Plastics in the cycle

Solvent-based recycling process

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With the solvent-based recycling process developed at the Fraunhofer IVV, a wide variety of plastics from packaging, but also from the automotive, electronics, construction and textile sectors, can be recycled and processed into high-purity plastic recyclates. In this way, waste fractions that cannot be recycled using conventional recycling processes according to the state of the art become available for a circular economy with the solvent-based process.

According to Dr. Andreas Mäurer the solvent-based recycling process is highly versatile. He is head of process develop-ment for polymer recycling at the Fraunhofer IVV and is a contact person in the Ad-vanced Recycling Research Department of the Fraunhofer CCPE. "We even recover plastics that are difficult to recycle using solvent-based recycling," explains Dr. Mäurer. Compared to mechanical separation processes, it offers the advantage that the target polymer can be selectively dissolved and recovered in high purity. Foreign polymers and other solids remain undissolved and are effectively separated. Dissolved impurities such as flame retardants, plasticizers, degradation products and odors are separated by

specific solvents, resulting in high purity recycled plastic. Solvent-based recycling is a physical process and an effective alternative to chemical recycling. This is because the polymers are not degraded and polymerization from chemically recycled raw materials is not necessary. A large-scale pilot plant is available at the Fraunhofer IVV to scale up solvent-based recycling to an industrial scale and to produce quantities of recyclate for industrial application tests. The Fraunhofer IVV is looking for partners to transfer the process to industrial plants.

Two men are in a technical or industrial setting. One is wearing a dark business suit with a white shirt, the other a white lab coat. They appear to be having a discussion or conducting an inspection. The man in the lab coat is actively working on a round metallic device or reactor, while the suited man listens or asks questions. In the background, there is a complex arrangement of pipes, valves, and technical components indicating a highly advanced facility.

Sample production of high-quality polymer recyclates for industrial application testing: Dr. Andreas Mäurer (left) with an employee in the large-scale pilot plant at Fraunhofer IVV. Copyright: © Fraunhofer IVV

High-purity recyclates for recyclable packaging

With the solvent-based recycling process, companies from various industries can achieve the ambitious goals of the new EU Packaging and Packaging Waste Regulation (PPWR). The process can be used for a wide range of applications and is suitable for both flexible and rigid packaging. Taking food safety into account, it meets the special requirements for cleaning efficiency. With the solvent-based recycling process, a cleaning efficiency of up to 99.8% has been achieved for both highly volatile and medium-volatile contaminants. The process enables the recycling of plastic from flexible packaging waste and the use of recycled materials in the production of new packaging for sensitive filling goods. The Fraunhofer IVV has already successfully implemented the integration of the recyclates obtained into flexible monomaterial packaging for food on a technical scale and realized a recyclate content of up to 30% in the developed pack-aging structure. In the sensitive personal & health care packaging sector, these recy-clates have been used up to a proportion of 62%. In the general non-food sector, up to 100% recyclate content has also been used successfully.

Two men in dark suits are in a highly technical environment with numerous pipes, valves, and additional technical elements. They are engaged in a discussion, likely during a tour or technical inspection. The man with a white shirt and dark suit seems to be the host or person in charge, while the other is also inspecting the facility.

Together with industry partners, recycling experts from Fraunhofer IVV, Dr. Martin Schlummer (left) and Dr. Andreas Mäurer (right), are implementing the solvent-based recycling process in industrial plants. Copyright: © Fraunhofer IVV

Thinking outside the box: plastics made from composite materials

"With our solvent-based recycling process, we also recover valuable plastic resources from composite materials or materials contaminated with harmful substances so that they can be returned to the cycle," explains Dr. Mäurer. "Plastics from old electrical appliances that cannot be recycled today, as the plastic content in electronic waste contains many different types of plastic and additional hazardous substances such as flame retardants, can be recovered free of harmful substances using our process." Foamed polystyrene from construction waste that is contaminated with the flame retardant HBCD can also be processed as flame retardant-free polystyrene recyclate using solvent-based recycling. "This is possible thanks to the effective dissolution of the tar-get polymers and the subsequent separation of the undissolved and co-dissolved com-ponents. We also adapt the recycling process specifically to plastic composites," adds Dr. Andreas Mäurer. "This allows us to recycle battery housing from vehicles as well as coated and lacquered textile and plastic materials." Matrix plastics are successfully separated from composite components such as carbon fibers, glass fibers or metal inserts and purified recycled polymers are obtained. "We also recycle PVC floor coverings and effectively separate the unwanted plasticizers. The recovered PVC material meets the requirements of EU legislation (REACH) and can be used for the production of new PVC flooring," says Dr. Andreas Mäurer, citing a further example of the cleaning pe-formance of the process.

Further Infos: News - Fraunhofer IVV