Outlook 2026: Enhanced performance of extruder gearboxes

  Mr. Alessandro Zambello

  Managing Director

  Zambello Group

  Website: https://zambello.it/en/

  Zambello has focused on gearbox specialization since    1957 with vertically integrated design and  manufacturing in Italy. Continuous investments in advanced gear design, precision grinding and test benches allow us to raise torque density while maintaining durability. Our engineering teams co-develop specifications with OEMs and end users, then validate on dedicated testing equipment before series release.  

Given the demand for high-performance extruder gearboxes that deliver increased output, reliability and speed, we responded with our range of gearboxes, such as the ZT Range for co-rotating twin-screw extruders, delivering torque density up to ~14 Nm/cm³ per shaft, enabling higher throughputs in compounding and recycling with compact footprints. We also offer TST-2H for counter-rotating parallel twin-screw lines, providing torque density up to ~22.5 Nm/cm³ per shaft for rigid PVC pipe, profile and sheet where high torque at low speed is critical. Another offering is the single-screw extruder gearboxes (sizes ~90 to 630) for blown film, sheet and pipe processors seeking robust reliability and efficiency.  For processors, the benefits are straightforward: more torque per size, stable transmission at demanding loads, and efficiency that supports energy-aware operations.

These gearboxes are intended for specific applications. For instance, the Co-rotating twin-screw (ZT) is ideal for compounding, masterbatch, recycling and filled formulations that demand high torque at medium to high screw speeds. The Counter-rotating parallel twin-screw (TST-2H) is for the production of rigid PVC profiles, windows, doors, siding and pipe where low-speed, high-torque operation is essential. Lastly, the Single-screw series is recommended for blown film, sheet and pipe lines requiring dependable torque transmission and long service intervals. We also supply gearboxes for injection molding machines where precise, efficient speed reduction matters.  

In the future, we will be extending options within our twin-screw ranges and expanding service features such as enhanced condition-monitoring and serviceability packages.  

- This article also appears in the International Plastics News for Asia  December 2025 issue. To read the digital version, click here.