08 September 2014 Analogue Printing Technologies

New generation UV printing

Generation next: New generation UV printing is set to be the Next Big Thing to happen to the printing industry. Why?

New generation UV printing has reached the UK, arriving here six years after Ryobi introduced LED UV curing to the world at Drupa 2008 and four years after Komori showed its H-UV technology at Ipex 2010.

Along the way Ryobi has shipped more than 150 LED equipped presses, Komori more than three times that number, Heidelberg and KBA are starting to sell machines with this technology and there are also machines from Mitsubishi and Sakurai with LED curing. Then there are hundreds of presses worldwide which have been retro fitted either with an LED UV diode array or a single-lamp UV system. And now the UK has six installations.

Japan remains the main market where new generation UV technology outsells standard litho printing, but Komori has made huge inroads into France and the Benelux countries; Heidelberg and others are doing well in Switzerland and Air Motion Systems, the leader in retrofit technologies, has successfully fitted LED systems to presses across North America and is making inroads in Europe. New generation UV printing is not going away.

The new generation technology is distinct from classic UV in a number of ways. Classic UV will typically use a three-lamp system to generate the UV energy to trigger photo initiators into a polymerisation process trapping ink pigments in a strong lattice structure. The ink does not dry through absorption into the material printed nor through evaporation of the solvent carrying materials.

However, the classic UV process is a broad spectrum approach where energy is generated as heat and as UV in wavelengths which cause ozone. This is considered an environmental hazard and has to be ducted to the outside air where it breaks down in the atmosphere. The technology is hugely inefficient, consuming vast amounts of energy. It is, however, widely used in carton printing where the UK has led the way. Perhaps this separation between commercial and packaging is one reason for the slow uptake of the technology here.

The advocates for new generation UV point out that there is no ozone generated, that the UV emissions do not heat the substrate, and that whatever is printed is perfectly dry when it reaches the delivery. With the growth in uncoated papers this is an especially welcome feature. What is not apparent yet because there are so few UK installations is that quality is a step up.

With classic UV, the inks can appear flattened, there is greater dot gain and there can be feathering of the image. In carton this is less of an issue than preventing migration of unwanted compounds through the substrate into contact with the product. But with new generation UV there is no loss of lift compared with standard inks, no dot gain because the sheet is dried immediately before the inks have chance to spread. There is also a thinner ink film, again with this really noticeable on uncoated papers. Details that on any sheet can be lost in shadows remain visible.

The inks are expensive and will not fall to the level of conventional inks, which makes this a process that suits companies with relatively short runs (ie where the ink is not a margin busting factor); that print extensively on uncoateds and non-absorbent substrates; that need to turn jobs the same day (perhaps for a premium); that need to fill the gap between the service aspect of digital and the cost/quality of litho.

The technology divides in two: single-lamp systems pioneered by Komori and Baldwin and endorsed by Benford UV in the retrofit sector; and LED UV promoted by Ryobi, Sakurai and by AMS in the retrofit market. The end result is the same, but at the moment the single lamp systems offer greater flexibility, certainly to ink makers in the choice of photo initiators and other components. At first Toyo was the only ink available. Now Huber is endorsed by Komori and in LED, Flint and Sun have joined the Japanese.

The German press manufacturers are beginning to wake up to the opportunity, not least because it is essential for success in the Japanese market. Heidelberg showed LED UV at Drupa, but has had more success with a single lamp system it calls LE-UV – Low Energy because the lamps use less energy than a standard UV set up and potentially less than a hot air/IR dryer. Now the first LED UV machine will be installed in Europe next spring. Before then the UK showroom will gain its own demonstration machine. “There is a power saving over LE-UV with LED,” says press specialist Matt Rockley. “And we can supply either according to what a customer wants. But if the extra ink costs contributes 3-5% of the total cost of a job and the company is running on a total margin at that level, you would have to ask can you sell the job for more?”

Rockley sees greater potential in using the technology to enhance inline coating where it is easy to achieve a range of effects, including pin sharp spot varnishes. A German printer saved €400,000 a year by retaining spot varnishing on a watch catalogue that had previously been put out. “Because UV inks retain the lustre of conventional inks, in the luxury goods sector there’s benefit in print and coating,” he says.

Another application is in web to print where the job can be finished on the day of order, provided the printer can levy a higher price for this service. “And because there are no gutters for the slowdown wheels to run down, there’s a 14% gain in printable space for planning.

“We are taking this very seriously indeed, because for certain customers it really works,” says Rockley, “but printers really need to do their homework. Success is more than just a dry sheet, it’s about super fast makeready and reducing waste as well.”

Heidelberg’s LED system has been developed in house and has been helped by the greater availability of powerful LED diodes. These remain expensive, but on the other hand are extremely long lived and require no start up time. Doubts about their potential surfaced when first launched, but now says LED UV expert Adrian Lockwood, managing director of ITL, there should be no concerns about their ability to work at press speed and full ink coverage. “You get far more penetration with LED than with normal wave lengths,” he says. “It’s going to be interesting to see what happens by Drupa, but this technology makes offset much more like digital.”

