The new generation UV movement, where UK printers lagged behind printers elsewhere in Europe, has finally taken hold in this country.
Komori’s H-UV technology is market leader in this country with more than 100 press units printing with the appropriate ink. Reports from users support claims for the benefits while saying that the supposed negatives, usually the raised price of the ink, have negligible impact.
The conversation around new generation UV has reached the point that the potential of retrofitting systems to existing presses or doing so to make a used press more attractive, is now openly discussed.
Benford UV has fitted a Lithrone S29 at Selsey Press with its EcoUV system; Hedgerow Print has a similar press using a GEW lamp system. Now retrofit UV is available from AMS in the form of LED, IST for both single-lamp and UV systems, Eltosch likewise and can also be supplied by original press suppliers, Baldwin having worked with Komori to perfect H-UV can also retrofit LED systems.
AMS European director Carsten Barlebo points out that the UK is lagging behind mainland Europe where AMS is installing one system a week across the continent. North American impact is even greater as AMS began installing retrofit LED systems there in 2008.
Komori has recently fitted out a six-colour B1 press with an H-UV system. Heidelberg is in advanced discussions about retrofits and Manroland presses have been retrospectively fitted with UV systems, albeit conventional UV in the instance of Jaymar Packaging and KEP. In mainland Europe, Ryobi presses have been fitted with new generation UV curing from both Baldwin and AMS.
The US has led the way in the retrofit movement, possibly because every press sold has to be imported from Germany or Japan, and the upgrade option is a financially attractive alternative to buying new. AMS began this way, Benford has successfully upgraded a number of machines and others can point to installations.
In the UK, West Park Graphic Equipment lists two presses with new generation UV and it supplied the press to Hedgerow Print in Crediton. DPM is watching developments and has fielded inquiries but has gone no further as yet, but Bill Jones, managing director at Exel Graphics, says that the buzz around the technology is spilling over into serious interest.
He says: “We are currently in negotiation with seven UK printers, mainly B2 users, all exploring this LED/single-lamp UV drying option. We can assist independently regarding what options are available and as a used machinery dealer, we are in a position to offer several options ranging from £60,000-90,000 depending on manufacturer and format.
“We can offer a turnkey independent solution to the printer, allowing part installation while the press is undergoing refurbishment, then coordinating the final installation and commissioning alongside demonstration.
“It can also have the added benefit of allowing for a single-source invoice for financing purposes.”
West Park sales and marketing manager Simon Jackson says that among the presses advertised with new generation UV is a ten-colour sheetfed press. “As the technology is taking over on the new side of things, the secondhand part wants to get involved as well,” he says. “And new presses are starting to feed through to the used equipment market. There is definitely interest in the subject.”
The Leeds dealer is happy to work with suppliers like IST, Benford and Grafix, says Jackson. BBR Graphics is understood to be working with AMS as its proposition in the new generation UV retrofit field.
What a secondhand dealer cannot do is offer H-UV as this is a package, including Baldwin technology, that Komori has put together. Komori will offer this as a retrofit, while single-lamp UV systems can be supplied by the other suppliers mentioned.
Retrofitting and preparing a press for new generation UV is simpler than upgrading a press to accommodate standard UV. The power demands are less. At Blackmore where a conventional Speedmaster SM74 was replaced by a KBA Rapida 105 with LED UV, the cable previously needed to power the dryer became completely superfluous.
Crucially there is no need to fit extraction equipment as the narrow sensitivity of the inks means there is no ozone generation. Ozone is a VOC and must be ducted to the outside air where it can break down safely.
Special seals over bearings are also unnecessary. There is no need to change the delivery to cope with heat from the UV systems because there is no heat transfer to the substrate. Nor are special grippers needed to avoid casting shadows which prevent UV energy reaching the ink.
With an inter deck system and standard UV inks, the ozone poses a risk to polyurethane gripper tips even where the troublesome chemical is ducted away from the press. In LED UV installations in commercial printing where there is no inter deck curing, this measure is not needed.
Water cooled rollers are recommended though not essential except for longer runs where the more viscous UV is apt to lead to more heat building up on rollers. Likewise ink agitators are preferred though not necessary. It depends on the shape of the duct, whether steeply angled or shallow.
The advice is to run with IPA in the fount, but Blackmore, running the UK’s first KBA Rapida 105 LED UV, has settled on a set up with Flint Xcura inks that does not need IPA in the fount.
It will be a case of finding what works in each set up. Likewise printers will discover the performance parameters of the press. UV inks may have a greater tendency to fly than conventional litho inks, which may keep print speed within the maximum.
New washing systems and roller coverings will be needed. The washers and fluid need to be capable of cleaning the different type of ink, demanding a different solvent and therefore management of this to prevent inadvertent mixing with standard washes. The pipework will need to be considered when making the change.
Roller coverings need not go as far as a covering that is designed for a conventional UV system. Hybrid coatings designed for presses that can print with both technologies should be suitable and will be more durable than UV-only coatings.
Again a system of recommendation, trial and error will lead to the right answer. That combination will of course change as developers come up with new combinations of consumables and materials to deliver results on the new technology. Already there have been advances in technology to reduce the degree of yellowing associated with varnishes developed for narrow width UV.
The UV units themselves will need cooling. They may not generate heat on the surface of the substrate, but as neither technology is 100% effective at turning electrical energy into UV radiation, the rest will become heat which will need ducting away from the press.
AMS has partnered with Technotrans to solve this issue. Non LED technologies may leave some residual heat that can be convected into the surrounding area, but not enough to cause problems.
Another area to consider is the press wiring loom. It will need inspection to ensure that the chemicals associated with UV printing cannot result in a long term problem. This will affect older presses rather than the latest models where UV compatibility is often built in.
It is also straightforward to build into the press control systems. The cabinets for an LED system are compact, those of a mercury vapour tube not quite so small, but small compared to an IR unit or conventional UV set up.
The control points can be built into the press console and into the delivery of the press, perhaps replacing a redundant spray powder control switch. Instant off systems are a feature of LED systems where the generation of energy is entirely digital.
It is possible to fit most presses with the technology which sits in the delivery. Earlier LED systems needed to be positioned close to the surface of substrate in order to deliver the energy levels needed. Those shown by Ryobi at Drupa 2008 for example could only cure to limited ink levels on a restricted range of papers.
Then the LEDs needed to be placed around 30mm from the paper, Now LED technology has reached the point that the diode array can sit 80mm from the ink, giving greater scope over positioning.
It remains difficult to retrofit on a press with a low pile delivery, say a Komori Spica or a Presstek DI, but says AMS chief executive Steve Metcalf: “We can essentially fit LED UV to any press model regardless of the age of the machine so long as there is sufficient mounting space. Presses with low pile delivery are sometimes a challenge and may require additional engineering.
“But in general we can fit LED UV into machines that simply are not designed to accommodate any other type of curing device.”
Blackmore put in a KBA Rapida 105 with LED UV, the cable previously needed to power the dryer became completely superfluous.
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Heidelberg will manage the retrofit of LE-UV or LeD-UV on XL generation presses, while directing enquiries for earlier machines and those from the CX/CD/SX to its ten-year partner IST.
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A Roland 706 sourced from the Czech Republic, has been commissioned by Crewe's Jaymar Packaging and retrofitted with UV lamps by IST (UK).
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