Pegging occurs when rocks get trapped in the openings of the screen surface. It can vary from minor pegging to the most challenging situation in which the entire cloth is clogged with rocks. Pegging limits screening capacity, and it can be difficult to know what the best solution for the problem is. However, there are some things to know that can help with the issue.
The size of the apertures can contribute to the different reasons for pegging to occur. In the case of smaller openings (<30 x 30 mm), factors like screen settings and conditions, level of flexibility and cloth design should be taken into account. With larger openings (>30 x 30 mm), crossbeams, ledge angles and other mechanical parts are factors to consider.
Moreover, the thickness and stiffness of a traditional, or woven, wire cloth can cause rocks to peg in the cloth. The wires in a self-cleaning wire cloth are not interlocked, so they are able to flex between each other – and that leads to less pegging. Therefore, choosing the right mesh for a screen, changing the screen cloth design, using smaller apertures, having blank areas and using more flexible media options can all help to prevent pegging.