“The aerospace coatings market has been growing steadily,” said John Griffin, AkzoNobel’s Aerospace business director. “Airbus and Boeing both had record deliveries in 2018 contributing to the growth of the commererical fleet, and high-performance coatings continue to support these production increases. Aviation growth in Asia-Pacific continued in 2018, with more orders and market developments coming from the region.”
“It is not a secret that the airline industry is growing very rapidly. According to many sources, it is expected that number of in service A/Cs doubles in the next 10 years,” said Andreas Ossenkopf, director – Head of Aviation at Mankiewicz. “Therefore, the whole airline industry is experiencing a continuous growth and hence the demand for coatings is expanding along with it.
“Although already in use for more than 10 years, materials like composites are still relatively new when used in structural components. Production processes have evolved since the very first use but yet parts coming out of the autoclave do present a not optimum surface. Fillers are then needed to improve the surface quality before the painting process starts. To meet this demand, we offer a wide portfolio of solutions to match every need and defect.”
According to Ossenkopf, airlines are also taking competition to a next level. “As the paint technology progresses, new solutions are available which allow airlines to create unique appearances. This is increasing in importance as it enable airlines to differentiate from other carriers. The thing that catches the eye first and foremost when seeing an aircraft is its exterior paint. Accordingly, there is a trend for special liveries and the use of micas and vibrant colors.
“The fact that paint can be used today where previously it was necessary to use decals also has a positive effect on the aerospace coatings market. The BaseCoat/ClearCoat system, originally developed by Mankiewicz in 2006, allows the use of paint to produce vivid colored liveries with the finest details. Its outstanding durability compared to decals, the excellent drying times of the BaseCoat and the paint’s special fading and blending properties make this coating a perfect match for the exacting demands of the aviation industry.”
According to Daniel Bencun, PPG global director, aerospace coatings 2018 was in line with previous years. “There was an increased backlog, and OEMs had more deliveries. The aftermarket boomed, taking the aerospace coatings industry to levels beyond expectations. All of our major segments, including military, commercial and general aviation, expanded. Regionally, PPG saw significant growth in North America and Asia. The Europe, Middle East and Africa (EMEA) region recorded lower growth, but it was still in line with our plans. In 2019, we expect industry performance to continue to have reasonable growth. We anticipate increased throughput at our customers and strong demand in the aftermarket will continue to pull coatings demand. Strong military programs in North America also should benefit industry performance.”
Reducing weight and improving efficiencies are major concerns when coating airplanes
Building lighter aircraft is generally beneficial for the industry and the aircraft operator. Reducing weight can result in more fuel savings and therefore increased financial and sustainability performance and longer aircraft ranges for airlines.
“PPG always strives to be at the forefront on developing innovative, new solutions for lighter aircraft, whether in coatings or other product lines that we offer, such as transparencies and sealants,” noted Bencun. “We collaborate hand in hand with our customers to envision, design and launch products that satisfy their latest needs.”
In the last couple of years, PPG has commercialized several products that are delivering weight savings to its customers. PPG DESOTHANE HD basecoat-clearcoat allows customers with liveries that have medium to high complexity to reduce the weight of coatings on their aircraft by up to 20 percent. PPG AEROCRON electrocoat (e-coat) primer, which is used to coat structural parts by electrodeposition instead of a traditional spray process, brings uniform film on the part. This can result in up to 75 percent weight savings on highly complex parts. In addition, it offers high transfer efficiency and is an environmentally sustainable technology.
“Reducing weight is always welcome by aircraft manufacturers and operators, especially during the design and certification phases, and we contribute to these benefits; perhaps dozens or a few hundred pounds overall, but our main focus is to develop products that perform functionally,” said Griffin. “For example, our new Aerobase and Aerodur basecoat/clearcoat systems were developed to improve durability and reduce application time, and then we found ways to optimize our color formulation for optimum brightness and opacity, which can lead to fewer layers and lower film build and weight. In addition, we provide and continue to develop coating systems for composites, thermoplastics, and lighter substrates to support manufacturers with minimizing total aircraft weight.”
“Weight is indeed of high concern to the airline,” said Ossenkopf. “Every kg on the aircraft makes a big difference in the operational costs. When talking about paint, two main aspects have to be considered: the paint itself and the application process or sequence. On the first, Mankiewicz works continuously in adjusting the pigment concentration in products to achieve the best results by optimizing the weight of the dry film layer. The use of special research techniques allows Mankiewicz´s researchers to play with the tolerances defined by the different specifications in an effort of satisfying these but still same some grams on each iteration. On the other hand, Mankiewicz continuously works with Airlines and MROs on defining best practices. Only working closely with the user of our products, the smoothest and most efficient results can be achieved, resulting in potential reduction of paint consumption and ultimately reduction of weight.”
