To overcome the problem of poor material flow, the installation of a discharge aids system will promote the flow of any product which is normally capable of flow, but which needs occasional or frequent help to get started or to keep it moving.

There are many reasons for powdered or granular materials not discharging from hoppers or silos. Material converging towards the outlet of a hopper builds up forces within itself, which can cause it to become self-supporting. Particle size, particle shape, material bulk density, moisture content and hopper design are some of the factors which determine whether or not a product will bridge, rat-hole or segregate upon discharge.