Composites Manufacturing - Spring 2022

CompositesManufacturing The Official Magazine of the American Composites Manufacturers Association Spring 2022 Will Advanced Air Mobility Take Off Soon? Volkswagen’s Sustainability Strategy Advantages of Multi-Material Solutions

As the Covid-19 pandemic continues to impact the economy and composites industry, Composites One has been a steady and reliable partner for aerospace composite part manufacturers by having products nearby and in stock. Our dedicated aerospace resources are positioned to help our customers find calm by combining an industry leading network of North American AS9120 distribution centers with freezer storage, and a Composites One owned and operated fleet of trucks and refrigerated trailers. Throughout its long history, Composites One has remained focused on making sure composite part manufacturers receive everything they need when they need it, quickly and safely. Dedicated to finding dependable solutions for our customers. That’s the Power of One. Composites One. 800.621.8003 | www.compositesone.com | www.b2bcomposites.com Advanced Products. Expert Service. Local Support. Choose from the broadest, deepest line of high performance aerospace composites from the industry’s top suppliers. North Region South Region East Region West Region Eastern Canada Distribution Centers (DCs) AS9120 Support Location DCs with Prepreg Freezer Storage DCs that are AS9120 Certified Additional Stock Points North America’s most expansive advanced composites materials distribution network, including several AS9120 sites with frozen storage facilities. See Composites One and Aerovac at Booth K9 at SAMPE 2022 in Charlotte, NC, May 23-26.

CompositesManufacturing The Official Magazine of the American Composites Manufacturers Association About the Cover: Joby Aviation’s fully electric, pre-production prototype aircraft uses high-end thermoset composite materials throughout the vehicle structure, propulsion systems and interior components. Photo Courtesy of Joby Aviation. © Joby Aero, Inc. Spring 2022 Features 6 8 21 Reaching for the Sky. ................................ 11 The advanced air mobility market has enormous potential, but companies face significant challenges moving from prototypes to fullscale production. Among them are defining and certifying materials and processes to repeatedly manufacture vehicles at high volumes. By Susan Keen Flynn Working in Tandem. ................................... 16 While the advantages of composites are well documented, FRP is frequently paired with other materials to create the ideal solution. Multimaterial applications range from bridge decks to electric vehicle battery enclosures. By Mary Lou Jay Graphene Gains Traction........................... 21 Companies are beginning to capitalize on the attributes of graphene, the strongest material ever measured. Adding a small amount of graphene to FRP materials can make a substantial difference in properties. By Mary Lou Jay Market Segments Architecture................................................. 6 Penthouse Roof Automotive ................................................. 8 Sustainability at VW Departments & Columns From the ACMA Chair.............................. 2 Tech Talk . ................................................... 3 Inside ACMA............................................ 26 Ad Index.................................................... 28 Photo Credit: Kittyhawk Photo Credit: ATL Composites Photo Credit: Volkswagen Photo Credit: Versarien

CompositesManufacturing 2 Innovation is the lifeblood of industry. From the time the first production Chevrolet Corvette rolled off the production line in 1953 with GFRP body panels, composite materials, technologies and processes have increased exponentially. Think about the products you make and market today. Were they available 10, 20 or 30 years ago? Even so, when we hear about advancements in the composites industry, such as the development of carbon nanotubes or biobased materials, we’re often skeptical. It’s easy to dismiss them as interesting, but impractical. That would be short-sighted. Not all new materials, technologies and processes will find a home, but many will. Advancements are happening at a faster and faster pace. So, too, is the overlapping of fields that once seemed separate and the combination of materials in non-traditional ways. It’s in our best interest to be aware of what’s on the horizon. This issue of Composites Manufacturing magazine includes articles on two budding areas – graphene-enhanced composites (page 21) and the advanced air mobility market (page 11). There’s also coverage of multi-material solutions, with applications ranging from bridge decks to battery enclosures for electric vehicles (page 16). By being proactive and learning about advancements such as these, composites companies can position themselves ahead of competitors and lead new business opportunities. Another great place for education and networking with companies on the forefront is CAMX 2022, which will be held Oct. 17 – 20 in Anaheim, Calif. The conference’s tagline is “Combined Strength, Unsurpassed Innovation.” Together, we can grow the composites industry and continue to revolutionize products and processes. Sign up today at thecamx.org. Sincerely, Fred Sanford ACMA Chairman of the Board fred.l.sanford@gmail.com From the ACMA Chair Composites Manufacturing Official Magazine of the American Composites Manufacturers Association Publisher Cindy Squires csquires@acmanet.org Editorial Managing Editor Susan Keen Flynn sflynn@keenconcepts.net Associate Director, Marketing Barry Black, II bblack@acmanet.org Editorial Design & Production Innovative Association Solutions, LLC twagner@ias-online.net ias-online.net Advertising Sales Manager of Business Development John Catapano jcatapano@acmanet.org All reprint requests should be directed to bblack@acmanet.org Volume 38 | Number 2 | Spring 2022 American Composites Manufacturers Association 2000 N. 15th Street, Ste. 250 Arlington, VA 22201 Phone: 703-525-0511 Fax: 703-525-0743 info@acmanet.org www.acmanet.org Composites Manufacturing (ISSN 1084-841X) is published bi-monthly by the American Composites Manufacturers Association (ACMA), ACMA Headquarters, 2000 N. 15th Street, Ste. 250, Arlington, VA 22201 USA. Subscription rates: Free for members and non-members in the U.S., Canada and Mexico; $55 for international non-members. A free online subscription is available at cmmagazineonline. org. Periodical postage paid at Arlington, VA and additional mail offices. POSTMASTER: Send address changes to Composites Manufacturing, ACMA Headquarters, 2000 N. 15th Street, Ste. 250, Arlington, VA 22201. The magazine is mailed to ACMA members and is also available by subscription. Canada Agreement number: PM40063731 Return Undeliverable Canadian Addresses to: Station A, PO Box 54, Windsor, ON N9A 6J5, Email: returnsil@imex.pb.com. Copyright© 2022 by ACMA. All rights reserved. No part of this publication may be reprinted without permission from the publisher. ACMA, a nonprofit organization representing the composites industry worldwide, publishes Composites Manufacturing, circulation 9,000, as a service to its members and other subscribers. Opinions or statements of authors and advertisers appearing in Composites Manufacturing are their own and don’t necessarily represent that of ACMA, its Board of Directors or its staff. Information is considered accurate at the time of publication, however accuracy is not warranted. Learn and Lead the Way in Industry Advancements