Products like Sherwin-Williams’ Basecoat/Clearcoat SKYscapes topcoats provide better coverage, which means less paint used. “Plus, through excellent opacity with our toner systems, full color hide with lower film build can be achieved,” said Julie Voisin, global product manager, Sherwin-Williams Aerospace Coatings. “However, we find the best way to control weight, is to help shops focus on the fundamentals. Ensuring the coatings products are being applied properly and optimally can contribute a lot of weight benefit. Even training for the most experienced painter can
“As our technical service professionals are working in the field throughout the globe, they really help customers focus on efficient processes,” she continued. “Coming up with repeatable systems that help ensure efficiency with every paint job is one of the top things that control the weight of the coating on the plane.”
In addition to reduction of weight, customers have a number of requirements of their aerospace coating. These include regulatory compliance, ease of application and durability.
“Reducing the total cost of ownership and complying with the ever-changing regulatory environment are two key trends that guide our developments,” said Griffin.”Total cost of ownership includes the durability of coatings, ease of application, process time, and lastly, the cost per liter/surface area. Durability is by far the biggest contributor to total cost of ownership. Delaying the need to repaint aircraft or components saves significant costs in terms of material and application. Additionally, if aircraft do not need to be grounded for repainting, they can continue to generate revenue or be mission-ready. We definitely see a continued shift to basecoat/clearcoat in the industry. These technologies were developed to improve durability and reduce application time. We have since found further ways to optimize our color formulation for optimum brightness and opacity, leading to fewer layers and lower film builds, potentially reducing weight.
Enhanced durability is one of many reasons why many airlines are switching to our basecoat/clearcoat systems, including Aerobase and Aerodur 3001/3002.”
According to Ossenkopf, ramping up is definitely a hot topic: to produce ever more aircraft it is necessary to produce ever increasing quantities of interior components – without having any extra time or production capacity available. “That is why the pressure on manufacturers is enormous and along with this the demand for faster, efficient solutions. Mankiewicz offers approved paint solutions that help producers speed up their processes, increase their capacities and improve the quality of surfaces, ensuring they are uniform. The automation of solutions with water or solvent based Topcoats and Fillers range from automated mixing to fully automated robot application.
“Furthermore, there is an apparent contradiction between the desire for individual solutions and a trend towards eye-catching design effects on the one side, and extremely cost-conscious budget airlines on the other side. Mankiewicz offers products to satisfy both these demands. For airlines that attach great importance to design and individual appearance, there is a great variety of colors, gloss levels and textures available – even special colors to match the airline’s own design can be developed on demand. For low-cost carriers, Mankiewicz offers special products that save both time and materials, and that make extremely efficient painting processes possible.
“Another request we presently encounter quite often is for training – either at our factory or on site with a customer. In our training courses operators can learn directly from us the optimal way to apply our paints and this ensures they are able to work as efficiently as possible. Not only does the training lead to savings in time and materials during the coating process, but also that as uniform as possible a finish is achieved with the paint, especially important when several producers are involved in the project. This kind of after-sales service distinguishes Mankiewicz as a family-run business and it is definitely something our customers increasingly appreciate. A further trend is for added functions in paints – not only with outstanding performance in terms of an efficient and effective delivery of gloss and color stability, they must also have useful additional features.”
PPG’s Bencun noted that their OEM customers are facing historical backlogs, and airlines are seeing the world traffic increasing. This results in specific needs for coatings solutions that allow customers to paint faster and increase their throughput. Reduced drying times can allow customers to speed their production process and minimize aircraft ground time.
“Both PPG Desothane HD basecoat-clearcoat and PPG Aerocron e-coat primer provide potential opportunities to increase productivity in addition to reducing weight,” said Bencun. “Our customers are also looking for coatings with higher durability. They want their assets to be performing better in terms of color and gloss retention compared to previous technologies. PPG Desothane HD basecoat-clearcoat can increase this performance, resulting in brighter and more colorful aircraft that support an airline’s brand and image. In addition to weight savings, productivity and durability, our customers are looking for more environmentally preferred solutions. Regulations, such as Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), are completely embedded in all our development efforts.”
According to Voisin durability is a major priority for aerospace coatings customers. “Customers want the product to maintain its color and gloss throughout the lifetime of the coating,” she noted. “The appearance of the coating can have a direct impression to customers and their feeling of safety so maintaining its appearance is important. Also, since the structures of most aircraft are still aluminum, corrosion control or prevention, is also an extremely important characteristic of aviation coatings.”
AkzoNobel has launched a new chromate-free exterior primer, Aerodur HS 2121, developed with and qualified at Airbus. For airlines, Aerodur HS 2121 promotes superior sustainability of the brand image and improves selective stripping of the decorative layer, enhancing rivet adhesion and reducing maintenance downtime. It was developed to meet all Airbus exterior system specifications, including the selective strippable systems. The product received its qualification from Airbus in March 2019.
