In addition to selecting proper compounds for cover material, it is also necessary to determine the proper cover thickness. The thickness of a cover is influenced by the amount of abuse and wear the belt will receive. The cover is usually the lowest cost component of the belt.
The severity of the wear depends on the nature of the material and on the size, weight, shape and trip rate of the material conveyed. Sharp edges, particularly on large pieces, can quickly cut a cover badly.
On the other hand, if loading conditions are ideal and the material being loaded is loaded in the direction of travel of the belt with only a slight impact onto the belt, even very sharp material may not seriously cut or wear the belt surface.
Cover wear is also influenced by the loading area being on the horizontal compared to loading a conveyor belt on an incline, which will result in the product bouncing around more before the load settles down. This increased product movement will adversely affect cover wear.
Another consideration in cover thickness selection is the ratio of carry cover thickness as related to carcass thickness and pulley cover thickness. A carry cover that has more mass than the combination of the conveyor belt carcass thickness and conveyor pulley cover can and normally does result in belt cupping. The more narrow the belt, the more consistent and serious the problem.