Extrusion International 5-2026

36 Extrusion International 5/2026 PROCESSING – CASE STUDY First Gear Pump for Rigid PVC The MAAG Group, a global leader in the development of conveying and processing systems for the plastics industry, is presenting a technological highlight at Fakuma 2026 (Hall A6, Booth 6202) : The extrex 6 EC is the rst gear pump speci cally designed for the continuous conveyance of challenging rigid PVC (polyvinyl chloride). The Swiss machine manufacturer has thus succeeded in overcoming a long-standing technological hurdle in PVC processing. Initial practical use at the REHAU Group con rms the enormous potential of the new pump system for the circular economy. The Challenge: Reliably Conveying Rigid PVC Due to its extreme thermal sensitivity and tendency to degrade, rigid PVC is considered one of the most chal- lenging materials to convey in extrusion. Conventional gear pumps often reach their limits in this context: the material remains in gaps and dead spaces for too long, which inevitably leads to deposits, material burning, and process instabilities. The MAAG Group developed the extrex 6 EC speci cal - ly to address this problem. Its gap-free design without dead spaces effectively prevents polymers from adher- ing to and accumulating inside the pump. This signi - cantly reduces the thermal stress on the PVC and elimi- nates the risk of degradation. Technological Highlights of the extrex 6 EC • Gap-free design with no dead spaces: Prevents pro- longed residence times and material burning, ensuring a clean process. • Increased extruder ef ciency: Uniform, pressure- stable conveying signi cantly reduces the load on the extruder. Depending on the application, material throughput can be signi cantly increased, or energy savings of up to 20% can be achieved in the extruder while maintaining constant throughput. • Reduction in process temperature by up to 10 °C: The optimized temperature control reduces the thermal stress on the melting process. This eliminates the need for expensive stabilizers in some cases. Successful Practical Application and Cost Bene ts in Recycling at REHAU The results of a multi-year development partnership with the REHAU Group demonstrate just how effective the system is under real production conditions. Follow- ing intensive testing at REHAU’s technical center be- tween 2022 and 2024, a nal prototype was successfully tested with a production pro le in early 2025. By opti - mizing the pump’s thermal balance, MAAG was able to ensure that the temperature increase through the pump did not exceed 6 C – even with a melt tempera- ture that was already 10 C lower. The extrex 6 EC particularly demonstrated its strengths when using cost-effective recycled PVC material with in- herently inhomogeneous batches. Pressure uctuations at the die were minimized by the gear pump’s constant output, resulting in a massive improvement in the prod- uct quality of the pro les. At the same time, the load on the extruder decreased by up to 20%, promising a lon- ger service life for the system and noticeable cost sav- New extrex 6 EC for Rigid PVC The MAAG Group PVC pump in use at the REHAU technical center in Germany