Loose wheel with PP hub and TPE tread, Ast

Loose wheel in TPE with PP hub, ESD conductive

This is a loose wheel with a tread in TPE and a hub in PP, made as an ESD wheel. The tread has a hardness of 85 degrees Shore A and is electrically conductive, which means it leads static electricity away from the cart down to the floor instead of charging it up. That is the property which makes the wheel an obvious choice in surroundings where static discharges can damage components or disturb sensitive equipment.

The ESD function is the point, but the ride is good anyway. TPE at 85 Shore A is a semi-firm elastomer that gives moderate rolling resistance and a quiet, smooth run. The tread is often gray and non-marking and rolls without leaving dark streaks on light floors. It damps small shakes and keeps the noise down, which shows in premises that are meant to be calm and clean, for example electronics manufacturing, laboratories and areas next to clean rooms.

Where does the conductivity fit in? In electronics assembly, in the handling of circuit boards and in spaces with ESD protected work stations, an ordinary wheel breaks the grounded chain. An ESD wheel keeps the continuity from cart to floor. Compared with a softer non-conductive wheel, which damps more but does not lead charge away, this wheel is chosen precisely to close the electrical circuit without you losing quiet running and floor friendliness. A hard nylon wheel would roll more easily but make more noise, and in its basic version it lacks the conductive tread.

The wheel comes with two bearing options. The plain bearing is simple, maintenance-free and takes dust and damp well, suitable where the wheel rolls now and then. The ball bearing lowers the rolling resistance and gives a softer run when the cart is moved often. The PP hub is light and corrosion-free and carries the load around the axle within the frame of the series. For the ESD function to work fully, the whole chain, from wheel through cart to a dissipative floor, has to hang together.

The diameters go from 50 to 100 mm. A larger diameter rolls more easily over joints and lowers the rolling resistance, while a smaller one keeps the overall height low where space is limited. The wheel is supplied without a bracket and mounted straight onto its own axle through the hub, so it can be built into existing ESD adapted carts and stands. The series handles load capacities up to 55 kg per wheel, which matches light loads in a controlled environment.

Where does it come in handy? The ESD version sits under assembly carts, instrument carts, ESD benches and transport carts in the electronics industry, labs and controlled workshop environments. The non-marking tread also makes it a clean choice on light floors where particles and tracks are not wanted.

Think about the operating environment. TPE is happy at normal indoor temperature and in dry to slightly damp surroundings, not in high heat or strong solvents. If the wheel stands still for a long time under load, the tread can take a temporary flat spot that rolls out after a while; that is normal for elastic materials. The ESD property rests on clean, unbroken surfaces, so keep the tread and the floor free from insulating coatings.

Do you need to secure the static dissipation in your setup? Get in touch and we will go through floor, load and the whole grounding chain together.