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 extrex⁶ EC is the first gear pump specifically 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 confirms the enormous potential of the new pump system for the circular economy.

Due to its extreme thermal sensitivity and tendency to degrade, rigid PVC is considered one of the most challenging 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 extrex⁶ EC specifically to address this problem. Its gap-free design without dead spaces effectively prevents polymers from adhering to and accumulating inside the pump. This significantly reduces the thermal stress on the PVC and eliminates the risk of degradation.

Technological Highlights of the extrex⁶ EC:

• Gap-free design with no dead spaces: Prevents prolonged residence times and material burning, ensuring a clean process.
• Increased extruder efficiency: Uniform, pressure-stable conveying significantly reduces the load on the extruder. Depending on the application, material throughput can be significantly 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 benefits 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. Following intensive testing at REHAU’s technical center between 2022 and 2024, a final prototype was successfully tested with a production profile in early 2025. By optimizing the pump’s thermal balance, MAAG was able to ensure that the temperature increase through the pump did not exceed 6⁰C—even with a melt temperature that was already 10⁰C lower.

The extrex⁶ EC particularly demonstrated its strengths when using cost-effective recycled PVC material with inherently inhomogeneous batches. Pressure fluctuations at the die were minimized by the gear pump’s constant output, resulting in a massive improvement in the product quality of the profiles. At the same time, the load on the extruder decreased by up to 20%, promising a longer service life for the system and noticeable cost savings in the maintenance cycle. In all trials with recycled material, no discoloration occurred, and no additional stabilizers were required. REHAU thus achieves a clear economic and environmental advantage, as expensive virgin material can be replaced with recycled one.

Global implementation on the horizon

The new PVC pump has since been successfully installed for production purposes at a REHAU plant in Spain. An extended lease agreement now provides the necessary time to gradually implement the innovative pump system across the plastics processor’s global fleet of facilities.

Martin Schwanck (Process Engineering, REHAU Industrial Solutions SE & Co. KG) offers an all-around positive assessment:

“The development of the melt pump into the current, near-production prototype was handled professionally and driven forward with great dedication by all involved. The necessary steps were coordinated in a spirit of partnership and on an equal footing. After commissioning and training at our production facility, our employees were immediately able to operate the pump independently—thanks in part to the very clear instructions. The robust design and wide process window meant that operators quickly gained confidence in the machine and came to appreciate it as an important contribution to stabilizing production.”

With the extrex⁶ EC, the MAAG Group once again confirms its leadership in innovation within plastics processing and provides a key building block for the sustainable and resource-efficient optimization of modern extrusion processes.