It has been found that mixing up to 10% compostable plastics with conventional plastics in post-consumer recycling streams shows no or negligible impact on the mechanical performance of the recyclates, according to a study by European Bioplastics, the European association representing the interests of the industry along the complete bioplastics value chain.

Bioplastics are biobased, compostable, or both. Biobased plastics films are chemically identical to their conventional counterparts and are easy to manage in recycling streams. Compostable plastics are designed for organic recycling and should be collected accordingly. They are marked for this purpose with logos such as the Seedling.

In the event that compostable plastics end up in recycling streams, the prevalent sorting technologies are able to sort them with little residual waste. Studies and field trials have demonstrated that in the uneventful case a small fraction of compostable plastics ends up in the PE recycle stream, this does in no way negatively impact the quality of the recycling stream, says Fran ois de Bie, Chairman of European Bioplastics. Remaining amounts are easier to handle than other residual wastes in the polyethylene (PE) stream such as polystyrene, or polypropylene.

According to Berlin-based European Bioplastics, the study was done independently by the Institute for Bioplastics and Biocomposites (University of Applied Arts and Sciences Hannover), the Italian National Packaging Consortium (CONAI) and the company Biotec.