Mechanical recycling post-consumer

Post-consumer plastic waste recycling is discussed with special reference to feedstock recycling, the advantages it has over mechanical recycling, and the techniques involved. Chemolysis and thermolysis are explained, and... 

Other approaches to providing post-consumer recycled content are possible besides depolymerization. Depending on food safety regulations, recycled content in central sidewall layers and the use of especially cleaned, mechanically recycled,... 

Post-industrial waste and sorted post-consumer wastes (PCW) are suitable raw materials. However, they contain different amounts of inhomogeneities formed during the service life and non-polymeric impurities. These contaminants account for differences in mechanical properties and ageing resistance between recyclates and the respective virgin plastics. Recycled plastics are often used in low-grade applications, and it is generally believed that the mechanical performance of recyclates is lower than that of virgin materials. 

In this chapter the technical as well as legislative aspects of mechanical (secondary) recycling of post-consumer plastics will be described. For packaging materials containing a certain amount of PCR plastics the most important point is the migration of the suspicious compounds from the polymer. 

The German BfR (former BgVV) published recommendations on the mechanical recycling of post-consumer PET for direct food contact... 

Textiles can be mechanically or chemically broken down to the fibre for recycling. Additionally, other forms of post-consumer waste such as PET bottles may be recycled into fibre for apparel. For all forms of recycling, considerations include the blend of fibres or polymers, the length of these fibres, to what degree the textile or product can be broken down and the cleanliness or degree of impurities of the feedstock to be recycled (Gulich, 2006b). 

In the first definition, CLR refers to recycling methods whereby the material being recycled is the same material being produced a product enters the production chain of the same product again after use (Klopffer and Grahl, 2014). Under this definition, provided that the waste textile or fibre re-enters a garment production chain, both pre- and post-consumer mechanically recycled textiles may be considered closed-loop recycled. Two approaches are illustrated in Figures 6.2—6.4. 

By mid-1996, ERCOM Composite Recycling GmbH had mechanically recycled over 1 million SMC parts. Production scrap accounted for 750,000 parts and post consumer scraps 250,000 (from the Mercedes Recycling System MeRSy, BMW repair shops and Deutsche Telekom dismantling plants). As a result, over 2 million parts containing recyclate were put back into service in automobiles, including spare wheel well (Audi 320,000), noise barrier shield (VW 250,000), truck bumpers and front end panels (Mercedes Benz 600,000), sunroof frames (350,000), and other components (450,000). 

Blending of polyolefins is increasingly used to produce usable materials from polymer waste, to improve the processing and to retain the good thermal and mechanical properties. Blend prepared from virgin and/or recycled components is a well-established strategy to handle post-consumer and post-industrial polymeric wastes. HOPE and PP constitute a significant portion of post-consumer waste [29]. 

Jansson A, Moller K, Gevert T. Degradation of post-consumer polypropylene materials exposed to simulated recycling— mechanical properties. Polym Degrad Stab 2003 82 (l) 37-46. 

Nanoscale inclusions, such as nanoclays and nanopowders, could upgrade if not compatibOize mixed plastic post-consumer and postindustrial recycle streams to improve their processability, mechanical properties, thermal resistance, and stability. 

---