Envalior, in collaboration with General Motors and Schaeffler AG, has been recognized by the Society of Plastics Engineers (SPE), Automotive Division, with a 2025 Innovation Award in the powertrain category. The award distinguishes an ultra-thin wall electronic throttle control (ETC) actuator gear that combines significant mass and cost savings with enhanced mechanical performance, based on Envalior's high-performance polyamide Stanyl PA46.
The application is used in the electronic throttle control systems of two of General Motors' 2025 model year compact SUVs. Envalior acts as the material supplier, while Schaeffler AG serves as the system supplier and material processor. The thin wall mid-gear design is engineered to ensure precise pedal-to-throttle response and high impact absorption, with a strong focus on wear resistance, durability and efficiency under operating conditions in the powertrain environment.
The award was presented to representatives of the three companies on 5 November 2025 during the 54th Annual Automotive Innovation Awards Competition & Gala at the Laurel Manor in Livonia, Michigan, USA.
Thin wall PA46 design for electronic throttle control
The winning solution is a thin yet robust actuator gear for an electronic throttle control application. The design focuses on reducing wall thickness while maintaining precise geometry and mechanical integrity in service. According to Envalior, the innovative mid-gear design contributes to precise pedal-to-throttle correlation and improves impact absorption, virtually eliminating tooth breakage under typical loading conditions.
To achieve these properties with a reduced wall section, the development team selected Stanyl PA46, Envalior's high-performance polyamide, in high-flow, wear-and-friction-optimized grades. The material is combined with 50% or 60% glass fiber reinforcement, and the parts undergo post-mold heat treatment. This combination is intended to ensure accurate gear geometry and optimized mechanical performance, particularly in terms of stiffness and wear characteristics.
Commenting on the development process, Tony Padden, Envalior Stanyl Technical Application Manager NA, said: "This initiative brought together a team of experts from every discipline, and the collaboration was exceptional. We overcame challenges, met ambitious targets, and delivered a solution that set a new industry benchmark. I’m proud to have been part of such a rare and successful effort."
Performance metrics and lightweighting effects
The thin wall actuator gear design delivers, according to the project partners:
- 30% higher stiffness
- 20% increased wear resistance
These material and design-driven improvements enable the electronic throttle control system to achieve, in comparison with a conventional actuator gear featuring a 1.5 mm-thick wall:
- 30% weight reduction
- 20% cost reduction
- 20% space reduction
Representatives from General Motors, Schaeffler AG, and Envalior are presented with the 2025 SPE Automotive Innovation Award (Powertrain Category) for their ultra-thin wall electronic throttle control actuator gear design
The reduced mass and package volume contribute to lightweighting and packaging efficiency in the powertrain compartment, while the cost reduction is associated with material savings and an optimized component design. The glass fiber-reinforced Stanyl PA46, combined with the heat treatment process, is intended to maintain dimensional stability and mechanical robustness despite the thinner wall section.
Jose Chirino, Envalior Technical Director - Americas, underlined the role of cooperation across the value chain: "This project exemplifies the power of collaboration and innovation across the value chain. Together with GM and Schaeffler, we’ve advanced what’s possible in precision powertrain components by combining lightweight design with exceptional mechanical performance and reliability."
Injection molding of glass fiber reinforced Stanyl PA46
The actuator gears are produced by precision injection molding using Stanyl PA46 resin, in glass fiber contents of 50% or 60%. The high-flow and wear-optimized grades of PA46 are designed to fill thin-wall geometries while maintaining fiber dispersion and surface quality. Post-mold heat treatment is applied to achieve the required crystallinity and dimensional stability for the gear teeth and overall geometry.
According to the partners, this process-window control, combined with material selection, enables the thin wall construction without compromising on durability or resistance to wear under repeated load cycles in the ETC system.
