Aviation plastic parts are used more and more widely

Plastics are much lighter than metals, making them suitable for more dynamic designs and lighter aircraft parts, and offer significant fuel savings. The advantage in weight-to-weight ratio means that to achieve the same strength, the plastic weighs only one-seventh of the metal, or half of the aluminum. Plastics also provide corrosion resistance for applications in harsh environments, as well as relatively high thermal and mechanical stability. Compared to glass, transparent plastics have several advantages in aerospace manufacturing applications. Transparent plastic parts are lighter in weight and offer higher impact resistance than glass, which is a key safety factor for aircraft. Transparent plastics can be formed in several ways and made into sturdy, transparent and complex parts.

In many aircraft applications, high surface lubricity is required for both bearings and shafts, but sometimes it is difficult to lubricate because of its location. The new self-lubricating plastic technology solves this problem in many cases and achieves a long service life without minimal maintenance.

As an efficient electrical insulator, plastic is the number one choice for aerospace applications. Many plastics have this natural insulating ability and thus offer a large selection of materials, although some plastics provide near zero conductivity. In military applications, plastic is an effective insulating material for radars to prevent detection. In addition, plastics offer great flexibility in design. Today, engineers have a wide range of high performance thermoplastics and composites to choose from to meet the high demands of any application. Finally, the manufacture of plastic parts is generally economical, and the key is to select the best method for most projects from a wide range of manufacturing methods.

Evolution of aviation plastic parts

Historically, the aerospace industry and the plastics industry took off very close together – all in World War II.

The advent of war has accelerated the development of aircraft used in combat. In 1940, US President Roosevelt increased the annual production of military aircraft from 10,000 to 50,000 to support the war. At the same time, the shortage of key industrial materials such as metals and rubber during wartime has rapidly promoted the use of plastics in manufacturing, including aerospace manufacturing.

As engineers discovered new ways to take advantage of the properties of plastics, successful chain reactions were triggered. In the 1960s and 1970s, the development of high-performance plastics opened a new door. Today, aerospace plastic parts are widely used in the FAA-approved parts market, the fastest and most cost-effective material to help aerospace manufacturers get the parts they need. Plastic parts are found in aerospace applications, from fuselage components to bushings, bearings, brackets and more.

Many plastic parts in aerospace applications are machined rather than shaped or extruded. Machining is the best choice when the number of parts that need to be replaced is limited, because of the very high performance and precision that can be achieved, as well as the very tight tolerances required for aerospace designs. In addition, machining is usually much cheaper. Unless you are going to produce a huge number of parts, the cost of mold opening will be quite uneconomical. The cost of an injection molding tool can be as high as $30,000. If you need thousands of parts, the cost of mold opening is acceptable, but the aviation industry usually only needs one hundred or less at a time.

Obviously, the replacement parts must be made of the same plastic. Not long ago, aerospace manufacturers provided samples of original parts to plastic suppliers for reproduction. Now, they let plastic engineers get FAA-approved samples directly from CAD design.

Aviation plastic

With so many high-performance plastics to choose from, engineers can choose the best material for any given application. Here are a few of the plastics commonly used in the aerospace industry.

Delrin (POM) - This material reduces the gap between metal and ordinary plastics, combining creep resistance, strength, stiffness, hardness, dimensional stability and toughness. It is solvent resistant, fuel resistant, wear resistant, low wear and low friction. Its basic mechanical surface properties allow the bearing to withstand moderate wear.

Ultem Polyetherimide - This is an amorphous thermoplastic polyetherimide (PEI) material that combines mechanical, thermal and electrical properties. Its mechanical strength, heat resistance, corrosion resistance and other characteristics, as well as easy processing and surface treatment, can be used in many aerospace applications.

Polycarbonate - This is a durable, high-performance plastic that is easy to process, provides excellent heat resistance, and is the preferred choice for optical components due to its transparency. It is a high-strength material with 25 times the impact strength of acrylic.

Polyetheretherketone (PEEK) – a polymer that combines strength, stiffness and hardness and is ideal for applications involving high temperatures, high humidity and heavy loads. Polyetheretherketone incorporates abrasion, chemical and moisture resistance as well as strength and stiffness. It also shows good friction and wear resistance. It provides hydrolysis resistance and can be exposed to high pressure water and steam for extended periods of time without severe degradation. Due to its high temperature resistance, polyetheretherketone is an ideal choice when the processing temperature exceeds the limits that conventional plastics can withstand.

Aviation plastic parts are widely used

Nylon - a core material, mainly due to its toughness and strength. It is resistant to abrasion and has good wear resistance. It is also easy to process, lightweight, and cost effective. Due to its excellent wear resistance, it is often a replacement for parts made of metal, rubber and other materials.

Ultra High Molecular Weight (UHMW) Materials - When engineers want to improve equipment efficiency and improve their wear resistance and noise reduction performance, they will choose ultra high molecular weight polyethylene to make plastic parts. UHMW also offers excellent performance including temperature, impact resistance and wear resistance. It has a lower coefficient of friction than steel or aluminum.

Polytetrafluoroethylene - This is a fluorocarbon that is well suited for use in high temperature and chemical environments where high purity and inertness are required. It maintains its performance over a wide range of temperatures and loads, and is commonly used in the aerospace industry for sealing and chemical resistance applications.

Polysulfone - This material has high thermal stability and the finished parts are stable and resistant to creep and deformation under continuous load and high temperatures. It has a high tensile strength, and as the temperature increases, the flexural modulus remains high. Polysulfone is highly resistant to aqueous mineral acids and oxidizing agents and is resistant to many non-polar solvents even at elevated temperatures and moderate pressure levels.

With the development of the aerospace industry, plastics and their applications have also developed. Due to the unique combination of plastics and the continuous development of new plastic materials, we have reason to believe that plastics will continue to play a key role in the innovation of the aerospace industry.