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DIGITAL PLATES -- Shortcutting the Process

October 2003
BY MARK SMITH

Technology Editor

The goal is basically the same regardless of what name is given to the technology—no-process, process-free or non-process plates. Since computer-to-plate production is all about taking steps, variables and labor out of the workflow, it naturally follows that people would look to eliminate the chemistry-based plate processor.

The leading plate manufacturers have very similar takes on the future of this development, even if they differ on what to call it. This shared vision begins with a focus on non-ablative switchable polymer and/or on-press development systems as promising technologies.

That is, with the exception of Presstek Inc. in Hudson, NH. The company has pioneered the market with its current generation of chemistry-free plates and use of thermal-ablation imaging. "This (choice) is not based upon an affinity for the technology itself, but rather because we believe this approach offers the best opportunity for chemistry-free and process-free plate products," notes John O'Rourke, marketing director, Digital Media.

Other manufacturers contend that thermal-ablation plates fall short of the grand vision for two reasons. One, a debris removal system generally is required on the platesetter. Two, plates must be put through some level of a water wash step after imaging.

Presstek has been working to minimize the process requirements in both areas, O'Rourke says. Its latest "process-free" offering, Applause, actually represents the fourth generation of the technology, he points out.

"Most CTP plate products have a coating weight of approximately 1 micron thickness," O'Rourke notes. "Our Anthem plate utilizes an ablative layer that is 0.25 microns thick. Applause reduces this by an order of magnitude to .025 microns in thickness."

This improved coating system eliminates the need for any post-exposure treatment (i.e., water wash or wiping), according to the marketing director. It also reduces the impact on the platesetter, he says.

"What we have learned so far is that each imaging platform is unique," O'Rourke explains. "While Applause may require use of a vacuum collection system, we can see an opportunity to simplify the air management system on our own Dimension platesetters, and we expect filter life will be extremely long—perhaps even achieving lifetime filters.

"Beta testing on other imaging platforms is under way, but it's too soon to determine exactly what will be needed in terms of air collection. It's possible that a very simple system will suffice," he adds.

Applause's commercial release date has yet to be announced, and the same goes for its pricing. "By eliminating all of the various cost centers around chemical plate developing, we know we can deliver a lower 'Plate on Press' cost with Applause," O'Rourke says. He expects the plate to be rated for 100,000 impressions.

When it comes to alternative technologies, the distinctions can get a little fuzzy. Fujifilm, for example, is developing a solution employing "controlled ablation" technology, according to Jim Crawford, group manager, Output Media, at Enovation Graphic Systems (Fujifilm USA) in Hanover Park, IL. The technology works by having the initial ink charge to the plate carry away undesired (exposed) material during roll up on-press, he explains.

"The advantage of this technology is that the platesetter does not require debris evacuation," Crawford says. "Also, no special laser/imaging systems are needed to image the controlled ablation technology."

The material's current run length capability is in the 25,000 impression range, based on normal press and paper conditions, he adds. An on-press imaging version reportedly is in limited trial with Komori S40D and Heidelberg SM 74DI presses in select markets.

Agfa Corp. is pursuing a non-ablative alternative, but its solution differs from the common form of switchable polymer technology, points out David Furman, senior marketing manager, CTP Systems, at the Ridgefield Park, NJ-based manufacturer. The company is developing "latex coalescence" technology.

"Our technology is a true lithographic coating," Furman explains. "The image area remains on a grained and anodized aluminum substrate, which acts as the hydrophilic medium."

With switchable polymer technology, the polymer coating is exposed to create image and non-image areas and isn't removed from either, Furman notes. While the substrate may be aluminum, the polymer controls ink/water balance and that can lead to problems, he asserts.

The working principle of Agfa's processless technology is similar to its existing Thermolite Plus product, which the company sells for on-press imaging/DI applications. The material will be compatible with 830nm thermal lasers and require no add-ons, such as debris removal systems, he adds. Initially, it will be targeted for runs of 100,000 impressions and fewer, with post-exposure requirements and product availability still to be determined.

Citiplate Inc. is in kind of a unique position because it is concentrating more heavily on being a custom plate manufacturer, says Robert Dainton, technical director of the Roslyn Heights, NY-based company. "We're looking to sell any new products through third parties, rather than direct," he explains. "We've had several companies ask us to make 'no-process' plates for them."

