Platesetting Faceoff: No-Chemistry Violet, No-Process Thermal Duel at Nexpo

By: Jim Rosenberg and Mark Fitzgerald

It was clear at this year’s Nexpo that the battle between violet- and thermal-exposure platesetting technologies is as hot as ever — though each side sounds a triumphant note.

“North America is thermal,” Brandon Casson declared flatly in an interview at Southern Lithoplate Inc.’s booth.

Casson, the company’s national sales and technology manager, argues that the the majority of early (computer-to-plate adopters have chosen thermal, and that the the smaller papers that have not yet taken the CTP plunge will opt for thermal as well.

A white paper from Agfa, however, contends that almost two-thirds of newspaper CTP installations “have been with violet platesetters.”

The rival sides have been slugging it out for several years, arguing the merits of up-front versus ongoing costs, relative plate sensitivites, laser cost and service life, and processing requirements.

This year, Nexpo marked the introduction of a chemistry-free violet plate and a processless thermal plate.

Arch-rivals Kodak and Agfa are the biggest players, respectively promoting thermal and violet technologies, although Agfa sells thermal systems to commercial customers (including the chemistry-free Azura plate) and Kodak reportedly sells violet-sensitive plates to newspapers overseas using violet systems.

The two technologies vie not only for those converting to CTP, but also for those with aging ND-YAG green-laser (or even older) systems.

A third, comparatively short-lived option — developed early but improved and accepted for newspaper use late — is ultraviolet platesetting, which uses a high-speed version of conventional analog plates.

But UV platesetters are no longer offered by the basysPrint business of Punch Graphix (laserless light source focused by digital micromirrors) or alfaQuest Technologies (UV laser diode exposure).

A year ago, however, Punch Graphix announced it already had achieved success in customer-site testing of a processless plate for its basysPrint UV-Setters. Commercial availability was expected about now, but basysPrint imagers for litho plates are no longer sold to U.S. newspapers (MacDermid Printing Solutions, however, offers basysPrint machines for UV exposure of photopolymer flexo plates), and there has been no further word on the fate of the processless UV plate.

So the competitors are now fairly down to proponents of heat and light.

“It’s that small community paper that’s got the pent-up [demand] for it, but nobody’s showed them how to do,” Casson said.

At Nexpo, though, Southern Lithoplate and another big thermal plate and platesetter manufacturer, Kodak, showcased products aimed at those smaller newspapers.

Southern Lithoplate introduced the lower-cost PlateRite News 2000 LE, a laser diode platesetter with slower throughput designed for small- to medium-circulation newspapers. The machine, with an introductory price of $69,750, can be the key part of a turnkey solution to CTP for about $115,000, Southern Lithoplate said. “If you really shave it, you can do it for $100,000,” added Josh Goodin, the company’s director of research and development.

The PlateRite News 2000 LE accommodates plates from 11.4 x 18.1 inches to 38.5 x 26.9 inches. The 32-channel head images 26 to 30 doublewide plates per hour, but can be upgraded to a throughput of 42 doublewide plates per hour, Southern Lithoplate said.

“This is for the paper that goes through 500 plates a month,” Goodin said. Southern Lithoplate is also positioning the machine as backup equipment for a larger paper that wants to build in some redundancy.

Not far away on the showfloor, Kodak spotlighted the lower end of its five-model Trendsetter News line of thermal CTP devices. Trendsetter model speeds range from 60 to more than 240 plates per hour.

Kodak’s competitive advantage, the Rochester, N.Y.-based firm believes, is its “processless” platemaking technology. The plate can go straight from the platemaker to the press without any chemicals or other processing, including a “wipe-down” stage, said Balfe Bradley, a product application specialist with Kodak.

“We are the only true no-process plate out there,” Bradley asserted. “It goes straight from the platesetter to the press with no steps in between.”

The plate lasts an hour to an hour and half in white lights, and is usuable for four hours in yellow light. “You can get 100,000 impressions under decent conditions,’ Bradley said.

Because the plate needs no special inks or fountain solution, it has clear environmental advatnages, added Bruce Davidson, Kodak’s regional prespress consumables leader for the Americas.

Thermal is holding its market because of its speed, and the resolution capabilities with the Staccato screening that Kodak includes in its platesetter systems. “Also, you can hang [a thermal plate] on the press, and get a good copy within 100 [copies],” Bradley said.

As with processless thermal, the chemistry-free plate announced at the show, at least initially, also will be aimed at smaller newspapers.

Promoting strong image contrast and no on-press contamination, Agfa debuted its expected chemistry-free non-ablative plate for computer-to-plate output as an environmentally sensitive product with much less waste and behaving like plates with which users are already familiar.

“It effectively works as a 91 V on the press,” Emma Isichei, Agfa director, newspaper segment, worldwide, said, referring to the violet version of Agfa’s widely used N91 plate.

Exposed by a 30- to 60-milliwatt blue-violet laser, the chem-free plates can be imaged on most existing violet devices. From there, processing consists only of the same preheat section and gumming stage. No chemistry is required to develop the image.

Agfa points out that eliminating developer dispenses with a chief variable affecting image quality. It also means a reduction in equipment maintenance – chemistry replenishment and processor cleaning.

Demonstration at Agfa’s Nexpo booth relies on a “normal processor that has been modified” to provide only those stages required by the new plate, according to Isichei. GDuring the gumming process, the non-image area of the plate surface (not hardened by the laser) is removed.

“The chief difference with this technology is that there is a latent image that you can see,” ensuring that the right plate is mounted at the right press position, said Isichei.

Given its 150,000 run length, the plate will be marketed to entry-level users before being sold to larger sites, according to Agfa.

Agfa began talking about the plate last year and by winter was planning tests. At Nexpo, Isichei said “we plan to release it at drupa 2008” — the giant quadrennial international print technology trade show, in Dusseldorf, Germany. In the intervening year, she continued, the plate will be field tests at various customer sites – where run length will be among the characteristics tested.

Also during that time, Agfa will continue work on a clean-out unit with preheat and gumming (to act in place of a conventional processor), which “is still in R&D,” said Isichei. An existing prototype unti will be used in field tests. But from the start, she said, “if you already have a capital investment, you can very easily build upon that, chemistry free.”

Plate pricing was not quoted, though presumably Agfa will hve something to say on price at drupa.

At this point, the only acknowledged limitation is that even using the fastest imagers, throughput tops out at 160 plates per hour owing to clean-out unit speed.

Users will have the option of modifying an installed processor (basically removing the middle stages) or buying a clean-out unit along with an imager — in which case the up-front and operating costs of a clean-out unit should be less than the cost of a conventional processor. Also, without a chemical-development stage, the clean-out unit will occupy a significantly smaller footprint than a processor.

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