Tim Wright08.02.10
The aircraft coatings industry in the United States is highly consolidated with four key suppliers: AkzoNobel, PPG, Deft and Sherwin-Williams. The market was valued at roughly $140 million in 2008, according to Chemark Consulting, and is dominated by the commercial aircraft segment, which accounted for 73.5 percent of the market. The military and general aviation segments accounted for 22.5 percent and five percent respectively.
Continued economic pressure in the airline industry continues to depress demand for both original equipment (OE) and maintenance coatings in both the commercial and general aviation segments. The military segment on the other hand is expanding at a higher growth rate due to increases in defense spending.
The commercial airline industry operates in a very competitive environment where margins are razor thin. “Any significant fluctuation in costs or revenues can have severe impacts on profitability,” said John Griffin, director, AkzoNobel Aerospace Coatings EMEA. “In down times, airlines will often postpone non-critical operations, such as repainting aircraft. However, a significant amount of paint is used during required maintenance operations, and airlines will repaint aircraft as part of a rebranding effort to improve the airline’s image, which often takes place in the difficult times. So, volumes are lower than in previous years, but our airline customers still need our products and services to operate.”
Corporate and general aviation is the hardest hit segment because the costs associated with private aircraft are discretionary and often the first to be cut in a recession. “The defense segment is less volatile due to aircraft maintenance requirements and long term funding plans for new programs, but ballooning deficits will impact this segment,” said Griffin. “Commercial manufacturing is relatively strong by historic standards, and it looks to continue at current production levels for the next few years.”
While rising fuel costs and the recession have taken their toll on the airline industry, the aerospace coatings market is on the up swing, according to Chris Athanasopoulos, director, international business, Deft, Inc. “Our commercial business is improving with new programs like Boeing 787, 747-8, Airbus 380, 350 and Bombardier C Series airplanes,” he said. “At the same time low-cost airlines continue to grow globally. Also as Asian countries grow their commercial airline industries, it increases the need for paints, specifically the markets in China and India.
“MRO (maintenance, repair and overhaul) business will improve with the global consolidation of major airlines as new logos are implemented and repainting becomes necessary,” said Athanasopoulos. “The military segment remains stable with the production of new airplanes and the repaint programs of existing airplanes.”
Cargo business is also expanding. “Airlines and cargo carriers are happy with the increased business,” said Athanasopoulos. “Coatings suppliers are excited with the increase in coating sales. Boeing’s new 747-8 cargo airplane is looked at as the future of profitable business. Private jets are by far the only segment that does not have any good news to cheer about. The private jet business will take the longest time to recover.”
Aerospace Industry is Looking East
While production of aerospace equipment is concentrated in North America and Europe, demand is forecast to be much more diverse over the next five years with roughly one-half of the global demand coming from developing countries.
This trend has been developing over the last few decades. “North America was the predominant producer of commercial aerospace equipment until Airbus emerged in the 1970s,” said Griffin.
Now maintenance and manufacturing operations continue to migrate to South America and Asia to take advantage of lower labor costs. China’s aerospace industry in particular continues to grow rapidly in terms of airline operations, maintenance and aircraft production.
“The market for aerospace coatings mirrors that of the overall aerospace market in China,” said Griffin. “Most products are imported, but this is not a sustainable solution for China. AkzoNobel is working with Chinese aircraft manufacturers, Airbus and Boeing to provide from local sources the high quality and high technology products required by the industry.
“Final assembly lines exist in China for the Embraer 145 and Airbus A-320. Indigenous manufacturing, such as the RJ21 will grow as well,” said Griffin.
AkzoNobel operates many facilities in China. Currently one of its coatings facilities in Suzhou is starting production of aerospace products and is looking to expand its local product range in the coming years.
“We will also continue to support the Chinese market from our North American and European factories through local distributors, who in addition to keeping inventory, have the ability to blend custom colors for our OEM approved finishes,” said Griffin.
China is becoming the next major aerospace market after North America and Europe due to their involvement in recent years in subcontracting for major OEMs, which has given them a better understanding of the industry needs. “With these experiences they have ventured out and are now manufacturing commercial and military airplanes,” said Athanasopoulos. “At the same time paint suppliers to Boeing and Airbus continue to establish manufacturing facilities to better service the market. A 10-15 percent increase in aerospace coatings business is not out of the question for the next 10 years.”
