In an overall coatings industry that is not particularly vibrant, rad-cure coatings are somewhat of an exception, representing a relatively robust and dynamic marketplace. As companies come under increasing pressure to reduce energy costs, speed production and comply with strict environmental standards, many are looking to the innovations of UV/EB technology for solutions to these problems.
Leading rad-cure coatings firms agree that the market will continue to grow. "From our perspective, we've experienced nothing but growth," said Timothy Tanner, UV product manager, Red Spot Paint and Varnish Co. "Last year our UV business experienced a 14.5% increase. The year prior, we recorded a 9.5% increase. This growth is due to our customers looking for cheaper alternative ways of coating their products to reduce costs in the face of rising energy costs. While switching to a UV system requires high initial cost investment in equipment and materials, utility savings over the long-term will pay for it."
Many early applications are showing signs of maturity but still have more active behavior than other mature markets, according to Steve Lundstram, general manager, Rahn USA Corp. "New markets are constantly emerging making this a very exciting market to be involved in," he said. "While the market is maintaining nice overall growth, profitability in some sectors needs to be improved to sustain development activity. In the coming years, consolidation is expected to bring these sectors to more profitable levels of operation."
As North American manufacturers look for innovative ways to compete against low labor cost countries abroad, UV technology might prove to be the difference between keeping production domestic or moving it overseas. "A UV system can provide faster throughput, fewer rejects and greater productivity, ultimately reducing per piece costs," said Chris Walters, global liquid marketing manager, Nordson Corporation. "The UV market for finishing applications is practically non-existent in these low cost countries, so the performance benefits achieved with UV coatings such as improved hardness and gloss, better adhesion, and scratch and chemical resistance can be a competitive advantage for North American manufacturers."
In mature markets, the growth of environmentally friendly technology is a major trend which should help accelerate the adoption of radiation-cured coatings over conventional coatings technologies. In the U.S., California has been driving this trend, according to Jeff Rodrigues, market manager, industrial coatings, Americas, Cytec Surface Specialties. "Being the sixth largest economy in the world, California is able to influence a lot of downstream customers. Some new emerging areas that can take advantage of this trend are coatings for coil and plastics, and wood furniture and cabinets.
"In addition, once the key issues of shadow-cure and improved efficiency in coating 3-D substrates have been mastered, radiation-cured coatings can be used anywhere conventional coatings are being used now," Rodrigues continued. "The key advantages of radiation-cured coatings including their environmental friendliness, lower energy consumption, higher throughput, better end-of-line and in-use properties, and lower total cost for most systems, should make the penetration of radiation-cured coatings in conventional coatings markets much easier going forward."
According to Romesh Kumar, technical manager of industrial coatings for the pigments and additives division of Clariant, there is a strong focus on water-based UV cured formulations. "A similar success story for two-pack polyurethanes has been predicted," he said. "The application would be mainly wood but also automobiles coated completely with UV curable coatings is a hot issue. The market is in many areas experiencing double digit growth, which will persist for the upcoming three to five years. Major growth will occur in inerior wood finish applications."
Jeff Noris, tactical marketing manager for hyperdispersants, Noveon Performance Coatings Group, said better gloss control is a constant need in today's market since 100% solids coatings do not shrink during cure and the matting agent needs to be optimally dispersed and suspended for maximum gloss reduction. Rheology control and flow and leveling are also areas he mentioned where assistance is needed.
According to Ciba, there is a growing interest in its in-house services. "Color matching, durability testing and analytical services we use to support our own internal processes are being offered to our customers," said Chuck Cameron, industry manager, automotive, Ciba Specialty Chemicals. As a result, the firm has developed a group that markets the services Ciba has developed for internal use to provide support and assistance to customers during the product development process.
One of the major challenges in the marketplace continues to be converting traditional coatings applicators to UV curable coatings. "There still is an assumption that UV is more costly, both from a coatings perspective and for the capital cost of purchasing equipment needed to implement the technology," said Werner Peter, business director, performance chemicals for coatings, plastics and specialties, for BASF in North America. "One obstacle that prevents new applicators from entering the market place of rad-cure coatings is the cost of lamps and systems required for the technology."
Overall, the rad-cure coatings market has shown great promise for general finishing, especially in the last few years. "Advances in UV coatings formulations and curing equipment have given us pigmented coatings, 100% solids formulations and the ability to coat and cure 3-D objects. Customers are realizing that the economic drivers behind UV technology are overwhelming," said Walters. "However, while coating capabilities have come a long way, coatings suppliers still have further to go. Like most new technologies, development time has been longer than anticipated and adoption a little slower than expected. Especially in a conservative market like finishing, where the attitude is 'If it's not broken, don't fix it,' it will take a significant market shift to radically increase UV adoption rates. This shift may come in the form of more strict environmental regulations, the continued increase of energy costs and competitive threats from abroad."
By focusing on customer demands, suppliers have introduced various new products for UV/EB coatings manufacturers.
Discussing Noveon's latest innovations on the additives front was Noris. "Reactive additives are needed to preserve durability of high-end coating applications," he said. "Dilutions of existing additive technology in 'reactive diluents' are commonly used today, but the preference would be for 100% active reactive additives for dispersion, flow and leveling, and rheology control. This is an area that has received quite a bit of attention lately."
