The German polymer specialist Rehau, the Swiss polymer distributor Meraxis and the French chemical company Kem One have launched a joint research project. The aim is to remove heavy metal residues – such as lead – from PVC recyclates and return them to the material cycle.

The plastics processing industry is increasingly committed to continuously improving its raw materials and products in order to promote the circular economy and make plastics reusable at the end of their life cycle. Three key companies in the industry have joined forces to pool their expertise in a joint industrial research project: The French PVC production and process company Kem One, the German polymer company Rehau Window Solutions as part of Rehau Industries and the Swiss plastics distributor Meraxis, a provider of polymers and services for polymer processors.

Combination of mechanical and chemical recycling

Teams from the three companies are working together on technological solutions to extract heavy metals from PVC. Mechanical and chemical recycling processes are combined: First, for example, PVC window frames are mechanically shredded. Heavy metals such as lead are then removed from the shredded plastic using a chemical process. The extracted lead is then to be fed back into existing material-specific recycling streams. The lead-free recycled PVC can be processed into new window profiles based on recycled material.

Initial trials with corresponding extraction processes were successful at Kem One in Saint-Fons (France), enabling the parties involved to expand the project to pilot scale. Chemical and process engineers are now concentrating on further optimizing the processes and preparing them for industrial use. This is planned for the year 2030.

Problem substance lead

The handling of lead is a highly relevant issue: this is reflected both in current EU-wide legislation and in the public’s increased awareness of its environmental impact. Lead released into the environment has a negative impact on ecosystems. The current research project has set itself the task of developing a recycling process that reduces lead exposure and thus contributes to the protection of nature and health. The development of such a process from the pilot phase to a scalable solution on an industrial scale requires extensive effort and investment.

Picture above: Together, the three companies want to produce heavy metal-free PVC recyclates. Photo: Rehau

By fil