Go straight to digital offset printing machine

The famous offset press makers believe that the future belongs to direct printing. CaryHolland investigated Drupa's post-market strategy based on technology and market. Everyone expects Drupa to be a digital watershed. Most people in the industry think it is a digital press, so the number of direct imaging offset presses is surprising. The industry does not intend to begin immediately, but it is clear that all major printer manufacturers believe that offset presses still have a future. Direct imaging is just a solution. Although Heidelberg has been selling GTO/Quickmaster DI machines for six years, it has only 1,500 units of various models installed worldwide, including 60 in the UK. Even so, it can't be compared with companies that have sold more than 1,000 Digimaster 9110 monochrome digital printing systems around the world, although Digimaster only launched in less than two years. There are now 10 major press suppliers offering about 13 direct imaging presses, which together guarantee a rapid increase in the number of installations. In addition, this industry is now the best time to use this technology. Live jobs are now being submitted in the form of digital data. They have to go to computer-based platemaking. Direct imaging does not make sense unless a high percentage of jobs are delivered digitally. Moreover, turning to direct imaging is not as simple as replacing old models with new ones. Like CTP, it basically has to have all the digital processes, which is also more companies that have not yet reached this point. Another factor of direct imaging is the changes that will occur in the market. There is an increasing demand for short-run color prints. Current market research shows that there is a significant increase in the market for less than 10,000 copies of four-color prints. Direct imaging is ideal for printing plates that are printed under 20,000 impressions. For example, Heidelberg estimates that Quickmaster DI's most economical print is about 200 to 5,000. Direct imaging fills the gap between the toner-based digital press and the traditional lithographic offset. In addition, compared with digital printers, direct imaging has a higher print quality. With standard printing inks, spot color printing and on-line finishing can be performed to suit various papers. There are also advantages compared to the traditional printing method using CTP. Since the printing plate development process is dispensed with, it is not necessary to take the printing press and the total production time is reduced, which is a consumable cost. The problem of the environment is even more negligible. There is no need for a large number of operators and a large floor space. In addition, the content of the printing can be changed at the last minute. However, direct imaging has its drawbacks. Printing presses are much more expensive than traditional presses, and although the price will fall, if the cost of a metalized CTP system is considered, the difference will not be too great. There must also be a clean printing environment. If the imaging head does not work for any reason, a single model machine will lose expensive printing time. Although the printing turnaround time is much faster than a conventional offset press, there is still the same length of drying time to end the printing of the job. Therefore, DryStar's compact infrared drying device used on Quickmaster DI, which Heidelberg introduced on Drupa, said that the drying time was reduced to less than one hour, combined with a special paper ink combination developed by Zanders and BASF. To further reduce the drying time, in fact, do not have to spray. The shortcomings of direct imaging can mostly be overcome in new developments, making this technique worthy of further attention. Direct imaging can be said to be plate making on the machine, that is, imaging is performed after the plate is mounted on the Cylinder of the printing press. This is generally automated, using either a traditional plate-up system or Presstek's internal automatic plate cylinder equipment. With this, the plate material roll is stored in the cassette on each roller. With the new plate in the plate, automatically positioned, and then imaged, the used plate is taken up by the reeling shaft. This solution is for smaller format printers using Presstek's PearlDry Plus waterless offset thermal plate, which is used by the 74Karat and Adast Dominant 705 DI four-press machines. The Sakurai 474 EPII DI press also uses Presstek technology, but it uses a development-free thermal Pearl Gold plate. Not all markets have owned Presstek. Dainippon Screen’s True Press 544 and 744 presses are basically a combination of graphic recorders, displays, and printers. They use Mitsubishi’s silver salt digital media or Is Agfa's Setprint, and Komori's Project D press uses a development-free thermal plate, which is currently a product of Kodak Polygram Image and Agfa. In addition, Asahi Chemical Company offers a third option. There is also a similar division in the imaging head. In addition to screen-based machines, Project D, Heidelberg Speedmaster 74 and 74 Karat machines, all presses use the Presstek system. In the last three examples, the thermal imaging technology of CreoScitex was used for imaging and was installed in CreoScitex's CTP system. The company says it has the fastest on-board imaging speed and highest optical resolution. On the other hand, the new Profire integrates with Presstek's imaging system introduced on Drupa, which believes that imaging on the press is clearly more suitable and easier to achieve. It integrates 4 laser diodes in one channel and all system components are in a compact package. It is said that the size is equivalent to an automatic ink roller cleaning or blanket cleaning system, added to a modular configuration, and multiple diodes can be selected depending on resolution and format (from A4 to A0). In addition to imaging systems, printing presses tend to be similar to traditional machines, but the degree of automation is higher. The Speedmaster 74 DI and Oliver 474EPII DI can be used in both conventional and digital applications because the imaging head is retractable. The configuration of the larger model is often the unit structure, while the smaller format models often use the satellite five-roller design, which is more compact. However, there are two exceptions. The first is 74 Karat, which is a joint venture between Se Angel and KBA. Its purpose is to produce a printing press that requires less offset printing knowledge. In fact, all operations are automated. The second special case is MAN Roland's DICOweb. As its name implies, it is a desk-press. Although it was announced that Didde had signed an unbounded memorandum of understanding with Presstek to produce the first hybrid DI UV web press, DICOweb is still the only web press to date. The heat transfer technology it uses is unique, which allows the “printing plate” to be used again after imaging. It can be imaged and re-imaged on the press, so it gets its name: Digital Change Over (abbreviation DICO) ). Imaging can also be performed using a thermal conversion tape with a polymer coating. The width of the tape is close to the width of the tape and it is placed in the box like a video tape. There are the equivalent of 20 plates. Once the tape is in contact with the plate surface, the Squarespot thermal exposure head of the CreoScitex laser diode, based on digitally generated data, spots the heated coating and transfers the inked material to the plate. In order to obtain a firmer plate, the plate can be heat-cured and then conditioned. The plate cylinder can be printed on conventional web offset printing. After the printing is completed, the ink and the heat-sensitive conversion material are removed from the drum using a special wiping solution and a cleaning cloth. At this point you can image the next job again. Like 74 Karat, DICOweb's design emphasizes flexibility. For example, its print length can be increased to 200mm, and caps of different thicknesses can be used to replace plate cylinders and blanket cylinders. The imaging part and the mechanical parts of the press have to be separated to ensure that DICOweb users can later adopt new imaging technologies and different printing technologies, such as the currently claimed convertible polymer technology. With this, the surface of the printing plate can be reused, and the on-board CreoScitex SP system can be used to coat the surface with a liquid polymer instead of a thermal tape. Agfa is the only company that has already claimed to have such a coating, although other companies (such as Asahi) are also in trial production. Agfa's LiteSpeed ​​is based on Thermolite plate technology. This water-based coating contains fine thermoplastic particles that are melted by the heat generated by laser exposure and then form a printed image. The imageless area is soluble. After wetting the coating with a dampening roller with a conventional dampening solution, it can be removed with the inking roller and printed on the first few sheets. The main benefit of this system is its potential to reduce the cost of platemaking. The performance is equivalent to a traditional plain printing plate, but the number of prints does not exceed 20,000. Agfa said that Mann Rolland and other printer makers are interested in this technology, including Komori and Shinohara. However, Agfa estimates that it will take less than a few years to put into commercialization. Although direct imaging is actually considered as a supplement rather than competing with traditional offset printing - so is digital printing. Undoubtedly, Heidelberg used the 2010 machine to provide direct imaging options for all sheetfed applications. It can be a bigger force in the future.