DuraTech pioneers UV LED curing for power, productivity and performance

About the company

DuraTech Industries has over 40 years’ experience providing screen printed decorative and functional identification products to OEMs worldwide, in the automotive, computer, electronics, industrial, and medical markets. Products include in-mould decorated (IMD) items, in-mould structural electronics (IMSE), membrane switches, metal nameplates, domed products and labels.

Founded in the 1970s, the company has now built an experienced team of over 300 employees. With its headquarters and key production facility based in La Crosse, Wisconsin, DuraTech serves customers around the globe. Pat Tully, Project Manager at DuraTech, briefly outlines the company’s history: “DuraTech was actually established in a garage back in 1977. As we grew, we decided to concentrate on the printing of plastics only, and we’ve been growing ever since, at a steady pace.

“In 1998 we received our ISO 9002 certification. We added digital printing and flexographic printing, and we got into in-mould decoration. In order to provide local support for our Fortune 500 customers, for the IBMs and the GE Medicals, we opened a facility in Beijing, China, in 2005. We do graphics there and user interface products.

“We continued to expand our capabilities and got into printed electronics, eventually we melded our printed electronics with our in-mould decoration… it was a natural fit to get into in-mould electronics.

“We are the first licensee for TactoTek in North America, for in-mould structural electronics. We do formed parts, specialty products for lots of different markets. Our main markets, however, are appliance and medical device, and we also do a percentage of automotive.”

Product diversity

The breadth of DuraTech’s product range means there is a proven product for almost every customer need, backed up by an experienced design team that specialise in creating tailored solutions for specific requirements. Dan Chandler, VP Manufacturing, sets the scene: “Everything that you can think of that you can print on, we’ll do, from polycarbonates to copolys, to polyesters to glass, metal, vinyls… if it can be printed on, we print on it.”

Due diligence and the move to UV LED

The process of printing and curing on these complex substrates is demanding, and the production team at DuraTech have been cautious in their approach to the adoption of UV LED technology, needing to be certain of its curing efficacy before introducing any such system into their mainstream production. They have followed the development of UV LED for many years and tested it thoroughly in their own laboratory, as Jeff Busse, Technology & Product Development Leader, explains: “We’ve been looking at LED units for 10 to 15 years, had a lot of different units over that time, different wavelengths, we’ve put them on our lab units in our R&D area, then when we’ve determined what units work there, we brought them in, put them in our production area, tried them out.” This same process was followed before the successful integration of five GEW LeoLED systems on DuraTech’s main production lines, in 2023.

The intensely demanding lifecycle of many of DuraTech’s products only accentuated the need to make the right choice, as an exceptional standard of curing is required to produce highly durable goods that can perform above and beyond their necessary lifetime. Dan Chandler explains: “For certain customers, we have to go through a very rigorous process, and then say ‘this is what we’d like to do’… and then they torture test it, in all the different conditions, putting it into a Thermotron at maybe -40°, taking it to high temperatures, dunking it in water… there’s just a variety of testing that it goes through, but we really took our time and after last year we started purchasing GEWs, and it’s been great since.”

Switching to UV LED inks

The long-term durability and performance of LED-curable inks were also under close scrutiny when GEW’s LED systems were being considered. However, in reality the switch has been routine, as Busse explains: “LED-cured inks perform just as well as the old conventional UV cured inks and solvent inks. We have not seen hardly a difference in them and it just cures so much quicker, and some of the material we’re working on are thin materials where the LED just doesn’t have the heat that other units have and distort them, so it does everything we want it to… and our main ink supplier put a GEW unit in their lab, so if we have any issues trying to cure ink they’re able to replicate what we’re doing on the line here. So if we tell them we’re curing it with this much power, they can do it down there, so this way it’s a win-win for us.”

Multiple energy savings

The conventional heat drying systems that UV LED replaces are far more expensive to run, and slow down production time. Heat drying has a two-fold disadvantage in that it is energy hungry, and the exhausted heat that it creates then has to be managed in the factory environment. By switching to UV LED curing systems, immediate curing is achieved, energy costs are dramatically reduced, and any unwanted heat is eliminated.

Chandler explains how this guided them to choose LED: “We realised how much more it would really save us when it comes to power, when it comes to HVAC… HVAC is huge for us because it’s very, very expensive to run air-conditioning. With these lamp systems, you have an incredible amount of exhaust, where that is 100% air-conditioned air that’s heading out, so it’s very costly. So we have about 120 tons of air-conditioning just for this room alone, so you can just imagine by putting GEW systems in, with no air make-up needs… just the huge savings of air handlers, matter of fact I just purchased one air handler, 70 tons, and I think we’re looking at like $170,000. There are so many advantages, we’re running at probably 50% of the cost of what a standard lamp system would cost, so that was really huge.”

