Energy Curing and Coil Coatings

Coil coatings have pretty much been applied the same way for a very long time, but leading manufacturers are finding that energy-curable technologies offer key benefits. Paint and coating industry leaders are applying their knowledge of UV and EB curing to successfully formulate new coil coatings for their customers.

Beckers CTO Gavin Bown noted that Beckers began exploring UV/EB curing for coil coatings in 2005 due to its potential to enhance efficiency and sustainability.

“Conventional coil coating requires solvent-borne paint formulations and high-temperature application processes that consume large amounts of energy, indicating a need for a faster, more energy- and resource-efficient process,” Bown observed. “UV/EB curing technology was already in use in industries such as wood and paper, but adapting it for coil coatings presented unique opportunities.”

Bown pointed out that at the outset, the R&D objectives for developing UV/EB paints included achieving the same durability and flexibility as conventional products.

“This required altering the chemistry of the coatings without compromising quality,” Bown said. “Ultimately, Beckers’ development of UV/EB curable coatings was a strategic move to meet the growing demand for more environmentally friendly, sustainable, and efficient technologies within the coil coatings industry.”

Kurt Bowen, global portfolio director for Sherwin-Williams Coil Coatings, said that the development of radiation-cured coil coatings was driven by their customers.

“About five years ago, several key customers approached us seeking assistance in developing radiation cure coating systems,” Bowen said. “Leveraging Sherwin-Williams’ extensive experience in other industrial segments, we adapted and tailored these technologies to meet the specific needs of the coil coatings market.

“Our commitment to sustainability and reducing carbon footprints, particularly in response to European carbon reduction goals, played a significant role in this development,” Bowen added. “It’s also worth noting that we utilize both electron beam (EB) and ultraviolet (UV) curing under the broader radiation cure umbrella, treating them similarly. Each method has its pros and cons, but both offer versatile solutions depending on the coating and pigment levels required.”

Craig Smith, PPG global technical segment director, coil and extrusion, noted that the coil industry has been applying and curing paint in the same way for the last 50 years or longer.

“We knew there was a more sustainable, energy-efficient method for coil coatings,” Smith added. “Ultraviolet (UV) and electron beam (EB) curing technology, often collectively referred to as energy curing or radiation curing, was the answer. These curing processes consume much less energy than thermal curing and produce little to no volatile organic compound (VOC) emissions when combined with PPG’s coatings formulations made without solvents.

“Plus, PPG has significant experience in energy-curable coatings and lead the way when they were introduced in the wood products industry more than 30 years ago,” Smith said. “We were able to leverage our knowledge and innovation in that segment to develop a new sustainably advantaged product line for coil coating called PPG DURANEXT.”

Christopher Bradford, market director of AkzoNobel’s Coil & Packaging segments, said that UV curing has long been a proven method for crosslinking solid paints, with successful applications in sectors such as wood, packaging,
and automotive.

“Leveraging this experience, we saw a clear opportunity to integrate UV curing into our efforts to promote and accelerate energy curing in metal coil coatings,” Bradford observed. “UV curing, alongside electron beam (EB) technology, naturally fits into this evolution. Both are complementary and, in some cases, used together to cure specific layers—offering a compelling vision for the coil coating lines of the future. The introduction of UV and e-beam curing enables a major opportunity in decarbonizing the coil coating process with drastic energy savings, electrification and elimination
of solvents.”

Advantages of UV/EB Curing for Coil Coatings

Energy curing offers plenty of advantages in general, and these benefits also apply for coil coatings. Sherwin-Williams’ Bowen observed that UV and EB curing for coil coatings offers several significant benefits.

“First, the use of 100% solids coatings means there are no volatile organic compounds (VOCs), making it an environmentally friendly option,” said Bowen. “Second, radiation curing significantly reduces energy usage since it eliminates the need for thermal ovens. This not only lowers operational costs but also contributes to sustainability efforts. The technology requires a smaller capital investment and has a reduced equipment footprint, making it a cost-effective solution for many businesses. Lastly, UV and EB curing are highly flexible and can be retrofitted to existing production lines, allowing companies to upgrade their processes without extensive modifications.”

PPG’s Smith said that unlike traditional coil coating systems that require very high temperatures to drive the curing process, UV/EB-curable coatings use an electron beam or ultraviolet energy to convert a liquid coating into a fully cured solid finish in seconds, without any significant loss of thickness or weight.

“Unlike thermal curing that requires heat, energy curing is performed at or near ambient temperature using photons of light or electrons to polymerize the components of the coating to form a cured film. This method is often called cold curing,” Smith noted. “From an operations perspective, UV/EB technology requires lower capital costs to get started and allows for smaller, more specialized curing lines with a reduced physical footprint compared to traditional coil coating lines.”

“Energy curable coil coatings are based on reactive formulations that demand a high-performance energy source to achieve rapid and effective crosslinking,” Bradford said. “A major benefit comes from the ability to switch the line on and off with great agility, providing ease in runs changeover, high productivity and materials waste reduction. UV curing delivers on that need with high-speed processing and compact equipment that can be easily integrated into existing lines, such as through a bypass configuration.

