Me & my: GEW LW2 LED UV Curing System

Tucked away under the arches of Camden Road station on the London Overground is C&D Print Media, one of those increasingly rare things, a commercial printer in the centre of London.

The majority of its work is for designers and agencies with the ultimate clients including a mix of prestigious names across sectors including architecture, education, fashion, media, publishing and retail.

Managing director Charlie Anderson has been at the helm of the 13-staff firm since the mid 90s. In that time he has overseen it transform from repro house to digital printer, relocate from London’s historic print heartland in EC1 to N1 and absorb a number of other companies. Diamond and Roach, as it was back then, bought its first digital press, an HP Indigo 1050 in 2004, upgrading to a 3500 when it relocated to Camden in 2006. In 2009 it merged with Compass Litho and rebranded as C&D, taking on that firm’s Heidelberg Speedmaster SM 52 to offer litho work. Along the way it acquired two other companies, taking on Indigo house Transfunction in 2015 and Portland Media Print Services in early 2018.

2018 was a big year for the company in other ways too, it decided to invest in new equipment, including making its first move up from B3 to B2 production. 

The primary reason to shift up a sheet size was to bring in-house work that had until then been outsourced but it was also crucial that it could deliver the quality the firm is known for and the rapid turnaround digital clients are used to. 

“Where we are, only 20 minutes from the centre of London, speed of turnaround is very important,” says Anderson. 

A B2 Indigo was seriously considered but his naturally cautious approach to investment ruled out a new machine and with “a secondhand 10000 unavailable for love nor money,” in the end the firm plumped to replace the SM 52 with a secondhand five-colour SM 74 and took on an additional unit to accommodate it.

While awaiting the delivery of the press Anderson started to pick up on the advent of LED UV curing for litho presses. Having been mulling a B2 digital press the ability to have litho work that was instantly dry was very appealing. 

“I was interested in the potential benefits, and although a lot of the information out there was about new presses, I wondered if it was available to be retrofitted,” he says.


His research identified that AMS and GEW both offered LED UV systems for sheetfed offset presses that could be fitted to the firm’s SM 74. In the end, GEW’s LW2 LED UV Curing System won out because of the supplier’s more collaborative approach and lower price. Anderson was also reassured that GEW had just completed an installation in Sweden on a very similar machine to his, and so had ironed out any potential installation issues specific to his press.

After two months running the SM 74 with conventional inks the GEW retrofit happened in May 2018 and was “considerably easier than the press installation, and worked first time”. 

“From GEW arriving on site to us being up and running with UV LED it took three days, which considering it’s a major conversion is a good time.” 

GEW has been producing UV curing kit for print since 1991. As the UK headquartered firm has grown and UV technology has evolved, it has expanded the range of products produced and the markets it addresses. In the last couple of years the advent of LED UV lamps has led the firm to expand further and alongside equipment for narrow-web, digital and metal decoration it now offers the LW2, a water-cooled retrofit LED UV system for sheetfed offset presses. The LW2 is available in a range of widths up to 2.1m wide, so can accommodate common sheetfed formats including B3, B2, B1 and VLF. Using LEDs means the lamps are mercury-free, do not generate ozone, have a long operating life in excess of 20,000 hours and are more energy efficient than conventional UV lamps. The energy efficiency is a combination of more effective conversion of electricity to UV and the generation of less heat in the process, and therefore less need for cooling. That said, the system does use water to keep the lamps cool. 

In addition to the lamp itself, which in C&D’s Speedmaster is fitted between the last print unit and the delivery, there is a wall-mounted power supply and a control unit, which monitors the system and provides remote feedback to GEW to enable pre-emptive servicing should any issues occur. So far there have been absolutely no issues with the LW2 itself.

“We get a monthly report and they troubleshoot remotely and are able to fix anything before it becomes an issue,” he says.

Being an early adopter of LED UV has been a steep learning curve. While the lamp has been trouble free the switch to UV has had a big impact on other areas including rollers, blankets, the inks themselves, chemistry, wash and plates.

“I was aware that being an early LED UV retrofit user meant there would be some issues, but I did think that with the new machines in the market that there would be enough expertise out there.”

In turned out that there was a lot of conflicting advice and in the end it took six months of trial and error before everything was running smoothly.

“I think a lot of people have been put off going down this route because there are so many unknowns. People gave me so many different opinions, in the end we asked and asked and asked until we got a majority answer.”

