Back in the early days of the development and use of casters – 100 years ago or more – there were few choices for wheel materials. If you wanted hard wheels, you used metal. If you needed soft wheels, natural rubber was the main option. And if you wanted something in between, wood was a popular choice.
That all began to change in the 1930s, when there were new technical developments in synthetic materials like plastics, resulting in an explosion of choices for caster wheel materials. In particular, two rubber-like synthetic materials began to replace natural rubber.
Neoprene
– This is a synthetic rubber made by the polymerization of certain chemicals such as chloroprene. It is an elastomer, meaning that when stretched it has a memory, and will return to its un-stretched position, much like rubber does. Unlike rubber, however, neoprene is highly resistant to grease, oils, harsh chemicals and high temperatures. This makes it an ideal material to use for caster wheels.
Polyurethane
– is also a synthetic rubber. It is most often made by combining solutions of two or more chemicals, pouring the mix into a mold, and casting the desired product. Producers can control the properties of the final product by varying the ingredients of the starting compounds, and through different manufacturing processes. Caster wheels made from polyurethane can be fabricated with a range of hardness, from soft to extremely hard. Depending upon the formulation, polyurethane casters can resist oil, grease and chemicals quite well.
Both materials have come a long way since the 1930s, and are now widely available in many different styles for caster wheels. In fact, because of their superior properties, they have almost totally replaced natural rubber as a choice for caster wheels.
These days, it's often hard to tell the difference between synthetic "rubber" materials and natural rubber itself. When many of our customers want soft casters, they'll ask us for rubber casters. We usually ask questions about their application requirements, then recommend polyurethane or neoprene casters.
Below we'll compare neoprene and polyurethane, with the goal of helping you decide which of the two materials is the perfect fit for your needs.
Neoprene Caster Wheels
One of the chief features of neoprene wheels is their smooth, quiet operation. Though they may seem soft, solid neoprene wheels are actually very durable. They are excellent for floor protection, and are frequently chosen as casters for office seating. They work well on many different floor surfaces, but will not mark or mar the floor. They are very quiet as they roll across office flooring, especially when compared to hard plastic casters used on some office chairs.
Another desirable feature of neoprene is its chemical resistance. This makes neoprene casters ideal for use in situations where oil or grease is present. Neoprene is not affected by water, steam or harsh chemicals.
For added strength, neoprene is often bonded to a harder core material. The outer layer of neoprene forms the wheel's tread, while the core provides the structure.
Neoprene's properties make it a popular choice in applications like these:
Medical and laboratory equipment, such as medical carts and IV stands
Carts for mobile computers
Office furniture and seating, especially ergonomic chairs
Harsh chemical wash-down areas, in hospitals or food processing facilities
Note that most of the uses mentioned above are for office, medical or light industrial settings. For heavy-duty industrial applications, polyurethane casters are popular. We'll discuss those next.