Mohamad Hassan Akhras, Paul Johann Freudenthaler, Klaus Straka, Jörg Fischer,
"From Bottle Caps to Frisbee?A Case Study on Mechanical Recycling of Plastic Waste towards a Circular Economy"
, in Dimitrios Bikiaris, in Polymers, Vol. 15, Nummer 12, MDPI, Seite(n) 2685, 2023, ISSN: 2073-4360
Original Titel:
From Bottle Caps to Frisbee?A Case Study on Mechanical Recycling of Plastic Waste towards a Circular Economy
Sprache des Titels:
Englisch
Original Kurzfassung:
This study demonstrates an open-loop recycling process of a specific post-consumer plastic waste stream. The targeted input waste material was defined as high-density polyethylene beverage bottle caps. Two methods of waste collection, informal and formal, were employed. Thereafter, materials were hand-sorted, shredded, regranulated, and then injection-molded into a flying disc (i.e., frisbee) as a pilot product. To observe the potential changes in the material throughout the entire recycling process, eight different test methods including melt mass-flow rate (MFR), differential scanning calorimetry (DSC), and mechanical tests were carried out on the various material states. The study showed that the informal collection led to a relatively higher purity in the input stream, which also appeared to have a 23% lower MFR value compared to that of the formally collected materials. The DSC measurements revealed a cross-contamination by polypropylene, which clearly affected the properties of all investigated materials. The cross-contamination led to a slightly higher tensile modulus in the recyclate, while the Charpy notched impact strength declined after processing by approximately 15% and 8% compared to those of the informal and formal input materials, respectively. All materials and the processing data were documented and stored online as a practical implementation of a digital product passport as a potential digital traceability tool. Furthermore, the suitability of the resulting recyclate to be used in transport packaging applications was also investigated. It was found that a direct replacement of virgin materials for this specific application is not possible without proper material modification.