All of the technologies Citiplate is currently pursuing are photopolymer based, according to its technical director. This includes non-ablative thermal (830nm, IR), ultraviolet and violet (30-40 mW) plates.

"They are cross-linking systems," Dainton notes. "In our scenario, the non-image portions are softened by the fountain solution, but removed with the ink and deposited on the paper. That keeps the fountain clean and stable."

Dainton contends that cross-linking offers advantages in durability compared to physical coalescence of the polymer coating. In the latter case, the action of the press or blanket wash can wipe the image off the plate, he contends.

Phase-change technology, however, produces a limited hydrophilic contrast on the plate, Dainton continues. "Also, no polymer can remain hydrophilic after a certain time on the press. It reverts back, so you run into a run length problem," he says.

Depending on the requirements of the plate, integrated dampening systems on presses can be a challenge for all plates that are "processed" on-press, Dainton admits. A separate dampening system enables the fountain roller to be dropped first, thoroughly wetting the plate, before the ink roller is dropped and the unexposed polymer is removed.

If a press is running an integrated system, the ink and fountain solution are applied at the same time. "In that case, it's better to 'hand' wet the plate down first. This is true with all plates 'processed' on-press," the technical director says.

Depending on the type of plate and press (web or sheetfed), Citiplate is looking to support run lengths in the 50,000 to 70,000 impression range. "We have worked with other types of polymers to give us a longer run length, Dainton adds.

Baking Issues

The current non-ablative, thermal plate theoretically can be post-baked for longer run lengths, but that creates a logistics issue. "If you put it on a press to get rid of the non-image area, then you've already got a crimped and folded plate that would be difficult to run through an oven. The plate would have to be "hand processed" off-line if you want to post-bake it," Dainton concludes.

Citiplate reportedly has done production runs of all these plates for review by potential vendors and/or limited field beta testing.

Brookfield, CT-based Lastra America is dealing with an added complication as it looks to develop processless technology, points out Josh Goodin, corporate research and development director. "Lastra bought the plate businesses of Western Litho and Mitsubishi Chemical, so over the past year we've been concentrating on integrating the technology we acquired," he explains.

A level of work has continued in pursuing a couple of approaches to processless plates, Goodin reports. One is a switchable polymer product (requiring no post-exposure step) and the other is an on-press wash-off technology, he says. Both are designed to be imaged by thermal IR lasers.

"With the switchable polymer, we are in the early days of product development," Goodin says. "The on-press processable is closer (to commercialization), but we have issues that still need to be resolved. Both materials are designed for short run lengths; under 50,000 impressions is the target."

Kodak Polychrome Graphics (KPG) is also working on a couple of options in developing a non-ablative, no-process plate, reveals Jack Weitoff, vice president, plate business, in Norwalk, CT. Weitoff adds that every so often he's asked why it's taking so long for no-process plates to be developed, regardless of whether they are conventional or digital.

"It's not that simple of a challenge," he says. "Every decade or so, there's been a no-process plate put on the market. For whatever reasons, none has ever made it."

Laser imaging does make the challenge a more reasonable proposition, Weitoff notes. KPG has been working on switchable polymer, or phase change, technology and "development-on-press" plates. "We're optimistic about those (develop-on-press plates)," he adds.

Weitoff prefers to talk in terms of the "goal" for product development. That is, to have a thermally imaged product that can be put through a standard thermal platesetter capable of using the "wet processing" thermal plates that the company sells today, he explains. "The goal is to have a product that is compatible with the broad base of installed platesetters and to use a standard fountain solution on-press."

Switchable polymer technology falls short on that last count, since it requires use of special inks and fountain solutions, Weitoff says. "Also, the visibility of the image after exposure is not so great and the length of run is limited."

Even given those limitations, "both avenues look interesting to us," the KPG exec says. "I expect we'll have a plate on the market sometime in 2004. Which one we market is still being tested and debated. We may even commercialize both."

Weitoff sees the length of run supported as a critical issue for all no-process plates. "Initially, these plates will be limited in terms of application because of their run length capabilities. We can produce runs that exceed 50,000 impressions, and maybe up to 100,000 impressions," he says.