www.acmanet.org 3 Understanding Fire Codes – Part 1 By John Schweitzer Fire codes can often seem rather mystifying. I’m not just talking about complicated code requirements. Development and enforcement of codes can also be puzzling. Throughout this discussion, keep in mind that the Occupational Safety and Health Act of 1970 requires that employers provide places of employment that are “free from recognized hazards.” Fire codes can be a very important resource for identifying recognized hazards in a workplace and providing the appropriate controls, safeguards and protective measures. The fire codes issued by the National Fire Protection Association (NFPA) and the International Code Council (ICC) are consensus standards, which means that code requirements are the collective opinion of volunteer committee members who have at least some knowledge about the fire hazards, risks and protections covered by those codes. The purpose of NFPA and ICC is to manage the consensus standards process by getting a balance of people to serve on code-writing committees and ensuring that the committees respond to public comments. People are often surprised to learn that the organizations are not responsible for the content of their codes, only for the proper operation of the consensus standards process. NFPA and ICC have no role in the enforcement of codes. And the codes are not really meant to be enforced in the same way as OSHA regulations, for example, that are legally enforceable requirements with no flexibility or exceptions. Rather, the codes are intended as recommendations for local building code officials and other Authorities Having Jurisdiction (AHJs) who are responsible for fire safety at a location. A code is designed for what the committee believes is a typical situation. A business owner and local code officials are expected to evaluate whether a potentially applicable code was written in consideration of the hazards and risks that are present at the location. Code committees must rely on generalized approaches. For example, to reduce risks across a very wide range of operations, the flammable liquid codes rely on a classification scheme that groups together materials with similar flammability characteristics and then limits the quantities of each class of flammable material that may be present at a location. The codes that apply to industrial operations allow a business owner to seek a specific variance to the generalized code – and resolve the resulting possible mismatch between the stringency and cost of compliance and the hazards and risks that exist at the location – by conducting a fire hazards analysis that identifies appropriate protection measures for the location. Before taking this approach, the business owner should consult with the AHJ, which ultimately decides if the results of a site-specific analysis will be accepted. I often get calls from plant managers with concerns that their local AHJ suddenly wants a change, such as a reduction in the number of resin and gelcoat drums permitted in the fabrication area. They ask when the code changed. In most cases, the requirement now being enforced has been present in the code for a long time. The truth is that codes have been enforced very inconsistently. However, this is changing. Investigation of recent fires at industrial locations, some unfortunately resulting in the deaths of first responders, revealed that the incidents would have been less severe or may not have occurred at all if the applicable codes had been effectively enforced. Aware of this, the fire safety community is working toward a more thorough and consistent enforcement of codes. Some business owners find that their insurers more aggressively enforces fire safety than their local code officials. Factory Mutual has its own standards that can be more restrictive than the fire codes. For example, the FM Global “loss prevention data sheet” for organic peroxides limits the permitted storage quantities more stringently than the NFPA code. People sometimes forget that insurance is a product just like gelcoat or fibers. The cost and “performance” or risk recommendations of a fire Tech Talk

Signi cant Cost Savings on Additive Tool Partnership between ermwood and General Atomics e Details Using a ermwood LSAM 1020, the tool was printed from ABS (20% Carbon Fiber Filled) in 16 hours. e nal part weighing 1,190 lbs was machined in 32 hours. Cost Savings of around $50,000 vs traditional methods Total lead time for the part decreased from 6-8 weeks to less than 2 weeks by utilizing the powerful LSAM system. e Results • Cost Reduction: 2-3 times • Faster Development: 3-4 times • Production Capable Tool • Vacuum Integrity • Suitable for Large, Deep 3D Geometries, Backup Structures & Vacuum Piping www.thermwood.com 800-533-6901 MADE IN USA Scan QR code to view a video of the LSAM and General Atomics process. See us at Booth 2213

