Digital Color Printing — Ink-jet in Line for Takeoff

NOT LONG after the close of Drupa 2004, the 2008 edition of the international printing exhibition was already being called the “ink-jet Drupa.” Upping the time frame, the title of a keynote panel at the just-completed On Demand Conference & Expo asked, “Is Ink-jet the Technology Story for 2007?” It should be clarified that both are references to color page printing in a production environment, and not wide-format or consumer photographic printing.

For 2006, the big story in ink-jet printing was industrial printing applications. It seemed as if every vendor was talking about flatbed machines capable of printing on a wide range of substrates. There have already been some signs of a shift in product focus back to page production this year.

Agfa Graphics, for one, had cited the opportunities in industrial applications as the primary motivation for several investments it made in developers of ink-jet technology. This February, however, the company introduced a new page printing system designed for “transpromotional” and direct mail applications.

The Dotrix Transcolor prints four colors in a single pass at a max speed of almost 500 ppm (A4 size) in duplex mode. It is designed with a static array of drop-on-demand, piezo ink-jet heads that spans the entire 25.6? paper width. Combining Agfa’s Agorix Nova UV-curable inks with non-linear (stochastic) screening is said to deliver a perceived 900 dpi resolution, but the device has a 300 dpi measured resolution.

IBM signalled its intention to finally enter the volume color page printing market at Graph Expo 2006, but waited until the same month to formally launch a product. The Infoprint 5000 continuous (webfed) printing system is based on the piezo-electric, drop-on-demand ink-jet engine used by Screen (USA) in its Truepress Jet520 product.

This engine uses water-based pigment inks to print a 20.4? maximum web width at a 720x360 dpi resolution. It runs at speeds up to 210 fpm, producing 916 ppm (letter size) in a tandem engine configuration printing in duplex mode.

Continuous Ink-jet Option

Credit for pioneering the use of ink-jet technology for high-volume page production goes to the Kodak (then Scitex Digital) Versamark product line, currently featuring the VX5000 and VX5000e models. It’s important to note that these machines are based on continuous ink-jet print head technology. The VX5000 is rated to print at 500 fpm (>2,000 ppm) with a maximum 300x600 dpi resolution, and the VX5000e (enhanced resolution) runs at 328 fpm (>1,400 ppm) with a 300x1,200 dpi resolution.

These types of high-volume systems can top the $1 million price range. RISO Inc., meanwhile, has shown what is possible at the other end of the ink-jet page production spectrum (sub $50,000).

It recently announced a relationship with Kodak to offer the RISO HC5500 color ink-jet printer as a complement to Kodak’s Versamark V-series systems, providing a solution for short-run applications such as reprints. The cut sheet device can be tied into the same workflow to take advantage of Kodak’s color control and image processing technology in replicating the look and feel of the high volume output.

The HC5500 uses piezo-electric ink-jet heads to output 120 ppm (A4 size) with a top resolution of 300x600 dpi and 123⁄8x185⁄16? maximum print area. RISO has positioned the device as enabling everyday documents to be output with a “communications color” level of print quality.

This range of currently available printing systems reflects one of the main points raised during the On Demand panel discussion—ink-jet production printing systems will not be a homogeneous category of products. That’s because vendors can trade off speed for quality or quality for speed to keep the capital cost down, or they can develop a solution that offers high speed and quality at a greater cost.

One company, Memjet Services, asserts that its ink-jet print head technology has the potential to change that equation. CEO Bill McGlynn (formerly with HP Indigo) says the company is looking to be a component supplier to other companies that manufacture output devices, rather than making any end products itself.

Given that, Memjet will not have direct control over how and when its print head technology is commercialized. Based on development work the company has already been a part of, though, McGlynn envisions an early market entry being a personal office device that prints 60 ppm at 800x1,600 dpi (1,600x1,600 dpi for text), with a retail price between $200 to $300 and per page cost of 3 to 5 cents (with 20 percent color coverage). He adds that the technology cuts ink costs to 20 to 25 percent of solutions currently on the market.

Cashing In Their Chips

The print heads are constructed from individual chips that measure just 20mm across, yet each contains 6,400 nozzles and incorporate five color channels. Thermal ink-jet technology is used in the current generation, but McGlynn expects a mechanical version of the head to be available within three years. That would enable a wider range of ink types to be used.

Charlie Corr, group director of the InfoTrends research firm, kicked off the On Demand keynote panel by explaining why there’s a high level of interest in ink-jet technology, even though it currently doesn’t account for a lot of the page production volume. The reasons are:

• lower cost consumables (somewhere between offset ink and toner);

• potential to offer print speeds comparable to offset and that EP (electrophotography) can’t match;

• flexible deployment, both in standalone printers/presses and hybrid applications such as in-line with offset presses; and

• high quality imaging, particularly for images.

Today, there are two “inhibitors” to wider adoption of ink-jet for page production, Corr asserts. One, it’s currently hard to get all three of the prerequisite characteristics—low cost, high speed and high quality—in the same box. Two, is the lag in “time to market” compared to EP systems.

The ink-jet imaging process is simple and direct compared to xerography, also known as EP, but has its own challenges, adds Peter Crean, senior fellow at Xerox Corp. The issues include drying (on the substrate and not in the nozzle), a tendency to produce “pattern errors” in output, no tolerance for failure in any of the thousands of systems in a print head, and interactions between ink and paper that are complex and unpredictable.

Solutions Made to Order

Ink-jet technology has the potential to offer different value propositions based on parameters such as footprint, speed, image quality and cost per copy, Crean says. Therefore, it is better positioned to compete for new opportunities, rather than current applications, he adds.

Part of what accounts for the focus on ink-jet is that EP technology is in the mature phase of its life cycle, believes George Promis, CTO and director of technology alliances at IBM Corp. It is a proven, stable process, but there appears to be no development on the horizon that would significantly alter its current cost and speed characteristics. However, incremental improvements will continue to be made and EP will co-exist with ink-jet for years, he explains.

Promis agrees that ink-jet print engines won’t just drop right into existing EP workflows. He believes development efforts should start with an application, which will be new for ink-jet, and not with the performance attributes of a device. Putting ink-jet heads on offset presses could be more disruptive than any pure ink-jet system for page printing, adds the IBM exec.

EP is not going away, also predicts Larry Tracy, marketing manager, graphic arts, at Hewlett-Packard. He, too, believes that the trade-offs mean ink-jet solutions will be specific to the application.

Tracy expects to see a variation of Moore’s Law (which says computer power will double every 18 months) in the development of ink-jet technology. He notes that HP’s new Edgeline technology, which was recently rolled out in multifunction printers for the enterprise printing market, already reduces the drop size to four picoliters.

It’ll take more than just advancements in print engines to make ink-jet the story for 2007 or any year, concludes Randy Vandagraff, Kodak’s vice president, Systems Research and Development, Digital Printing Solutions. Full solutions—including substrates that keep ink on their surface for better color density, drying systems, finishing options and workflow systems—will be needed for ink-jet to capture page production market share, Vandagraff says. PI

For More Information
on the ink-jet color printing systems mentioned in this article, visit www.piworld.com/infocenter and enter the numbers below.

Agfa Graphics 384
Eastman Kodak 385
IBM 386
RISO 387
Screen (USA) 388