The Future of Plastics

Q: Do you see an increased role for plastics in the aerospace industry?

A: Absolutely, that is largely because recent advances in materials science have resulted in high-performance polymers with unique properties. For example, polyimides provide dimensional stability at high temperature, and longer life at higher loads and speeds. These enhanced performance properties have opened doors to applications once considered unsuitable for polymers, including many in the aerospace sector such as components in auxiliary power units (APUs), de-icing systems, cabin air-conditioning systems, actuators, jet engines, and landing gear systems.

Q: Could you talk about the increased importance of plastics?

A: As fuel costs continue to rise, so does the importance and value of lightweight components in aircraft systems. Lighter than other materials you might find in aircraft systems, such as metals, ceramics, and carbon graphite, polyimides can help decrease costs for structural and bearing parts in aerospace applications without sacrificing quality or safety. By reducing the weight of aircraft systems, and in turn, the overall weight of the aircraft, polyimides can actually decrease the total amount of fuel consumed. This can provide airlines with big cost savings over time.

Q: What are some of the maintenance issues that plastics can resolve?

A: Maintenance can make up a hefty portion of operating costs for an airline – as much as 10% to 20%. That can mean as much as a billion dollars a year for some of the larger carriers. Parts made using polyimides, such as Meldin 7000, require less maintenance and replacement, reducing airline outlay.

The high temperature performance we discussed earlier allows polyimide parts to withstand continuous use up to 315°C (600°F) and intermittent use up to 482°C (900°F). So even at extremely high temperatures – such as inside a jet engine – polyimides will not melt and will maintain their shape. Polyimide parts withstand thermal shocks, a technical term for cracking under rapid temperature change, adding to the overall dimensional stability of the material. Polyimides also exhibit excellent thermal insulation properties, ensuring that heat does not transfer from one part of the plane to another. Take, for example, the skid pads under the composite wings of an aircraft. In the unlikely event of a touchdown without landing gear, the skid pads ensure that the wing does not make direct contact with the runway. As you can imagine, extremely high frictional heat generates when these pads contact the runway. Polyimide parts act as heat isolation spacers, preventing this heat from spreading to the wing and damaging the aircraft.

Polyimides also exhibit excellent wear resistance, decreasing rattle and shake. That is when various parts and components erode from bumping and scraping one another. This is not good for the parts, the systems, or the aircraft. Less wear and tear equals longer component life and better performance with reduced maintenance.

Q: What impact will plastics have on improving parts-to-market?

A: Good question, and the short answer is that we think polymers can make things faster. We all know the airline industry is ultra-competitive and has a long and complex sales cycle, so being first to market counts for a lot.

The manufacturing process for polyimides, including molding and machining finished parts, is much shorter than the lay-up manufacturing process typically used for carbon composites and other thermoplastics. The lay-up process takes longer due to the layering and combining of various materials to create parts that can withstand aerospace applications, as well as added time for curing. Thanks to the inherent performance properties of polyimides, they do not require lay-up processing, saving time and work hours. In addition, polyimides are more machineable than composite materials, making it faster and easier to bring a finished part to market.

However, that goal can bog down thanks to the proverbial challenge of having too many cooks in the kitchen. If OEMs and fleet owners seek out material suppliers with the ability to design, manufacture, and test its products – and minimize the number of players in the supply chain – they stand to reap major benefits. Working with one supplier instead of two or three streamlines the production process, gives fleet owners more oversight, and fosters collaboration. For example, starting in the early design phase, consultation with materials science experts and engineers ensures exact materials and part design specification. This level of total powder-to-parts control can result in the ideal aerospace part; one that provides a high level of performance over a long period.

Q: What role do plastics play in the R&D sector for aerospace?

A: We would like to think that they go hand in hand. Engineers and materials science experts are continually working on developing the next polymeric breakthrough. Once considered fiction were lighter weight aircrafts made using high-performance plastics traveling farther and using less fuel. Beyond what we are currently experiencing with components in key aircraft systems, in the not-too-distant future we may be looking at polyimides replacing existing materials in other parts of an aircraft. Technological innovations in materials science will help drive the bigger advances in aviation, and ultimately, the way people travel.

Q: What is next for plastics in the aerospace industry?

A: The holy grail of aerospace plastics, so to speak, is to be able to handle higher temperatures. This will allow plastics to play an increased role in overall aircraft manufacturing and performance.

Saint-Gobain Performance Plastics
Bristol, RI
meldin.com