Jan 18, 2005Printing company George Schmitt & Co., based in Guilford, Conn., is patenting a process and apparatus for screening out defective UHF RFID tags embedded in smart labels. The recently launched system is so effective that the company says it guarantees that all UHF RFID labels it produces are working.
"We don't ship defective tags," says George Schmitt's president and COO, Bill Gunther, who adds that any company would be compensated for defective tags based on an agreement with George Schmitt & Co. established when the labels were ordered.
In general, RFID label manufacturing is not yet 100 percent successful since the transponders embedded in the labels on a roll are often not readable. Despite the efforts by many label-printing companies to identify and remove nonoperating tags, according to George Schmitt, nonreadable labels have been a reality for buyers of RFID labels, although the rate of nonreadable RFID labels is usually low. Some tags fail because the antenna or chip is defective or because there is a flaw in the electrical connection between them. George Schmitt claims to have completely eliminated nonreadable labels through its method.
George Schmitt is not the only label maker to make such claims. In August, both Avery Dennison Retail Information Services (RIS) and Paxar have added RFID capabilities to their label service bureaus (see Service Bureaus for Smart Labels) that encode, print and deliver RFID labels. Avery and Paxar say they, too, use a process to verify that 100 percent of the smart labels they provide are functional. George Schmitt claims its screening method is unique, however, because it screens tags in motion at production speeds. Most other systems verify the functionality of tags within a roll of labels by energizing each tag in the roll through an antenna at relatively low speed, according to George Schmitt, and they often use shielding to prevent adjacent tags from responding. George Schmitt states that its method is more productive than any other guaranteed label-screening systems since it reads the tags at real time.
Since March 2004, George Schmitt has been using its screening system for labels it produces for pharmaceutical companies. The system works by reading and discriminating between dead, weak and good tags, and automatically removing those that are found to be inefficient (that is, cannot be read by a reader when the tag moves at real-world conveyor speeds). A tag is considered weak if readable but only at 24 inches (or more, if that is the way a customer will be reading the tags themselves) at 0.5 watts, and dead if not readable at any distance or power level.
"What we provide our customers is certification that we have successfully read every tag on each roll of labels," Gunther says. "Our guarantee is that 100 percent of the tags we ship will be readable by our customers as they receive them into their plants."
George Schmitt buys tags made by manufacturers of its customers' choosing. It then integrates those tags with its own printed labels and begins the process to verify that the tag embedded in each label is fully functional. If requested by a client, George Schmitt can also use printed labels from an outside source. The company then runs the labels through four separate verifications at four separate reading stations before shipping them to the customer.
Unlike the RFID readers in many other tag-encoding systems, the reading stations in the George Schmitt system do not rely on conventional shields to block the radio transmissions between the reader and tags adjacent to the label being tested. Instead it reads and tests tags individually by focusing on each label as it passes through the screening process—just how it does this, however, is proprietary information, Gunther says. By doing so in real time, the process comes closest to the actual environment in which the labels will be read by George Schmitt's customers.
The labels available include EPC Class 0, Class 0+ and Class 1. They are also upgradeable to Gen 2, Gunther says, with modifications to the existing software to incorporate the changes and new features of the Gen 2 specification. The company does not screen non-UHF labels.
Although the company thus far sells its RFID labels only to drugmakers, it is hoping to expand to other industries.
