The Growing Role of Plastics in Aerospace Assembly
Demand for Lightweight Applications Is Creating a New Role for Thermoplastics
For the past decade, carbon-fiber composites have been the darling of the aerospace sector, receiving countless praise and widespread attention. Reinforced polymers have dramatically changed the way that many types of airframes are designed and built.
While composites are still hot, traditional plastics have been quietly making inroads in civilian, commercial and military aircraft. As new generations of planes take to the skies in the years ahead, thermoplastics will be along for the ride.
Polyetherimide is another popular material used in the aerospace industry, because engineers can produce parts that meet the strict flame, smoke and toxicity requirements set by the FAA.
Polyetherketoneketone (PEKK) is an advanced, high-temperature engineering polymer that features excellent mechanical properties, chemical resistance, thermal stability and flame retardancy. The high strength and light weight of new grades of PEKK, such as HT-23, make it a competitive alternative to aluminum.
Plastic is typically used for interior applications, such as air ducts, cabin partitions, floor panels and overhead luggage bins. It’s also used for avionics sensor plates, electronic component mounting brackets and ventilation impeller blades.
Structural applications include wing ribs and spars. In addition, plastic is used on the exterior of aircraft for things such as fuel tank covers, landing gear hubcaps, pylon fairings and radomes.
Plastic offers many advantages over aluminum and other traditional aerospace materials, such as light weight, high strength and durability.
Heat-resistant, noncorrosive plastics like PEEK can be machined to replace metal fasteners and screws. There is no change needed in the overall design of existing machined parts, allowing for the direct replacement of OEM components.
Brackets, gaskets, guides, seals, spacers and washers are lightweight aerospace components where high-heat plastics can outperform metals, providing thermal and mechanical stability, insulation properties, zero flammability, low outgassing in a vacuum, and resistance to jet fuel and other chemicals.