www.acmanet.org 5 insurance policy varies by supplier and purchase agreement. Failure to follow or resolve risk recommendations may have adverse impact on premiums or coverage. Business owners may want to consider proactive engagement with their insurance carriers and conduct periodic risk surveys. The existence of two separate organizations promulgating fire codes – NFPA and ICC – is also a source of confusion. With occasional exceptions, local code officials enforce ICC codes, while insurance carriers refer to NFPA codes. Even when the ICC code is the official code being enforced, the applicable NFPA code can provide requirements that better fit operations and hazards at a location. It’s often effective for a business owner to work with the AHJ to evaluate the applicability of an NFPA code when the requirements of the ICC code are too costly or restrictive given the hazards. If the situation is complex, there are code consultants engaged with ACMA and its members that can be retained to help guide an owner. Finally, we need to consider the role of fire codes in meeting OSHA fire safety requirements. When OSHA was established, Congress allowed the agency to codify the NFPA codes that were in place at that time. While the NFPA codes have since been updated, many of the OSHA regulations remain frozen in the 1970s. The OSHA regulation for fire safety for spraying of flammable liquid (29 CFR 1910.107), applicable to resin and gelcoat spray operations, is based on what was the NFPA code for spray painting, a more hazardous operation. One of the subsequent updates to the NFPA standard for spray application of flammable liquid (NFPA 33) was to add requirements specifically for resin and gelcoat spray. For example, the updated NFPA code, unlike the original spray-painting code, does not restrict resin spray operations to spray booths but also allows them in spray areas, accommodating the fabrication of large composite products. In recognition of the outdated nature of many of their regulations, OSHA does consider as de minimis (without penalty) the violation of an OSHA regulation if the applicable NFPA code is followed and if it provides an equal or greater level of protection. Per this policy, OSHA should issue only a de minimis violation for a composite resin spray operation not fully in compliance with 29 CFR 1910.107 if the facility is fully in compliance with NFPA 33. In the summer Tech Talk column, I’ll tackle the intricacies of some specific fire codes applicable to composites manufacturing operations. John Schweitzer is senior advisor to the president at ACMA. Email comments to jschweitzer@acmanet.org. Disclaimer: Opinions, statements and technical information within the Tech Talk column are that of the authors. ACMA makes no warranty of any kinds, expressed or implied, with respect to information in the column, including fitness for a particular purpose. Persons using the information within the column assume all risk and liability for any losses, damages, claims or expenses resulting from such use. PULTRUSION Zoltek PX35 pultrusion is ideal for structural reinforcement applications. Available in a variety of thicknesses and complex shapes, our pultrusion products deliver optimized properties with high fiber volumes, nearly zero void content, and locked-in filament alignment. Pultruded profiles are production-ready carbon composites for infrastructure applications, deep sea exploration, wind energy, and other applications benefiting from the unique properties of pultruded carbon fiber parts. Visit our website at zoltek.com/pultrusion

CompositesManufacturing 6 Architecture Modeled on the angular wings of an F-117 Nighthawk fighter jet, a roof made from composite sandwich panels soars atop a lounge and deck above the penthouse of a Sydney, Australia, apartment. Part roof, part sculpture, the structure, which was designed by Australian architect Richard Goodwin, isn’t merely eye-catching. It also reduces the building’s carbon footprint by channeling rainwater into ground level tanks. The roof features 1200 g quadriaxial E-glass/KINETIX epoxy skins with a 60 mm end grain balsa core (150 kg/ m3) fabricated by ATL Composites of Queensland, Australia. “The fabrication involved an internal steel skeleton, much like an aircraft wing spar arrangement, with the composite panels forming the structural shell,” says ATL CEO Lorraine Duckworth. She adds that the design offered the best way to bring Goodwin’s design to life – especially a 17.5-meter-long cantilevered section. “The challenges of weight, strength and stiffness associated with a cantilevered roof of this size made it a natural for composites,” she says. “With its unique shape and associated loads, it could not be achieved with normal steel fabrication.” The balsa also provides excellent fire performance, as well as sound and thermal insulation. The roof features ATL’s DuFLEX® panels, which are available in prefabricated kits. The company used hot compression molding to manufacture the 3.6 x 1.2-meter panels. Duckworth says this method increases E-fiber volume, producing panels with 62% E-glass fiber volume by weight. It also saves time and resources. The panels were finished with peel ply to protect the laminate. “Time-consuming laminating, coring and vacuum bagging steps normally required to fabricate high-performance composites are avoided,” Duckworth says. “And material waste, labor and tooling costs are also greatly reduced.” Once cured, the roof panels were cut into the required component shapes using a CNC router. Each pre-cut part remained attached to the panels with one or two small tabs to ensure they remained secure during shipping to Azzura Marine in Sydney. Once there, the small tabs were cut, and the individual roof parts were removed and joined to the underlying stainless-steel frame. Afterward, the roof was disassembled into four components, the largest of which measured 3.6 x 17.5 meters. These were shipped to the penthouse, where they were lifted onto the rooftop by a 140ton crane and reassembled. “DuFLEX panels are specifically designed to reduce construction time and to optimize structural weight in high-performance composite structures,” says Duckworth. “Complex forms can be created relatively easily, and made-tomeasure units can be manufactured to be adapted to existing structures, broadening design freedom and offering rapid processing and construction, which helps to lower costs significantly.” ATL’s DuFLEX panels are used in a variety of industries, including marine, road and rail transportation and industrial. Duckworth says that architecture is a promising market for composites, in part because of the design freedom the materials offer. “[Our panels] are lightweight, thermally insulating and easier to transport, install and maintain than traditional materials and their flexibility of design allows architects to create stunning structures like the Sydney rooftop,” she says. “Often associated with bold projects – both aesthetically and architecturally – composites are emerging as the leading building materials to replace timber, steel, aluminum and concrete.” Melissa O’Leary is a freelance writer in Cleveland. Email comments to melissa@ good4you.org. An Eye-Catching Penthouse Roof The roof on this Australian penthouse apartment, designed by Richard Goodwin and fabricated by ATL Composites, features a structural shell made from composite sandwich panels. Photo Credit: Richard Goodwin/Anthony Browell

