Is the presence of some compostable plastic in PE film recycle stream always detrimental to the performance properties of the final recycled material? According to a study just published by European Bioplastics--the Berlin-based European industry association representing the interests of the complete bioplastics’ value chain--up to 10% compostable plastic mixing with conventional plastics in post-consumer recycling streams show no negligible impact on the recyclates’ mechanical properties.
The Behavior of Bioplastic Films in Mechanical Recycling Streams is a meta-study—an analysis that gives a thorough summary of several studies on the same topic, and this key finding was confirmed by independent studies of the Institute of Bioplastics and Biocomposites (University of Applied Arts and Sciences Hannover), the Italian National Packaging Consortium (CONAI) and the German company Biotec.
Clarifying terminology, the study notes that bioplastics are biobased, compostable or both. That said, biobased plastic films are chemically identical to their conventional counterparts and are easy to manage in the recycling streams. Compostable plastics are designed for organic recycling and should be collected accordingly. When compostable plastics do end up in recycling streams, the prevalent sorting technologies are able to sort them with little residual waste. Says chairman of European Bioplastics Francois de Bie, “Studies and field trials have demonstrated that in the uneventful case a small fraction of compostable plastic ends up in the PE recycle stream, this does in no way negatively impact the quality of the recycling stream.” In fact, he notes that remaining amounts are easier to handle than other residual wastes in the PE stream such as PS or PP.