In vibrating feeders, the factors for determining the flow rate of material includes tray frequency and displacement, head pressure of material on tray, width and depth of loading on the trough, linear speed along the trough, and material properties such as bulk density, particle size and angle of repose. These features taken singly or in combination, as well as the hopper design, are important to obtain the required feeder capacity. One of the advantages of vibrating feeder is that it can handle material gently, hence it can be used to move materials that could damage or be damaged by screw or belt feeders.