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LED technology as door opener

Verlag Nürnberger Presse uses LEDcure system from IST Metz to open up new fields of business for coldset
By Klemens Ehrlitzer
Newspaper publishers have always been looking for ways to extend the use of their presses beyond the production of print editions with additional jobs. In this context, Verlag Nürnberger Presse asked itself whether the trend towards LED UV technology from commercial printing could also be successfully applied in the newspaper segment. To answer this question, the company has retrofitted its Colorman with a LEDcure system from IST Metz. As Jens Untermeier, Head of Web Printing, explains in this article, the experience gained in various tests was so promising that he will be targeting new business areas in the future with the possibilities offered by this technology.


The two daily newspapers 'Nürnberger Nachrichten' and 'Nürnberger Zeitung', which are produced on the publishing house's printing presses, are of great local importance. In addition, the sports magazine kicker, which is known nationwide among football fans, is also produced here. Together with other periodicals that are produced as third-party orders, the capacity of the printing presses is still only partially utilized.
LED UV enables a leap in coldset quality
For Jens Untermeier it was therefore obvious to take up the idea expressed at an IFRA event to considerably expand the application possibilities of the coldset process with the aid of UV-curing printing inks. The Nürtingen-based UV supplier IST Metz was approached as the supplier of the corresponding technology. The project partners agreed on a test installation of the LED technology in two steps. The first system was installed in May 2019, so that the first printing tests could already take place. With the integration of the second LEDcure system, which is planned for the end of September, the tests can be extended to double-sided color curing, so that the print products can also be marketed commercially.
But even the first results achieved with LED technology caused an internal sensation, reports Jens Untermeier. Very few people had expected that such a high print quality could be achieved with a newspaper press on various glossy papers. This has given rise to numerous ideas about the possibilities this leap in quality opens up for demanding third-party projects. With its clear focus on quality, the publisher does not see itself competing with web offset printers in the heatset segment. "For this market," explains Jens Untermeier, "other economic conditions would be necessary.
Project motivates employees
All the people involved in the LED project had already been involved in the run-up to the project, so that everyone was familiar with the various aspects of the technology. At the latest with the start of the test prints, a positive dynamic of its own developed among the employees. They were particularly motivated to adjust the technology so that the extensive potential of LED technology could actually be exploited. In prepress, this meant adjusting dot gain, RIP curves, etc., in particular. In the printing sector, it was also necessary to find suitable products, e.g. rubber blankets, printing plates, inks, dampening solution, cleaning agents, etc.
At present, the selection of LED-suitable materials for newspaper printing presses is small - this is understandable, since there is currently no established clientele for this. "Not yet," says Andreas Bosse, responsible for marketing and communications at IST Metz. "There is great interest in the possible use of UV technologies in coldset production. How great is the incredibly fast spread of information on the market, which shows that a LEDcure system has been installed in Nuremberg, even though there has been no official communication about it so far. It looks as if the market is just waiting for an initial spark that will bring the breakthrough."
In this situation, Verlag Nürnberger Presse is following the path of actively involving suppliers in the project. The blanket manufacturers involved - neither of which had any suitable products in their product range to date - can thus incorporate practical experience from the printing tests into the development of special blankets for coldset. The situation is similar with printing inks for LED use. Their rheological properties differ greatly from those of classic newspaper inks. This means that there is also a need here to adapt the ink formulation to the existing inking unit technology and the associated requirements. Even though Jens Untermeier believes that there is still a lot of potential for optimization in all areas, the significantly higher level of print quality can still be seen.

Higher color strength and more brilliance in images
This quality improvement, which is an enormously important factor for the project, has various causes. In LED printing, higher density values can be achieved than in conventional newspaper printing. As a result, the test prints showed a much higher ink coverage. In the printed image, this leads to stronger colours and more brilliant images.
This is in line with expectations, so that the product range has been considerably expanded in terms of both print quality and substrate selection. The publishing house Nürnberger Presse benefits from the fact that there is hardly any need to acquire new customers, as the majority of existing customers already have a demand for high-quality print products. In the tourism segment, for example, where the Nuremberg publishing house has several customers, publications live from attractive photos of well-known travel destinations. These images are far more effective in LED printing than in classic coldset printing.
However, the supply industry still has to adjust to the expansion of the range of substrates if the various ideas are to be implemented. Currently, the search for special materials such as transparent paper or label material is still a challenge because they are not yet available in suitable roll form and with suitable core sizes.
Higher quality more than compensates for additional costs for ink
Jens Untermeier does not consider other arguments, which are often cited as obstacles in the discussion about LEDs, to be serious. These include, for example, colour costs and deinkability. "When it comes to colour, many people make the mistake of comparing only the price per kilo of colour. In our tests to date, however, we have found that ink consumption is significantly lower." While in newspaper printing a large part of the ink is absorbed by the paper, the ink for LED UV printing is a so-called 100 percent system. When printing on coated paper qualities, the ink film lies completely on the surface after UV curing. "This is the reason," says Jens Untermeier, "that in practice there are only minor additional costs for the ink. According to initial estimates, they are likely to be in the single-digit percentage range. The fact that the total production costs increase slightly as a result is more than compensated for by the large increase in quality". Further test prints are planned in which the exact consumption is determined, so that the estimated values can be made even more precise.
Inks with comparable deinkability
A second point that is often put forward as a counter-argument to LED technology is deinkability. Important progress has been made in this area recently. For example, the printing ink manufacturer Siegwerk has investigated the deinkability of LED UV inks in the paper recycling process in a joint research project with the paper manufacturer Stora Enso. Building on this, Siegwerk has developed an offset ink system for LED printing that is comparable to conventional oil-based sheet-fed offset inks in terms of deinking properties. The deinkability was tested with heavy and lightweight coated paper as well as uncoated, improved newsprint. INGEDE Method 11 and the EPRC Scorecard were used. Both are officially recognized industry standards for determining and evaluating deinkability.
Experienced partners in LED technology
The new ink system was also the focus of an information event held by Siegwerk at the IST Metz premises in Nürtingen in March 2019. According to Jens Untermeier, the fact that the publishing house Nürnberger Presse chose IST Metz as project partner and supplier of the LED system was due in particular to the company's extensive experience in the printing industry with all variants of UV technology. The hubergroup was chosen for the printing ink part. It has been the main supplier for many years and also has experience with LED inks.
Tricky integration on your own initiative
The company itself has gathered a lot of know-how about the integration of LED technology into a newspaper printing press. With a great deal of meticulousness, it was involved in the installation of the LEDcure system, including the control cabinet and cooling unit. The tricky installation in the printing unit was carried out by the in-house technicians. In order to accommodate the LED unit, the fitters had to convert the printing unit and construct a special frame. The electricians were responsible for setting up the electrical connections and signal transmitters for machine control. In addition to many other details, the infeed rails were also rebuilt so that the automatic infeed of the paper web is still possible without any problems.
Although an inspection by the employers' liability insurance association was not necessary at this stage, the company invited them to inspect the shielding and the installation situation in the building. The technical inspectors, who were very familiar with the IST Metz system, only submitted a detailed suggestion for improvement, but otherwise had no complaints. To this end, they offered another visit in order to carry out safety measurements after the installation of the second system.

www.ist-uv.com

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