Deft is looking to be a player in China in the coming years. “Presently we are studying and evaluating the business environment,” said Athanasopoulos. “Our cutting edge technologies in chrome-free primers and fluorinated topcoats will help Chinese manufacturers improve production and help the environment.”
Beyond China, which is the market everyone seems to talk about, Athanasopoulos says not to forget the market in India. “The middle class in India is burgeoning and its need for air travel is in high demand,” he said. “A recent marketing release by Boeing reported that India will experience an 8.2 percent annual aircraft sales increase over the next 20 years, which is anticipated to outpace China at 7.2 percent. Based on these projections it’s estimated the growth in aircraft coating sales in India will be equal to or maybe even larger than China. North American and European OEMs have major investments in India.”
Sherwin-Williams Aerospace recently expanded its global presence with increased distribution support in Asia, Africa and the Middle East. A deal with McGean-Rohco Singapore PTE Ltd. in October 2009 brought ten new Asian and Pacific Rim agents to Sherwin- Williams Aerospace’s distribution network, offering coverage and support in Brunei, China, India, Indonesia, Korea, Malaysia, Singapore, Taiwan, Philippines and Thailand.
Sherwin-Williams’ European distributor, Paint Services Group, based in Surrey, England, is now offering distribution services in the Middle East and Africa—two new, active global markets for the aerospace market segment.
Chrome-free Technology Takes Off
The aerospace industry today is demanding greener products from their coatings suppliers that also reduce cycle times, improve performance and improve durability—ultimately helping them to reduce their costs. This is a major challenge for aircraft coating manufacturers, but significant advancements have been made to deliver greener, higher performance products.
“The elimination of chrome from primers and the pretreatment has and continues to be the challenge that keeps engineers developing new products,” said Athanasopoulos. “Regulations like REACH in Europe has brought another challenge to both paint suppliers and airframe manufacturers. Coatings qualified to commercial and military specifications need to be reviewed and certified. If they do not meet requirement reformulation becomes necessary, which then requires requalification to the specification. This is a major expenditure for both OEMs and paint manufacturers.”
New coating development for composite surfaces has taken place in the commercial segment. Improved exterior durability topcoats have also found their place in the commercial market. Deft with recent qualification to Boeing BMS 10-103, BMS 10-125, BMS 10-126 and Bombardier 565-14 is becoming an active player in the commercial market.
However, according to Athanasopoulos, the military has taken the lead in the qualification of chrome-free primers and they are looking to replace the chrome pretreatment.
“Deft, along with other companies, has developed and is promoting such technologies,” he said. “Deft is offering a true self-healing conversion coating, not an adhesion promoter, as a replacement for Alodine 1200.”
Currently, Deft’s chrome-free system—pretreatment and primer—is being tested on the U.S. Airforces’ F-15 and the Norwegian Air Force’s F-16.
As environmental regulations direct aerospace coatings technology, Deft has been successful in qualifying chrome-free primers to MIL-PRF-23377 and MIL-PRF-85582 military specifications.
“Our cutting edge technology for commercial and military fluorinated topcoats has been another success story for Deft with the qualification to Boeing BMS 10-125 and to MIL-PRF-85285 military specifications,” said Athanasopoulos.
AkzoNobel Aerospace Coatings is putting significant resource towards eliminating chrome from all its products. “Utilizing magnesium-based pigments has proven, in laboratory testing, to be as effective as chromates in preventing corrosion on high strength aluminum alloys,” said Griffin.
The new technology is not reliant on chrome pretreatments to be effective. AkzoNobel expects the technology to be approved by the U.S. Air Force, under MIL-PRF-32239 in 2010.
AkzoNobel also recently launched the Aerowave series of waterborne structural coatings. The series includes a corrosion inhibiting primer, topcoat and composite primer, all approved by Airbus and all with a VOC content less than 250g/L.
AkzoNobel has launched the Aerodur 3001/3002 basecoat/clearcoat system for commercial aviation, and the Alumigrip basecoat/clearcoat system for general aviation.
“Applications in both OEM and maintenance environments have confirmed that using a basecoat/clearcoat system will reduce process times by 30% when compared to current paint systems used for aircraft exteriors,” said Griffin.
For the general aviation segment, ANAC has launched Alumigrip 4001, recently approved by Cessna, as a dual purpose primer and sanding surfacer, eliminating one whole step in the exterior painting process. This technology is also being tested in Europe by the Norwegian Air Force, Italian Air Force and Airbus.
