As new types of high-strength, high-quality plastics and polymers are developed, the use of plastic parts in aerospace applications continues to rise. While metal materials are still required in many situations, plastics are often used to make aircraft more lightweight while allowing for significant cost savings. A range of plastics is available for use in various aerospace applications, offering unique properties and benefits for this demanding sector.
Driving Efficiency in Aerospace
In recent years, plastic parts have replaced both metal and glass in many aerospace applications. Some of these applications include:
Using plastic enables aerospace manufacturers to complete large, cost-effective production runs of replacement parts. Maintenance personnel can easily access a wide range of standardized aftermarket components from approved distributors. These plastic aerospace parts are fabricated from CAD designs, which can be easily shared by OEMs.
Plastics have replaced aluminum as a more affordable, more lightweight material option, useful for both the interior design and functionality of airplane cabins. Plastic can be used for everything from overhead luggage storage compartments to ductwork to ventilation fan rotors. This can allow for a significant reduction in aircraft weight, improving fuel efficiency and creating additional cargo capacity.
Aircraft bodies traditionally contain thousands of metal-based structural components that can add significant weight and expense to the final aircraft. As aerospace manufacturers continue to modernize existing aircraft and development new, more efficient designs, thermoplastics are increasingly being used to replace metal brackets and other components in airframes. Boeing’s 787 Dreamliner, for instance, incorporates a range of thermoplastic composite components in place of traditional metal parts.
As additive manufacturing technology continues to evolve, its uses in aerospace expand as well. Advances in 3D printing enable aerospace stakeholders to print parts on-demand from trusted, tested materials. Plus, additive manufacturing allows aerospace manufacturers to quickly develop and adapt light plastic prototypes.
Plastic parts offer significant benefits for the aerospace sector, namely cost efficiencies and speed of production. Plastic can also be more easily molded, allowing for the creation of larger single parts, rather than multiple components that must be welded or connected in some way. And compared to heavier metals such as titanium or steel, the lighter weight is a major advantage.
Limitations of Plastics in Aerospace Applications
Although use of plastic in aerospace applications has increased fourfold since the 1970s, the material still has certain limitations. One of the most notable problems is the low conductivity of plastic. Aircraft are at risk of lightning strikes, and must be able to absorb strikes without risk of critical failure. Plastic fuselages cannot offer this benefit unless they are supplemented with aluminum or copper coverings.
Plus, the longevity of plastics is still being explored in many aerospace applications, as some types of plastic are subject to deformation or may become brittle throughout extended service life. Therefore, it’s crucial for aerospace manufacturers and MRO departments to understand the fatigue limits of the materials they choose.
The Future of Aerospace
Despite these limitations, there is little doubt that plastic use will continue to see steady growth in the aerospace sector. While aluminum alloys can often be created to achieve certain properties, plastic can do so much more cost-effectively.
The flexibility and customizable nature of plastics make them especially useful for demanding applications in the aerospace sector. Plastics can even be developed with specific properties in mind, such as thermal resistance, shock resistance, chemical resistance, high strength-to-weight ratio, flame retardancy, and low smoke and toxicity.