Summary
• Becker Acroma has developed LED curing of coatings on all substrates.
• The absence of heavy metals in the coatings improves working conditions.
• Finish quality is equivalent to UV curing, but with about a 40% energy saving.

LED (Light Emitting Diode) curing is common in printing, but in other sectors, including industrial coating of wood products, the breakthrough in its use has remained elusive. Until now that is. Becker Acroma, part of the Sherwin-Williams Group, is claiming a world first for LED curing of coatings on all substrates, including wood.

The breakthrough, it says, has the capability to further improve the efficiency of coatings operations run by larger scale joinery and furniture manufacturers and offers benefits over UV processes, particularly with resinous species like pine, as well as reducing energy consumption.

The first plant to utilise LED technology will go into service in the Czech Republic in February 2012, where furniture manufacturer BJS will produce bedroom furniture. UV lamps on its production line are currently being switched for LED units.

Two major UK potential users have already expressed an interest in the development process.

“We’ve done an incredible amount of research and testing to get to the point where we are now sharing the benefits of LED technology with our wood finishing customers,” said Dave Wright, managing director of Sherwin-Williams Product Finishes UK & Ireland.

“We can provide LED curing solutions for virtually every wood finishing need, whether clear or pigmented.”

The Becker Acroma LED cure wood coatings range will be officially launched in January and will cater for interior joinery, home and office furnishing and kitchen and bathroom fittings.

Working with equipment manufacturers, particularly Burkle, Becker Acroma had to overcome numerous challenges to achieve an effective LED curing solution and develop the right mix of resins in its coatings products.

Challenges included stability of the production environment, surface curing, the need for an inert environment, and the need for close proximity between the curing diodes and the substrate.

Unlike traditional UV curing solutions, the Becker Acroma LED cure coatings harness narrow peaks of UV energy, namely 365nm or 395nm (+/-20nm) compared to 200nm to over 400nm for UV. The energy in the infrared range of the UV spectrum can cause severe heating of the wood substrate with UV curing.

“LED lamps do not produce high heat or harmful ozone,” added Mr Wright. “With this lower temperature technology, it is possible to finish pine and other resinous wood species without high reject rates.”

He said these factors, combined with the absence of heavy metals in the coatings, could also improve working conditions for production line staff and reduce environmental impact for the manufacturer.

Energy savings

Finish quality is said to be equivalent to UV curing but with energy savings of about 40%, while Becker Acroma also points to the longevity of LED lamps, decreasing maintenance costs. The absence of a warm up cycle also means less downtime.

The company says it can help customers switch from traditional UV curing technology to LED curing technology by either designing new production lines or redesigning existing ones, from project planning and testing all the way to start-up and beyond.

“We have found that production lines can even be shortened,” Mr Wright added.

The LED products are capable of being used on any finishing line combination, with manufacturers able to use the new curing system for the primer and an existing UV solution for the top coat, for instance.

“Basically it’s difficult to pinpoint a downside to switching to LED technology, said Mr Wright.

“This is a new technology and there are bound to be some sceptics, but once a major plant is up and running and the benefits are there for all to see, we believe that anybody can be won over.”

Sherwin-Williams intends to follow the Becker Acroma launch with a similar LED cure wood coatings range for its Sayerlack brand.