DIGITAL PLATE TECHNOLOGY -- Platemaking Loses a Step

BY MARK SMITH

Technology Editor

At the risk of having this sound like yet another Drupa story, the quadrennial international exhibition traditionally has served as a status check for industry innovations. Developments in printing technology often are marked in "Drupa time"—such as the Digital Printing Drupa, CTP Drupa and, for this year's show, the JDF Drupa. The concentration of international vendors and worldwide attention given the event put pressure on exhibitors to show that they are keeping pace with each other.

While not as broad-based of a trend, 2004 also heralded the Processless Plate Drupa. This technology has been talked about for years, some might say prematurely. Even though it wasn't always the doing of plate manufacturers, that build up made it time for vendors to "put up or shut up" about this expected Holy Grail of process efficiency.

In the end, what Drupa 2004 showed is that processless plates are here—sort of. It should be noted that Presstek Inc. would rightfully argue that it eliminated the need for plate processing—in the conventional sense—years ago. What the industry was still awaiting, though, was mainstreaming of the technology in the form of product offerings from multiple vendors and compatibility with a broader array of platesetters.

A number of the plates that have been introduced are positioned as "chemistry-free" rather than being truly processless. They require some type of post-imaging process—such as water rinse, wiping or gumming—before going on-press.

Another caveat to the story is that several technologies are still yet to be commercialized. At Drupa, there were claims and counter claims made about which plates were commercial products, working solutions (in beta testing) or simply technology demonstrations (alpha or even pre-alpha).

See the Savings

Vendors generally make the same case for processless technology. Eliminating the need for a processor does away with the costs, maintenance hassles and process variables associated with this production step. It also saves space, simplifies the workflow and can have ecological benefits.

All of the plate manufacturers seem to see small- to mid-size printers as the primary target market, at least for the current generation of plates. The obvious reason is, while a few of the near-processless products claim to support run lengths of up to 100,000 impressions, most of the plates are rated for far fewer impressions.

In addition, users can expect to pay a premium for these products compared to other digital plates due to the newness of the technology and limited production. Smaller shops are considered more likely to be willing to make this tradeoff for the simpler operation and space savings. They are less likely, on a percentage basis, to already have a CTP solution in place that would have to be replaced in part or as a whole, thereby adding to the cost of adoption.

Printers that do feel processless plates are a fit with their operations now have several solutions to choose from, and that number should grow to almost a dozen plates in the near term.

Presstek's primary CTP plate offerings continue to be its Applause and Anthem thermal ablative products, both rated for up to 100,000 impressions. Applause addresses what were widely viewed as shortcomings in the older Anthem product, including the need for a robust debris removal system in the platesetter and a water cleaning step after imaging.

The company has introduced upgraded models in its platesetter line, called Dimensional Excel, that are capable of imaging the plates at a 300 lpi resolution with a 16-micron spot size to support stochastic screening options.

In addition, Presstek had previously teamed up with A.B.Dick to offer the Freedom thermal plate material. It is said to use a chemistry-free, "sub-ablative" process that requires no debris removal system in the platesetter. The image area is revealed by a special water wash unit and supports up to 25,000 impressions.

The future of this product potentially could be impacted by A.B.Dick's recent Chapter 11 bankruptcy filing, if Presstek is unsuccessful in its bid to acquire the assets of the company.

Agfa Azura is a new chemistry-free, non-ablative thermal plate based on the company's Thermolite technology. Imaging is accomplished via a physical, rather than chemical, process in which thermoplastic particles melt together and adhere to an aluminum substrate. A "clean out" or gumming step is required in non-image areas only.

Providing Lengthy Support

The plate supports run lengths of up to 100,000 impressions and holds a resolution of 2-98 percent dots with wide exposure latitude. According to the manufacturer, it is intended for medium-volume applications and offers good robustness for pressroom handling.

Agfa's announced acquisition of Lastra was still pending final approval at presstime. The companies have stated an intent to keep Lastra's products as an independent brand, but were constrained from making more definitive statements until after the deal had been completed.

In the meantime, Lastra has been proceeding with beta testing of its Cosmic no-process thermal plate, which is based on switchable-polymer technology. The plate reportedly will support runs of up to 100,000 impressions, has an image resolution of 1-98 percent dots at 150 lpi and produces a green to yellow latent image. It is designed to work with standard thermal (830nm) platesetters and should be available in early 2005.

Kodak Polychrome Graphics says its KPG Thermal Direct no-process plate supports up to 75,000 impressions, is compatible with thermal platesetters currently on the market and releases no debris during imaging. It offers a resolution of 1-98 percent dots at 200 lpi and is suitable for use with 20-micron FM screening. The plate is compatible with a wide range of inks and fountain solutions, including alcohol and the most popular alcohol substitutes.

Shown at Drupa as a "technology demonstration" only, Creo calls its new Clarus PL product a "true processless" aluminum plate since it requires no gumming, processing or post-imaging treatment. Upon its commercialization, the switchable-polymer product is expected to handle runs of up to 50,000 impressions, support Creo's Staccato 20 FM screening and be compatible with 830nm thermal platesetters.

Creo characterized the product as pre-beta and says it expects to have a plan in place by the end of 2004 for its commercialization.

Fuji Photo Film simply claims to have a processless plate "under development." It reportedly will be based on the intelligent polymer technology used in the Fujifilm Brillia LH-NN thermal, negative plate for the news-paper market (set to be released in the fourth quarter of 2004) and uniformed grain technology used in the Brillia LH-PJ thermal, positive plate currently available in the Asian market. The product will also implement a new on-press development technology.

No time frame has been publicly announced for the technology's commercialization, but the vendor has said the final product should handle up to 50,000 impressions.

Konica Minolta has introduced a processless system for on- and off-line imaging applications. The off-line version uses a flexible, thermal plate material (TF-200) supplied in rolls for imaging by the SR-830 platesetter. A thermal sensitive, hydrophobic layer is exposed in a non-ablative process, with unexposed areas then removed on-press by the action of fountain solution and ink. The finished plate is said to be capable of 1-99 percent dot reproduction and supports stochastic screening. The platesetter outputs plate sizes from 12.8x15.6˝ up to 26x32.7˝.

Also taking a systems approach, but with an entirely different technology, is Glunz & Jensen. Its ink-jet computer-to-plate (iCTP) technology produces press-ready aluminum plates without chemical processing. The PlateWriter 4200 system (pictured on the left) jets a patented Liquid Dot solution onto a non-photosensitive aluminum printing plate. Imaged plates are then fed through a finishing unit that bonds the material to the plate's surface via a drying process. This unit, which is located just below the ink-jet engine, has a built-in gumming station to protect the plates from damage before going to press.

According to the manufacturer, benefits of iCTP technology include a lower capital investment and cost per plate compared to conventional platemaking. Its system operates in normal daylight conditions, supports FM screening (emulating a conventional 175 lpi screen) and is capable of imaging plates in two- and four-up formats (28x35.8˝ maximum plate size).

The range of technologies and capabilities represented in the current crop of products works against making any general statements about the plate category as a whole. Nonetheless, issues such as run length limitations, premium pricing, slower imaging speeds and need for post-imaging cleaning (in a few cases) have caused some to continue asking whether processless—or at least chemistry-free—plate technology is ready to go mainstream.

Individual printers will have to answer that question for themselves based on the particulars of their organizations and needs. Some industry pundits clearly got ahead of the curve, though, when they speculated about violet processless plate technology in post-Drupa 2004 discussions. That development is more likely to end up being part of a Drupa 2008 story.