Occasionally while wandering the aisles of the many trade shows I attend, I see something truly revolutionary. The Heidelberg GTO-DI, and its successor, the QuickMaster-DI, are examples of revolutionary technologies that caught my eye when they were announced. At this year’s GraphExpo show in Chicago, while visiting the CreoScitex booth, I watched a demonstration of a new prototype press that seems revolutionary indeed. The press uses the CreoScitex’ SP plate exposure technology, a new twist on digital imaging for offset presses.
CreoScitex is not new to the digital-imaging industry. The company’s plate-imaging systems are resident on the Heidelberg Speedmaster 74cm DI press, and on the new Komori Project press — the 40-inch digital-imaging press unveiled at Graph Expo. These are breakthrough machines in their own right, and they have some amazing potential in an industry that is quietly moving away from conventional materials and methods in all manifestations.
The Heidelberg and Komori presses both use removable plates, imaged on-press to make their marks on paper. Each press is really a press and platesetter in one, the platesetter components being laser imaging systems mounted to each unit of the press. Unexposed, fresh plates are mounted, and the platesetter units run gently across each cylinder to expose the plates. They are both remarkable and highly productive machines that answer the demand for shorter press runs — and more of them — in today’s printing plant.
The CreoScitex SP system is one step more revolutionary. This is the Buck Rogers of plate technologies. The company showed a prototype of its invention on a 66cm press printing one color during the Graph Expo show. And, at every demonstration, the crowds were standing-room only.
SP is essentially the same laser imaging unit used on the presses from Heidelberg and Komori. But, unlike those machines, there are no removable plates. Instead, a permanent, blank, grained hydrophilic stainless steel plate is mounted on the plate cylinder. The exposure unit has, in addition to an array of lasers for exposing the image, an emulsion spray gun, a water nozzle, and a vacuum-cleaner head. The blank stainless steel plate is washed by the water nozzle and vacuum cleaner, then coated with an Agfa plate emulsion liquid, sprayed in several passes onto the cylinder to form a 6-micron thick laser-sensitive emulsion layer.
A historic note here: In the 1960s, we used plates called “wipe-on” where we would spread a liquid ultraviolet-sensitive emulsion onto grained aluminum plates — with a sponge — to create a photosensitive plate for printing. These plates were inexpensive and easily processed but usually suffered from inconsistencies of emulsion thickness, because they were hand-coated. In retrospect they were awful, but they certainly were inexpensive!
But back to CreoScitex’ invention: Moments after the coating is sprayed onto the cylinder, the lasers pass across the plate, exposing the newly sprayed emulsion, and then the press is run like a conventional press. Dampener solution dissolves any unexposed plate emulsion, and ink adheres to the oleophilic areas — those struck by the laser beams. It’s just like any other litho plate at this point, and it prints like any offset press with conventional plates. The demonstrator told the audience that a one-gallon bottle of emulsion will coat approximately 1,000 plate equivalents.
When the press run is complete, a wash-off process is initiated. The plate exposure unit crosses the plate cylinder again, this time spraying water onto the plate cylinder, and simultaneously vacuuming the residue — emulsion and ink — off the plate, making it blank again and ready for the next use.
In the prototype demonstrations, CreoScitex was able to wash-off, coat, expose, and print in a cycle taking only eight minutes. Though this was only a demonstration press, full production machines will use multiple imaging units to expose four or more plate cylinders in as many minutes.
Though plate mounting systems on modern presses consume five or fewer minutes, there is still the time taken to expose and process the plates, then wash-up when done. If the plates never have to be removed from the press, the speed of replating can be improved by a significant amount. Idle time, the biggest source of waste in a printing plant, will be reduced.
Though CreoScitex estimates that it will be a couple of years before such technology finds its way to a production machine, the crowds were wowed and eager to see the printed samples made by this technology. To say it was impressive is both a pun and an understatement!
Close examination of the printed sheets reveals dot quality, densities, and tonality that rival conventional plates and traditional printing, and the prototype’s resolution is equal to that of the production machines being sold by Heidelberg and Komori. This is clearly a technology that needs no wait-and-see to be adopted by press manufacturers or buyers.
Another advantage of a press with this SP technology would be a gapless image on an offset press. This means that the gap created by the plate and blanket grippers on conventional presses can be eliminated, making continuous printing possible with no break between one end of the plate and the other. Though an obscure concept, this might herald new presses that print on roll-fed material with continuous patterns, or printing of packaging materials without gaps. This would allow for waste reduction and the ability to print products like wrapping paper with ease. Most wrapping papers are printed on more costly gravure presses whose cylinders offer continuous printing without image breaks.
The only other gapless offset press in existence now is the new Heidelberg Sunday technology press announced at this year’s DRUPA show in Germany. This web-fed news press has a seamless blanket cylinder that reduces waste in printing and trimming on long-run newspaper editions.
The potential benefits of CreoScitex’ new SP plate technology will undoubtedly revolutionize the printing industry — once again. It will be fascinating to see where this new technology finds itself. I can imagine new generations of news presses, packaging presses, specialty presses, and short-run commercial sheet-fed presses using this technology in just a few years. Personally, I remain dazzled by this new product, and I applaud CreoScitex for bringing this new plate technology to market.
This article was last modified on December 13, 2022
This article was first published on October 10, 2000
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