If RFID is going to make it to the item level, package printers are likely to play a leading role.

by Alex Hamilton

Advocates of RFID are fond of pointing to the day when consumers can load up a shopping cart and march right past the checkout line. In this scenario, all the transactional details for the customer and accounting and supply chain management tasks for the merchant happen in the background, seamlessly enabled by RFID.

Obviously, for this scenario to become a reality, all consumer products must carry tags, and the most obvious place for that will be either in the packaging or labeling that is currently used.

In fact, at a conference held earlier in 2004, the major drivers behind the RFID movement - Wal-Mart, the Department of Defense and Procter & Gamble - implied that they view RFID technology as being part of a printing process.

Yet there's a bit of a problem at the moment. Current tag production lines are running at speeds of approximately 10 inches per second, which translates into 50 feet per minute. And the format of these systems is limited to widths of about 4.25 inches. As anyone familiar with packaging will tell you, that's just not going to cut it, at least when it comes to integrating with a conventional package printing/converting line.

Today's narrow web flexo presses often run at speeds of 500 feet per minute or more on webs ranging from 5 to 14 inches wide. And it gets worse from there. Not only are offset presses capable of equal or higher production speeds than flexo, gravure presses can run at speeds of up to 3,000 feet per minute - on a 9-foot-wide web!

The other major obstacle for RFID is cost. Current prices range from $.25 on up to $.50 or more per tag - far too expensive to be used on individual products and borderline for even cases of low-cost items. Many analysts have suggested a $.05 tag price as the threshold for widespread implementation, with a penny the magic number often cited for item-level tagging.

Silver Linings
Fortunately, there is some very promising R&D work going on that promises to bridge this gap. At least three companies with ties to the printing industry are racing to develop conductive inks that can be used to print RFID tag antennae. Although this will not entirely solve the problem, it's a major step in the right direction and could open up ways to integrate the transponder in a near-line or off-line workflow while scientists work to develop a printable transponder.

A major driver for all this activity is, not surprisingly, the almighty dollar. There's no question that RFID has enormous revenue potential, so that's attracting investment. However, the base technology for printable RFID antennae has other applications that have captivated venture capitalists, specifically the ability to print displays and monitors. With some 60 million computer monitors sold annually - not to mention TVs - it's no wonder that scientists and engineers are burning the midnight oil. All of this will yield results that can be applied to developing a way to produce RFID tags in the volumes and at the prices necessary for widespread implementation in the packaging industry.

There are at least three significant players working to develop conductive inks for printing RFID antennae: Coates Group, a division of Sun Chemical; Parelec Inc.; and Precisia, a division of Flint Ink. Other companies have been active, including Cabot Superior MicroPowders and Carlco plc.

Parelec Inc., based in Rocky Hill, NJ, has developed what it calls Parmod VLT inks, which can be used with screen presses and in rotogravure presses. This ink uses silver particles suspended in an organic solvent. When the inks are exposed to heat, the solvent evaporates and causes a chemical reaction in which the silver particles fuse together to form a porous, but continuous metal structure, which provides the necessary conductivity for the antennae to communicate with the RFID reader. Parelec's patented Parmod VLT ink technology is about three times more conductive than inks that are manufactured using a polymer-based process. As a result, these antennae can be printed with two-thirds less ink, which means the ink dries faster and, equally important, lowers the cost per application.

According to Mike Caterina, sales director, for 13.56MHz RFID, antennae produced using conductive silver are quickly becoming the standard for 13.56MHz applications such as transit fare tickets because of the ability to be printed directly onto paper.

Although Parelec has been shipping production quantities of screen print inks for both 13.56MHz and UHF applications for a few years, more recently it has been conducting production trials on a gravure printable ink, focused on supporting emerging high-volume, low-cost UHF applications. Caterina notes that Parmod VLT inks are intrinsically well-suited to the gravure process. And, on the production side, he points out that gravure presses are certainly capable of handling the volume. "Gravure is a highly scalable printing process and the presses have the capability to produce between 40,000 and 50,000 antennae or more per minute," he observes. "And, gravure printers are comfortable working with solvent-based systems."

With the emergence of the global standards for EPC (Electronic Product Code), Caterina believes it will be imperative for members of the printed conductive ink industry to position their process capability to handle the impending very high volume demand for low cost, ultra-high frequency antennae that support 915MHz tags. "We're still a few years away from ubiquitous adoption of UHF RFID technology, but that's where the RFID market is headed," he remarks.

