Since the beginning of the automotive industry, many changes have been made in automotives. Cars, vans, public transport vehicles and trucks are constantly updated to improve their performance. Steel and aluminum are the main materials in the automotive industry, and then polymers are widely used there. The use of polymers in the automotive industry has increased over time, and polymers have replaced metal parts in cars, which causes reduction in production costs, vehicles weight, fuel consumption, and thus CO₂ emissions. In this article, we will discuss the plastic and rubber parts of the Automobiles .

One of the cases is replacing polymer parts with metals in car bumpers.  illustrates this replacement.  Engineering plastics, elastomers and foams are polymer materials used in the automotive industry.

 

Engineering Plastic Parts of the Automobiles

Plastic materials are polymers that can be shaped or molded, usually by applying heat and pressure. These materials are made from a wide range of synthetic and semi-synthetic polymer compounds that are ductile and therefore can be molded into any shape. The low weight, flexibility and high quality of plastics make them suitable for the automotive industry, reducing the overall weight of cars and leading to lower fuel consumption.

Typically, plastics are used in exterior parts such as body panels, bumpers, and fenders, and in interior parts such as dashboards, door panels, steering wheels, and decorative parts

Polymers used in plastic parts of cars include:

1. Polypropylene
2. Acrylonitrile Butadiene Styrene (ABS)
3. Polyvinyl chloride
4. Polycarbonate
5. Polyethylene

 

Polyvinyl Chloride (PVC)

It is a flame-resistant plastic that exists in two forms, flexible and hard. PVC is another common plastic that used in cars due to its ductility and glossy cover. Rigid PVC is often used to make dashboards and car body parts.

 

 

Polycarbonate

Polycarbonate is impact resistant and is often used in car bumpers and headlight lenses. This type of plastic has a good resistance to atmospheric factors and different weather conditions, i.e. rain and snow, heat and cold, do not disturb its performance. Polycarbonate is lightweight, thus reducing overall vehicle weight, which in turn improves vehicle efficiency and fuel economy

 

 

Polyethylene

Metal-polymer-metal structures, such as aluminum (Al)-low density polyethylene (LDPE) panels, have gained importance in automotive applications due to their light weight and energy dissipation properties. These structures produce new car parts with good mechanical properties. These structures produce new car parts with good mechanical properties [1].

Elastomers

Rubber is a flexible and elastic polymer that can be found in both natural and synthetic forms. Natural rubber is the elastic material obtained from the sap of the Hevea tree

 

 

Because of their resistance to heat build-up, natural rubbers are widely used in racing cars, airplanes, trucks, and buses. The distinctive characteristics of tires such as high strength and resistance to tearing while being flexible have highlighted their role in the automotive industry.

Rubbers are a group of elastomers that have significant flexibility due to the presence of cross-link in their structure. Rubber parts are present in various parts of the car, some of which are mentioned.

• Tires

Most of the tires include natural rubber and styrene butadiene rubber. After that, poly-cis butadiene rubber and butyl rubber are added with a smaller percentage.

• Vibration Dampers

Polyurethane elastomer, neoprene, olefin rubber, silicone and fluorocarbon are used in their construction. Semi-flexible polyurethane foams are also used in some parts.

 

 

• Sealants

All types of olefin rubber, natural rubber, styrene butadiene rubber and polyurethane elastomers are used. Polyurethane glue is generally used to bond them to the car body. Also, most USA car manufacturers use one-component moisture-curable polyurethane sealants to bond windshields and rear windshields to car bodies.

 

 

• Gaskets

Their raw materials are thermoset polyurethane resins, olefin rubber, neoprene and styrene butadiene rubber.

 

 

• Car belts

These parts are also made of polyurethane elastomers.

• O-rings

 

 

• Radiator hoses

Olefin rubbers are used in this section, because they can be used in different weather conditions [3].

Polyurethane foam Parts of the Automobiles

These foams have different types and are used in different parts of the car.

1-Rigid foams

Their density ranges from 0.5 and 1.5 lb/ft³ and are used to barrier corrosion and body sound absorptions.

2- Semi rigid Foams

These foams have very good shock and impact absorption properties, which makes them used in car dashboard panels and seat cushions.

3- Semi flexible Foams

Semi-flexible Foams consist of microcellular urethanes. High compressibility, small lateral expansion, and resistance to abrasion and environmental stresses make these materials ideal for many seal applications. higher-density grades are used in the motor base and handle, because they have sound and vibration insulation properties.

4- Flexible Foam

Flexible urethane foams are used for automotive cushioning and upholstering furniture. These foams have high strength against high weights, on the other hand, their weight is less compared to the old fibers used in the past

 

 

References

[1]. Vieyra, Horacio, et al. “Engineering, recyclable, and biodegradable plastics in the automotive industry: A review.” Polymers 14.16 (2022): 3412.

[2]. https://www.acplasticsinc.com/informationcenter/r/plastic-used-in-cars.

[3]. Walter, G. “Elastomers in the automotive industry.” Rubber Chemistry and Technology 49.3 (1976): 775-822.

[4]. Szycher, Michael, ed. Szycher’s handbook of polyurethanes. CRC press, 1999.