To deliver on consumer expectations, including lower costs and improved noise behavior, manufacturers are replacing metals used to produce gears with engineering thermoplastics. Compared to metal, these materials offer shorter, more cost-effective production cycles, as well as better noise, vibration and harshness (NVH) characteristics. Advanced thermoplastics are also required to develop very thin and durable gears that fit into miniature appliance designs and are suitable for high torque applications, such as 1,000-watt food processors.
Yet, polyamide 66 and polyoxymethylene (POM), both of which are commonly used to produce appliance gears, are proven to deteriorate under the strain of high torque levels. These materials also provide limited heat resistance, which makes them unsuitable for applications that operate in temperatures above 80°C. These heat levels frequently occur when worm drives designed for high torque and speeds generate significant amounts of frictional heat. Over time, high torque and heat levels typically wear out or deform the teeth of gears made from PA66 and POM, which can cause an appliance to stop working and may result in costly repairs or product recalls that damage your brand’s reputation.
Selecting an insufficient gear material can also drive up the time and costs spent finalizing gear designs, as thinner lighter gears for smaller appliances, typically need to undergo several design iterations before manufacturers can approve them. To ensure gears meet the needs of OEMs and consumers, manufacturers need to select cost-effective materials that provide ample design flexibility and maintain high mechanical strength throughout part lifetimes.
DSM’s Stanyl® PA46 is a market-leading aliphatic polyamide that offers best-in-class mechanical properties at high temperatures. Manufacturers worldwide use the material to produce gears for state-of-the-art appliances, such as blenders, robot vacuum cleaners and washing machines. Stanyl’s inherent high crystallinity provides excellent tensile strength, as well as fatigue, wear and friction resistance required for gears used in small high-speed motors that run at 24,000rpm, and its high flow properties make it ideal for injection molding processes.