The use of sustainable plastics in aviation (I/II): do aircraft manufacturers have a strategy for disposal and reuse?

This article is part one of a series on sustainable plastics in aviation. You can find part two here.

The race to enhance aerodynamics' efficiency, cost-effectiveness and sustainability practices in the global aircraft manufacturing market has caused industry big players such as Airbus, Boeing, Embraer, Raytheon Technologies, Northrop Grumman, General Electric, Leonardo, Bombardier and others, to adopt material, design, and technological innovations not to only remain competitive but to play the leading role in the Net Zero duel. 

This is no joke as a recent study by Polaris Market Research forecast the aircraft manufacturing market to be worth an estimated $626 billion in 2030 from its current estimate of $413 billion in 2021, with the aerospace plastics market projected to grow at a Compound Annual Growth Rate (CAGR) in the excess of 6.8% from 2021 to 2026. The projected increase in passenger traffic post-pandemic as forecasted by the International Air Transport Association (IATA), International Civil Aviation Organization (ICAO) and Airport Councils International (ACI) provides assurances of the booming days ahead for the manufacturing industry as they strive to meet new aircraft demands amidst manufacturing bottlenecks.

The game-changing effect of plastics on the aviation industry 

The use of plastics in aircraft manufacturing dates back over 70 years. However, its application in the 1970s in a post-World War II world quadrupled as Airbus and Boeing began experimenting with the first carbon fiber reinforced plastic (CFRP) components. This revolutionized the industry and continues to have a game-changing impact today as reinforced polymers have significantly altered how airframes are designed and built in civilian, commercial and freighter, and military aircraft. For example, the Boeing 787 Dreamliner entered service in 2011 as the first long-haul commercial aircraft made of 50% plastic while Airbus introduced the A350 a few years later with a 52% fibre-reinforced plastic (FRP) content. A wide variety of plastics (Polyetheretherketone (PEEK), Polyphenylene Sulfide (PPS), Thermosetting Polyimide, Polyamide-imide (PAI), Acrylonitrile butadiene styrene (ABS), Polychlorotrifluoroethylene (PCTFE), Polymethyl methacrylate (PMMA), Polytetrafluoroethylene (PTFE), etc.) are used in the manufacturing process from structural components, navigational functions, aircraft doors, aircraft engines, control panels and electrical electronics, air ducts, exterior panels, luggage storage compartments to interior wall panels amongst others.

The advantages of aircraft weight reduction, production speed, cost-efficiencies, fuel efficiency, corrosion, and chemical and impact resistance make plastics a desirable choice over metal and glass materials for manufacturing. Plastics are also used as ideal materials in the packaging and protection of aerospace equipment during handling and shipping which offers benefits including protection from shocks, erosion, vibrations, extreme temperatures and humidity. Moreover, plastics offer freedom in assembly, versatility, flexibility and customizability of complex geometric designs and shapes. 

These varied uses and benefits of plastics in the aircraft manufacturing ecosystem have created a massive aerospace plastic industry with leading industry players such as Victrex plc, Ensinger, SABIC, Solvay, BASF SE, Evonik and Industries AG developing different plastic products to solidify their competitive market position. Most importantly, the recent Aerospace Plastics Market Report (2023) discloses an estimated market size value of $7.61 billion in 2023 with a projected value of $13.89 billion in 2030.

The expanding demand for plastics for various aerospace applications and functions is anticipated to propel the expansion of the aerospace plastics industry, which also explains why the oil and gas industries are diversifying into the plastic industry. While this expansion cannot be hindered, the argument for sustainable plastics usage in this industry cannot be undervalued as the whole supply and value chain of the manufacturing process makes use of plastics in one way or the other. Thus, the question of how aircraft manufacturers and aerospace plastic producers understand the fatigue limits of the plastics used in this industry, the strategy for “sustainable disposal” of plastics during the production of aircrafts, and the “sustainable end of life management” of plastics components from obsolete aircraft is a topical issue that needs more attention for the future of plastics in the aviation industry considering that most plastics used in aircraft manufacturing are currently not recyclable.  

Management of plastics by aircraft manufacturing 

Currently, the aviation industry contracts the services of the Maintenance, Repair, and Overhaul (MRO) industry for a myriad of aerospace applications with companies in Southeast Asia dominating the field as a result of government policies such as duty-free imports and tax incentives that impact positively on MRO service delivery. Though such policies enhance the business of the MRO industry in reaching more airlines, it does not impact what they do with recovered aircraft components such as plastics nor does it impact how recycling companies in the aviation space operate in terms of end-of-life management of plastics.

Plastic composites are presently not recyclable and therefore MRO companies and recycling companies within the aviation industry result in old waste management practices such as incineration and landfilling which is not environmentally sustainable in the long run. Thus, most recovered plastics and leftover plastics during the production of aircrafts are barely reused as secondary unconsumed plastics in making new aircrafts, further compounding the issue of fast-depleting landfill space and the overreliance on fossil fuel for raw materials to produce fossil fuel-derived plastics.

