According to GMI, aircraft producers are focusing on using high quality paints and coatings in their manufacturing process. The business is witnessing regular innovations to reduce the overall manufacturing cost and enhance product efficiency. Nano coatings has gained prominence in the industry in the last decade owing to benefits offered such as resistance to dirt and retention of shiny colors for longer duration.
“Aerospace coating have benefited from overall growth in the aerospace sector in 2017, growing 3.4 percent,” said John Griffin, segment director, Aerospace & Film, AkzoNobel. “Manufacturers continue to have a healthy backlog of work to produce, and high-performance coatings support that ramp-up in production. There has been particular growth in Asia, which is why we have opened a new Specialty Coatings facility in China to help us supply aerospace coatings and local support to the expanding North and South Asian markets.”
“The aerospace industry has been growing for the last couple of years now, and 2017 was no exception,” said Daniel Bencun, PPG global director, aerospace coatings. “All segments contributed to the positive performance, which benefited aerospace coatings. The growth has been fueled by the rise in aircraft production rates to meet strong demand for new aircraft combined with higher aftermarket demand. An especially bright spot has been the Asia Pacific region. The Americas and Europe, Middle East and Africa regions have seen major volumes growth as well. We expect that the industry will continue this upward trend for the next couple of years.”
“The market certainly did experience growth last year, though it was fairly slow out of the gate,” said Chip Mullins, global sales manager, Sherwin-Williams Aerospace Coatings. “As a reminder, our refinish and refurbish business tends to trail the overall economy. Around June the market began to turn around and has continued to strengthen all the way into Q1 of 2018. The general aviation and business jet markets have rebounded remarkably. We should see this year continue on an upward trajectory.”
“The whole airline industry is experiencing growth at the moment, and the demand for coatings is expanding along with it,” said Andreas Ossenkopf, director head of Aviation at Mankiewicz. “The use of new materials like composites also calls for new coating solutions: as their surfaces are not as perfect as aluminum, fillers are needed. To meet this demand, we offer fillers to match every need and defect.”
“Another stimulus is the competition between airlines, Ossenkopf added. “Having a unique appearance is of ever increasing importance, to differentiate from other carriers. The thing that catches the eye first and foremost when seeing an aircraft is its exterior paint and 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,” Ossenkopf said.
Probably the most important issue facing the aerospace coatings market is weight reduction. Manufacturers need to produce coatings that will contribute to overall weight reduction, thus decreasing fuel costs and repaint time.
“Prior to the development of our Base Coat/Clear Coat systems, airlines were often forced to choose between lighter single-stage coatings with poor erosion resistance and more durable two-part systems that were heavier and took longer to apply,” said Griffin.
“By formulating our colors for optimum brightness and opacity, fewer layers are required, making the overall system lighter and eliminating the need for compromise. We also develop and provide coatings for composites, thermoplastics and lighter substrates to support manufacturers in keeping total aircraft weight down.”
“Weight reduction has long been on our radar, and it remains priority number one in our industry,” said Bencun. “We target weight reduction through a number of product lines beyond coatings, such as transparencies and sealants, where we are also an important player in aerospace. In coatings, we have launched several initiatives for weight-saving products as well as from the process and application standpoint, where reducing weight is even more important.”
The PPG DESOTHANE HD basecoat-clearcoat line is one example of a new product that PPG developed to help reduce painted aircraft weight. With higher pigment load and coverage compared with traditional direct top gloss systems, these basecoat-clearcoats can offer lower weight even with an additional clearcoat layer.
A few years ago, PPG launched PPG DESOPRIME 7530 chrome-free pretreatment primer that customers can apply with electrostatic spray equipment. This technology combined with PPG Desoprime 7065 chrome-free polyurethane primer offers a better transfer ratio, allowing customers to save weight. Chrome-free coatings are formulated without chrome as an intentionally added ingredient.
“In structural coatings, PPG’s aerospace business has been working on a technology new to the aerospace industry that uses a different application process – electrodeposition,” said Bencun. “PPG AEROCRON anionic epoxy primer replaces traditional structural primers that use chrome. Beyond not having chrome as an intentionally added ingredient and offering very low volatile organic compound (VOC) content, PPG Aerocron electrocoat (e-coat) primer offers weight savings. With a transfer ratio that can approach 98 percent, PPG Aerocron e-coat primer allows for superior coating uniformity even for the most complex-shaped parts, saving material and resulting weight on the aircraft. Achieving such uniformity is nearly impossible with spray-applied primers.”
