MAAG Group introduces the extrex⁶ EC: the world’s first gear pump specifically developed for processing rigid PVC. This innovation, developed in collaboration with REHAU, opens up new opportunities for energy savings and the use of recycled material.
Rigid PVC is known in the plastics processing industry as a challenging material. Due to its high thermal sensitivity, it degrades rapidly if left stationary in one place for too long. In practice, traditional gear pumps often become blocked in dead corners and crevices where the material accumulates and burns in. With the extrex⁶ EC, the MAAG Group is changing this.
Technological breakthrough
The extrex⁶ EC has been designed with a completely gap-free design with no dead spaces. This prevents the polymer from sticking to the inside of the pump, which significantly reduces the thermal load on the PVC.
The main advantages of the system:
- Gap-free design: Prevents long residence times and material scorching, ensuring a clean and stable process.
- Higher efficiency: The pressure-stable output reduces the load on the extruder. This results in either a higher material throughput or energy savings of up to 20% on the extruder whilst maintaining the same output.
- Lower process temperature: The process temperature can be reduced by up to 10 °C. This reduces the strain on the melting process, meaning that, in certain cases, expensive stabilisers are no longer required.
Successful field trial at REHAU
The pump was extensively tested during a multi-year development partnership with the REHAU Group. Following tests at the technology centre, a final prototype was successfully deployed in profile production in early 2025. Even with a melt temperature 10 °C lower, the temperature rise within the pump was limited to a maximum of 6 °C.
The pump demonstrated its added value particularly when processing cheaper, recycled PVC with varying batch qualities. Pressure fluctuations at the die were compensated for, which significantly improved the product quality of the profiles. During testing with recycled material, no discolouration occurred and no additional stabilisers were required.
Global roll-out
The new gear pump is now in operation on a production scale at a REHAU factory in Spain.
Under a lease agreement, the technology is being rolled out in stages to other REHAU sites worldwide.
“The robust design and the wide process window meant that our operators quickly gained confidence in the machine. They see it as a key factor in stabilising production.”
Martin Schwanck, Process Engineering at REHAU Industrial Solutions
