Casters are used on a variety of applications that range from rough terrain to debris ridden floors to ovens and freezers. Using the wrong caster for an application can seriously degrade the caster performance and, in extreme cases, may even cause injury to the user.
There are a variety of components that are affected by extreme temperatures but the most common caster performance failure is found in the wheel. The wheel is comprised of two main components: the wheel and the bearing.
High Temperatures Affect Rollability of Casters
The material that makes up the wheel is heavily affected by extreme temperatures when it’s made of a polymer, the most common being polyurethane, phenolic and rubber. Most polymers, under room temperature, will remain rigid and keep their proper form. However, when these casters are put in a high temperature environment, they begin to lose some of that rigidity, becoming soft and easily deformed. When this happens under load, the wheel begins to “flatten out”, also known as compression set. This leaves flat spots on the wheel, which affects the rollability of the wheel. Once this happens, the push/pull forces begin to rise significantly leading to increased potential for injuries.
Bearings can also be affected by high temperatures when they’re not sealed. This is because the grease can lose its viscosity, which makes it easier to seep out of the bearing. The lack of grease translates to poor lubrication in the bearing, which can make it increasingly difficult to move a cart around. This same condition can be observed within the swivel head of a caster that is not sealed.
It’s important when choosing a caster for a high temperature application to check the recommended temperature for a given wheel material and choose a rig that includes a swivel seal for the swivel head and precision sealed bearings in the wheel.
Wet Environments + Casters = Corrosion
Another extreme environment that casters can typically see is wet conditions, which can potentially corrode the caster rig and bearings. If enough corrosion occurs, the steel of the rig and/or the bearings can catastrophically fail, potentially causing injuries to the user. Therefore, when choosing a caster for wet conditions, ensure that there is a chrome plating to protect against corrosion, as well as stainless steel bearings and a swivel seal for the swivel head.
It is crucial to choose casters designed to meet your high temperature or wet application requirements while maintaining ergonomic mobility. Ask a caster expert about your specific extreme temperature needs; Darcor can help you choose the best option for superior caster performance for your environment.