Over the last few years growth in demand in Europe for UV – as well as electronic beam (EB) – has been around double that of the coatings market as a whole, according to industry analysts. Now the gap could be widening further as UV/EB moves into higher value and higher margin areas.
Among the main driving forces have been the lower energy costs of radiation curing, fast curing speeds which raises productivity and the desire for surfaces with a high gloss and color intensity.
However, more improvements and breakthroughs have to be achieved if the UV coatings sector is to keep up the momentum.
“The big technological challenges are how to find ways of achieving the same performance while lowering costs in UV coatings,” explained Stefan Van Den Branden, technology director at Belgium-based resins producer Allnex Group, formerly Cytec Industries Inc.
“Then there are more specific performance demands like hard coats with improved scratch and abrasion resistance and surfaces with a soft touch,” he continued. “A lot of innovation is also being driven by regulatory constraints, like restrictions on materials of concern because of their possible toxicity. These are imposed not just by the EU and governments but companies like retail chains. IKEA, the furniture chain, is setting its own standards, for instance tin-free resins, which go beyond what legislation is prescribing.”
UV curing by light emitting diodes (LEDs) is by far the fastest growing of the UV segments – at a rate of around 30 percent a year in equipment sales. It is also one of the most innovative sectors mainly because there is scope for so many improvements in the hardware, resins and photoinitators needed for its efficient application.
In line with the general trend in the coatings sector to greater sustainability, UV coatings users are also wanting renewable materials to be included in them. As with other UV innovations, their cost and performance has to be comparable to existing materials because most end-users are not willing to pay more just because they are renewables.
Geographically, the fastest areas of growth in UV/EB have been in Eastern Europe, where its expansion may have been even quicker if the capital costs of radiation curing equipment has been lower.
Across Europe the main fields of application are printing inks and industrial coatings, according to figures from Radtech Europe, Brussels, the UV and EB industry’s trade association. Each accounts for around 45 percent of energy curing applications in the region.
In industrial coatings, the main segments are wood coatings, mainly furniture and flooring, plastics, metals and electronics.
Radiation curing is increasingly being used on casings for smart phones and laptops because of its effects of brilliance and shine. But it also now being applied to give matte finishes to a variety of products after the development of alternatives to the conventional matting materials of silica and wax particles.
UV/EB is also now making significant advances in leading manufacturing sectors such as automobiles which should gradually provide scope for more innovations in curing.
“With automobile manufacturers there was a chance around 10 years ago that they might adopt UV for application of clear coats but it did not happen,” said Van Den Branden.
“Instead the move to UV in automobiles has been taking place incrementally,” he explained. “UV scratch-resistant coatings on headlamps is now a well established technology. Also UV is now increasingly being used to achieve a high gloss on plastic parts in interiors.”
UV/EB has also slowly been gaining ground in coil coatings, which could provide a new route into the automobile market. The energy consumption of radiation curing can be as much as 90 percent lower than the traditional heat curing in the coil coating process.
“In big sectors like coil coatings it is going to take a lot to persuade producers to make a major move into UV coatings,” said Van Den Branden. “ It will require new processing steps which will necessitate a lot of investment in new machinery. You do not get changes like that happening overnight. It happens gradually.”
Powder coatings been a sector which at one time looked promising for UV. But now it is struggling to make further inroads.
“The high operational costs and limited application robustness makes UV technology in powder coating only useful for niche applications,” said Marcel Schutte, new business development manager at DSM Coating Resins in the Netherlands.
“Despite huge development costs, only a very few UV-curing lines survived,” he continued. “We have to conclude that it has not found a breakthrough in the powder coatings sector.”
UV-LED looks likely, however, to be a success story. By 2023, UV-LED’s share of the market for radiation curing lamps has been expected to rise from 13 percent to 35 percent, according to Radtech Europe.
In a recent report on the UV-LED market worldwide, Yole Developpement, a market research company in Lyons, France, forecast that UV-LED sales will increase almost six times in 2014-2019 to $520 million, double the growth rate in 2008-2014.
“Less than 10 companies were developing and managing UV-LED devices (in 2008),” said Pars Mukish, Yole’s UV-LED specialist. Now more 50 companies have entered the market, the majority of them in 2012-2014, with most being attracted by the high growth in demand and the high margins due to falls in prices for LEDs due to overcapacity in the production of the diodes.
More chemical companies are becoming involved in the development and production of the resins and photoinitiators required to raise UV-LED’s performance.
“One of the big advantages of UV LED is its low energy costs and the fact that the lamps can be turned off and restarted instantly,” said Van Den Branden. But currently UV LED still has limitations. The LED lamps have to be held close to the coatings to be cured so that they can be used only on flat surfaces. Also the power of LED lamps is still limited, although improving.”
As with the UV/EB sector as a whole in the past, a lot of development work on UV-LED seems to be necessary. Provided some key parts of the technology can be improved, it appears poised to be at the forefront of radiation curing’s growth in Europe over the next several years.