That means the technology, at least initially, will be best suited for the small- to medium-sized shop producing short runs, the plate manufacturing representatives all agree. However, run lengths under 100,000 impressions represent the majority of printing sales, they add.

One company looking to possibly buck that trend is PDI Printing Developments Inc. in Racine, WI. In its quest to develop a processless plate, the company discovered a polymer surface technology that enables fast (typically two minutes or less), one-step processing, according to Tom Bevan, director of sales and marketing. This first led to the introduction of its Eclipse plate (500,000 impressions with no baking), and now a next-generation version, Delta 830 (1 million impressions with no baking), which was slated to be introduced at Graph Expo 2003.

Both plates use a polymer that is developed with a solvent, which accounts for the added strength compared to aqueous formulations, Bevan explains. No chemistry replenishment is required in the processor, since the solvent has a very low vapor pressure (minimizing evaporation) and doesn't oxidize, he adds.

These products are still not processless systems, Bevan readily admits. He says PDI continues to work toward a thermal, non-ablative plate that would be washed up (or "developed") on-press by the action of the fountain solution. "We wouldn't necessarily take solvent-based technology to a processless plate because fountain solutions are water based," he points out.

"Our Delta plate is another step toward what we think will ultimately be a very exciting processless plate. By the time we get there, we hope to have a long-run processless plate," Bevan concludes.

Noting that he's not comfortable trying to look more than two years out, Citiplate's Dainton says he thinks no-process plates will probably remain a niche product category in that time frame for several reasons.

"A lot of printers have a regime in place where the processor is not an issue anymore. They have tight quality controls, systems to deal with chemistry, and someone to service or maintain the processor," he asserts. "In addition, automation and technology have eliminated a lot of the labor involved. Processors plug straight into CTP devices. This has negated a lot of the no-process arguments that used to be there.

"I don't think you can use the standard arguments like environment and ecology, either, because of the way we run processors today," Dainton continues. "Except for silver-based systems, most are very environmentally friendly and the chemistry—in most areas of the U.S.—can be dumped down the drain."

Cost Concerns

The expected higher plate cost will be an issue for those considering adopting the technology, and, so too, could be concern about being locked into one supplier, the technical director says. Even the focus on shorter runs could work against some plates, he notes, if they don't roll up on-press instantly and extra paper must be wasted cleaning the plates up.

"The technology is best suited to customers with space constraints because the overall CTP system footprint can be significantly smaller," adds Lastra America's Goodin. These shops are more likely to be two- and four-page platesetter users, which raises another issue, he says.

"Thermal platesetters typically are not made in a two-page model and the four-page machines don't fit in a small printer environment because of cost," the R&D director points out. "It's difficult to achieve an ROI on the kind of volumes those shops would be putting through a machine."

Agfa's Furman sees processless technology co-existing with the many other CTP technologies available today. "With processless technology, the big benefit is the elimination of chemistry. But, processless does have its drawbacks," he says.

While run length is an obvious restriction, platesetter productivity is another drawback, Furman contends. "The sensitivity of processless technology is much lower than that of traditional CTP systems. Plate-setter throughput will be reduced (compared to traditional 'wet' plates) by up to 70 percent," he says.

The direct cost for the plate material undoubtedly will be higher, but one will need to factor in other costs like chemistry, processor maintenance, etc., to really get an understanding of the total cost of ownership for processless, the Agfa exec asserts. On the flip side, adopters will pay a cost of ownership premium for a processless platesetter (i.e., higher acquisition costs, higher service contracts) compared to violet technology, he says.

"CTP has been evolving for almost a decade now, and printers have been able to reduce their costs and increase productivity by adopting the technology, by in large without processless," Furman notes. "At the end of the day, what matters most to a printer is whether or not a technology improves cash flow and the bottom line."

Matching all of the features currently offered by wet-process plates is going to take some time, says KPG's Weitoff. "Therefore, those plates will remain the bulk of the business for many years," he asserts.

Given the industry track record he noted earlier, Weitoff expects there to be a lot of skeptics in the market. He thinks those people will be in for a surprise. "If you buy a thermal system today, you will have the option of going no-process in the future. I believe that more today than I did two months ago."
 

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