RFID Brings ROI to Air-Filter Maker

Once attached, the tags are written with the current date—the birth date—to track the filter throughout the 14-day production cycle. The encoding takes place when tagged filters pass the antenna of a Tripod Data System (TDS) RFID interrogator, installed near a computer terminal used by workers to monitor the production process.

After completing the production cycle, the company erases the birth date from the tag and encodes it with an article number (indicating the model of the filter), a serial number and the date on which it passed Herding's quality inspection. This second writing also takes place at a workstation equipped with an RFID antenna. To make visual identification easier for customers, the company attaches a label printed with the filter's article and serial numbers. It then sends the filter to a warehouse until orders for new filters come in.

Companies using Herding's filtering systems include car manufacturers and pharmaceuticals makers. Some customers order dozens of filters at a time; others order hundreds. When an order comes in, Herding stacks the ordered filters in boxes and shrink-wraps them. A worker then reads the tags for the third and final time by wheeling the shipping box through a gate reading station. The gate interrogator includes four antennas and a long-range TDS reader. The data on the tag is saved to a computer to record the dates on which filters are shipped to specific customers.

Herding makes about 400 different filters by combining various features and sizes. After a certain amount of use, the filters become clogged and the filter elements must be cleaned or replaced. When customers return the filters for refitting, Herding can identify each unit by means of its article and serial numbers, then link that filter with its owner. This keeps filters from getting switched and returned to the wrong customers.

Down the line, Herding says it wants to equip employees with mobile RFID interrogators for identifying filters at the customer's premises. This would allow workers to know the quality-inspection date and service history of each filter. At present, factory managers have one TDS mobile reader to use for ad-hoc filter identification.