What Is a POM Bushing?
POM bushings are molded bushings. Taking advantage of the self-lubricating properties of Duracon®, they are used to support and secure rotating or linearly moving shafts.
Compared to (ball) bearings, POM bushings have advantages in terms of cost, ease of installation, lightweight, and space saving.
Duracon® is a registered trademark of Polyplastics Corporation and is one of engineering plastics called POM (polyacetal resin). Being a crystalline resin, it has a very low coefficient of friction and self-lubricating properties.
Applications of POM Bushings
POM bushings are applicable to any movable shaft because they allow rotation and linear motion between the shaft and housing. They are used to secure the shafts of mini 4-wheelers and toys, as well as the movable shafts of various parts of household appliances and automobiles.
POM bushings have higher sliding resistance and lower load capacity than bearings, but they are also available at low cost, require little additional space, and simplify installation and maintenance, such as fitting and lubrication. The POM bushing is a simple and cost-effective solution.
Principle of POM Bushings
Plastic with a higher crystallinity will have a lower coefficient of friction. Duracon® (POM) is a highly crystalline resin, which has a very low coefficient of friction and self-lubricating properties. Therefore, POM bushings can be used without lubrication even though they are sliding parts.
On the other hand, its disadvantages include flammability due to the presence of oxygen in its molecular structure, low weather resistance, poor adhesiveness, and inability to bond using adhesives (welding is possible), and resistance to strong acids. Therefore, care must be taken when selecting materials for use in explosion-proof designated areas, outdoors, or in environments where strong solvents or cleaning agents are used.
Regarding heat resistance, Duracon® can be used at temperatures up to 100°C without deformation, so there is no problem with hot water, but when used in automobiles, it must be used away from the engine, which is the heat source.