For now, it's possible to print UHF antennae using screen printing - which is also used with the current technology based on etching.

Sparking Interest
As a division of Flint Ink, the largest privately held ink manufacturer in the United States, it's no surprise that Precisia wants to help package printers implement RFID. And it's progressing toward that end, notes Dan Lawrence, director of technology and commercialization.

The company's longstanding relationships with the graphic arts industries is making it proceed with caution, though, as they understand that the capital-intensive nature of the business makes it unlikely or unfeasible that a package printer will convert their operations to an entirely new methodology. "We don't like to railroad our customers into a new process," he maintains. "We want to provide them with inks that run on their existing equipment if at all possible."

The company is preparing to release conductive inks for gravure presses that will enable packaging printers to print the antennae part of an RFID transponder. And it's already possible to print antennae using screen presses, though Lawrence concedes that screen printing isn't the most popular process. "Screen printing has been around for decades," he observes. "It runs slower and requires more drying time than most printers can tolerate."

Lawrence says that printing the antennae is an important part of the solution, but that the stumbling block remains the transponder. "The bottleneck is not the antennae, it's the chip," he asserts. "How do we attach it to the final tag?"

Lawrence says that R&D efforts on the chip side are focusing on developing extremely small integrated circuits, sometimes referred to as "glitter dust" that will facilitate both higher production speeds and lower cost. "Integrated circuits are the only game in town," he remarks, adding, "We're still at least two years - or more - away from widespread release."

The economics surrounding RFID are creating a chicken-and-egg situation as the price prevents widespread deployment which means volumes have not sufficiently risen to the point where there are lower prices. "It's the million-dollar question," Lawrence admits. "The economics of a $.38 tag mean that demand is uncertain and, therefore, that supply is uncertain. Supply has to scale up to change that situation."

Printed antennae will help on the cost front. Lawrence says that printing the antennae using conductive inks can reduce the cost from $.03-$.05 to $.01-$.03 each. Now it's up to the chip companies to develop a transponder that will bring the cost of an entire tag down, Lawrence believes: "once that happens, you can imagine a $.05 chip within a few years."

The other issue that needs to be resolved, Lawrence suggests, is where the antennae and transponder are integrated to create the RFID tag. "How will the tags finally be assembled?," he wonders. "Will it be the packager, an RFID company?"

But there's no doubt in Lawrence's mind that the tag needs to be integrated into the package or label substrate if the price is going to drive RFID own to the item level. "For the lowest absolute cost, you've got to use the packaging substrate," he insists.

While there's considerable R&D work remaining, Lawrence believes the next generation of equipment is almost ready and that it will provide an interim solution that will move RFID beyond the pallet level. "The next generation must at least be capable of integrating inline or near-line such that it won't slow down production too much," he suggests. "The good news is that answers are coming soon, in the next six to 12 months."

One of these interim solutions may use inkjet printing technology, possibly in a near-line configuration. UK-based Conductive Inkjet Technology Limited, a division of Carclo, is developing an inkjet system that can spray the antenna onto the substrate, where it then connects with the transponder to create a functional RFID tag.

According to Director Mike Johnson, CIT's system will run at approximately 100 feet per minute. Though that's a lot slower than many packaging production lines, it's still about twice as fast as the current crop of tag printers, and Johnson notes that package printers could run multiple inkjet heads in parallel to increase throughput. He adds that a high-speed production line is in development and is slated for introduction in 2005.

The system also works in a manner similar to existing production lines. First, the chip is affixed to the tag; then an optical vision system determines where to apply the conductive ink to connect the chip with the antenna and create the transponder. Johnson says that this approach has the potential to dramatically reduce the cost of a tag. Further, Johnson says this approach is compatible with any type of chip design, making it well-suited to item-level tagging applications.

Another important capability of the CIT system is that it can print on both porous and nonporous substrates, and Johnson says that they usually demonstrate the system by printing on Melinex PET. In terms of cost, CIT says that they can print an antennae measuring about 3.1 square inches (20 square centimeters) for 1.7 cents.

Although the ability to print RFID tags remains a few years away, there's no doubt that this is the most likely methodology for widespread implementation. The work by several suppliers to develop printable antennae is nearing commercialization, and the retailing mandates and governmental regulations are likely to spur the development of chips that can be inserted or, possibly, even be printed using processes well-known to package printers and converters. It will be a few years before this becomes a reality, but it is certainly within the realm of feasibility.