Recycled plastic from waste electrical and electronic equipment

Usable polymer recyclates via spectroscopic sorting and separation of contaminants

The Recycled Plastics business unit of the Fraunhofer IVV coordinated the joint InnoNet project SpectroDense: Usable polymer recyclates from waste electrical and electronic equipment (WEEE) via spectroscopic sorting and density-based separation of contaminants. This project brought together research organizations and industrial companies to demonstrate that it was technically possible and economically viable to recover WEEE plastics and reuse them in injection moldings. This was made possible by a combination of effective material flow management in the disassembly companies, good material processing, and spectroscopic and density-based sorting methods.

Cooperation of research and industry

Besides the Fraunhofer IVV the network comprised BTU Cottbus, the Leibniz Institute of Polymer Research (Dresden), five WEEE disassembly companies, and two reputable machine building companies, Flottweg AG and RTT GmbH. Also involved were Erlos GmbH, the plastic recycling company, and Reifra Kunststofftechnik GmbH, the injection molding specialist.

Recyclates for injection molding

The recycling of WEEE plastics has failed hitherto because no satisfactorily pure recyclates that are low in contaminants have been able to be produced from the varied and often contaminated plastic waste that is available. This will became possible for the first time with the sorting and separating methods developed in the SpectroDense project. The recyclable plastics comprising impact-resistant polystyrene, ABS, and PC-ABS have excellent material properties and are suitable for injection molding.

The key to the success of the project was the bringing together of diverse expertise covering the recycling of WEEE plastics, process engineering for waste treatment, plastic processing, and plastic analysis. Falling raw material prices and falling new plastic prices due to the economic recession hindered industrial implementation at the start of 2010, but as the project drew to a close at the end of 2010 there were renewed initiatives for industrial implementation.