VISIT CHEMTREND.COM ZYVAX® 1070W Water-based mold release agent for aerospace applications. With Zyvax® 1070W, we’re doing more than advancing the possibilities. We’re changing the game. Zyvax® 1070W: The gold standard for complex aerospace applications. Chem-Trend has always been on the forefront of release agent innovation. Our global research and development facilities and dedication to the most complex and critical applications have made us a clear leader in the aerospace industry. *NON-SILICONE-BASED ZYVAX® 1070W: • Simple application, requiring only a spray/wipe-on and let dry • Reduces tool prep time from hours to minutes, with no heat cure • Minimizes buildup and fouling • Easy tool cleanup, eliminating the need for sandpaper or aggressive cleaning agents • Reduces VOCs *Zyvax® 1070Wmay contain trace levels of silicone, however they are not a component of the active release ingredients. © Copyright 2022 Chem-Trend L.P. All Rights Reserved. To learn more about Zyvax® 1070W and how we’re helping the aerospace industry soar, contact us today.

CompositesManufacturing 8 Automotive Photo Credit: Volkswagen Sustainability has become a core part of Volkswagen AG’s corporate strategy, and it’s shaking up the company’s supply chain, processes and material selection. This presents an excellent opportunity for composite suppliers. “We are seeing large corporations going against very small startups – and sometimes the startups have the more interesting materials for automotive applications,” says Timo Achtelik, a material engineer at Volkswagen AG. Suppliers looking to get their foot in the door with Volkswagen will find their products must first pass through a four-step stage-gate process Volkswagen implemented in 2021. The steps include idea collection, a feasibility assessment, material testing and validation, and testing and validation of the material within a specific component. Step 1: Idea collection – Suppliers, as well as Volkswagen team members from vehicle designers to construction engineers and material development engineers, are encouraged to suggest new materials. “We try to implement a process where every department works together and can push forward ideas,” Achtelik says. Currently, Volkswagen has approximately 250 sustainable materials in its database to assess for potential use across all vehicle components, from seats and steering wheels to body panels and batteries. Companies not already serving as suppliers can submit suggestions to the Procurement Department’s Innovation Offices via innovation@volkswagen.de. Step 2: Feasibility assessment – Next, material engineers assess the technical characteristics of the suggested materials in their database. This includes screening sustainability data and creating first-cost estimations. “Since sustainability is a fuzzy concept, we’ve tried to make it measurable,” Achtelik says. Suppliers are asked to provide details on product composition that help classify the material within Volkswagen-set norms for post-consumer recycled materials, post-industrial recycled materials, renewable materials and virgin material. Material engineers also evaluate these characteristics in accordance with their internal sustainability goals. Volkswagen Evaluates Sustainable Composites Volkswagen’s ID.Life concept car features recycled materials, including components made from recycled PET bottles.

www.acmanet.org 9 “We always have to focus on the recyclability of the material, as well as our decarbonization and circular targets,” Achtelik explains. “A carbon fiberreinforced plastic might lead to huge decarbonization measures, but at the end of the day we cannot recycle this material. We try to get composites that fulfill all targets into our cars.” While Achtelik notes that the strength and light weight of CFRP will likely prove crucial for meeting overall sustainability targets, Volkswagen is also searching for renewable fibers used in conjunction with recyclable thermoplastic polymers. The company is also interested in biodegradable materials that can be recycled and even compostable on an industrial scale. One solution that Volkswagen is developing is a leatherette for vehicle interiors that uses coffee bean waste as a principal component – in this case to replace petrochemical-based plastics. Another area of interest is around chemical recycling, where polymers are broken down to get material with virgin qualities again. “Currently, the chemical recycling industry faces challenges when it comes to its life cycle analysis (LCA) and energy demand in general, so it’s not reasonable or useful for the automotive industry to use it for now. But we will see about the future,” Achtelik says. Step 3: Material testing and validation – This pre-development step includes testing of product characteristics, such as tensile strength and aging, as well as sustainability characteristics, such as emissions generated during production. At this stage, testing is still performed without the aim of incorporating the material into a specific vehicle project but to ensure that it meets Volkswagen’s stringent requirements. Achtelik notes that one of the biggest challenges suppliers face at this step is ensuring a consistent level of quality at the high supply levels demanded by automotive applications. “We have a lot of new suppliers entering the market right now that have little or no experience with the automotive industry,” Achtelik says. “When we talk about automotive applications, we’re talking about tons of material per year, not kilograms per week. Sometimes we have to remind manufacturers of this.” Step 4: Testing and validation of the material in a part – During the last stage, design and construction engineers collaborate with suppliers to validate the material in a part that will ultimately move into production for a specific vehicle. This is an area where composite materials may find progress stalls. “The biggest challenge with implementing sustainable materials in automotive applications is actually the limited knowledge of how to handle this whole new way of sourcing and working with sustainable materials,” says Achtelik. “With sustainable materials it may be the same polymer, but it’s a different process.” For example, he explains, the availability of recycled material and potentially higher upfront costs change the procurement processes. There may be differences in how engineers need to manage critical emissions and odors generated by recycled material. Sourcing decisions may need to balance LCA values against inconsistent material supply and quality. All of the changes require new processes. “This is all new for us, and we all have to learn – at Volkswagen and in the OEM world, as well as in the supply chain,” says Achtelik. That said, the company is finding ways to incorporate recycled materials in unique ways. The ID.Life concept car is proof of that. This electric mini-SUV does not feature any conventionally manufactured plastic. However, the hood and roof are made using an air chamber textile composed entirely of recycled PET bottles, and recycled PET is featured in other components as well. The vehicle is slated for production around 2025. Volkswagen is also still evaluating how to strike the best balance between incorporating new materials without sacrificing component quality. While the OEM aims to use the highest possible percentage of recyclable materials possible, each material switch comes at a cost. “We have to think about the real customer requirements and needs in balance with where we can put in reduced material or materials,” Achtelik says. Megan Headley is a freelance writer in Fredericksburg, Va. She can be reached at megan@clearstorypublications.com. Unlimited Applications Unmatched Performance Is it possible to increase strength and stiffness while reducing weight and cost? With Vectorply composite reinforcement fabrics it is! Our wide range of fiberglass, carbon and aramid fabrics, combined with industryleading technical services and support can take your product higher, farther, and faster with less weight and labor. Giving your product the competitive edge is our business. Learn more at vectorply.com. 1-800-577-4521 | www.vectorply.com