Sherwin-Williams Aerospace Coatings has introduce a full line of primers that are free of chrome and lead hazards. These priming options meet applicator needs for commercial, military or general aviation aircraft and meet three key requirements—faster priming, protection of the aircraft substrate and providing key environmental benefits.
“We provide the painter a choice in environmentally supportive primers, including our latest Chrome Hazard Free Epoxy Primer, Epoxy Primer Surfacer and Urethane Primer,” said J. Marc Taylor, Sherwin-Williams Aerospace director of sales. “These new low-VOC, two-component, corrosion-inhibitive products contain no hexavalent chromium (CR(VI)) and subsequently meet the Occupational Health and Safety Administration’s (OSHA) latest standard for occupation exposure.”
Meeting SAE’s Aerospace Material Specification 3095 (AMS 3095), Sherwin-Williams Aerospace Coatings also launched a two-component Wash Primer (CM0484646) designed for pretreatment of aluminum and provides an alternative pre-treatment option to chemical chromates like Alodine and/or Anodized.
“Wash primers have been popular with European MROs for a while and they appreciate a cost-effective option that provides an effective aluminum pretreatment while meeting their regulatory and safety requirements,” said Taylor. “We see wash primers like our new CM0484646 product having similar advantages for use in North America and predict they will gain in popularity.”
SKYscapes is a new basecoat and clearcoat exterior paint system developed by Sherwin-Williams Aerospace. It is designed to deliver faster processing time, more color options and easier maintenance. This allows aviation MRO (maintenance, repair and overhaul) facilities and their paint shops to augment production schedules and turnaround more paint jobs.
SKYscapes modified polyester topcoat is applied using a basecoat-clearcoat process in which all colors are applied as a basecoat. After the basecoat dries, the entire surface of the aircraft is sprayed with a clearcoat finish. Color coat dry time is approximately two hours, compared to six to 10 hours for other systems. This allows shops to apply numerous colors in a single shift and move the aircraft more quickly through the painting cycle.
The new paint system offers a longer recoat time of up to 72 hours, which means no sanding is required between coats. Also, baking between topcoat layers is not required.
SKYscapes improved color palette offers nearly an infinite selection of consistent colors that hide well and offer features such as easy-to-apply pearl and mica finishes.
“Commercial aircraft can now get a business jet finish with a simpler, faster-to-apply product,” said J. Marc Taylor, Sherwin-Williams Aerospace director of sales. “Livery brand image is improved because planes look better longer; and easier maintenance and repair means shops can potentially be more profitable and deliver services more cost effectively.”
Another benefit is that using SKYscapes coatings can potentially deliver less overall paint weight. For example, one coat of this new basecoat with its higher pigment load—teamed with a clearcoat finish—weighs less than two coats of a traditional pigmented coating. Less weight can lead to fuel savings for airlines and aircraft owners.
Ultraviolet A (UVA)-curable coatings are being researched as an alternative to traditional two-component (2K) polyurethane aerospace topcoats because of their rapid cure rates, low volatile organic compounds (VOCs), low volatile hazardous air pollutants (VHAPs) and high performance properties.
Bayer MaterialScience LLC and Deft Inc., one of the leading suppliers of coating systems for the aerospace and industrial markets, developed UVA-curable coating formulations that were evaluated against aerospace standards for topcoats. Based on these findings, Todd Williams, industrial post-doctoral researcher, Bayer MaterialScience LLC, presented “Development of UVA-Curable Coatings for Aircraft Topcoats” at the recent RadTech UV/EB 2010 Technology Expo and Conference in Baltimore.
Conventional coatings in the aerospace market historically have been based upon 2K polyurethane coatings that require 72 hours to fully develop their physical properties. The development of UVA-curable aerospace coatings is targeted to significantly decrease refurbishing time through greatly reduced curing time.
According to Williams, UVA-curable coating formulations display promising physical properties. A UVA-curable formulation was applied to C-130 and F-16 aircraft as a stencil coating and was periodically evaluated for color change and gloss retention. After 600 flying hours, the stencil coatings on the C-130 had ∆E values comparable to the conventional polyurethane fluoropolymer coatings.
Aerospace coatings require a compromise of both chemical resistance and flexibility while maintaining hardness. In this study, formulations that yielded such a balance of chemical resistance, flexibility, and hardness were obtained using a combination of hard and soft urethane oligomers and reactive diluents.
