastics from mixed post-consumer packaging waste represent a major hurdle for the circular economy, as existing cleaning and recycling processes often do not reach the quality level required by the industry. In addition to the mechanical and processing properties, the odor profile of the recyclates is increasingly being complained about. Unpleasant odors can be perceived as particularly annoying when used in automotive interiors, for example.
In order for recycled plastic waste to be used again as a secondary raw material in high-quality products, interfering odors must be eliminated. Quarzwerke Division HPF The Mineral Engineers offers RESCOFIL®, special additives for odor optimization. The mineral-based odor absorbers were formulated with a proportion of 5 wt% blended into a post-consumer polypropylene recyclate in a twin-screw extruder. The resulting product was subjected to olfactometric testing according to the VDA 270 standard. The results show that the addition of the newly developed high-performance fillers reduces the odor intensity of the recyclate significantly below the threshold value of 3 and is thus no longer perceived as annoying.