WEB OFFSET REPORT -- Make Ready for ChangeMay 2003
Shaftless drive technology has helped to enable the engineering of wider presses, notes Chris Clement, product manager for commercial web presses with Heidelberg Web Systems in Dover, NH. "The technology continues to evolve, with the latest press systems featuring independent, a.c. servo drives for each component. The advantages include low maintenance, smoother acceleration and deceleration to reduce web breaks, faster makereadies and the flexibility to de-couple printing units," Clement says.
The product manager also sees potential for further exploitation of gapless blanket technology to reduce vibrations. "Heidelberg sees an opportunity to develop wider and more productive single- and double-circumference gapless presses without sacrificing print quality or the one-to-one cylinder ratio. Gapless is not a static technology," he asserts.
For the makereadies that are required, the industry needs presses that can be set up faster, GATF's Prince continues. This need cuts across all sizes of web presses—along with sheetfed machines, for that matter. JDF (Job Definition Format) is poised to become the common solution, according to the veteran consultant.
The XML-based specification, which is on its way to becoming a standard, provides for bi-directional communication of data between printing systems.
"Basically, it enables an entire press setup to be done automatically," Prince says. The degree of potential makeready savings will provide greater incentive to implement JDF for web offset operations than, say, in the bindery, he adds. "JDF will drive down setup times, plus eliminate mistakes."
The challenges involved also are greater due to the number of control systems and peripherals incorporated into a state-of-the-art web offset press. In theory, each component should be JDF-enabled in order to capitalize on the full potential of the technology. This means implementations from a number of manufacturers will have to work together seamlessly.
In the near term, the most significant developments in web offset technology will be incremental and related to system automation and integration, contends Heidelberg's Clement. "The goal is to link prepress, press, postpress and also business management functions to realize the full potential of an integrated, digital workflow (otherwise known as computer-integrated manufacturing and the Smart Factory)."
The product manager expects to see improvements in currently available systems, along with automation of additional steps in the web offset printing process. "Automation provides exponential benefits," he notes. "The automated functions are completed faster and more accurately, while operators have more time to focus on completing manual functions faster and more accurately.
"Web printers are in an intensely competitive business environment. These areas of development hold the most immediate promise in terms of increasing productivity and efficiency," Clement concludes.
Komori is looking to sheetfed presses as the model for web production, reports Terry Bradley, technical director for Komori America in Rolling Meadows, IL. For example, the company is addressing the long-grain, eight-page web market as an extension of its sheetfed product line.
"The web models incorporate many of the same automation features, including KHS (Komori High Performance Inking)," Bradley points out. "The timing for their introduction hasn't been set, but we plan to introduce plate changers and various presets for web width and thickness to further reduce makeready time and waste. These features are particularly important on this press, since it's typically in makeready about 50 percent of the time due to its short-run, high-quality market niche."
In a bit of surprise, GATF's Prince believes the industry does "need" direct imaging (on-press), rewritable cylinder/plate technology. "It is one of the few ways to achieve a strong reduction in makeready time," he explains. "That technology, in part, is already on the market with the DICOweb (from MAN Roland). It may constitute a large segment of the market in the future, say in the next five years."
Off-line imaging—whether of a digital plate or some type of removable sleeve—isn't what is needed because of the time required to install/remove the material, Prince asserts. "That takes too much makeready time."
One of Switzerland's leading commercial printers, Stämpfli in Bern, has become the first facility in the world to commercially run the heatset version of MAN Roland's plate-free DICOweb offset press. The system uses an imaging cylinder that is laser imaged on-press, then erased and reimaged. Stämpfli is running a 16-page configuration with four double printing couples, enabling it to operate at 11.4 feet per second. It is housed in a newly built plant that also is home to three sheetfed presses and a toner-based digital printing system.
According to Peter Stämpfli, company board member, a complete make-ready of the press takes about 20 minutes, while a form change within a run can be accomplished in 15 minutes. The company exec notes that one of the pilot jobs produced was a 16.5x11.6˝ catalog with 1,460 pages and a segmented circulation of 10,000 copies. He says the project was produced considerably more efficiently on the DICOweb than would have been possible on an eight-color convertible sheetfed press.
Stämpfli claims the system is suited to short runs of 500 to 3,000 copies. The printer also sees potential to extend editorial and ad deadlines. Publication customers reportedly are being told it is now possible to integrate new advertising or editorial pages up to one hour before run time.
Both heatset and coldset versions of DICOweb are said to be available for order in North America.
Heidelberg's Clement has a considerably more reserved take on direct-to-press technology. "There are some niche applications for on-press imaging in the web offset arena, but there is more potential in automation and process integration improvements," he says. "Presses only earn money while they are running. When a single operator can change all of the plates simultaneously in less than two minutes, using systems like Heidelberg's Autoplate, much of the appeal of on-press imaging is lost."
