The main function of engineering plastics for automobiles is to make cars lightweight, so as to achieve high fuel economy. Applied plastics for the automotive industry include nylon, polyester, polyoxymethylene, polycarbonate, andpolyphenylene ether.

Developed countries take the amount of plastics used in automobiles as an important indicator to measure the level of automobile design and manufacturing. The world’s single amount of automotive plastics is in Germany, and plastics account for 15% of the total materials. In recent years, China’s automobile industry has developed rapidly. At present, the annual output of automobiles exceeds 4 million. According to the forecast of foreign plastics consumption, the annual use of modified plastics in the automotive industry is over 500,000 tons, of which engineering plastics account for a large proportion. The performances of the five engineering plastics are different, and their use in automobiles is also different.

1. Nylon
Nylon is mainly used in automotive engines and engine peripheral components. The main varieties are GFPA6, GFPA66, and enhanced flame retard PA6.

1) Application on peripheral parts of automobile engines
Since the peripheral components of the engine are mainly heat-generating and vibrating components, most of the materials used for the components are glass fiber-enhanced nylon. This is because nylon has a good overall performance. The main properties of nylon modified with glass fiber are greatly improved, such as strength, product precision, dimensional stability, etc. In addition, there are many different kinds of nylon, easy to be recycled, and the price is relatively cheap. These factors make nylon an ideal choice for engine peripheral components. Intake manifold is a typical application of modified nylon in automobiles.

2) Application on automotive engine components
The engine cover, engine decorative cover, cylinder head cover and other components are generally made of modified nylon. Compared with the metal material, the weight of cylinder head cover is reduced by 50% and the cost is reduced by 30%. In addition to engine components, enhanced nylon can also be used for other force components of the car，such as oil filters, wipers, radiator grills, etc.

2. Polyester
In the automotive industry, PBT is widely used in the production of bumpers, carburetor components, fenders, spoilers, spark plug terminal plates, fuel supply system components, instrument panels, automotive igniters, accelerators and clutch pedals. PBT and enhanced PA, PC, POM competition in the automotive industry is very fierce, PA is easy to absorb water, PC heat resistance is not as good as PBT; in automotive applications, because PBT is better than PA, it gradually replace PA. In the case of relatively high relative humidity environment, the plasticity performance is likely to be lowered due to moisture, and corrosion is easily caused at the electrical node, and the modified PBT can often be used. At 80 ° C, 90% relative humidity, PBT can still work well, and the effect is very good.