The newest Noveon additives for UV-cured coatings are for dispersing and stabilizing pigments, particularly matting agents. Solsperse 71000 was recently introduced as a stabilizer for silica and wax treated silica-matting agents in UV coatings. "Coatings formulated with Solsperse 71000 have lower overall gloss and better matting reproducibility," said Noris. This new dispersant joins Noveon's established line of additives for UV coatings including Solsperse 41000, which is used for reducing the viscosity of silica and inorganic pigment dispersions, Solsperse 36000, designed for dispersing and stabilizing TiO2, and Solsperse 39000, a dispersant for carbon black and organic pigments in UV-cured coatings. All of Noveon's Solsperse hyperdispersants designed for UV-cured applications are 100% active.
Cytec Surface Specialties has launched a number of new products for both the energy-curable coatings and graphics markets including the Ucecoat line of UV-PUDs for the wood, composite flooring and metal coatings markets. The company has also introduced low-cost polyester acrylates, a basecoat primer for plastic substrates and a range of products for the auto refinish market.
New products from BASF include several high-performing resins and photoinitiators including Laromer UA 9033 V, a urethane acrylate designed for high flexibility applications such as coil coating, in which 0-T bends are required; Laromer PO 9026 V, a nano-particle modified polyether acrylate designed for resistance to micro-scratching; Laromer PE 9024 V, a polyester acrylate designed for compatibility with nitrocellulose and systems that incorporate UV with conventional coatings; and Laromer PA 9039 V, an additive adhesion promoter designed for adhesion to different metal types such as aluminum and polished CRS.
Phoseon's RX Firefly is a small format/high intensity UV light source with a 20 mm diameter target spot size and a typical peak intensity of greater than 1.5W/cm2. It is ideal for small area and spot cure applications. The RX Firefly complements Phoseon's RX family of wide area UV light systems that serve larger-format UV applications.
New from Ciba Specialty Chemicals is a photo latent base used for curing two-pack urethanes. According to the company, this photo latent base is a catalyst for the polyol isocyanate reaction. A new class of compounds is also available as part of the latest developments from the company's bisacyl phosphine oxide (BAPO) chemistry, which is used for promoting deep cure in pigmented coatings. In this product line there are four to five different products including a photoinitiator for waterborne coatings available in several options-one solid product and three different liquids. Another product developed specifically for the UV curing market is a leveling agent called EFKA 3883, which was developed specifically to crosslink into UV curable coatings and it can be used in all UV-curable systems where flow and leveling are problems.
Sartomer Company has launched 23 new oligomers and three new monomers. The oligomers are designed for a variety of high performance applications including pressure-sensitive and laminating adhesives, and coatings for spray, plastic, paper, wood and hardcoat applications. They fall into seven different categories including aliphatic urethane acrylate oligomers, specialty oligomer/monomer blends, acrylic monomer/tackifer blends, brominated aromatic acrylate oligomers, hyperbranched polyester acrylate oligomers, polyester acrylate oligomers and acrylic oligomers. The three new monomers consist of mono- and multi-functional acrylates designed for various applications including adhesives and plastic coatings.
UV Curing Equipment
Today more companies are recognizing the value and merit of upgrading their technologies to adopt UV systems. As such, UV curing equipment suppliers are focusing on delivering clean, efficient, long lasting UV sources that can cure wide areas uniformly.
As UV coatings evolve from their use in high-speed technical installations to commercial processes such as boat building, car repair and floor refinishing among other applications, safe, portable and easy-to-use UV sources will be critical to these markets' growth.
For decades the same equipment was used to cure coatings-namely the medium pressure mercury lamp, according to Paul Mills, Phoseon Technology. "The underlying technology behind curing equipment had not changed much for years, while at the same time coatings evolved and improved, yielding faster cure, better properties and safer materials," Mills said. "However, now there is a revolution occurring in curing devices with the arrival of solid state curing. Ironically, coating technology is now the obstacle. Since most of today's coatings have been developed to be cured by mercury lamp technology, new coatings are now needed that are optimized to be cured by solid-state UV light sources."
In the years ahead, as industries such as automotive, aerospace and appliance manufacturing begin to embrace and adopt UV technology, Mills said the market will be fueled by a demand for curing larger, more complex shaped parts.
Phoseon's UV light systems, which include its family of RX products usedfor adhesive curing and the curing of paints and coatings, are based on its Semiconductor Light Matrix (SLM) technology, which provides uniform, high-intensity UV light output similar to multi-kilowatt arc lamps but consume a fraction of the energy and provide pure UV spectral distribution. In addition, SLM light sources have longer life cycles than traditional UV lamp technologies, according to the company.
Nordson Corporation recently introduced its LightTite shutter system, which instantly opens and closes to block UV light for accurate control during curing operations and was designed for use with the company's CoolWave system. Added to each CoolWave system lamp head, the pneumatically powered LightTite shutter opens and closes intstantly, without turning off the lamp head and power supply.
The AirShield ventilation system is another new product from Nordson for use with the CoolWave system. The AirShield ventilation system provides the user with the means to capture the hot exhaust air from the lamphead and remove it easily from the cure zone, which eliminates any possible contamination issues in curing applications.