North America I South America Baltek Inc. I High Point, NC 27261, USA T +1 336 398 1900 I F +1 336 398 1901 corematerials.americas@3AComposites.com Europe I Middle East I India I Africa Airex AGI 5643 Sins, Switzerland T +41 41 789 66 00 I F +41 41 789 66 60 corematerials@3AComposites.com Asia I Australia I New Zealand 3A Composites (China) Ltd. I 201201 Shanghai, China T +86 21 585 86 006 I F +86 21 338 27 298 corematerials.asia@3AComposites.com www.3ACcorematerials.com IF YOUR SUPPLY CHAIN HAS BEEN CORRODED BYWATER... WE MAY HAVE THE MISSING LINK. Most every fabricator has felt the pain of backed-up supplies. And experienced the crippling cost of stalled production. We have the solution. Our AIREX® T92 PET foam core is made in the U.S.A. This recyclable polymer foam delivers impressive mechanical properties in lightweight sandwich structures and works with all resins and processing methods. Plus, it can reach you via national distribution. Quickly! For information, see our website or call us today. AIREX® T92Foam Core for Composites MADE IN THE U.S.A. See us at SAMPE Booth S11

www.acmanet.org 11 On March 9, two U.S. Air Force pilots became the first airmen to fly an electric vertical takeoff and landing (eVTOL) vehicle. The milestone stems from a twoyear partnership between BETA Technologies, which developed the aircraft, and Agility Prime, the Air Force’s initiative to partner with the commercial sector to accelerate development of eVTOL aircraft. Pilots Hank Griffiths and Maj. Jonathan Appleby conducted several flight demonstrations of BETA’s ALIA aircraft at the company’s Plattsburgh, N.Y., testing facility. With a wingspan of 50 feet, the ALIA can fly 250 nautical miles and carry a pilot and three standard pallets or a pilot and five passengers. Operating under the Air Force’s AFWERX innovation arm, Agility Prime was launched in 2020 and has awarded 22 contracts to 14 eVTOL aircraft developers, as well as more than 250 contracts to small businesses and universities to conduct research and development. In a YouTube video promoting Agility Prime, Col. Nathan Diller, AFWERX director, said, “If there is an entirely new way of doing mobility in the air, we have to be in the middle of that.” The Air Force is not the only organization immersed in the expansive advanced air mobility (AAM) market aimed at using transformational designs and technologies to move people and cargo more easily between destinations. An aircraft directory maintained by the Vertical Flight Society cites more than 200 companies working on eVTOL vehicles, from startups to aerospace OEMs like Boeing and the mobility service provider Uber. There’s energy in the burgeoning market – and growing pains, too, as companies develop vehicles and move toward commercialization. Stages of Development “The challenge for the advanced air mobility market is that we’re aiming to eventually reach volumes more familiar to the automotive industry while retaining the extremely high standards required by aerospace regulations,” says Oliver Walker-Jones, head of marketing and communications at Joby Aviation Inc., a developer of eVTOL aircraft. Transitioning from prototypes to full-scale production presents numerous hurdles for both aerospace leaders, with little expertise in high-volume production, and new players to the market. “If you look at eVTOL aircraft, they are quite often being designed by people outside the normal aerospace industry,” says Jim Sherman, director of strategic development for the Vertical Flight Society. “They bring a different perspective, but they also don’t quite understand all of the nuances of getting to production and getting the necessary material and process certifications.” Reaching for the Sky The advanced air mobility market has lofty goals, but companies face challenges as they move toward commercialization. By Susan Keen Flynn Photo Courtesy of Joby Aviation. © Joby Aero, Inc. Joby Aviation’s aircraft are powered by six electric motors, have a maximum range of 150 miles and can travel at up to 200 mph.

