Smellstop – Odour reduction as a key technology for the use of recycled post-consumer polyethylene

Odour reduction as a key technology in the reuse of post-consumer polyethylene

To promote the recycling of post-consumer polyethylene and reduce downcycling, odor reduction is emerging as a crucial technology. The funding initiative ‘Resource-Efficient Circular Economy – Plastic Recycling Technologies (KuRT)’ aims to sustainably increase the recycling rate

Currently, mainly fossil-based virgin materials are used for the production of plastic packaging. Although a recycling rate of around 43% could be achieved for plastic packaging within the lightweight packaging (LVP) collection in 2019 and around 74% of plastic packaging wasrecyclable in 2020, PCR use for virgin packaging was only around 3%. The remaining recyclate was used for lower-value products(downcycling) or recycled thermally. Increasing the recycling rate while simultaneously reducing downcycling isthe aim of the Resource Efficient Circular Economy – Plastics Recycling Technologies (KuRT) funding initiative.

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During the conception phase, a strong odour (especially during processing) of recyclates was identified as an obstacle to the widespread use of recycled content in packaging products. Thus odour loads in PCR materials must be minimized, in order to increase product acceptance and achieve a resource-efficient circular economy in the area of lightweight packagings. To this end, the first step is to analyze odour-causing substances and reduce them by targeted process engineering as a key technology for the recycling of lightweight packaging. Since August 2023, the project partners Institute for Plastics Processing (consortium leader), 3S GmbH, Coperion GmbH, Kreyenborg GmbH & Co. KG, Reifenhäuser Cast Sheet Coating GmbH & Co. KG, RKW SE and Siegwerk Druckfarben AG & Co. KGaA are working on the holistic process engineering reduction of odour contamination in PCR along the entire value chain of PCR-PE films

In this process, shredded PCR polyethylene film pieces (flakes) are first subjected to thermal pretreatment in an infrared dryer and silo storage at elevated temperature under the influence of water vapor. They are then processed into regranulate using a suitable degassing strategy. Finally a virgin polyethylene film is produced in a blown film and flat film extrusion line. Here, the process parameters are to be optimized to keep odour development as low as possible. At the same time, a sensor will be developed to quantify the odours generated in the production-related plant environment in order to provide information on any necessary adjustments to the process parameters.

Project Data and Funding

We would like to thank the BMBF for funding the project (funding code 033R387A) and the project partnersfor their cooperation.
Project Duration: 01.08.2023 – 31.07.2026

Project Partners

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