Heidelberg has declared that its hand for new generation UV printing will include an LED UV option.
The press manufacturer thus joins KBA, Ryobi LED UV and Sakurai with LED systems for sheetfed presses. But unlike KBA and Sakurai, which are using technology developed by Baldwin or AMS, Heidelberg has worked with LED providers to build its own system. It is also supplying an LED UV compatible ink in its Saphira consumables range.
The first press into Europe is an eight-colour perfecting Speedmaster XL75 which has been installed at Swiss printer Abächerli Media. However, this follows on from 20 or so successful installations in Japan where LED curing is well established, partly to satisfy requirements to reduce the energy profile of industrial machinery and partly as a result of government support to enable businesses to take this step.
Demonstrations about LED UV are taking place within the Commercial PMC at the Wiesloch site which opened this summer. It runs alongside demonstrations with LE UV, Heidelberg's single-lamp UV system, and conventional presses with and without coating. The supplier believes in matching the press to the customer requirement, says Heidelberg UK sheetfed press specialist Matt Rockley.
The UK company has supplied an LE equipped press to Danish web to print business Lasertryck where the ability to handle the sheet immediately after printing is key to it ability to deliver simple jobs quickly, says Rockley.
But such performance is not always needed. He explains that if a printer is working on jobs where the run is 35,000 and there are multiple sections, there will be adequate time for a job to dry through oxidation before folding and stitching and there is no benefit to new generation UV technology. “Printers need to ask themselves 'Is this technology suited to my markets?'” he says.
Heidelberg has identified three markets where LED could play a significant role: where there are energy considerations forcing printers to reduce power consumption, which is the position in Japan; where the printer is positioned to offer very fast turnaround work; and where the printer wishes to be seen as a technology leader.
Rockley picks out another opportunity: taking on digital print. “New generation UV has not taken off in the 520mm format. Ink consumption is less and many of these printers are competing against digital and, like digital, an LED press is delivering an immediately dry sheet,” he says. Heidelberg first demonstration of LED UV in its technical area at the last Drupa, used this format of press.
Heidelberg says that its LED system is retrofittable on post 2008 Speedmaster XL75, Speedmaster CD102/Speedmaster CX102 and Speedmaster XL106 models. Its Drystar LED system has also been designed from the ground up with print production in mind. The power shuts off immediately on any stoppage, such as a sheet becoming wrapped around the unit.
While the UV energy generated by the diodes will not heat the sheet, the unit that holds the LEDs becomes hot and needs cooling, so needs to shut down quickly. Heidelberg's system will adjust automatically from the press control system to compensate for a narrow sheet, which others do also, and for the gap between sheets, which others do not.
It is not all LED. The company continues to offer LE UV which uses a single tuned mercury vapour lamp as well as conventional UV systems. The LE system is initially less expensive and while consuming less energy than conventional UV or IR/hot air drying, needs more power than an LED system. It is possible to have multiple systems on one press, either to cope with the range of materials or run lengths that a printer might encounter. A press with new generation UV curing for its print units may have a conventional UV lamp to cure varnishes, for example.
The LED and LE suitable inks are more expensive than conventional inks, so the greatest benefit comes from shorter runs. However, while a mercury vapour lamp may need replacement after several hundred hours use, Heidelberg is claiming a life of 25,000 hours for LED based on its experience with the presses it has running in Japan.
Whatever system is used, the data on power used is gathered by the Prinect Digital Print Manager system and is available to calculate a CO2 value either for a job or as part of an overall calculation of a printer’s environmental impact. It can also form part of the job record to an end customer that can include details of colour printed and variations reported through Analyse Point.
This now includes LED UV, coming to Europe after successful installations in Japan. The company argues that while very useful in certain areas, it is not the solution for every printer.