Process consistency

He also highlights the process benefits they have found with UV LED: “Sustainability of the millijoules and watts… number one. Right now with any of our lamp systems, if you look at like an IR lamp system, you’ll start out and you’ll have the perfect millijoules and watts, and after 20 hours or 20 minutes it already starts to drop, so there’s no real consistency… so you will have to measure that every single time that you run. When it comes to LED it’s flat, and then you do the proper studies on it and you know exactly where to set it per ink system, per material type.”

Increased productivity

Chandler adds a comment on the impact LED has had on productivity: “Another one was the post-cure: we’ve got probably 250 to 300 jobs that we run through here every week, well a good portion of those, when they’re printed, we actually have to wait 24 hours before we can laminate and move on to our next process. Going to the GEW LED system eliminated that, which you know just helped us with pushing our capacity, shortening our lead times.”

Customised solutions for each line

DuraTech has a wide variety of production lines in the La Crosse facility, each with different UV curing requirements. GEW worked closely with the company’s technical team on the UV system design and integration for each conveyor, to be sure to engineer the optimal solution for every line. This included options such as width-switching and height adjustment, as Chandler describes: “We went with a variety of different sizes, we’ve got three 30-inch wide units it’s a continuous lamp and we have a 42-inch wide lamp and then we also have a 50-inch wide lamp. The 50-inch goes on one of our larger cylinder presses where we need that width, but not all the time, so GEW has different levels of which you can run it. So if I run it on level one then just the centre section works. If I want wider, then the right and left engage and then now I’m utilising the full length of it… we love it. The height adjustment, it’s very user-friendly, we adjust according to the material type and just how much power we need, so it could be down as low as a quarter inch and up as high as maybe a couple of inches off the deck, but it’s all dependent on the material that you’re putting through there.”

Installation simplicity

As a result of precise forward planning by both parties, the installations were seamlessly executed with minimal disruption to production. Chandler comments on this: “I’ve done a lot of installations over the past 30 years and this was very, very turnkey. We purchased the chiller system, we purchased the LED system and carrier from GEW and they worked with our fabricators and we fabricated the rest. They helped us in every single piece of it and it was smooth and it’s rare, it’s very rare… so hats off to GEW.”

Current and future capability

A further, less expected benefit that LED has introduced is the increased rate at which product can be cured. DuraTech invested in GEW’s high power LeoLED lampheads for all five installations, and the dose and irradiance delivered is more than sufficient for their current work. Chandler explains how they optimise the speed: “When it comes to measuring the irradiance, we use EIT power pucks, power maps and we do a full study in a wide variety of speeds and feeds, from maybe 80 to 200 feet, or we actually go from the power output, so by adding those two, putting that math together, you can use the millijoules and watts to maximise the productivity. So you can go as fast as you possibly can with such a large unit. You can adjust the lamps to whatever power output you would need.”

However, they also wanted to future-proof their business and ensure that they are more than capable of taking on whatever work may arise in years to come. Chandler comments on this: “We actually purchased the largest unit that GEW has and there’s only about 10% of the work that we’re actually going to run at 30 watts… you never know what the next customer’s going to get you, because it’s never the same, everybody’s technology is changing, ink systems are changing and we have to be ready for that, so we bought the Ferrari and we only run it at the highest speed once in a while, but we’re usually just coasting with this machine, it’s great.”

Learning from past mistakes

Despite the level of research and due diligence invested into the acquisition of capital equipment, it is still possible to make the occasional error of judgment, as Chandler illustrates: “We’ve looked at LED for probably 10 years I would say, and over those years we made a few purchases. One of the first purchases was because it was affordable compared to all the other LED systems… that is the wrong way to go. You’ll get what you pay for… we had problems with the quartz and the LEDs blowing out, and the design, and just the technical support that was not there… every single piece of that purchase was, it was horrible, and they just couldn’t achieve the power that the GEW could achieve.”

Return on Investment

Moving on to more positive matters, Chandler points to their recent purchase from GEW: “RoI happens immediately, the second we put the GEW systems in, I took out a Switchback system and had a 16-inch exhaust on it that took so much of my air make-up out. That’s immediate cost savings, right now, today. Flow of product: the 24-hour cure, it’s gone, I get to move product through faster, our customers get to see their product a day sooner than they normally would.”

Why switch to LED?

In summary, Chandler gives an overview on what switching to LED has achieved, for DuraTech: “You know, we have got to continue to bring our prices down for our customers, even though supplies are going up, so that’s all the savings that I’ve talked about: the air-conditioning, the power savings, quality… just the quality of product, of not delaminating. That alone is a huge driver just to push to LED. That was massive.

“If there’s some of our competitors out there that are looking at the GEW system, I would highly recommend that they go with somebody else… this is our edge!”

Watch the Duratech case study video

To learn more about GEW’s next generation, highest power UV LED curing system, LeoLED2, go here.