CompositesManufacturing 12 Bill Bihlman, president of Aerolytics LLC, an aerospace market research and consulting firm, says there are four fundamental stages to developing new aircraft and each one is arduous. • Functional Prototype – The first step is to build an aerodynamically stable prototype that can fly. “I don’t care what you build it out of. Build it out of balsa wood if you want,” says Bihlman. “The focus is proving that your concept is viable. But as soon as you check that box, you move onto the next round.” • Type Certificate – The second step is receiving type certification. One of the Federal Aviation Administration’s 14 CFR Part 21 certifications, the certificate approves the design of a new aircraft and all component parts, such as propellors and engines. It indicates that the design complies with airworthiness, noise, fuel venting and exhaust emission standards. • Production Certificate – “The production certificate, which is an extension of the type certificate, is all about quality control,” says Bihlman. “Put simply, it indicates that what you built the first time you are going to build a thousand times.” The certificate signifies that a company can repeatedly manufacture a product or article that conforms to the FAAapproved type design. • Sustainment – During the final stage, companies prove continued airworthiness of the new aircraft, including development of a maintenance and repair strategy. Materials and processes are key to all four steps. In Pursuit of the Right Solution “The advanced air mobility business model requires both manufacturing and materials excellence,” says Bihlman. CFRP is commonly used in traditional aerospace applications, and it has become the standard for AAM. Using hand lay-up to fabricate prototypes from carbon fiber and thermoset resins works, but it presents roadblocks for high-rate production. “You need an automated tooling and material system, which is not in place right now,” says Bihlman. “Instead of taking six to eight hours for autoclave curing we need to cure parts in minutes.” Dana Jensen, a senior industrial policy analyst with the U.S. Air Force/Agility Prime, asserts that thermoplastic composites will need to be part of eVTOL solutions. “Thermosets are not going to go away. It’s not a question of moving from one to the other. It’s about incorporating thermoplastics on a bigger scale,” says Jensen. “If you want to achieve high rates, then you need to move to thermoplastics. And there aren’t many qualified thermoplastic materials out there.” It’s a monumental task to create a working prototype, one that many companies have achieved. But if a prototype built with conventional thermosets earns type certification, the company may need to go back to the drawing board to re-imagine the aircraft using thermoplastic composites or quick set thermosets to achieve production certification. Maj. Jonathan Appleby, left, and BETA Technologies’ test pilot Camron Guthrie fly the ALIA eVTOL. Photo Credit: BETA Technologies/Brian Jenkins

www.acmanet.org 13 “How do you move from one material to another without having to go back and redesign the part?” says Jensen. “The more closely the prototype material and tooling resembles what you will use for production the better.” The crux for eVTOL aircraft manufacturers is hitting on the right combination of materials, production tooling and automated processes. “We can do all this with engineered materials, but it’s very nuanced,” says Bihlman. “It takes a while.” One Company’s Path One company striving to find that right combination is Joby Aviation, which has set an ambitious goal of launching an air taxi service in 2024. Its pre-production prototype began flight testing in 2019 and logged more than 5,300 miles last year. A second prototype received FAA Special Airworthiness Certification for experimental research and development in late 2021. It also earned U.S. Air Force airworthiness approval, allowing the company to fly its aircraft as an Agility Prime contractor. Joby’s prototypes incorporate high-end thermoset composite materials throughout the vehicle structure, propulsion systems and interior components. The company used conventional manufacturing processes for the prototypes, including hand lay-up and autoclave curing, and has added two automated fiber placement machines to help support pilot plant volumes. In 2019, Toyota invested $394 million in Joby Aviation and began sharing expertise on high-volume production. “Toyota’s investment has allowed us to work closely on manufacturing and engineering processes, from the design of tools to the layout of our production facility,” says WalkerJones. The automaker also worked alongside Joby to design a Material Matters High-performance materials are critical to the advanced air mobility (AAM) market. owever, material development takes time and resources. And that poses a conundrum for suppliers. They can’t invest in dozens of companies entering the AAM space, hedging their bets that they pick a winner. And OEMs haven’t made material development a top priority. “OEMs don’t see material as a differentiator. They see it as a commodity,” says Bill Bihlman, president of Aerolytics LLC. “All they are trying to do is use their particular design and get to market first.” In the race to be first, manufacturers are tight-lipped about their materials. But this secrecy could be detrimental to advancing AAM. “Each of these companies is working on their own special recipe. If they only knew how close their recipes were to each other they could probably agree on a handful of materials,” says Dana Jensen, a senior industrial policy analyst with the U.S. Air Force/ Agility Prime. “Then, we could certify those materials instead of a plethora of slightly different ones, which is an expensive process.” Various groups are working toward material identification and development, with the goal of creating a public database that qualifying authorities could reference. For example, SAE’s Aerospace Materials System Group formed a working group for AAM in 2021 that’s currently focused on material standards for rapid cure systems. “SAE and the ASTM International are ramping up their standards committee activities to stay in lock step with developers so when the day comes to sign off on certification, there is a raft of paperwork available for people to point authorities to,” says Jim Sherman, director of strategic development at the Vertical Flight Society. Information on qualified material systems could be stored at the National Institute for Aviation Research at Wichita State University in the shared materials database maintained by its National Center for Advanced Materials Performance (NCAMP). This would allow manufacturers to pull a material system from NCAMP, prove equivalency and more easily gain FAA certification. The pioneers in laser-assisted, thermoplastic production technology www.afpt.de