“Gloss reduction of these coatings was achieved through a combination of flatteners and oxygen inhibition, leading to flexible, low gloss formulations,” said Williams. “Weathering of UVA aerospace systems is another critical property that can be chiefly controlled by raw material selection.” Through this evaluation, the overall performance of UVA-curable coatings has been shown to rival that of conventional polyurethane coatings.
Continued economic pressure in the airline industry continues to depress demand for both original equipment (OE) and maintenance coatings in both the commercial and general aviation segments. The military segment on the other hand is expanding at a higher growth rate due to increases in defense spending.
The commercial airline industry operates in a very competitive environment where margins are razor thin. “Any significant fluctuation in costs or revenues can have severe impacts on profitability,” said John Griffin, director, AkzoNobel Aerospace Coatings EMEA. “In down times, airlines will often postpone non-critical operations, such as repainting aircraft. However, a significant amount of paint is used during required maintenance operations, and airlines will repaint aircraft as part of a rebranding effort to improve the airline’s image, which often takes place in the difficult times. So, volumes are lower than in previous years, but our airline customers still need our products and services to operate.”
Corporate and general aviation is the hardest hit segment because the costs associated with private aircraft are discretionary and often the first to be cut in a recession. “The defense segment is less volatile due to aircraft maintenance requirements and long term funding plans for new programs, but ballooning deficits will impact this segment,” said Griffin. “Commercial manufacturing is relatively strong by historic standards, and it looks to continue at current production levels for the next few years.”
While rising fuel costs and the recession have taken their toll on the airline industry, the aerospace coatings market is on the up swing, according to Chris Athanasopoulos, director, international business, Deft, Inc. “Our commercial business is improving with new programs like Boeing 787, 747-8, Airbus 380, 350 and Bombardier C Series airplanes,” he said. “At the same time low-cost airlines continue to grow globally. Also as Asian countries grow their commercial airline industries, it increases the need for paints, specifically the markets in China and India.
“MRO (maintenance, repair and overhaul) business will improve with the global consolidation of major airlines as new logos are implemented and repainting becomes necessary,” said Athanasopoulos. “The military segment remains stable with the production of new airplanes and the repaint programs of existing airplanes.”
Cargo business is also expanding. “Airlines and cargo carriers are happy with the increased business,” said Athanasopoulos. “Coatings suppliers are excited with the increase in coating sales. Boeing’s new 747-8 cargo airplane is looked at as the future of profitable business. Private jets are by far the only segment that does not have any good news to cheer about. The private jet business will take the longest time to recover.”
Aerospace Industry is Looking East
While production of aerospace equipment is concentrated in North America and Europe, demand is forecast to be much more diverse over the next five years with roughly one-half of the global demand coming from developing countries.
This trend has been developing over the last few decades. “North America was the predominant producer of commercial aerospace equipment until Airbus emerged in the 1970s,” said Griffin.
Now maintenance and manufacturing operations continue to migrate to South America and Asia to take advantage of lower labor costs. China’s aerospace industry in particular continues to grow rapidly in terms of airline operations, maintenance and aircraft production.
“The market for aerospace coatings mirrors that of the overall aerospace market in China,” said Griffin. “Most products are imported, but this is not a sustainable solution for China. AkzoNobel is working with Chinese aircraft manufacturers, Airbus and Boeing to provide from local sources the high quality and high technology products required by the industry.
“Final assembly lines exist in China for the Embraer 145 and Airbus A-320. Indigenous manufacturing, such as the RJ21 will grow as well,” said Griffin.
AkzoNobel operates many facilities in China. Currently one of its coatings facilities in Suzhou is starting production of aerospace products and is looking to expand its local product range in the coming years.
“We will also continue to support the Chinese market from our North American and European factories through local distributors, who in addition to keeping inventory, have the ability to blend custom colors for our OEM approved finishes,” said Griffin.
China is becoming the next major aerospace market after North America and Europe due to their involvement in recent years in subcontracting for major OEMs, which has given them a better understanding of the industry needs. “With these experiences they have ventured out and are now manufacturing commercial and military airplanes,” said Athanasopoulos. “At the same time paint suppliers to Boeing and Airbus continue to establish manufacturing facilities to better service the market. A 10-15 percent increase in aerospace coatings business is not out of the question for the next 10 years.”
Deft is looking to be a player in China in the coming years. “Presently we are studying and evaluating the business environment,” said Athanasopoulos. “Our cutting edge technologies in chrome-free primers and fluorinated topcoats will help Chinese manufacturers improve production and help the environment.”
