Plastics used in aerospace technology

Technical plastics contribute to making applications more efficient and competitive in many industrial areas. The aerospace industry places high demands on materials. The impressive properties of high-performance plastics include their low weight and fire behavior.

Benefits at a glance

• Weight savings of up to 60 % compared to aluminium reduce energy consumptions.
• Plastics can be processed better than other materials.
• Greater freedom in component design results in reduced production and installation costs.
• Good chemical resistance.
• Inherent flame-resistance: High-performance plastics meet the requirements of UL 94 -V0 and fire behaviour standards in accordance with FAR 25.853.
• Fire behaviour with regard to: smoke gas density, smoke gas toxicity, heat release.
• High specific strength due to fibre-reinforced plastics.
• Convincing gliding properties with outstanding dry-running characteristics and freedom from maintenance in the application.
• Low outgassing in vacuum.
• Good radiation resistance.

Continuous improvements in performance and fuel cost savings are crucial to success in the aerospace industry. This is why weight reduction and the optimization of mechanical aircraft component properties are key.
When selecting materials, specific strength is a key indicator. This determines the tensile strength of a material relative to its density, and indicates the ratio of strength to weight.
But in this sector are also very important Creep resistance, melting point, the long-term service temperature, the resistance to temperatures below freezing, the resistance at short-term peak temperatures, resistance to electromagnetic radiation, to ultraviolet, to ionizing radiation, electrical or dielectric properties may be required, and, of course, of great relevance are also the characteristics of fire resistance and combustion.
The mechanical machining, the precision and the applied tolerances can also be of fundamental importance and the stabilization processes.

Some of the main plastics used in the aerospace industry:

(POM-C) Dimensionally stable. Grease-resistant. High resilience
(POM-H) High mechanical strength. Very good machining properties
(PA66) Easily glued and welded. Electrically insulating and good machining properties
(PA66+MoS2) Good UV-resistance. Low abrasion
(PA66+GF) Glass-fibre reinforced. High strength
(PTFE) Exceptional chemical resistance. Particularly low coefficient of friction.
(PPS+GF) Extremely high strength due to glass-fibre reinforcementˌ Very good chemical resistance
(PEEK) High long-term service temperature (250 °C). Excellent mechanical properties even at high temperatures
(PEEK+GF) High temperature resistance. Dimensionally stable.
(PEI+GF) High temperature resistance. Inherently flame-retardant. Very strong and rigid.
(PI) Low outgassing in accordance with ESA standard. High rigidity with low weight.

Engineering and high-performance plastics used in aerospace engineering are required to comply with extremely stringent requirements.

Aircraft components

The airframe, aircraft fairing components, wings, nose, fuselage and tailplane are made of a number of components. The materials used for these must have good thermal and mechanical properties as well as good resistance to aging.

Material and parts

Plastics used for such functions as fixing elements, ball bearings, seals or sliding bearings have excellent technical properties.

Equipment and systems

For materials used in the propulsion elements, control units or landing gear, good electrical and thermal properties are essential. Controlled fire behaviour, low fume toxicity, good sliding properties and high chemical resistance are also a requirement.

Cabin interior

Because plastics are used in lighting systems, seats, the on-board kitchen and cooling systems, in the oxygen supply, drinking water and disposal systems, as well as freight loading facilities, in some cases supplementary specifications such as FDA, fungus test and drinking water approvals are additionally required.

Propulsion systems