“In addition, we are in the late stages of qualifying our Aerodur 2111 chrome-free primer to Boeing specification BMS 10-72. Production trials have been successful (dozens of applications), and the updated Qualified Products List should be released by late Q2 2019,” Griffin said. “This product is similar to our AMS 3095 approved Aerodur 2118 that is currently used by several major airlines and being mandated for use by several military platforms.”
This year Mankiewicz is presenting a new generation of Fillers that was specially developed for use on 3D-printed components. As shapes are getting more complex within aircraft components, the use of 3D printing process is increasing. While previously the technique was mostly used for producing spare parts, increasingly manufacturers are working with 3D-printed components from the outset. As with any new technology it brings new challenges to overcome. The 3D printing technique typically produces furrows, which particularly poses a problem for their subsequent coating – in order for the paint to achieve a shiny and smooth surface it is necessary to first compensate for the furrows with fillers. However, it is not as easy as it sounds. As the furrows made by a 3D printer are deeper than the unevenness normally found on aircraft components, a larger amount of filler material is needed. When applied in thicker layers many fillers no longer pass the heat release rate test and so are unsuitable for the aviation industry. Our new fillers pass the heat release rate test even in cases of deep furrows – and consequently a thicker layer of the product – without any problem. The filler is specially adapted to the demands of the aviation industry – and enables unhindered exploitation of 3D-printed components!
Mankiewicz has also developed and qualified a primer that is highly flexible and able to withstand the massive vibrations under which a flexible nacelle composite remains stable and intact: ALEXIT FlexPrimer 493-23. Not only does the primer prevent the paint from cracking, it also fulfils all properties of a normal exterior primer and is chromate-free. When used as a substitute for regular primer, there is no need for a further layer and thus no additional weight is added. This way the engine nacelle stays looking good, there is no loss of availability caused by unplanned maintenance and in general less repairs are necessary.
PPG has launched several technologies in recent years, and now is working on enlarging its qualified systems portfolio. “In pretreatment, for example, we have qualified PPG RECC 3007 sprayable chrome-free pretreatment to U.S. Military Specification MIL-C-81706, Type II, Class 3, Form IV, Method A,” said Bencun. “The pretreatment is formulated without chrome as an intentionally added ingredient. Our chrome-free primer technologies, including PPG Aerocron e-coat primer, are being approved by a growing number of OEMs and tier-one subcontractors. PPG CA7088 chrome-free integral fuel tank coating has been qualified to SAE International’s Aerospace Material Specification AMS-C-27725, Type 3, Grade 2. The coating can help protect the interior of an aircraft’s fuel tank against corrosion from fuel contaminants, such as water, salt water, aircraft fuels, hydraulic fluids, engine oils and dilute acid solutions, as well as diethylene glycol monomethyl ether (DiEGME).”
PPG Desothane HD basecoat-clearcoat has three new AMS3095A qualifications, and one major player in the industry has approved the same version with solar heat management. Airlines often avoid using dark colors in their liveries because they can absorb solar energy that heats the interior while the plane is on the ground. With this innovative technology, the coating reduces external aircraft skin temperatures, helping keep interior cabin temperatures cooler by 5 to 7 degrees Fahrenheit, so airlines are able to use dark colors in their liveries.
Bencun said another OEM has approved a thermally accelerated version of our new wing coatings technology, which improves our OEM customer throughput.
“We are also working very closely with customers on how to apply products,”added Bencun. “PPG’s Aerospace Coatings Academy has had great success, with more than 70 companies participating in the program to date. We have worked with more than 300 painters, engineers and other customer representatives through this multiday program, which includes classroom and hands-on applications. We plan to conduct 10 sessions in all respective regions in 2019 for our customers globally.”
From an exterior coating standpoint, Sherwin-Williams Aerospace Acry Glo Urethane has now been formulated with its Metallic HLG Acrylic Urethane topcoat finish for a metallic finish suitable for quick drying stripes on small aircraft and helicopters, and as an overall finish for GA equipment. Acry Glo is a multi-component topcoat that has been a versatile, proven performance system in the aviation industry for more than 30 years. It is a high-quality, rugged aerospace coating that offers outstanding durability, gloss retention and chip resistance that keeps equipment pristine and protected in harsh environments.
On the interior front, Sherwin-Williams Aerospace has just introduced Jet Suede, a two-component urethane topcoat designed to enhance the feel of aircraft interiors. Jet Suede delivers an upscale, textured feel to any surface to which it is applied. Perfect for application on rigid and flexible plastics and substrates, this interior topcoat provides a durable finish that will look great for years to come. Jet Suede is offered in low gloss, solid colors, including an array of OEM colors.