How to choose rubber castors

What's the difference between rubber castor wheels and polyurethane castor wheels?

Castor wheels come in a wide variety of materials, sizes, and hardness. The most common materials used to make wheels are rubber and polyurethane. Don't worry, this article will talk you through the differences and help you decide which castor wheel material is best suited to your project. When it comes to determining the best wheel or tread for your specific castor or wheel application, it helps to understand the relative pros and cons of each material.

When choosing which material to use, consider these points:

Load capacity/maximum weight

Perhaps one of the most important considerations of castor selection is determining the maximum load. Polyurethane castors are more of a heavy duty castor and can usually carry heavier weights than rubber castors because of the hardness of the material. Also, polyurethane castors can have very thin threads compared to rubber castors, which increases their load capacity. Polyurethane castors are also more resistant to splitting and tearing.

Floor conditions

Soft rubber castors are manufactured using carbon black filler which can mark floors. Hard rubber castors tend to be grey in colour and are produced in a material which will not leave marks on the floor. However, as wheel tread is relatively hard, it can sometimes dent and scratch floor materials and therefore would not be recommended for soft flooring surface, such as hard wood, linoleum or terrazzo.

Where floor protection is a concern, polyurethane wheels are often most suitable. Although polyurethane castors come in a variety of colours, the basic chemistry used in their production does not allow any colour transference. So if your floors are expensive and/or critical to your operation, a polyurethane wheel, a hard floor castor, may be the best choice for your application.

Roll resistance

Roll resistance is a vital characteristic for ease of use. The lower the roll resistance, the easier it is to manoeuvre the equipment. This reduces operator fatigue and increases the efficiency of the equipment. When it comes to reducing roll resistance, it’s the consistency and the hardness of the material that counts.

Because of the synthetic nature of polyurethane castors, they are more uniform than natural rubber. The highly consistent nature of the material gives consistent levels of rolling friction which creates lower roll resistance. Polyurethane castors tend to be manufactured in harder compounds than rubber. Because harder materials create a lower roll resistance, this also makes polyurethane wheels easier to manoeuvre than rubber wheels.

Cushioning and resilience

The comfort or smoothness of the ride is governed by the cushioning and resilience factor of a castor wheel. Cushioning levels are determined by the stiffness of the wheel. The softer the material, the more it will deform when it moves over an obstacle. And the more it deforms to absorb the shock, the smoother the ride. Rubber castors tends to be softer than polyurethane castors and therefore usually provide better cushioning.

Bear in mind that higher cushioning tends to mean higher the roll resistance. Therefore, you need to decide which is more important to you – smoothness or manoeuvrability –before deciding on which material would be best for your application.

Wear and tear

Although rubber castors offer a softer ride, they will not wear as well as polyurethane. As rubber castors are used, they will lose pieces of tread over time, whereas polyurethane castors tend to have much higher levels of resistance to wear and abrasion. Under controlled tests, polyurethane castor wheels can last up to three times longer than rubber castor wheels. Depending upon the formulation, polyurethane castors also tend to outperform rubber when it comes to resisting oil, grease and chemicals.

 

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Questions?

Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.