Coperion GmbH is implementing a closed-loop concept for the production of flexible multi-layer film. Recycling multi-layer film has long posed a challenge since such films can only be reclaimed in very complicated ways and not without residues.

Now, however, Coperion has developed a closed-loop approach solution in which up to 100% of multilayer film production waste can be reprocessed and fed back into the production process in a closed-loop. For a concrete project Coperion will deliver a recycling system, including bulk material handling, high-accuracy feeding from Coperion K-Tron, and the heart of the system, a ZSK Mc¹⁸ twin screw extruder.

Multilayer film waste resulting during the production process is shredded as a first step before it is fed into the ZSK extruder via pneumatic conveying and highly accurate feeding from Coperion K-Tron. There, the material is homogenized and devolatilized with very high intensity in the co-rotating ZSK Mc¹⁸ twin screw extruder. Within the extruder, dispersion and devolatilization performance are crucial to end product quality — with gentle product handling and very good mixing behavior even at very high throughput rates, thus achieving consistently high product quality.

Following homogenization in the ZSK extruder, in the closed-loop concept, the recycled material is added back into the multi-layer film production process; with no quality loss and the proportion of added recyclate is very high. Multi-layer film manufacturing thus takes place sustainably, highly efficiently, and resource-friendly with the aid of advanced technologies.