Seiko’s Colorpainter H series of solvent-based printers has printheads that can print tiny drops very rapidly, making a speeds of over 1,000 square feet an hour possible at 720 dpi. Inkjet printer technology has come light years from the days when it was considered an interesting novelty. Every year, printers get faster and more industrial—engineers are always pushing the envelope of what was thought to be possible. The speeds and print resolutions of even low-end and mid-range printers today far outpace the quality and speed of the high-end printers of yesteryear.

At the apex of the category are the high-production printers—those units geared primarily for high-volume output. The bar definitely has gone up as speed and quality no longer seem to be at odds. Some of today’s printers can produce quality output at speeds well over 1,000 square feet an hour and, in some cases, five or six times that rate, yet they somehow maintain sellable quality with resolutions at 600 or 700 dpi and better.

SPEED AND QUALITY?

It used to be that when it came to wide-format inkjet printing you could either have speed or you could have quality, but you could never have both together. That is no longer the case. So, exactly what has changed over the past few years that allows such a major paradigm shift? The answer, of course, can be found in several areas working in concert.

Among the most profound change has been the performance capabilities of today’s industrial piezo printheads. High-tech printhead engineering and improved manufacturing techniques—such as the Micro Electro-Mechanical Systems (MEMS)—mean that many of today’s printheads have more nozzles per printhead (760 or more); offer grayscale capabilities, more accurate dot placement and smaller and/or variable drop volumes (8 to 80 picoliters); as well as increased firing frequency (up to 30KHz); wider print swaths; and much more. But these incredibly sophisticated printheads would be useless with the emergence of faster, more powerful RIP software systems that are better able to process all that ink-to-nozzle information at light speed.

Another important factor is the chemistry of the inks and their enhanced compatibility with today’s printheads. Ink temperature tolerances, better viscosity ranges, higher ink density at high speeds, improved drying and curing times and improved pigments are all part of the package. And, in the case of UV-curing systems, ink and cure-lamp compatibility have been greatly improved, allowing for more complete cures at higher speeds on more types of substrates and with fewer adhesion and/or cracking issues.

Couple all of this with the improved mechanics of the printers themselves. With better, more robust and accurate media handling mechanisms, more precise printhead shuttling systems, larger roll capacities, etc.—and you can see how high-quality, super-fast inkjet printing is coming of age.

In defining the term “high production” for this article, we arbitrarily chose to consider only those printers that offer maximum print speeds of more than 700 square feet an hour or higher. We asked several manufacturers to discuss the technology that makes today’s super-fast, high-quality inkjet printers possible.

A new generation of inkjet printers, such as EFI’s new GS3200 UV-curing hybrid, combines high-speed productoin with high resolution output.

Innovations in printer technology, such as the continuous board workflow system employed by the Durst Rho 1000, eliminates the time needed for loading and unloading boards.

UNIQUE OFFERINGS

Manufacturers of high-production printing equipment bring different strengths to the table. Highlighting these strengths helps make their product stand out from the crowd. And the consensus is that it’s not just speed that sets them apart.

Ken Van Horn, product marketing manager for EFI/VUTEk, stresses resolution options. “The dual resolution modes we have on the VUTEk GS3200, GS2000 and GS5000r UV-curing printers are a leap forward for super-wide format printing,” he says. “And with the GS3200 and GS2000, we’re delivering true photorealistic quality images at amazing speeds.” The GS3200 offers output speeds of more than 2,000 square feet an hour and addressable resolutions of 600 and 1,000 dpi.

Design intent is another factor. According to Tom Leibrandt, product manager, print on demand solutions, for Screen USA, the Truepress Jet 2500UV printer “was designed from the ground up as a hybrid production press.There is no loss of speed or quality when printing roll material or rigid material up to 2" thick. This design plus the adoption of drop on demand eight-level grayscale printheads, and a linear motor deliver the quality and speed that is needed for today’s demanding consumers.” The unit offers print speeds of 726 square feet an hour at 1,500 dpi.

For others, it’s about in-shop durability. “Our printers have become synonymous with high-performance and long-term reliability,” says Pat Ryan, general manager for Seiko I Infotech. “In high-volume environments, build quality and component quality become very important. Second, our printheads can print very small drops very fast, making a quantum leap in the speeds of ‘useable’ prints—specifically, 720 dpi produced at high speeds. We see this as the ‘sweet spot’ in the durable graphics market.” Seiko’s ColorPainter H series offer print speeds of 1,075 with 720 dpi.

Though not aimed at our markets, the industrial HP Inkjet Web Press employs high-speed inkjet technology to produce 400 fpm on a 30”-wide web, double sided. Media handling systems used in presses like this are being adapted to wide-format printers.