C&D took three ink vendors into consideration, Huber, Sun Chemical and Toyo, with Huber winning out. 

“Toyo’s ink was quicker drying, but more aggressive, and I didn’t want an aggressive ink.” 

Out of the other two vendors Huber was more proactive, and the clincher was its willingness to mix LED UV specials up. LED UV uses different base colours for specials and although the firm now mixes most colours in-house, while anything particularly out of the ordinary is supplied by Huber. 

One issue the firm had was with the inks interacting with plates. Previously it used Agfa Azura TS plates, but found that the plates were blinding and could only run for 8,000 impressions.

“The reduced run length wasn’t such an issue as most of our runs are below 5,000, but when we had an issue with a small area blinding after 2,000 impressions we decided we needed more security.”

As a result it switched to Kodak’s Sonora X plates. 

A further issue it discovered is the reduced operating latitude of the LED UV inks. “We don’t have temperature control on the press and we found that there’s only a five-degree window, which it can go outside of in the summer and winter, so we are air conditioned now.”

Fortunately the press had come with dual compound rollers, so that was one area where there wasn’t an issue. 

There has been no difference in press running speed in switching to LED UV, with typical running speed 8,000 sheets per hour.

“Our main aim is quality and we’re short run, so the difference of a minute or so on a run of a thousand sheets makes no odds.”

The best thing about switching to LED UV is a toss-up between the improved print quality and the benefits of instant drying.

“It’s dry instantly; there is no dry back even on uncoated, which is great for press passing.” 

Best of both

He likens it to having the vibrancy and ease of use of a silk stock while retaining the tactile and visual appeal of an uncoated. 

With no set-off, there’s no need for spray powder and no risk of any jobs being ruined. It’s also widened up the range of substrates that can be printed to include synthetics and mirror board. 

Switching back to conventional when needed is also less of an issue than might be expected. Swapping between ink technologies needs a wash-up, but other than that the rollers, blankets, chemistry and plates can all be used with both types of ink.

As for the worst thing, “there are too many areas of conflicting information that could send you down the wrong path”.

He puts that down to being an early adopter, adding that all of the suppliers were learning along the way too. He found it very useful to talk to another early LED UV retrofit user to compare notes and share best practice.

 “It’s been mostly internal advantages for us so far. It’s reduced the space we need for pallets of work sitting around drying and enabled quicker turnarounds.” 

One of the aims of the install was being able to offer a super-quick turnaround, even same-day. To date it hasn’t capitalised on that. The firm hasn’t been heavily promoting its new capabilities and potential customers aren’t yet aware of the possibilities. While there is a growing awareness of B2 digital, there is hardly any awareness that with LED UV, litho can be as quick, is competitive on short runs, much more cost effective for larger volumes and offers very high quality on a wide range of materials. The hope is that now it has got to grips with the technology it can focus on filling the press with plans afoot to recruit a salesperson to promote its capabilities. 

C&D Print currently operates on a single shift with plans to add a second shift when sales warrant it.

Overall, despite the teething troubles, it’s been worth the considerable effort and he would have no hesitation in getting another LED UV system. As for recommending it, Anderson quips that he’d much rather other printers didn’t follow his lead so he can keep the benefits to himself and his customers. 


UV irradiance 25W/sqcm

Width Up to 2.1m

Press compatibility Any sheetfed litho press. Machines converted to date include Heidelberg, Mitsubishi, Ryobi and Shinohara presses.

Price Dependent on press type and site specific factors as well as the sheet size.

Contact GEW 01737 824500

Company profile 

C&D Print is a Camden-based commercial printer with a focus on high-quality design-led work and on offering rapid turnaround within central London. It employs 14 people with sales of £1.3m

Why it was bought...

Bringing all of its print production in-house and to opening up new markets led the firm to move up from B3 to B2. A cautious approach to capex made secondhand equipment attractive. UV LED promised turnaround times as quick as digital with the quality and cost benefits of litho print. Retrofitting the GEW LW2 offered the best of both worlds combining the laterst litho technology with the lower capex of a secondhand press.

How it has performed...

The GEW LW2 lamp and controller have been trouble free throughout from installation to day-to-day operation. Getting to grips with the impact of UV curing inks on press consumables, chemistry, plates and operating practice has been challenging but the benefits have been worth it.


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