How to Choose Safety Zones for your Packaging Conveyor Line

November 13, 2012

When purchasing controls packages, many people still view safety circuits as an added expense. But, if the safety system was designed for the lowest possible price, it would be initially inexpensive, and cost more in the long run.

Take the layout as an example. If you were to draw a circle around the whole layout, the simplest and cheapest safety system with a single safety circuit begins at the depalletizer discharge and runs to the infeed of the case packer.

Although this would have the lowest acquisition costs, it would also end up having a substantially higher cost of ownership due to lost productivity.

A more efficient approach, shown in the above layout, is to split the safety circuit into 2 or more zones.  This allows some equipment to continue running while others are stopped.

By splitting the system into 2 zones near the Rinser discharge, an e-stop downstream of the Rinser would stop just the conveyors in that zone.  The conveyors upstream of the Rinser would continue to run until the buffering conveyors become full.