“Products are not the only driver in terms of weight savings,” Bencun added. “Very often, application is the key coatings contributor to aircraft weight. This is why we stay very close to our customers, working together to optimize their processes for the best combination of product and application techniques. We even audit application processes and capabilities so that we can offer advice to enable customers to achieve the best results with PPG coatings in their facilities.”
PPG’s training programs also help customers optimize their processes and coatings use on the aircraft. These include customized training that the company offers at their customers’ facilities on their equipment as well as a complete program through the PPG Aerospace Coatings Academy. During training sessions, customers learn application techniques and industry best practices.
“We believe that the combination of product and process optimization is the best way to achieve weight reduction,” Bencun added.
“Weight, in regard to aircraft and their coatings, is obviously a huge issue,” agreed Mullins. “ The truth is, there’s only one way to reduce weight – and that’s to reduce the volume of coating on the plane. This isn’t always easy, and some colors are notoriously difficult to hide. It’s not uncommon to need four or five coats for full hide on shades of yellow, for instance. Through excellent opacity with our toner systems, full color hide with lower film build can be achieved. Instead of needing three coats to get a color, leading systems can perform well with one or two coats, which not only reduces weight but saves a tremendous amount of application time (i.e., less labor time equals lower costs and faster aircraft turnaround).”
Besides weight reduction, durability and the ability to retain gloss and vibrant color appearance are important properties sought by aerospace coatings customers.
“One of the most vital concerns for any aircraft is durability,” said Griffin.”Throughout a single flight, an aircraft may be subject to a wide range of temperatures, altitudes and humidities, along with UV radiation and corrosion. That’s why we tailor our coatings to endure such harsh conditions, protecting our customers’ aircraft while retaining high levels of gloss and color. This can help to increase the expected lifespan of an aircraft, and keep it looking ‘factory new’ for longer. We are confident that our coatings meet and exceed customer expectations, especially because we received the ‘Best Performer’ award from Airbus this year, reflecting how much our customers value us as a supplier.”
Beyond traditional performance qualities, such as durability and gloss retention, PPG noted that customers look for coatings that offer process time savings. Shorter turnaround times for coatings application benefit both aircraft manufacturers and operators by helping them be more productive and, therefore, generate more revenue.
“Faster paint process cycles facilitate increases in the aircraft production rate,” said Bencun. “They also reduce the amount of time an aircraft sits on the ground for repainting, which can reduce operational costs or potential revenue loss. Our customers also look for coatings to provide other functions. We have been working on several of these functions, including heat management, ice mitigation and easy cleaning solutions.”
“Aerospace is a high-end industry where technology is quite important, and all characteristics need to deliver high performance,” Bencun added. “We believe strongly in innovation, and we continue substantial investments in new technologies. We believe that this is the best way to deliver long-term value to our customers and our entire value chain.”
Chemical resistance is a constant requirement. “Owners always want protection from hydraulic fluid, de-icing fluid, jet fuel and the like,” said Mullins. “Another must for customers is the ability to adjust dry times based on climate and environment. Someone painting in colder weather is going to want a faster dry time, while it’s less of a concern in warmer climates. So, the ability to adjust accordingly through versatile reducers is critical. And of course, long-lasting gloss retention and good adhesion to a variety of substrates, primers and surface treatment products features customers will always value.”
According to Ossenkopf, one very important demand is a coating solution for nacelles. “The nacelles are the protectors of the heart and muscles of every aircraft, the engine. Their aim is to be aerodynamic and limit noise pollution, but most importantly to safeguard the engine. Special composite materials are used to reduce weight, provide acoustic protection and reinforce the structures they are part of.”
“Can you imagine the amount of stress a nacelle is exposed to?” Ossenkopf continued. “Stress not only comes from movements that the aircraft and in particular the wings make, but also from strong vibrations that emanate from the engine. However, these are not the only stress factors for an engine nacelle – another is erosion. In addition, the composite materials used are much more flexible than aluminum. Finally, a nacelle has the task of image booster for the airline, because it is often the part of the livery that sports the airline’s logo.”
