In your facility, your wheels bear the weight of heavy loads while also being a critical point of contact with dirty, abrasive surfaces. An early or unexpected wheel failure can cost both time and money, in equal parts, as well as create a safety risk. While polyurethane wheels perform better, in most environments, they are also subject to the same sort of wear and tear as metal or rubber wheels. Over time, an improperly specified wheel will deform and degrade. Decreasing its life expectancy and increasing your maintenance costs.
For those reasons, choosing the right polyurethane wheel and caster requires many factors. Not all polyurethane wheels and casters are the same, choosing the right one will make a difference in your long-term maintenance costs, and lead to a smoother operation. Before engaging with a distributor or consultant, there are questions you or your engineer must be ready to answer. Having this information will lead to a better, more durable specification.
Common performance characteristics to consider when choosing a polyurethane wheel include:
Each wheel maintains a very small point of contact with its rolling surface. This makes weight distribution critical. An overloaded wheel will deform over time, creating greater friction and resistance leading to failure. Understanding and planning for the greatest load will help specify the right wheel.
Though durable and forgiving of rougher surfaces, polyurethane wheels will be affected by the surface that they are running on. Depending on if the wheel or caster is running on smooth concrete or over rougher terrain, a different material or diameter may work better. Besides mechanical considerations, there are situations where wheels or casters may encounter chemicals. Polyurethane can perform exceptionally well in this environment, but it is still a consideration.
Braking and acceleration are an expectation and may have an influence on the specification particularly when these factors are extreme or precise. Maintaining stable contact with the rolling surface with consistent, predictable traction is a requirement. Polyurethane wheels and casters maintain excellent traction. Yet, in some environments where maintenance challenges lead to dust build-up, grease, or oils, traction can decrease. These environmental considerations should be included in the planning stage. A regimented protocol for cleaning surfaces and tracks can increase the life and efficiency of wheels and casters.
Like rubber, polyurethane wheels and casters will experience thermal expansion (or contraction) in response to environmental conditions. These ranges work in situations where short-term exposure to extreme temperatures will be necessary, such as moving in and out of a deep freezer or a mining operation for example. In extreme cases, special formulations are available which can extend wheel life.
Exposure to extreme temperatures outside of the general range is often reversible. Exposure to extreme heat will damage a polyurethane wheel or caster beyond recovery. Operating outside the low-temperature spectrum can lead to brittleness which will also cause irrevocable damage.
Indoors, Outdoors or Both
Transitioning wheels or casters from indoor to outdoor environments introduces every environmental variable to the equation. From temperature to humidity as well as physical challenges of different surfaces. Often, transition points may have saddles or other seams that can also wear or damage the wheel. Though polyurethane wheels are very durable and resilient, it is essential to limit the variables from one environment to another. This helps maintain the integrity of the wheel and prevent delamination. A smoother work area with fewer changes in the surface can extend the life of a wheel.
Build Up On the Wheels or Tracks
Loss of traction or wheel deformation can often be attributed to unexpected environmental conditions. These can create build-up on the wheel or caster or even on the track. Build-up can affect any polyurethane wheel or caster causing early wheel failure. The best way to avoid these situations is to do a careful evaluation of the ventilation system, where air movement could be redirected away from tracks or regimented cleaning of tracks.
Impact and Shock
In the more rigorous environment, wheels and casters may be subject to bumps, abrupt load, or dropping. Polyurethane is rigid enough to withstand impact, within the formulation’s specifications. But as with all conditions, this can wear the wheel, axle, or load bearings. The impact is measured differently than load. And while the wheel may be well-designed for the intended load, it is sufficient for impact, dropping, or shock. In some cases, this could lead to a different material design that is more accommodating of abuse.
While polyurethane wheels and casters have replaced rubber and metal in many industries and applications, it is important to understand that not all polyurethane formulations are the same. All polyurethane offers quiet, smooth operation but choosing the right formulation, size and tread will make a dramatic difference to the life of the wheel and the efficiency of your operation. Extending the life of your wheel will increase productivity and reduce cost.
A qualified distributor or consultant will help you make the right choice. And knowing that these are the concerns and questions that they will need to understand will help you be more prepared for the conversation moving you quicker to a finished specification.
It’s important to understand that while tires and wheels on-road vehicles are governed by safety standards set and enforced by the US Department of Transportation (D.O.T.), the wheels on your automation line are not. This can lead to less predictability and consistency from one manufacturer to another making it difficult to know exactly which is best. Choose a trusted expert who knows how to match the wheels to the application to keep your material handling at peak performance.
Contact us to learn how Raeder Vogel polyurethane wheels can improve the performance of your wheel and increase the productivity of your line.