DRUPA highlights graphic-arts technology trends
The world's largest trade fair for the graphic-arts industry, DRUPA (the name is derived from the German words for printing and paper, or Druck und Papier) was held May 16–19 in Düsseldorf, Germany.
The world's largest trade fair for the graphic-arts industry, DRUPA (the name is derived from the German words for printing and paper, or Druck und Papier) was held May 16–19 in Düsseldorf, Germany. The event is held every four years and is said to be a monitor of industry trends.
One of the major applications of lasers in graphic arts is in computer-to-plate (CTP) devices—imaging machines that write to offset and flexographic printing plates with thermal and visible-light laser systems. Approximately 15,000 CTP systems are in use worldwide; sales for these systems in 2004 will likely reach 2500 units. Analysts say that, only 20% of print shops are using CTP, while others still use film imagers, which are usually equipped with a single red-emitting (680-nm) laser diode. These shops are expected to adopt CTP within the next six to eight years.
Lasers used in the CTP market are primarily of three types: green frequency-doubled (510-nm) YAG lasers, at one per CTP system; violet-emitting (450-nm) laser diodes, at one per CTP system; and near-IR "thermal" (810-nm) diodes, at 19 to 96 diodes per CTP system. Currently, the world market is split in half, with about 50% relying on visible-light systems, with the rest devoted to thermal imaging.
Some significant trends for lasers with CTP were evident at DRUPA. For example, within the next three to four years, all systems using green frequency-doubled YAGs will be phased out and replaced by violet-diode systems. The standard violet laser diode for the graphic arts will have an output power of 60 mW; suppliers other than Nichia will be welcome. The industry is interested in even more-powerful violet diodes, so that so-called processless plates could be used with violet systems in the future.
Thermal imaging—a leading CTP technology for the last six years—is expected to drop in market share. There are two reasons for this. First, small-format systems will dominate CTP sales from now on and for these applications, technologies other than thermal are favored because they are less expensive, use only one diode or even none, and have less-complex optics. Second, as was evident at DRUPA, systems using either inkjet heads or a conventional UV lamp (in combination with a Texas Instruments digital-micromirror device) to image standard plates will gain a significant market share in the years to come (see figure). Thermal systems will not disappear, but will be restricted to a portion of the market below 20%.
Based on an inkjet printer, the PolyJet (TechNova; Bombay, India) is an example of what future CTP systems without any lasers might look like.
Trends at this year's DRUPA confirmed that a major change in CTP technology occurs every three to four years. Starting with the blue argon-ion laser as the predominant light source in 1990, the industry switched to the green frequency-doubled YAG in 1994, to thermal in 1997, and to violet laser diodes in 2000. Now it appears that CTP without any laser at all (the UV-lamp/digital-micromirror combination) will gain considerable market share in the future (see figure).
Michael Mittelhaus is a consultant in the graphic arts industry and can be reached at www.mittelhaus.com