All this makes a nacelle’s requirements especially complex for the coating system used, and it must have a very high level of flexibility to permit all movements. According to Ossenkopf, the question is whether a standard exterior coating system, comprised of a primer and decorative paint system, can meet all these new requirements on flexible surfaces.
ALEXIT TopCoat, BaseCoat and ClearCoat from Mankiewicz do have enough flexibility. “A major vulnerability is that although most exterior primers are indeed flexible, the extreme movements and vibrations that the new composite materials can easily withstand will push all existing primers to their limits,” said Ossenkopf . “That is why we developed a completely new primer to meet these requirements: The ALEXIT FlexPrimer 493-23.”
Increasing the amount of time between paint jobs is a cost-saving measure that many customers are looking to achieve. Some customers that operate in the commercial segment repaint their aircraft more often than others, depending on the regions and routes in which they operate. Most of the time, there is a general trend of around five to seven years of commercial aircraft operation.
“Concerning livery change, there is no rule; it is very dependent on the customer,” said Bencun. “We have seen some customers not change liveries for decades, while others change their liveries every couple of years. What is important in a livery change is the support that is offered to the customer.”
PPG usually works at three levels of varying involvement when a customer makes a livery change.
“The first and simplest level is when customers know the final colors they want to achieve,” said Bencun. “In this case, we provide coatings in the colors that customer design teams have identified. These are not only the exact same colors for the operator’s repaint program around the world but also for new aircraft builds.The second level is where we work with airlines and their designers to offer color choices when they have a rough idea of the color palette they want. PPG color teams collaborate with them to identify specific colors and shades that best match those identified previously. The third and most complicated level is when customers and their designers want to change the livery but have not identified the colors. We work with the designers to create colors that support customer branding and corporate values. After much consultation and work, we suggest the colors that best match customer criteria and initial requests.”
Bencun said all levels of involvement are interesting and PPG has participated in all types in the last two years. “We also work with customers on special liveries, such as those with sports themes and for anniversaries, special events and promotions,” he added. “As with all other instances, we provide broad support from color selection to technical service during application when required by the customer. This is usually very important to them, and they invest a lot during campaigns around special liveries.”
“Market segment is a major determinant. In the commercial market, unless there is a livery change, aircraft can go five to seven years between repaints,” said Mullins. “Typically, repaints are scheduled in conjunction with another major maintenance activity, while the plane is already going to be grounded for an extended period of time. In the corporate and private markets, aircraft are typically kept in a hangar when not in service, so these paint jobs will last longer. Plus, they usually are not flown every day.
However, they tend to be repainted more frequently because owners tend to update for image reasons.”
Aerospace coatings manufacturers have launched a number of new products for both interor and exterior applications.
AkzoNobel recently launched INTURA, a premier interior cabin coating system tailored for ease of application by MROs and OEMs.
“INTURA is offered in both full liquid and film systems so that we can provide a versatile option for the needs of aircraft cabins,” said Griffin. “AkzoNobel has also recently acquired Disa Technology, a leader in aerospace technical marking systems. Disatech specializes in manufacturing self-adhesive vinyl, polyester and polycarbonate films for aircraft and other vehicles.”
PPG has launched a number of products in the past couple of years across the coatings line, from pretreatment, structural and external primers to topcoats and several specialty products. “Airbus and Dassault qualified PPG Desothane HD basecoat-clearcoat. Dassault qualified PPG Desoprime 7530 chrome-free pretreatment primer and PPG Desoprime 7521 chrome-free epoxy primer, which are formulated without chrome as an intentionally added ingredient,” said Bencun.
Sherwin-Wiliams launched a number of products over the last two years, including SKYscapes GA for the general aircraft market, and SKYscapes Shimmer Basecoat, which adds a shimmer effect to an intermediate clearcoat to give a metallic or mica look to any solid color. “We now offer a complete line of military topcoats that provides specifiers their choice of topcoat systems in gloss, semi-gloss or lusterless sheens. And for interiors, we will be introducing an innovative interior effect addition to our JetFlex Elite system this year,” said Mullins.