Even though recycling is touted as one of the best options for plastic waste management, research shows that volatile gases which kill plant structures and wildlife when inhaled are released during the recycling process. This also contributes to greenhouse gas emissions and acid rain affecting the terrestrial and aquatic environment (biodiversity loss) in diverse ways especially those residing close to recycling plants. Aircrafts that are left in huge graveyards for aging and retired aircrafts are exposed to environmental conditions results in the the fragmentation of the plastic parts in aircrafts, contributing to microplastic pollution. The ensuing paragraphs, therefore, highlight some recommendations the aviation industry could adopt to engender the sustainable use of plastics in the aircraft manufacturing and servicing industry.

Green investment in alternatives

While plastics are a burgeoning component in aerospace manufacturing, aviation manufacturers should avert their actions to investing in green aerospace technologies that maximize plastic use and eliminate or limit plastic waste during aircraft manufacturing. Plastics still present a lot of limitations in this sector such as deformity issues, fatigue limits, and brittleness (generating microplastics) during the extended service life of aircrafts. Investing in research to develop alternatives that are resistant to these issues is key to ensuring safety.

Additionally, investing in procuring plastic alternatives that have the ability to be recycled with little to no emissions during their end-of-life stage is also crucial. Plastic producers for the aviation industry could also test non-fossil fuel-derived plastics to limit overreliance on fossil fuel-derived plastics. Research and development among industry players should also be encouraged to allow co-learning and collaboration in the field to prevent the use of plastic resins that do not currently have an end-of-life management plan. Investment should also focus on advancing technologies that can effectively manage plastics that are currently used in aircraft manufacturing which would contribute to reducing the plastic footprint of the aviation industry.

Develop and fully implement international sustainability criteria for plastic use in aircraft manufacturing

The ongoing negotiation of the global plastic treaty is considering the development of international sustainability criteria to harmonize plastics use towards sustainability. Aircraft manufacturers, their associated original equipment manufacturers (OEMs), relevant stakeholders such as (IATA and ICAO) and aerospace plastic market leaders (including Paco Plastics Inc., 3P Performance Plastics products, Loar Group Inc., Ensinger GmbH, Toray Industries, Inc.,) could work together to develop international sustainability criteria for plastics used by aerospace OEMs patterned after the proposed international sustainability criteria for plastics being considered for the global plastic treaty.

Adopting such an approach could be a similar procedure to harmonize plastics that are used in the aircraft manufacturing space and therefore limiting the complexity of the plastic waste stream that is generated. As plastics have more than 10,000 chemical additives, processing aids, and monomers with over 2000 recognized as being potentially hazardous, the criteria could specify inter alia the additives to be used; types of plastic resins to be used for plastic used in aircraft manufacturing; labeling; circularity measures; its end-user application; flame, smoke, and toxicity (FST) standards; annual plastic sustainability report, the management of plastic residue (including macro, micro and nano-plastics) in the production stage, end-of-life management such as pyrolysis as thermoplastics composites are increasingly being used in aerospace applications compared to thermoset composites; and bioremediation.

Adhering to existing international treaties and environmental management systems 

Since plastics are primarily made of chemicals and carbon, it is imperative that the aerospace plastic industry adheres to the tenets of existing treaties that regulate chemicals and some aspects of plastics (for example, plastic trade) such as the Basel, Rotterdam, and Stockholm (BRS) Conventions. Others associated with human health, safety, and the environment include inter alia International Labour Organisation (ILO) Conventions such as the Chemicals Conventions, Benzene Convention, Occupational Safety and Health Convention, and the Promotional Framework for Occupational Safety and Health Convention.

Additionally, environmental management systems such as ISO 14001 which covers pollution prevention and compliance could also be adopted.

Governmental policies 

Domestic legislation has already been used in banning some single-use plastics in many countries such as Bangladesh, Kenya, the United Kingdom, Rwanda, and France. The use of domestic legislation to ban or restrict the use of plastics with no end-of-life management option could also be considered. Economic measures such as taxes and incentive-based solutions could be used as a two-edged sword – in encouraging or reprimanding companies manufacturing plastic for the aviation manufacturing industry and aviation manufacturers themselves to up their game as far as using sustainable plastics is concerned. 

Concluding remarks 

Plastics undoubtedly have contributed to enhancing the daily lives of people through their basic applications across various economic sectors. However, their physicochemical composition has negatively impacted human health and the environment. Adopting the aforementioned measures could serve as a step in the right direction for the aviation (plastic) manufacturing industry to minimize plastic pollution and by extension their plastic footprint towards a more sustainable use of plastics.