CompositesManufacturing 14 580,000-square-foot pilot production facility in Marina, Calif., that it plans to open in two phases. Joby began its FAA certification program in 2018 when it applied for type certification, which it hopes to complete in 2023. In March, the company moved closer to that goal when it submitted its first area-specific certification plan to the FAA. The plan details the design reports, analysis and testing Joby will employ to demonstrate compliance with FAA safety standards in one functional area of the aircraft – cabin safety. It Takes Teamwork The technical prowess, time and resources required to develop, certify and commercialize an eVTOL necessitate collaboration. In addition to Toyota, Joby Aviation partners with Uber, Toray Advanced Composites, Garmin and others. The Agility Prime program was structured to foster relationships with academia, industry and investors. “The traditional government procurement process is requirements driven, while Agility Prime attempts to turn this model on its head,” says Jensen. “We don’t have a requirement for these new vehicles being built, but we think they could be useful. So, we’re going to help advanced air mobility succeed commercially, then come back on the back end and do procurement.” The Air Force can provide corporate partners with capabilities such as wind tunnels, acoustic testing and flight test planning, as well as expertise in areas such as computational fluid dynamics. It has awarded more than $100 million in contracts and a handful of companies have earned military worthiness, including Joby, BETA Technologies and Kittyhawk. More contracts and certifications are sure to come. “We didn’t specify a sunset for this,” says Jensen. “Agility Prime is now a program of record, and we are taking new applications on a rolling basis as companies start to mature and fly.” While the Air Force has no immediate plans for eVTOL vehicles, a study it conducted with MIT indicated where the new aircraft would complement the military branch’s portfolio of capabilities. “We don’t anticipate they will operate in highly contested environments,” says Jensen. “But there’s a lot that eVTOL aircraft can do in terms of logistical support and movement of personnel in uncontested areas or ship-to-shore transport.” Early Applications for eVTOLs Despite the challenges to implementation, the advanced air mobility market is generating a lot of enthusiasm, as well as speculation over when the first vehicles will take flight and in what capacity. “It’s incredibly exciting and in some ways a little unnerving,” says Sherman. “But I’m confident that teams are pulling together – and pulling in the same direction – trying to achieve a 2024 commercial introduction of air taxis.” He suspects that air taxi service will be limited at the outset. Jensen agrees. “I don’t think there will be thousands of air taxis swarming around cities – at least not initially,” he says. Jensen cites the prohibitive cost per mile for air taxi commuting and hurdles with insuring eVTOL aircraft as primary inhibitors to nearterm adoption. However, he and Sherman both envision other potential early applications, such as cargo and medical transport. “If you could put a first responder in a single-seat eVTOL with some drugs and an automatic external defibrillator to respond to cardiac arrest cases where time is everything, you could save tens of thousands of lives a year,” says Jensen, citing a study from MIT. Bihlman shares Jensen’s conservative stance on AAM, envisioning commercial introduction between 2028 and 2030. In addition to vehicle development, the accompanying infrastructure to support eVTOL aircraft must be created. But he doesn’t want to discourage innovators, adding, “The AAM market will happen.” Suppliers and manufacturers need to be prepared. “Being proactive in getting materials and production certified will be key,” says Sherman. “The companies that can show that are going to have the most orders to start with.” Susan Keen Flynn is managing editor of Composites Manufacturing magazine. Email comments to sflynn@keenconcepts.net. An Air Force pararescue jump expert participates in a medevac exercise with Agility Prime partner Kittyhawk using its Heaviside eVTOL vehicle. Photo Credit: Kittyhawk

