June 12, 2017

Auto Detonator Assembly Line

Machine No. 6637

This is a total machine cell that processes mining and blasting detonators. Due to the extreme volatility of the explosive material used in the detonator, all powder loading operations are done inside blast cabinets designed to withstand inadvertent detonation of the bulk powder. All control hardware is supplied in E, F, & G Class 2 Div1 enclosures and positively pressurized to keep powder from infiltrating inside and causing an explosion. The machine is designed to process several different sizes of detonators with a minimal tooling changeover. With the size change, comes powder load size, change. This is accomplished by changing out the ‘spoon’ that is used to transfer the load from a stream of powder inside a specially designed feeder bowl, and out to a loading transfer funnel. These spoons are specifically sized to the load requirements. Detonators are designed to use several different types of explosive powders to control the final detonation of the main explosion pack. This machine is equipped with three powder loading stations. After each load. With the size change, comes powder load size, change. This is accomplished by changing out the ‘spoon’ that is used to transfer the load from a stream of powder inside a specially designed feeder bowl, and out to a loading transfer funnel. These spoons are specifically sized to the load requirements. Detonators are designed to use several different types of explosive powders to control the final detonation of the main explosion pack. This machine is equipped with three powder loading stations. After each load dispense, the powder is consolidated by a ram that applies 400lbs of linear force to the powder. To verify proper loading of material, weigh stations are placed in between the loading stations to weigh the assembly. A tare weigh is first performed before the loading operations. This weight is then removed from the secondary weigh amounts to determine actual powder weight. Once all powder volume have been loaded and consolidated, a cardboard disc is inserted and consolidated to seal off the chamber. The final process of the detonator is loading them into bulk trays and transferring to a final packaging station. This is accomplished by a Cartesian robot that loads all acceptable detonators, one at a time, into a tray that is fed from a magazine.

CONTROLS: The system is controlled by an Allen-Bradley Control Logix PLC. Human interface and data collection are provided by a custom Windows application written in Visual Basic using commercially available communication drivers communicate with the PLC over Ethernet.

CYCLE RATE: A complete assembly leaves every 6-8 seconds depending on powder loading requirements.