IST Metz: Making UV the perfect cure for print - The Noel D'Cunha Sunday Column

IST Metz is in Nuertingen, Germany. Can you tell us more about the facility here?
We are providing our customers with a one-stop-shop for LEDcure and LAMPcure systems. The core components are produced and developed in-house. All of our units are tested under production condition before leaving the house.

Describe your partnership with Heidelberg?
We have a very strong relation to Heidelberg which gives the possibility to integrate our systems into their machines perfectly. Furthermore, we have a very good relationship with Heidelberg India too, and meet up frequently for joint customer visits on site.

What are the new developments that would be of interest to the Indian printers?
Energy efficient equipment. In that sense, we are steadily improving our systems with our very well equipped R&D department.

What’s the role of a good UV curing system?
A very well working UV curing system stands and falls by its heat management. The temperature has to be adjusted such that it is stable. This is the main reason why we produce the core components in-house. This procedure gives us the possibility to adapt all items to each other accurately and ensures the best curing performance.

IST-M manufactures its own lamps for your systems. How does this backward integration help?
That’s unique. We design the lamps for our equipment in-house. It is very important to have a perfect adaption. It ensures perfect output performance and long shelf life.

What are the sizes of UV/LED systems available? Is there a specific length that the printers should look for?
The length of a UV/LED system is always related to the maximum format of the machine. Our longest lamp in the sheetfed printing measures 215cm. In other application areas, we can produce even longer lamps. In LED you have the advantage of format switching, which means you can scale down the length in case of smaller formats.

Team IST Metz at the UV Transfer Center – a demo centre

You spoke about the benefits that the reflector surface / heat management provides. Can you elaborate how?
The mainly used reflector from IST in the printing world is called URS (universal reflector system). We apply a multilayer coating (about 80 layers on an aluminium profile in a vacuum chamber). These special layers provide a very effective reflection of the UV light, absorbing the IR rays. That reduces heat transfer on the substrate and machine parts.

Company fitted UV systems or retrofitted? When and why?
All of our systems are individually designed to suit the different press models and ensure the best output. We use special software called ray-tracing to calculate the best design related to the installation situation.

How strong are you in the packaging segment, and are you eyeing the potential of UV retrofits for commercial printing?
The packaging sector is still our biggest area of installations. Our first installation in the commercial UV application dates back to more than 20 years. We are facing a significantly growing acceptance in the last six years. A lot of LE (low energy) systems were sold within this segment of printing predominately to new customers.

Lately LED is getting more and more importance and offers great potential for further growth in all application segments.

IST UV systems working on coated uncoated / metalised substrates?
We have a very wide range of substrates that can be used with our system. Metalised substrates are mostly produced with the UV because you can easily run such jobs; instantly cured in one pass and it can be finished immediately. In case of coated or uncoated papers, there is normally no restriction. Especially on uncoated papers you have the benefit of a more brilliant printing results in comparison to conventional inks. The reason, therefore, is minimised ink absorption by the paper which is almost fully eliminated by fast curing.

There are different pigments, and each is different from the other. For example, a yellow can cure faster than a black. Why is this, and how would you explain it?
The reason is the absorption of the UV light through the pigment. Black has a very strong absorption behaviour to the UV light. That means from the beginning it is more difficult to transfer the UV light through the entire ink layer. If the light is not transmitted through the full ink layer you will have curing issues. This effect worsens with growing ink densities.

IST Metz manufactures over 1,000 different types of lamps with, about 30,000 lamps produced per year

In terms of the operating environment, what is an ideal condition to run a UV curing system – is air-conditioning in a country like India essential?
An air-conditioned environment is always an advantage for the printing process. Hot temperatures as you often find in India, can influence the ink and coating viscosity, which can result in unstable printing.

Tell us about the new LEDCure?
The new LEDcure offers industry-leading modularity and upgrade-ability with flexible optics and chip array, seamless integration concepts and a very small footprint. As a result, we can manufacture different LED systems based on one platform – with optics for long distances (as we have in sheetfed), as well as optics for short distances, and without optics. In order to deliver a focused and intense light to different distances within the machine, optics becomes an important element.

What are the benefits?
With these different types of LED systems, we can serve a wide segment of the printing industry as well as other application segments. The new LEDcure operates with the same power supply devices as we have in UV lamp operation. So if you invest today into a UV lamp system, the electrical cabinet is already prepared for the LED operation. Additionally, the possibility of format switching and cylinder gap clocking are good energy saving aspect.

The Hot Swap technology, what is it? How easily can you change the lamps?
The Hot Swap gives you the opportunity to run a LAMPcure (UV sheet-fed-drying system), as well as a LEDcure system in the same press with only one electrical cabinet. A similar design of the housing helps that you just have to remove the UV cassettes from LED to lamp or the other way around.

What is your LED installation numbers, worldwide and in India?
Together with our Subsidiary Integration Technology, we have more than 3,000 LED UV installations for different kinds of applications. Most of these installations are on digital presses.

And sheetfed presses?
In comparison to digital printing, the installations in sheetfed printing are of course lower but fast growing.

I see.
In India, we are still waiting for the first possibility.

LED UV and hybrid curing systems – which are the segments these technology are in use now?
We still see that the main installations are going to the commercial sector. The interest in other areas as packaging is also getting higher. Yet this is not reflected by many installations.

Switching from UV system to a LED UV means a move to more expensive UV inks. What are the benefits versus the costs?
To compare a normal UV system to a LED system is not really correct. These days we are still talking about two different printing segments. The major LED printing area in sheetfed application is producing commercial, while the full UV solution is used for highly sophisticated printing products.

So if you are comparing the use of LED ink to conventional inks you have the advantages of direct finishing, no powder, high pile production, no dry back, brilliant results on uncoated paper, and reduced inventory.

The lamp being fitted into the case during the manufacturing of LED UV curing system

And LED?
The LED system can be instantly switched on and off, while a lamp system needs a start-up and cool-down phase. That helps during stopovers to reduce the energy consumption, respectively. Further cost for energy can be saved with the format adjustment options of a LED system. Last but not the least, there are no frequent costs for lamp replacement on a LED system as there are on a UV lamp system.

India is a tough market for LED UV. How are you planning to breakthrough?
Yes, that’s what we have also learned in the last few years. We hope there will be a change in future to think more in the direction of LED. With our product range, we are very well prepared.

And finally, what are your plans for India?
We are keeping a close eye on the Indian market, and are making efforts to intensify our market presence.

The main building, one of the four buildings which comprise 21,800 sq/m of production area and office space in Nürtingen in Germany