- LGF polyamide features high stiffness & creep resistance at high temperatures
- Replaces metal & outperforms materials such as PPS or PEEK
- Application: 7-gear dual clutch transmission for Audi
Dual clutch transmissions and automated gear boxes are taking an increasing market share in modern vehicles. Reasons for this trend are, among others, the higher driving comfort and their high efficiency which allows lower fuel consumption to be achieved. FTE Automotive, based in Ebern, Germany, recognised the trend to automated gear shift systems at an early point and offers a series of highly sophisticated systems in the field of gearbox actuators and gear shift cylinders. The company uses long glass fibre reinforced polyamides for a new gear shift module that replaces the previously used heavier and more cost-intensive metal solution.
Material outperforms PPS and PEEK
In practical use, the gear shift module is exposed to a complex loadcase. In order to achieve reliable performance, the material has to fulfill high requirements regarding stiffness and creep resistance at high temperatures as well as low shrinkage and warpage. For this reason HT1VL-50X of EMS Grivory, a surface-optimised Grivory HT1 with 50 weight percent special, long glass fibre reinforcement, was chosen for the newly designed gear shift module for a 7-gear dual clutch transmission for Audi. This material is characterised by very high stiffness and strength as well as very good resistance to oils and chemicals. The material maintains its mechanical properties even at high temperatures and outperforms other high-performance materials such as PPS or PEEK, according to the company.
Evenly oriented glass fibres have positive effect on shrinkage and warpage
The long glass fibre reinforcement further improves the property portfolio of the short glass fibre reinforced Grivory HT1 grades. Grivory HT1VL-50X features higher stiffness and strength, increased energy absorption and notched impact strength, a higher heat deflection temperature and increased creep resistance. In addition, the long glass fibres are more evenly oriented in an injection-moulded component which reduces directional dependency of the material properties. This has an extremely positive influence in particular on the shrinkage behaviour of the material and therefore on warpage. During the injection moulding process these form a tightly-meshed, physical fibre felt network and provide the component with a structural “skeleton”.