Beyond China, which is the market everyone seems to talk about, Athanasopoulos says not to forget the market in India. “The middle class in India is burgeoning and its need for air travel is in high demand,” he said. “A recent marketing release by Boeing reported that India will experience an 8.2 percent annual aircraft sales increase over the next 20 years, which is anticipated to outpace China at 7.2 percent. Based on these projections it’s estimated the growth in aircraft coating sales in India will be equal to or maybe even larger than China. North American and European OEMs have major investments in India.”
Sherwin-Williams Aerospace recently expanded its global presence with increased distribution support in Asia, Africa and the Middle East. A deal with McGean-Rohco Singapore PTE Ltd. in October 2009 brought ten new Asian and Pacific Rim agents to Sherwin- Williams Aerospace’s distribution network, offering coverage and support in Brunei, China, India, Indonesia, Korea, Malaysia, Singapore, Taiwan, Philippines and Thailand.
Sherwin-Williams’ European distributor, Paint Services Group, based in Surrey, England, is now offering distribution services in the Middle East and Africa—two new, active global markets for the aerospace market segment.
Chrome-free Technology Takes Off
The aerospace industry today is demanding greener products from their coatings suppliers that also reduce cycle times, improve performance and improve durability—ultimately helping them to reduce their costs. This is a major challenge for aircraft coating manufacturers, but significant advancements have been made to deliver greener, higher performance products.
“The elimination of chrome from primers and the pretreatment has and continues to be the challenge that keeps engineers developing new products,” said Athanasopoulos. “Regulations like REACH in Europe has brought another challenge to both paint suppliers and airframe manufacturers. Coatings qualified to commercial and military specifications need to be reviewed and certified. If they do not meet requirement reformulation becomes necessary, which then requires requalification to the specification. This is a major expenditure for both OEMs and paint manufacturers.”
New coating development for composite surfaces has taken place in the commercial segment. Improved exterior durability topcoats have also found their place in the commercial market. Deft with recent qualification to Boeing BMS 10-103, BMS 10-125, BMS 10-126 and Bombardier 565-14 is becoming an active player in the commercial market.
However, according to Athanasopoulos, the military has taken the lead in the qualification of chrome-free primers and they are looking to replace the chrome pretreatment.
“Deft, along with other companies, has developed and is promoting such technologies,” he said. “Deft is offering a true self-healing conversion coating, not an adhesion promoter, as a replacement for Alodine 1200.”
Currently, Deft’s chrome-free system—pretreatment and primer—is being tested on the U.S. Airforces’ F-15 and the Norwegian Air Force’s F-16.
As environmental regulations direct aerospace coatings technology, Deft has been successful in qualifying chrome-free primers to MIL-PRF-23377 and MIL-PRF-85582 military specifications.
“Our cutting edge technology for commercial and military fluorinated topcoats has been another success story for Deft with the qualification to Boeing BMS 10-125 and to MIL-PRF-85285 military specifications,” said Athanasopoulos.
AkzoNobel Aerospace Coatings is putting significant resource towards eliminating chrome from all its products. “Utilizing magnesium-based pigments has proven, in laboratory testing, to be as effective as chromates in preventing corrosion on high strength aluminum alloys,” said Griffin.
The new technology is not reliant on chrome pretreatments to be effective. AkzoNobel expects the technology to be approved by the U.S. Air Force, under MIL-PRF-32239 in 2010.
AkzoNobel also recently launched the Aerowave series of waterborne structural coatings. The series includes a corrosion inhibiting primer, topcoat and composite primer, all approved by Airbus and all with a VOC content less than 250g/L.
AkzoNobel has launched the Aerodur 3001/3002 basecoat/clearcoat system for commercial aviation, and the Alumigrip basecoat/clearcoat system for general aviation.
“Applications in both OEM and maintenance environments have confirmed that using a basecoat/clearcoat system will reduce process times by 30% when compared to current paint systems used for aircraft exteriors,” said Griffin.
For the general aviation segment, ANAC has launched Alumigrip 4001, recently approved by Cessna, as a dual purpose primer and sanding surfacer, eliminating one whole step in the exterior painting process. This technology is also being tested in Europe by the Norwegian Air Force, Italian Air Force and Airbus.
Sherwin-Williams Aerospace Coatings has introduce a full line of primers that are free of chrome and lead hazards. These priming options meet applicator needs for commercial, military or general aviation aircraft and meet three key requirements—faster priming, protection of the aircraft substrate and providing key environmental benefits.
