Round drive belts tend to slip as they reach maximum load capacity. Struggling with this occurrence, Dura-Belt Inc. (Hilliard, OH) chose Stevens Urethane's (Holyoke, MA) thermoplastic polyurethane for its groove sleeve. The substance enables the groove sleeve to increase the load-bearing capacity on industrial conveyors.

The groove sleeve, which is a flat loop, slips into the drive belt groove on conveyor rollers. The thermoplastic polyurethane provides a high coefficient of friction with the steel roller and drive belt, reducing slippage of the belt under heavy loads, and increasing conveyor weight capacity by up to 50 percent.

The company currently uses a flat sheet of SS-1485 material, 0.03 inch thick and cut into strips 1/4-inch wide. The strips are then welded into the closed loop groove sleeve.

Conveyors typically comprise a series of motorized rollers using a system of belts to drive nonpowered rollers. Conveyor load is limited by the amount of power the motors can transfer before the round drive belts begin to slip on the metal rollers. The groove sleeves compress around the drive belt as it turns, forming up the sides of the groove and around the belt. This increases the contact surface area between the belt and the roller and provides a higher coefficient of friction for better traction under heavier loads.

"The thermoplastic polyurethane allows us to produce a groove sleeve that improves performance and extends the weight range, without having to redesign the conveyor system. This is a real advantage for our customers," says Jim Hammond, president of Dura-Belt.

The new sleeves prevent slippage in applications and increase load capacity by as much as 50 percent. Even in tough end-use environments, such as a post office where paper dust can infiltrate equipment and reduce the coefficient of friction, conveyor performance has demonstrated improvement.

For more information on thermoplastic polyurethane, call Stevens Urethane at 413-533-8100, visit