The product manager believes there is broader potential for a different type of on-press imaging: ink-jet printing of variable data in-line with a web press. "We've just seen the technology realized on a press startup," Clement points out. "As run lengths continue to come down and product customization increases, we will see a growing number of printers using this technology."
KBA's Rehmann adds that the engineering of modern presses makes it easier to integrate ink-jet systems. "Individual drive (or shaftless) technology has resulted in more effective and cheaper solutions for adding imprinter equipment. This capability supports the increasing demand for print products to address specific target groups."
Again with an eye toward makeready savings, Prince predicts the web offset segment will see a reemergence of waterless printing. "It makes sense in terms of tremendous paper savings," he asserts. "There are still issues regarding the plates (price, run length supported, scratching) and inks (chiefly price). Having a digital waterless plate now available is a positive development. If paper prices keep going up, the process will become a more interesting option."
The GATF consultant says the industry potentially could see significant ink-related developments on several other fronts.
"We need an ink that comes up to color faster, which is being worked on by a number of ink companies," Prince reveals. "Another technology in development that could have a very profound impact—if it pans out—is 'just-water' printing technology. The idea is to use ordinary tap water as the fountain solution, which allows you to reduce your dryer temperature by 100°F in the middle chamber."
Dropping the temperature by that degree would significantly reduce the cost to dry a sheet, Prince says. However, he cautions, it's still too early to gauge the viability of the technology and its impact on other production issues.
"The problems with any new technology don't often come up right away. We need to look at print quality and characteristics, like rub and scuff resistance. Also, we don't know what impact there would be on air pollution equipment or VOC emissions. A grant has been promised to GATF to underwrite further testing, but we're waiting to receive the money before beginning. The industry could see very rapid adoption of the process, if it is proved effective and practical," Prince says.
The process is enabled by use of a special ink vehicle, which a number of ink manufacturers have licensed, according to the print expert. Sheetfed ink formulations already have been released, and the findings in that segment are "all good," he adds.
A very different approach to tackling the same issue—energy demands in drying—has been suggested in the past. In this case, electrostatic energy is employed to create turbulence in the "laminar" boundary layer that forms above the substrate as it is being dried. Since the technology (known as E-field supported drying) has found some interest in the gravure world, Eltex Elektrostatik GmbH in Weil am Rhein, Germany, undertook proof of concept testing with a manufacturer of heatset web drying equipment.
"We were not able to integrate our equipment into the hottest (first) section of a heatset web offset dryer, where our technology would be the most effective," reports Lukas Hahne, managing director. "However, we were able to demonstrate the principle in other dryer sections."
The future of the concept remains an open question, Hahne admits. "It is difficult to integrate our technology with a state-of-the-art dryer, therefore we cannot prove our technology on a existing dryer. Our original cooperating partner stopped the project, and the industry in general doesn't seem ready to accept new drying concepts."
Returning to inks, the potential for single-fluid formulations has created a lot of buzz in recent years. As with the water-only technology, the greatest progress has been made in sheetfed applications.
Flint Ink, in Ann Arbor, MI, has been one of the companies leading the way, and already has trademarked SFI (Single-Fluid Ink) as a brand name. But even it has pulled back in the web arena.
"After early testing, it was determined that single-fluid ink (SFI) would be more cost-effective for sheetfed printing," says Rita Conrad, director of corporate communications. "For that reason, the decision was made to focus our efforts on developing a more robust product for sheetfed applications, and that work continues today. Once we are fully comfortable with that product, we will re-visit possibilities for web applications. So, for all practical purposes, the web formulation is currently on hold."
Heidelberg's Clement characterizes the technology's outlook as "almost a certainty" that it will still become a reality for web offset applications. Once a commitment is made to single-fluid ink, he says there could be a need to reengineer presses.
"Dampeners on presses could hinder the technology's development," the product manager explains. "In challenging situations, printers would be tempted to revert back to traditional dampening rather than overcoming any problem with single-fluid formulations and thus advancing the new technology."
Press peripherals also factor into the outlook for the process, points out KBA's Rehmann. "Production flexibility increases commercial printers' chances in the market," he explains. "For example, the KBA variable gripper folder already supports the production of long- and short-grain products from a fixed-format commercial web press.
Paper may not be web offset technology, per se, but it is a very integral part of the process and key to long-term success, Rehmann adds. "Printers will continue to demand better and cheaper paper for heatset production," he says. "Quality differences between papers remain a problem."
Fluting, in particular, is a vexing problem that needs to be addressed in the future, GATF's Prince adds. The research done so far has been inconclusive, the consultant notes. Fluting is the waviness exhibited in some bound magazines and catalogs, he explains. "Some very expensive papers do it, some cheaper ones don't. Some stocks do it more, some less," the consultant says. "When you look at the findings, it's apparent that we know a couple ways to make it a little bit better and some ways to make it worse, but we don't know how to eliminate it."
The web offset process may be mature, but it's not without mysteries and surprises. It also still holds potential to keep print competitive.