“We provide the painter a choice in environmentally supportive primers, including our latest Chrome Hazard Free Epoxy Primer, Epoxy Primer Surfacer and Urethane Primer,” said J. Marc Taylor, Sherwin-Williams Aerospace director of sales. “These new low-VOC, two-component, corrosion-inhibitive products contain no hexavalent chromium (CR(VI)) and subsequently meet the Occupational Health and Safety Administration’s (OSHA) latest standard for occupation exposure.”
Meeting SAE’s Aerospace Material Specification 3095 (AMS 3095), Sherwin-Williams Aerospace Coatings also launched a two-component Wash Primer (CM0484646) designed for pretreatment of aluminum and provides an alternative pre-treatment option to chemical chromates like Alodine and/or Anodized.
“Wash primers have been popular with European MROs for a while and they appreciate a cost-effective option that provides an effective aluminum pretreatment while meeting their regulatory and safety requirements,” said Taylor. “We see wash primers like our new CM0484646 product having similar advantages for use in North America and predict they will gain in popularity.”
SKYscapes is a new basecoat and clearcoat exterior paint system developed by Sherwin-Williams Aerospace. It is designed to deliver faster processing time, more color options and easier maintenance. This allows aviation MRO (maintenance, repair and overhaul) facilities and their paint shops to augment production schedules and turnaround more paint jobs.
SKYscapes modified polyester topcoat is applied using a basecoat-clearcoat process in which all colors are applied as a basecoat. After the basecoat dries, the entire surface of the aircraft is sprayed with a clearcoat finish. Color coat dry time is approximately two hours, compared to six to 10 hours for other systems. This allows shops to apply numerous colors in a single shift and move the aircraft more quickly through the painting cycle.
The new paint system offers a longer recoat time of up to 72 hours, which means no sanding is required between coats. Also, baking between topcoat layers is not required.
SKYscapes improved color palette offers nearly an infinite selection of consistent colors that hide well and offer features such as easy-to-apply pearl and mica finishes.
“Commercial aircraft can now get a business jet finish with a simpler, faster-to-apply product,” said J. Marc Taylor, Sherwin-Williams Aerospace director of sales. “Livery brand image is improved because planes look better longer; and easier maintenance and repair means shops can potentially be more profitable and deliver services more cost effectively.”
Another benefit is that using SKYscapes coatings can potentially deliver less overall paint weight. For example, one coat of this new basecoat with its higher pigment load—teamed with a clearcoat finish—weighs less than two coats of a traditional pigmented coating. Less weight can lead to fuel savings for airlines and aircraft owners.
Ultraviolet A (UVA)-curable coatings are being researched as an alternative to traditional two-component (2K) polyurethane aerospace topcoats because of their rapid cure rates, low volatile organic compounds (VOCs), low volatile hazardous air pollutants (VHAPs) and high performance properties.
Bayer MaterialScience LLC and Deft Inc., one of the leading suppliers of coating systems for the aerospace and industrial markets, developed UVA-curable coating formulations that were evaluated against aerospace standards for topcoats. Based on these findings, Todd Williams, industrial post-doctoral researcher, Bayer MaterialScience LLC, presented “Development of UVA-Curable Coatings for Aircraft Topcoats” at the recent RadTech UV/EB 2010 Technology Expo and Conference in Baltimore.
Conventional coatings in the aerospace market historically have been based upon 2K polyurethane coatings that require 72 hours to fully develop their physical properties. The development of UVA-curable aerospace coatings is targeted to significantly decrease refurbishing time through greatly reduced curing time.
According to Williams, UVA-curable coating formulations display promising physical properties. A UVA-curable formulation was applied to C-130 and F-16 aircraft as a stencil coating and was periodically evaluated for color change and gloss retention. After 600 flying hours, the stencil coatings on the C-130 had ∆E values comparable to the conventional polyurethane fluoropolymer coatings.
Aerospace coatings require a compromise of both chemical resistance and flexibility while maintaining hardness. In this study, formulations that yielded such a balance of chemical resistance, flexibility, and hardness were obtained using a combination of hard and soft urethane oligomers and reactive diluents.
“Gloss reduction of these coatings was achieved through a combination of flatteners and oxygen inhibition, leading to flexible, low gloss formulations,” said Williams. “Weathering of UVA aerospace systems is another critical property that can be chiefly controlled by raw material selection.” Through this evaluation, the overall performance of UVA-curable coatings has been shown to rival that of conventional polyurethane coatings.
