RFID Helps Continental Clean Up Its Operations

When it came time to put components through the washing machines, employees had to check lists carefully to make sure they set the washing machine to the correct program. They also had to take notes about each step they made, because some components required different wash settings.

In addition, the staff did not know which components needed to be delivered to which of the four clean rooms without consulting yet another piece of paper. Once a bin left a clean room, workers placed a kanban card in a sleeve on the carrier, then sent it back to the washing area. During this process, some cards were lost or damaged, and in some cases, employees at the wash plant did not know which material to send to the clean rooms.

At each juncture in the process, RFID interrogators read a carrier's tag, helping to make sure the appropriate program is being used to wash the parts inside the bin.

The company considered placing bar-coded labels on the metal carriers, but it quickly became obvious that these labels could not survive the washing machines. It opted instead to test RFID, and chose tags that function at 13.56 MHz and comply with the ISO 15693 standard, because of the tags' good read ranges and anticollision properties. Workers sometimes carry stacks of bins past readers, and all tags must be read simultaneously.

CMC tagged 6,000 metal carriers. Each received four transponders—one on each side. The transponders are encased between two pieces of plastic that keep out water, and then screwed or welded onto the bins.

As part of the new process, a worker using one of the application's 20 Datalogic PDAs connected to the company's manufacturing execution system (MES) is prompted regarding which parts to pick from the warehouse shelves and deliver to the washing machines. Each PDA is outfitted with a bar-code scanner and an RFID interrogator. The employee scans the bar code on the carrier in the warehouse, and enters basic information about product amounts and lot numbers by scanning bar codes on a sheet of paper.