The number of components which can be loaded in a vibratory bowl feeder is limited either due to the volume or weight of the components. Volume is especially important in case of rubber or plastic components and weight when the components are metallic.

In case extra loading capacity is required, then the choice is to either use a bigger bowl feeder or else to use an auxiliary feeding unit like a flat vibratory hopper or elevator, silo etc. These auxiliary equipments can increase the loading quantity tremendously and the bowl feeder can become a totally man-less operation requiring refilling at longer intervals.

A Silo as well as a stock feeder is used to hold extra parts for replenishing the supply in a vibratory bowl feeder. While a stock feeder is set to operate automatically by a signal from a level control switch, thus eliminating either a deficiency or an over-supply of parts in the bowl, a Silo is mounted on the bowl itself and the components keep on percolating down from the bottom of the Silo into the bowl.

Thus a Silo and a stock feeder are competing products and while deciding on which one to opt for, the following points require consideration –

  1. Dimensions / sizes of the parts – In case of Silo, only certain parts like Needles, Rollers etc. It cannot be used for components like screws, hooks etc. Any size / dimension of parts can be accommodated in a hopper feeder.
  2. The disadvantage of Auxiliary Hoppers is the extra space which they occupy and plus the extra cost and electrical consumption and wiring required for the same. As against this, Silos offer the advantage of increased loading capacity and they do not require any Electrical Supply. The increase in height is also nominal. The overall Table size also does not increase to that extent.

Though the Silo has a lot of advantages, the only disadvantage is that it can only be used for certain components and this is its real limitation.