Bauser, an injection molding company specialized in precision parts located in Wehingen, Germany, has successfully introduced a production process for automotive gears, using DSM Engineering Plastics Stanyl PA46 annealing technology. The company was the first plastic gear supplier in Germany to jointly commercially introduce the technology, almost 2 years ago. Annealing is a high temperature after-treatment of an injection molded part, during which significant morphological changes occur. Stanyl is annealed when heat treated above its glass transition temperature [Tg80°C], but below its melting temperature [Tm295°C], preferably at temperatures around 220°C for 2 - 4 hours. The effects obtained through annealing are irreversible. At the indicated annealing temperatures (>210°C), a nitrogen atmosphere is recommended to avoid any thermal oxidation of the material.
The process is especially applied when aspects like performance, durability and safety has to be boosted. Key applications for annealed Stanyl gears are those with high demands on load or safety performance and where polyacetal cannot be used. These include wiper systems, sliding doors, roof systems using worm gear actuators. In non-automotive, the process can be used for general applications such as sliding, folding and roll-up door openers. Bauser is a main partner in a new extensive Gear Research Program (Project Lead DSM EP) with a focus on innovative steel replacement solutions applied in future under the hood applications, details will be enclosed in the upcoming years.