Pneumatic Press Automation

DeRoyal Corporation in San Luis Obispo manufactures splints and restraints for human joints that have been overstressed or injured.  The splints consist of ductile aluminum plates or wires coated with foam.  The foam is bonded to the aluminum in an oven.  When it is removed, it is cut with a die.  The press used for this operation was pneumatically actuated by a press operator.  The cutting sequence consists of a low-pressure pressing operation, a wait and hold operation, and a high-pressure cutting operation.  If the press operator did not time these three sequences properly, the edges of the foam would not have the clean cut required for a quality product.

I proposed that DeRoyal use an automated procedure utilizing a Programmable Logic Controller (PLC).  I designed the automation system to have the PLC drive three relays, which, in turn, actuated pneumatic solenoid valves to drive the press's pneumatic cylinder.  Built the relay board.  Then I programmed the PLC to run the automated cutting sequence.  Thus the operator simply has to load the press and push one button to produce a quality splint.  DeRoyal likes the flexibility afforded by the PLC.  The cutting sequence can be modified for different splints, so that the cutting operation is optimal for each one.