High-Speed, High-Resolution Coding

Drug manufacturers are bracing themselves for the inevitable—FDA bar coding requirements for every unit dose. And some medical device makers expect the same sort of rules to follow sometime in the future. While most manufacturers recognize the benefits of bar coding each unit with product information, lot number, and expiration date, some fear that the technology needed to pull it off is lagging. They question whether two-dimensional codes needed for such information, like DataMatrix and Reduced Space Symbology, can be printed, without slowing down packaging lines, in resolutions high enough to guarantee scannability. They also need programmable printers, since data change from lot to lot.

Printer suppliers are confident it can be done. This year many have introduced new systems designed to produce such codes at high speeds in scannable resolutions. Next-generation systems are also in the works, as suppliers try to achieve the right balance between printer speed, motion control, and other factors. For instance, Scott Liniger, strategic marketing manager for Videojet Technologies Inc. (Wood Dale, IL), says that success in high-speed, high-resolution printing depends heavily on product presentation and handling, so suppliers are devising methods to control product movement.

Below are some of the latest company developments in printing two-dimensional codes.

Bell-Mark Sales Co. (Pine Brook, NJ). "Unit-of-use packaging is ultimately where the pharmaceutical packaging industry is headed, and small packages need two-dimensional codes to get product data, lot codes, and expiration dates onto packages," explains Tom Pugh, vice president of Bell-Mark. To keep pace with industry needs, Bell-Mark's printers, the EasyPrint II line in particular, can produce PDF-417, DataMatrix, Reduced Space Symbology (RSS), and Maxicode. The new line, just introduced this year, employs a 300-dpi printhead and a 32-bit processor. "Such processing can handle large files, like two-dimensional codes, and it won't slow down printing—it can reach speeds of up to 1200 mm per minute," Pugh adds. The printers are available in continuous and intermittent models. They also use a proprietary method to mark such codes on foil. "Foil typically repels ink, since it is cool, but we have a method to warm the foil just before printing so print adheres permanently."

Adolph Gottscho Inc. (Union, NJ). For years, flexographic platen printers from Gottscho have produced nonvariable codes, text, and logos in high resolutions. But to encode lot and date information two dimensionally with such printers, users would need to change print mats with each run. Sales engineer John Wilson says his firm has been looking into possibilities of using flexography for printing variable information, and he says for large firms that create their own print mats in-house, such a task wouldn't be inconceivable. But he says that since most companies aren't in a position to produce their own or can't afford new mats every day, Gottscho has coupled an ink-jet printer with its flexographic printers. "You can use the platen printer for drug names and other nonvariable information and employ an ink-jet for variable two-dimensional codes," he explains. He says that typically an ink-jet printer is limited in resolution because of its printing speed, so he recommends using multiple ink-jet heads to increase the amount of data put down while maintaining line speed. Gottscho will be showing such a system at Interphex in New York City this month.

Griffin-Rutgers Inc. (Ronkon-koma, NY). Pete Umbdenstock, vice president of sales for Griffin-Rutgers, says that to produce codes of proper resolution and clarity on a wide variety of substrates, firms should rely on traditional UV flexographic print plate based systems that are already mounted on many thermoformers. "Such an approach possibly requires no additional capital for new machinery, has absolutely no chance of slowing the overall production line output, and a properly operated system will have no problems," he says. And, while the cost of a new print flexographic plate for each batch is "critical for very small batch quantities, many blister batches are of sufficient size to easily amortize the cost of the plate over the batch." And companies shouldn't worry about delays in getting new plates for each batch, since they can be acquired overnight from plate manufacturers like Quint Co. (Philadelphia), Umbdenstock says. In addition to flexographic printers, Griffin-Rutgers also offers the Codajet 6000, which uses high-speed piezo jets to create bar codes and other marks in an ultrahigh-resolution. Bar codes can be printed at a speed of 30 meters per minute.

Videojet Technologies Inc. (Wood Dale, IL). Videojet offers a range of printing technologies, but Scott Liniger says his firm's best current model for printing consistent, readable two-dimensional codes is its IPro, a continuous ink-jet printer. "The IPro produces dots close enough together to form a readable, reliable DataMatrix code. While the code won't be as crisp as one produced with thermal-transfer methods, it can be printed consistently onto products on high-speed conveyors." Videojet is also upgrading its laser printers to add two-dimensional code printing, which he feels holds long-term promise. "Laser technology gives customers speed, resolution, and crispness," he adds. Videojet also recently introduced the DataFlex, its thermal-transfer overprinter, featuring 300 dpi print resolution. "It provides the capability to produce high-quality two-dimensional symbologies, which we expect to incorporate in the future," Liniger said.

Markem (Keene, NH). Markem's SmartDate 3+ series of thermal transfer printers supports four types of two-dimensional bar codes, explains Markem's Andy Gray. They are PDF-417, QR code, RSS, and DataMatrix. Models for continuous and intermittent lines are available. The SmartDate 3+ will be introduced at the Interpack show this month in Dusseldorf. In addition, the firm also offers the SmartLase laser coder, which can mark characters at about the same rate as the SmartDate.