Engineered plastic (EP) wheels (nylons, acetals, polycarbonates) are a popular choice with a range of properties that fit well into many caster applications. They have a harder Durometer compared to polyurethanes, which greatly improves their ergonomic properties and rollability. This makes carts equipped with EP wheels easier on the operator.
Since EP wheels are softer than steels or cast irons, they are also easier on floors, so ergonomics does not have to be sacrificed for floor protection.
Most of the EP wheels withstand higher temperatures than polyurethane wheels. EP wheels also have higher load capacities than polyurethane wheels and won’t rust like steel or cast iron wheels. They also operate well in extremely humid and wet environments and where chemical exposure is an issue.
Engineered plastics are generally RIM casted or extruded and hence can be purchased in bar forms. Generally, the bars are cut to length and CNC machined to a specified profile of the face of the wheel. For larger quantities of wheels, the material can be RIM casted to a very near net shape or final configuration.
Despite their advantages of good ergonomics, easy on flooring, ability to handle extremes and higher load capacities, there are some disadvantages to using EP wheels in an industrial caster application.
1) The EP materials have a low coefficient of friction, which makes the wheels more prone to sliding when cornering at higher speeds. This of course can be avoided by taking corners at lower speeds or having a rougher floor.
2) The engineered plastic materials can be more expensive, especially for the high-performance grades. This higher price could make EP wheels less appealing when comparing to polyurethane or cast iron wheels. There are tradeoffs: In some applications, only an engineered plastic will perform to the desired specifications making them worth the extra cost.
3) In applications where debris on the floor is an issue, especially metal shavings. EP wheels are vulnerable to the embedding of foreign material which can have a significant impact on wheel operation. EP wheels perform best when used in clean applications where foreign matter or material is not lying on the floor or track. Heavy Duty Casters