CompositesManufacturing 16 The strength, durability and light weight of composites have made them the material of choice for many applications in aerospace, automotive and other industries. But composites can’t always provide all the properties that customers need for specific applications. Combining them with steel, aluminum or other materials often yields the ideal solution. Creative Composites Group’s (CCG) GFRP rail platforms and bridge decks are installed throughout the U.S. But when it came to joining the different sections together, the company realized that they needed metal reinforcement to form a secure connection. A bolt put into a composite part will pull out at a lower load than a bolt put into a steel part. Years ago, CCG started embedding carbon steel plates along the edges of GFRP panels during the vacuum infusion process, using a primer on the steel to strengthen its chemical adherence to the resin. Threaded bolt holes are then drilled in the GFRP/ steel edge. Installation crews use external hardware to attach the FRP panels to support the structure and join the FRP sections together in the field, then seal the hole with caulk to try to prevent water intrusion. However, since water tends to seep in despite these precautions, CCG switched from carbon steel to stainless steel for the reinforcement plates. “Composites are generally at a premium price over steel or concrete, and part of the value that we’re selling is longevity,” says Scott Reeve, business development for CCG. “You want to have the steel on the inside of a product to be a type that’s going to last as long as the FRP.” The company also embeds steel into composite components that require added stiffness, such as extended cantilevered structures. “The basic structure is composites, which keeps the weight down and keeps the corrosion resistance, but there are steel channels totally encapsulated in the FRP. It’s the most economical use of the two materials,” says Reeve. In the past, CCG has also used thin steel strands instead of glass or carbon fibers when manufacturing FRP components for certain applications. This provides added stiffness while reducing thickness, since fewer layers of the steel-fiber-reinforced composite are required. The drawback to this material is that the steel fibers provide reinforcement only in one direction; they don’t have the multi-directional properties of composites reinforced with other types of fiber. Reeve says that owners of vehicle bridges with composite railings often request that steel reinforcements be placed inside railings. If a vehicle hits the structure, bridge owners are more comfortable knowing that the load from the impact will be transferred to the steel – a material they’re familiar with – rather than to the composites, which they may not know as well. Although engineers are growing more knowledgeable about composites, the multi-material approach provides extra reassurance, adding the longevity of composites with the known strength of steel. One of SGL’s first projects was the development and prototype production of the battery case for the NIO electric smart car. The materials included extruded aluminum for the side rails, composites for the top and bottom plates, and steel for the mounting parts. The combination was chosen to meet weight targets, performance requirements and crash behavior. “In general, in the field of battery enclosures, metallic parts are used for the load introduction as well as for crush zones, while the composite overtakes the load distribution,” says Dan Gillig, SGL’s North American technical sales manager. When developing a mixed material component, SGL considers not only the process of combining the different materials but also how to prevent problems like galvanic Working in Tandem By combining composites with other materials, manufacturers capitalize on the distinct properties of each one. By Mary Lou Jay Jarod Weber, left, CHMI Program Manager, and Chuck Zhang, CHMI Director, perform and monitor plasma surface treatment for a composite panel before it is bonded with a metal piece in the Composite Joining and Repair Lab at the Georgia Tech Manufacturing Institute. Photo Credit: Candler Hobbs, Georgia Tech Finding the Right Combination In the automotive industry, companies like SGL Carbon and Katcon are designing and producing multi-material battery enclosures for electric vehicles (EVs).

www.acmanet.org 17 corrosion during the vehicle’s lifetime. The design takes into account the different materials’ properties, how they react to specific forces and the load transfer/distribution between parts. SGL varies its joining technologies according to the materials used and the specific part’s function. Liquid adhesive technology, for example, is important not only to attach the parts to each other but also to carry loads and avoid the creation of weak spots in the assembly. Some assemblies are supported by bolting or riveting, which provides a local mechanical connection in an area where adhesive bonding is carrying the load transfer. Inserts directly integrated into the composite structure or easily bonded threaded studs are often used for mounting points in the assembly when lower loads are being transferred. Katcon, based in Santa Catarina, Mexico, has worked with Forward Engineering in Munich, Germany, to develop a toolbox of materials, processes and design knowledge that’s intended to help manufacturers achieve the best configuration for their specific battery electric vehicle (BEV) platforms. “The goal is to have a lighter battery enclosure that is also economically feasible, safe and sustainable and that can be mass produced,” says Juan Armendariz, Katcon’s general manager. “We found that steel and composites make a great combination,” he says. “We use the steel in the structural members. We use the composites for large panels that are typically expensive to produce in steel due to machinery, tooling and the associated capital expenditures. We can produce those parts more effectively with composites, and the composites are very well suited for intrusion resistance and fire resistance.” Steel is a good choice in combination with composites because it is cost effective for large-scale production, has excellent fire-resistance and OEMs are already familiar with it, adds Armendariz. When designing the battery enclosure, “we need to be very aware of the parts count and the job each component is doing. When you approach this with the whole picture in mind, you get to choose where you want those joints, where they are least exposed and where they add more value,” he says. In most cases, Katcon uses both mechanical connections and adhesives in the joints. Although mechanical fastenings add some complexity, Armendariz doesn’t expect that the industry will switch entirely to an adhesive solution anytime soon. “It’s not just about lightweighting; it’s also being efficient with material allocations, energy utilization and the need to be sustainable. So, the optimal combination is when we use adhesives in combination with other joining methods,” he explains. In the future, Armendariz expects to see greater use of multimaterial components throughout vehicles. “In the end, I think that’s going to help us design better vehicles, grow efficiencies and be more sustainable,” he says. Better Solutions for Bonding In 2014, researchers working on a composites technology roadmap for the National Institute of Standards and Technology questioned manufacturers about the areas of research they were most interested in. Finding the best way to join composites with other materials was one of their top three concerns. Established in July 2021 at the Georgia Tech Manufacturing Institute, the Center for Composite and Hybrid Materials Interfacing (CHMI) will research this topic through a five-year, renewable grant from the National Science Foundation’s (NSF) Industry-University Cooperative Research Center (IUCRC) program. The three universities involved – Georgia Tech, Oakland University in Michigan (OU) and the University of Tennessee, Knoxville (UTK) – will collaborate with members of an industry consortium to develop and disseminate methods, technologies and tools that facilitate rapid, reliable and cost-effective composite and hybrid materials joining and interfacing. CHMI’s goal over the next 10 years is to reduce, by at least 50%, the cost, cycle time and variation of these operations. Industry input is built into the project. Consortium members vote on which projects to pursue, and they fund the research through their membership fees. In addition, company representatives will serve as mentors to review progress and In this manual process for low volume/prototype production of a strut brace, an SGL Carbon employee applies adhesive to join coated aluminum cast parts and coated stamped steel parts to the braided CFRP parts. Photo Credit: SGL Carbon

RkJQdWJsaXNoZXIy MjE3MDU=