“Additionally, the flexibility of UV source technologies—ranging from arc and modified arc lamps to LEDs and excimer systems—allows for a variety of line configurations and solutions,” Bradford added. “This adaptability even enables gloss control through dual-cure processes, such as combining UV and EB curing.”

Bown noted that UV/EB curing offers several advantages.

“First and foremost, it uses solvent-free formulations, which significantly cuts down on volatile organic compounds (VOCs) and carbon dioxide emissions,” Bown said. “This not only helps in meeting stringent environmental regulations but also improves the overall workplace air quality.

Bown said that the curing process is also instantaneous and at ambient temperature, allowing for higher line speeds and greatly reduced energy consumption.

“Traditional high temperature curing processes can take several minutes to cure the coatings, whereas UV/EB curing happens in seconds,” he said. “Instead of burning natural gas, renewable electricity can be used. Together, this leads to increased productivity and lower operational costs, specifically significant energy savings and carbon tax savings.

“With UV/EB coatings being 100% solids, this allows for higher dry film coverage per kg paint while still maintaining effective surface protection,” Bown added. “UV/EB curing can provide up to twice the surface coverage per kilogram of paint compared to conventional methods. This means that less paint is needed to achieve the same or even better-quality finish, resulting in material savings and reduced waste.”

Feedback from Customers

Bowen said that the feedback from customers has been generally positive.

“We are seeing interest from many customers around the globe,” said Bowen. “However, the adoption process has been slow, with customers taking a cautiously optimistic approach as they wait to see how the technology plays out. Development with each customer is unique and tailored to their specific needs. We help by providing guidance focused on their market and area, offering lab evaluations and panels, wet coatings, and pilot line trials.”

“Our customers want data-driven proof points, and we deliver together with industrial partners, working on new solutions for coils,” Bradford said. “With a global R&D footprint and dedicated energy cure experts, we are well-equipped with state-of-the-art UV and EB curing facilities. These resources allow us to demonstrate the performance of our coatings firsthand and collaborate closely with customers to optimize their processes and prepare for future investments. Customers are as well thrilled to investigate the differentiation possibilities provided by a ‘cold’ curing process.”

Beckers’ Bown reported that customers have responded positively to UV/EB curing technology, appreciating its environmental benefits and efficiency.

“Many are in the process of retrofitting or fully replacing their existing lines with UV/EB curing systems, with enthusiastic feedback from early adopters,” Bown said. “While the benefits of this revolutionary technology are clearly evident, there is a transition effort for customers in retrofitting the existing coil coating lines to accommodate UV/EB curing technology, adjusting the process and gaining expertise.

“We also acknowledge that we still have some way to go to fully prove all key performance dimensions of UV/EB paint systems versus the current solvent-borne technology,” Bown added. “However, we have successfully commercialized the first generation of paint systems, and we have a clear R&D plan and roadmap to get there.”

Smith noted that PPG launched its portfolio of PPG DURANEXT coatings in summer 2024 and introduced it to customers at METALCON later that year.

“The response has been overwhelmingly positive, and we’ve even seen interest from those we did not initially expect: people who are thinking about the technology in unique ways,” Smith added. “Our applicator customers are excited to see how they can get involved and incorporate the technology into their operations.”

The Future of UV Coatings for Coil Coatings

Coil coating industry leaders anticipate that UV curing will become a leading technology in the coil coatings segment in the coming years. Bowen said that radiation cure technology is poised for significant growth in the coil coating industry.

“Although it is relatively new to this segment, ongoing improvements in resin performance and coating application methods are expected to drive future advancements,” said Bowen. “The market’s increasing focus on sustainability and stringent environmental requirements will further improve the adoption of radiation cure technologies.”

“UV curing is already part of the technology mix used in coil coating lines and pilot setups,” AkzoNobel’s Bradford said. “As the industry moves toward more sustainable practices, energy curing technologies like UV and EB will play a pivotal role by eliminating solvent emissions and significantly reducing energy consumption.

“In addition, high productivity can be reinforced with a remarkable flexibility in coating line utilization,” Bradford added. “In the near future, we expect UV curing to be widely adopted—not only for full curing but also for pre-gelling and advanced gloss control—benefiting from the strong synergies it shares with EB curing.”

“UV/EB curing can be a game changer for the coil coatings industry,” said Bown. “We have developed an industry-first, peer-reviewed LCA (life cycle analysis) for UV/EB coil coatings, which clearly shows that it has the potential to halve the carbon footprint of the coil coating process versus current practices. It’s the most impact technology we’ve identified for decarbonizing our industry.”

“We see UV/EB coatings as an ongoing trend that is really just getting out of the gate,” Smith concluded. “Although these coatings have been around for decades, they were primarily used in other sectors, for example, in coating wood flooring. Their potential in metal coil coating is really just beginning to be unveiled to the industry, and we see it as a huge growth opportunity.”