ITL’s work has concentrated on the inkjet market where LED is used in label presses and on wide format machines. The inks are more fluid than sheetfed inks with simpler to manage chemistry. But the advantages of instant cure, low energy and no heat generated remain the same.

AMS has been offering LED UV almost as long as Ryobi and like the press manufacturer has enjoyed rapid adoption in recent months. It has been working with Flint as its ink partner as Flint develops a whole range of Xcura inks for LED UV. At Ipex AMS announced a partnership with Technotrans , because cooling is needed for the diodes themselves though the UV they emit generates no heat. More recently it has struck a deal with KBA, by which KBA can retrofit the AMS system to KBA presses, or those of another manufacturer. The LED array needs to be around 100mm from the paper at maximum to be effective and says AMS chief executive Steve Metcalf, these are compact enough to fit on almost any press. There are no moving parts and no venting needed. It is also possible to have flexible mounting units to move the array to different positions on a press.

Provided there is enough space to accommodate the fitting, the age or model of the press is irrelevant, though those with low pile deliveries may require some extra engineering. “In general we can fit LED UV into machines that simply are not designed to accommodate any other type of curing device,” he says.

Like Heidelberg, KBA had LED UV on the stand at Drupa, but pushed the single-lamp system, HR-UV, to start with. Now it is building presses that are preprepared for LED UV. It will offer LED as an extension of its VariDry system and will fit it to any sheetfed press in the KBA portfolio from the B3 Genius to the Rapida 205.

“LED is cool, it offer instant start up and the diodes last many, many years – 20,000 hours compared to 750 hours for a mercury lamp,” says area sales manager Craig Bretherton. The life of the mercury lamp is less affected by its operational hours than by shutting off and starting again. Currently while LED is good for commercial printing, KBA does not consider it suited to packaging. Nor to end of press coating where a standard UV lamp is preferred, if only because of the cost and availability of high sensitivity varnishes.

“But one big area of interest is in perfecting presses running both HR and LED UV,” he continues. “There is a perfectly dry sheet and because of this there is no need for protective jackets to prevent marking and both sides are printed perfectly. And there is no need for spray powder in the stack to prevent the sheets sticking together.”

KBA has installed long perfecting B1 presses with the technology in Belgium for very short run printing, 2,000 sheets average, where there is little difference in the price of ink whether printing UV or conventionally. “To understand the real benefits, people have to look beyond the cost of the ink,” he says.

That means looking at the doors that the technology can open. David Ryan, country manager for Sakurai, says that after the two machines have been installed at B&B Press in Rotherham, a third machine has been sold in the UK. But he is giving nothing away except that this is a niche application where the requirement is clearly not standard paper printing. “We’ll also have our own five-colour plus coater in the showroom here which we plan to have an open house around next month,” he says. “The first press was installed and then Baldwin added the LED systems and while it has been a steep learning curve, it has been a good experience.”

WHY INKS ARE NO LONGER A BARRIER

One of the barriers holding back the widespread adoption of new generation UV printing is no longer an issue. Where once ink had to be imported from Toyo or one or two other suppliers from Japan, inks that are produced in Europe are fast becoming available, with consequences for support and price.

When a number of printers first looked at the technology, ink prices were prohibitive. They remain expensive, perhaps £40 per kilogram set, but the cost is mitigated by three factors. There is no aqueous coating to buy to seal a sheet for faster handling; there is no spray powder needed (nor the inevitable cleaning that goes with this material) and anecdotally, ink consumption falls by 15% or more. This makes sense because the ink is cured on the surface of the paper and does not percolate into the fibres, but nobody in the UK has enough experience to measure ink use on an annualised basis.

The ink is more expensive because its formulations are markedly different from conventional inks and the limited range of photo initiators available to work at the wavelengths used in LED UV in particular, are not cheap. Higher output LEDs would change this. There is a broader range of compounds for the doped lamp systems, which should mean readily available inks. Nevertheless ink prices will not fall to match conventional inks, but it will settle as demand kicks in and economies are achieved in production.

Huber was swift to produce an ink for Komori’s H-UV system and which works on other doped lamp systems, including Heidelberg LE-UV. Richard Gill, UK technical manager, says: “We are fielding a lot of questions about the energy saving impact of iron doped lamps from UV printers, and even more so from conventional sheetfed printers looking at UV to give them the ability to print on a wider range of substrates – plastics, metallised papers and boards and of course uncoated papers. Using UV takes away the ink absorption and drying issues.”

While Huber has worked closely in developing inks for the H-UV system, it has inks that will work with any of the press suppliers and the retrofit technologies. “There are still technical issues with some of the LED materials,” he says. “In varnishes for example the wavelength for the photo initiators is too narrow, so it makes sense to apply a standard UV varnish. There are also some instances where the pigment is light or dark that can affect performance. The doped lamp systems are very workable.”

Toyo bought Belgium company Arets to acquire its UV inks experience and is investing in European production including a plant to produce LED UV inks. Sales manager Andrej Andrez says: “We are investing because there is growth in this market, both from new installations and from retro­fitting existing presses, which seems a pretty simple process.
“The inks are relatively expensive because of the raw materials which are more expensive than for standard inks, but competition will drive down the price, though not too far. It is still early days for these technologies, but we see a lot of potential for LED.”

