What's Driving Web VS. Sheetfed? Case for Sheetfed

Sheetfed's traditional strengths lie in runs under 10,000 impressions. Its appeal rests on the capability to print heavier and non-paper substrates, using a variety of specialized inks and processes. And sheetfed presses handle odd sizes not amenable to web's fixed cut-off lengths.

With a new selection of larger format sheetfeds—and new entrants into full-size, eight-up formats (Sakurai and Ryobi)—the platform is poised to compete even harder for folio work normally reserved for web. Inline finishing and curing advancements also give sheetfed printers greater opportunities.

At the same time, the market overlap between sheetfed and web format presses remains wide and may be growing. The old rules of thumb that guided production managers and shop owners in deciding what presses to buy, and which kinds of jobs should be run on them, have been cast aside. There are plenty of cases where sheetfeds are running 100,000 impression jobs. And we talked to a number of printers who routinely put 1,500 impression jobs on webs.

With the newest wave of larger format and ever more automated sheetfeds coming to market—larger (44´´ to 56´´) machines from Akiyama, Komori and Mitsubishi and VLF (even larger sizes) from Heidelberg, KBA and MAN Roland—sheetfed engineers have licked problems with register control that bedeviled earlier generations of large presses, often restricting them to 1- and 2-color formats. Improvements in press engineering, as well as in inks and papers, are helping sheetfed rival efficiencies and productivity of web offset for signature work.

In addition, sheetfed's flexibility in substrates also helps. For example, a new 81´´ KBA Rapida 205 being installed at Edison Litho & Printing, North Bergen, NJ, is equipped with options that allow it to print on styrene and other plastics. “The Rapida 205 enhances the speed and quality of this specialized type of printing,” says president George Gross. “Having the additional capability of printing on substrates like plastic, vinyl and styrene really rounds out our ability to service our customers with their entire large-format printing needs. We've found that there are very few printers who have this ability, thus differentiating us from our competition.”

Dave Kornbau, VP operations for Strine Printing, York, PA, reports making full use of the flexibility of his firm's two Roland 900 55´´ presses and a first-in-the-U.S. 63´´ Roland 900 XXL. He runs a wide variety of substrates through the presses, from plastics to heavy board, and has the option of aqueous, UV or hybrid UV coatings. He finds he is printing a variety of commercial print jobs that formerly were only run on a web press because he can now run substrates that would have required the drying units of a web press to handle.

The improved ability of larger sheetfed presses to handle paper is seen in new generations of large format perfectors from Heidelberg (see sidebar) and MAN Roland. To be introduced at drupa are larger Plus size Rolands and a 900 XXL 72´´ perfector. These larger sheetfeds will incorporate production quality controls: ProcessPilot, a standardization tool to maintain approved production standards (and suitable for supporting ISO 12647 standard and additional System Brunner evaluations); InlineColorPilot, which measures and regulates color inside the press without having to pull sheets from delivery; and okBalance, a gray balance control for more stable quality over the entire run.

All of the manufacturers of wide-format sheetfed presses offer CIP3 ink-key settings either standard or as an option, as well as automatic plate loading and plate, blanket and roller washing. These features have generally cut makeready times by half and, in many cases, considerably more. Printers boast total makeready times of 15 minutes or less; in fact, that appears to be the norm.

Also indicative of the levels of automation are offerings that Komori will show at drupa. The firm is adapting technology from its webs to the Lithrone sheetfeds. Dubbed KHS-AI, the system is a sophisticated computerized press monitoring system. Komori Electronics has added Artificial Intelligence to its fast start-up system so the press can learn and recall changes made by the operator during any job set up, allowing for reduced changeover between jobs. The new SX40 press also has faster running speeds than previous models, and the KHS-AI feature allows the press to reach run speed in as little as five seconds. The AI component allows the press to continuously monitor the press run and adjust ink levels, air flow and other settings on the fly.

Komori also offers a PQA-S print quality assessment system that renders a digital video image of the entire press sheet and monitors subsequent sheets, tagging any defects such as hickies so they can be pulled from the final delivered job. PQA-S captures up to a million lines per minute and can detect defects larger than 1 pixel.

Sheetfed builders compete with webs in other ways. Bill Fitzgerald, president of Universal Millennium, Rockland, MA, likes the perfecting method Akiyama uses on its 6- and 5-unit Jprint presses. Grippers take hold of the lead edge and carry it straight through the press, not unlike a web, as top and bottom units print. “The Jprint's straight-through design is unique,” says Fitzgerald. “Registration and marking problems associated with flipping the sheet are never a factor.”

UV curing has also become an important feature for many sheetfed printers—a rock-solid rebuttal to web offset's heatset advantages. UV curing delivers sheets dry even on high coverage jobs, speeding up the finishing process or allowing rapid back-up of jobs going through the press more than once. The fact that sheets can go back through a press allows a greater range of spot colors, special inks and varnishes to be applied.

Eric Frank, KBA North American marketing manager, notes there are some things a web press simply can't do. “There's a wider range of substrates you can run on a sheetfed. You can also run more spot colors and different ink and coating effects.” Improvements in engineering as well as inks and substrates have helped make it possible to build presses that can maintain register over very large sheets, Frank says. KBA holds the biggest share of the very large-format sheetfed market. It also offers the largest sheetfed press—the 81´´ Rapida 205. The firm is adept at incorporating productivity-enhancing features, such as large-format UV perfecting, large-format roll-to-sheet, and inline slitting at the delivery.

While Mitsubishi president Marke Baker is happy to sell both sheetfed and webs, “I'm surprised that more people don't go over to a web. The quality is there. The waste is nowhere near as big as it was just a few years ago.” And he points out you can now readily print 10-pt. cover stock on many web presses. But Baker also provides one answer: web presses are significantly more expensive, especially with dryer and chiller factored in. As fuel costs rise, “Maybe that's what scares people off,” he says.

Mitsubishi makes 40´´, 51´´ and 56´´ sheetfed presses, and although the widest presses have traditionally gone into the packaging market, Baker has seen a significant rise in sales to commercial printers.

“The people who are buying 56´´ are not seeing the same slowdown as those running 40´´ presses,” Baker notes. “They use the same number of people and not that much more floor space to produce a lot more work.” The bigger presses also can include the latest SimulChanger, which can complete a plate change in 75 seconds on all units at once, regardless of the number.

Another sheetfed advantage for sheetfed is avoiding environmental and regulatory obstacles faced when adding web presses in some locales. Both press platforms can adopt waterless and UV curing systems, which can help on the green front.

Storage factors also favor the sheetfed printing process. Part of the savings that comes from buying in volume is lost through the cost of storage. In an era of “just-in-time” manufacturing, large paper inventories—a requirement for web operations—is fiscally undesirable.

The sheer size of the press sheets for larger presses presents new challenges, notes Clarence Penge, VP for sheetfed equipment at Heidelberg. His firm will introduce large-format sheetfeds at drupa (see sidebar, p.45). “Handling is the challenge; we're talking about logistics challenges; space and organizational skills will be required. You can't make a mistake and over-order your sheeted material; you simple won't have the space to handle it, and that space costs you money.”