When the conveyor belt is running normally, the belt speed should not be lower than 95% of the roller speed. If the friction between the roller and the conveyor belt is not sufficient, the conveyor belt is prone to slipping. There are many reasons that can cause insufficient friction between the roller and the conveyor belt, including insufficient tension, load initiation, and insufficient friction coefficient on the roller surface.

The reasons for insufficient tension include: insufficient tension stroke, insufficient counterweight weight, and too long conveyor belt;

The reasons for the insufficient friction coefficient on the surface of the roller include: excessive wear of the rubber coating on the roller surface, the belt being too wet or stuck with lubricating oil, and the material adhering to the belt surface (which is easily swollen by water).