Primary Advantages of Plastics

Plastics are being used on an ever-increasing scale and are frequently replacing some of the more conventional materials such as metals, wood and natural rubbers. Plastics have properties, which make them a popular choice over conventional aircraft materials. Some of the more important characteristics of plastics that help to explain their popularity are sated below.

• Lightness: Most plastics have specific gravities of 1.1-1.6 whereas the more common engineering materials, such as aluminium and steel, have values of 2.7 and 7.8 respectively.
• Corrosion Resistance: Plastics will tolerate hostile corrosion environments and many of them resist acid attack.
• Low Thermal Conductivity: This property makes many plastics that are ideal for thermal insulators.
• Electrical Resistance: Plastics are used in enormous quantities for electrical insulation applications.
• Formability: Many plastics are easily formed into the finished product by casting moulding or extrusion, often in a single operation.
• Surface Finish: Excellent surface finishes can be achieved in the basic forming operation, so finishing operations are not necessary.
• Relatively Low Cost: Although some of the materials may not be particularly cheap, the lack of machining is necessary. The high production rates are possible, keeping the costs down.
• Light Transmission: Some plastics are naturally clear, whilst others are opaque. Consequently, these characteristics provide the possibility for a range of light-transmission properties. Optical properties can also be achieved with some plastics.
• Vibration Damping: Many plastics are naturally resistant to fatigue and because of the high value of internal damping present, resonances will tend to be of relatively low amplitude.