Then there’s the heavy-duty side of commercial wide-format printing. “We offer a truly industrial printer with a very robust and rigid design,” says Michael Albrecht, vice president of sales and marketing for the printer division of Polytype America, the U.S. arm of Swiss printer maker WP Digital. “The Virtu is specially adapted for heavy applications, and can handle substrates up to 3.7" thick and up to 10 pounds per square foot. We also offer top-class linear drives (instead of drive belts) for exceptional performance.” The Virtu RR 50 roll-fed printer from WP Digital is a 196" -wide UV-curing unit with print speeds in excess of 3,440 square feet an hour, and resolutions up to 1,200 dpi.

And enhanced workflow is another huge differentiator. According to Chris Howard, vice president of sales and marketing for Durst Image Technology U.S., “What sets the Rho 1000 apart from anything else is its production workflow. By having a linear feed to output of sheets we can utilize our continuous board feed technology so that the time needed for loading and unloading boards is eliminated.”

Ease of maintenance is yet another factor. “The AdvancedJET AJ-i series achieves very high production speeds while being much easier to maintain than other solvent printers in its class,” says Robert Ozankan, product manager, Roland DGA Corp. “In traditional solvent printers, a daily maintenance routine is required. Unlike other industrial printers, the AJ-i series includes automated maintenance systems that eliminate the need for daily manual cleanings while keeping heads, caps and wipers performing optimally.”

For Matan, makers of the Barak series of UV-curing hybrid printers, it’s a combination of usability, versatility, performance, environmental benefits and cost of ownership. According to the firm’s marketing director Hagai Valach, they offer “the only five-meter hybrid printer; with high productivity and top quality without ink switching. Our performance—3,400 square feet an hour at true 600 dpi, using 30-40 picoliter drop sizes—speaks for itself.”

The heavy duty Virtu RR50 from WP Digital offers print speeds in excess of 3,440 square feet an hour, and resolutions up to 1,200 dpi. Roland’s AdvancedJET AJ-i series offers very high production speeds while being very easy to maintain. COOL TECHNOLOGIES

Some of the more interesting technologies being used today in high-speed inkjet include sophisticated media handling systems, such as the automated loading and unloading systems being used by Inca Digital (with the Onset printer), HP Scitex (with the FB7500), and Agfa (with the M-Press and M-Press Tiger). These systems borrow ideas appropriately from high speed screen-press systems to efficiently move heavy sheets on and off the press. Other nice innovations include how printheads are arranged in their printing blocks. We are seeing a growing number of printers using a staggered head design, and many, including Mutoh and Roland, are using various forms of firmware to help offset banding and other problems.

Roland utilizes six industrial ultra-wide piezo printheads in its AdvancedJET AJ-i series, according to Ozankan, which work together with Roland’s new Intelligent Pass Control technology, which “ensures consistent quality and reduced banding even at high print speeds,” he says. “This patent-pending system precisely controls dot placement and creates a series of patterns that accurately fill in the smallest gaps between passes.”

For Durst, Howard says that, the key technologies in the Rho platforms are the segmented rail and linear magnetic drive system that allow for extremely accurate droplet placement along with the Quadro Array printhead design. “The recently announced updates to the Quadro Array family are the 30D and 30M versions which both feature a 30 picoliter drop and true 600 x 600 dpi addressability,” he says. “The 30D has doubled the nozzle count of our previous Quadro Array, and the 30M has quadrupled the nozzle count per array.” The new Rho 1000 can print 200 4' x 8'- boards per hour, or about 6,400 square feet an hour.

Hewlett-Packard developed the HP Scitex X2 Printhead used in the HP Scitex FB7500 flatbed printer, which “brings together silicon-based MEMS technology and innovative piezoelectric inkjet technology,” says Francis McMahon, director of marketing, U.S. Graphics Solutions Business, HP. In addition, HP developed the Designjet L65500 printer featuring unique latex-based aqueous inks and three staggered 4.25" Wide Scan printheads (31,680 nozzles) that produce an 8.5"-wide print swath. “The HP Designjet L65500 printer enables consistent, high-quality output at exceptionally fast print speeds of up to 800 square feet per hour,” he says.

LOOKING AHEAD

When asked to prognosticate the future, manufacturers voiced some interesting ideas.

“Both solvent-based inks and UV inks will continue to improve within the environmental and employee health realms,” says Ryan. “Although some companies are experimenting with water-based inks again, the energy required to ‘bake’ pigments onto substrates, the costs of these printer and the limited media on which they can work, will, in my opinion, prove to be ineffective for outdoor durable graphics in the long run.”

“Print speed and quality will continue to improve,” says Albrecht. “This will result from further developments of printheads, UV-curable inks and cure-lamp technology.”

McMahon says that, “Based on increasing market demand for technologies that offer increased productivity and quality—but also lessen the impact of printing on the environment—we expect to see HP Latex Technology continue its momentum and play a large role in shaping the future of the graphic arts industry.”

Van Horn sums it up this way: “I think the market is going to continue to drive towards higher quality and higher speeds. With that we’ll continue to see a migration away from solvent and toward advancements in UV. Beyond that it’s difficult to speculate.”