Then there are the two giants of ink making. Flint is ahead of Sun Chemical. Its Suncure Lite ink is formulated for new generation UV and is coming to market in a controlled release phase. Flint Group has been working with AMS, producer of retrofit LED systems, and has inks across the markets, including one that is for web offset applications.

“We are ahead of where we expected to be in terms of take up,” says Jim Buchanan, global business development director at Flint, “and that is driving us to expand the portfolio. There are standard versions of the Xcura inks for LED UV, we have just released a Low Migration version and a bio renewable system as well. We are serving installations across the world covering Scandinavia, Brazil, Sweden.” In the UK it is the prime ink supplier to B&B Press with the first LED UV machine in the country.

Many of the users are working with the Air Motion Systems LED retrofit “because printers want to breathe new life into their old machines and to change the dynamic of their organisations with higher quality and more flexibility on materials printed”. As the press manufacturers are starting to offer LED technology, Flint has a proven ink technology, and with B&B as an example, has shown how it can assist with the set up in terms of other consumables and factors to consider. One is the blocking of sunlight as the UV element of daylight will trigger the photo initiators. Cheap and easy to fit filters are available for fluorescent lighting, and with these in place, there is no reason why inks cannot be left in the ducts overnight.

The bio renewable inks are in demand from the more environmentally conscious countries in Scandinavia, Buchanan says. The low migration inks are not yet in demand as almost all carton converters are running with standard UV set ups with little incentive to change, an observation that Huber UK endorses. One opportunity lies in printing a white on the first unit of the press and using LEDs to cure this to provide a better background for overprinting.

An area that Buchanan believes may have traction in future is in web offset. The big difference in ink price is the key issue, though the LED ink will have a 50% better yield per litre than conventional he explains. The benefit is the removal of the dryer, which is a bulky high cost item consuming vast amounts of energy. As environmental legislation tightens, after burners, catalytic incineration and solvent recovery may not be enough.

Komori has demonstrated a web offset press with its UV technology while Flint is supplying ink to a company that has converted an Octoman press. The change will come he says with the availability of higher power LEDs which will allow the ink maker to reduce the concentration of expensive photo initiators. A scattering of newspapers is already using classic UV technology to improve print quality on poorer quality papers.

There is a long journey ahead for UV cured ink in commercial print, as diodes are developed, as chemists work on improving formulations and at lowering costs, inks are not going to be a barrier to progress.

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'LED is cool,' says KBA

'LED is cool,' says KBA

Like Heidelberg, KBA had LED UV on the stand at Drupa, but pushed the single-lamp system, HR-UV, to start with. Now it is building presses that are preprepared for LED UV. It will offer LED as an extension of its VariDry system and will fit it to any sheetfed press in the KBA portfolio from the B3 Genius to the Rapida 205.

Currently while LED is good for commercial printing, KBA does not consider it suited to packaging. Nor to end of press coating where a standard UV lamp is preferred, if only because of the cost and availability of high sensitivity varnishes.

KBA has installed long perfecting B1 presses with the technology in Belgium for very short run printing, 2,000 sheets average, where there is little difference in the price of ink whether printing UV or conventionally.

The company has secured one UK order to date.


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Blackmore leads with KBA LED-UV for green performance

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Komori leads with H-UV

Komori leads with H-UV

Komori's H-UV technology is the best established of new generation UV technologies with hundreds of users across Japan, the US and Europe, including more recently the UK.

It uses a doped mercury vapour lamp to deliver a limited bandwidth UV energy which is matched by special inks. The result is lower energy consumption than conventional drying and a fully dry sheet in the delivery, and the ability to print on uncoated stocks and synthetic materials that are beyond the scope of conventional printing.


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Hunts adopts H-UV for value added approach

First B1 Komori H-UV for Image Data

Severn updates with H-UV

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About the lamps

About the lamps

New generation UV technology divides in two: single-lamp systems pioneered by Komori and Baldwin and endorsed by Benford UV in the retrofit sector; and LED UV promoted by Ryobi, Sakurai and by AMS in the retrofit market.

The end result is the same, but at the moment the single lamp systems offer greater flexibility, certainly to ink makers in the choice of photo initiators and other components.

At first Toyo was the only ink available. Now Huber is endorsed by Komori and in LED, Flint and Sun have joined the Japanese.


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B&B Press installs Sakurai LED UV

Selsey Press chooses retrofit Benford

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Ryobi LED

Ryobi LED

Ryobi pioneered the application of LEDs to generate UV energy in the printing industry, introducing the technology at Druap 2008. At that time the power was relatively low so applications were limited. That is no longer the case and the company has customers across Japan and Europe and now into the UK.
Apex Digital Graphics has a demonstration machine at its Hemel Hempstead showroom where interest has been high since the machine was delivered. The first UK press has gone to ABC Group in Hereford.

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The Anthology

The Anthology

Think of the Print Business website as an encyclopedia. To make it easier to find what you are looking for (or indeed don’t know what exactly that is) we have deviseda way of grouping articles into sections, or anthologies.


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The New Generation UV Anthology

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