Introduction
Are your automotive plastic components wearing out too quickly? Do they struggle with heat resistance? Choosing the wrong plastic material can result in costly failures that compromise safety and performance.
Manufacturers in automotive parts production often turn to plastics like ABS, polypropylene, and nylon because they are durable, heat resistant, and lightweight. Choosing the right plastic material can go a long way to improve performance and safety, and keep costs low in vehicle production.
Now that we’ve covered the uses and benefits of automotive plastics, let’s explore the specific plastics used in automotive parts manufacturing.
What Are the Key Properties of Plastics Used in Automotive Parts?
Plastics play a crucial role in the automotive industry due to their versatility, light weight, and cost-effectiveness. When selecting plastics for automotive parts, manufacturers consider a range of key properties to ensure performance, safety, and durability. Below are the primary properties that make certain plastics suitable for automotive applications:
Mechanical Strength and Durability
The ability to resist pulling forces without breaking. Long-term resistance against sudden shocks or impacts – an essential property for safety components like bumpers. The polymer also needs to withstand repeated stress cycles without failure, which is the case with many moving parts in an automobile.
Thermal Stability
Plastics must retain their excellent mechanical properties under high temperatures, especially under the hood where temperatures can reach extreme levels. They must also retain flexibility and strength under low temperatures to prevent brittleness.
Chemical Resistance
The ability to withstand exposure to automotive fluids such as fuel, oil, coolants, and cleaning agents without degradation. Plastics must also resist degradation due to moisture, salts, and other environmental factors.
Light Weight
Plastics are lighter than metals, contributing to a decrease in overall vehicle weight, and subsequently, to improved fuel efficiency and reduced emissions.
Moldability and Design Flexibility
Plastics can be molded into intricate shapes, enabling innovative design solutions and the integration of multiple functions into single components. Parts that are required to meet tight tolerances also possess high dimensional stability.
Cost-Effectiveness
Plastics generally cost less than metals and require less energy for processing. Techniques such as injection molding also allow for the rapid production of parts at low labor costs.
Aesthetic Qualities
Ability to achieve various textures and finishes, an important consideration for interior parts. Plastics can be produced in a wide range of colours without additional painting processes.
Flame Retardancy
Certain applications in the automotive industry require materials that are self-extinguishing or slow-burning in order to meet safety regulations.
Electrical Properties
Non-conductive properties are essential for electrical housings and connectors. Some plastics can be formulated to provide EMI shielding for electronic components.
Types of Plastics Used in the Automotive Industry
The automotive industry relies heavily on plastics due to their ability to reduce weight, improve fuel efficiency, and provide high durability.
Here are some of the most common plastic materials used:
Acrylonitrile Butadiene Styrene (ABS)
Acrylic (Polymethyl Methacrylate – PMMA)
Polypropylene (PP)
Polyamide (PA/ Nylon)
Polyethylene (PE)
Polycarbonate (PC)
Polyvinyl Chloride (PVC)
Polyurethane (PUR)
Polystyrene (PS)
Polyoxymethylene (POM)
Acrylonitrile Butadiene Styrene (ABS):
Acrylonitrile Butadiene Styrene, commonly known as ABS, is one of the most versatile and widely used plastics in automotive manufacturing. ABS is valued for its strength, impact resistance, and glossy finish, and is used in the production of both functional and aesthetic components in the automotive industry.
ABS is commonly used to produce the following automotive applications:
Dashboard components
Interior trims
Wheel covers
Grilles
Instrument panels
Decorative pieces
A key advantage of ABS is its ability to be molded into complex shapes with a smooth, high-quality surface finish. This material is used to create components that require both functionality and visual appeal. ABS is also resistant to heat and chemicals, ensuring its durability in demanding automotive applications.
Acrylic (PMMA)
Acrylic, or Polymethyl Methacrylate (PMMA), is known for its excellent transparency and optical clarity. It is commonly used as a substitute for glass in various automotive applications due to its lightweight nature and shatter resistance.
PMMA is typically used in:
Headlamp lenses
Taillights
Sunroofs
Window glazing
The main advantage of PMMA is that it is not only lighter than glass but also more resistant to impact, making it a safer option for automotive glazing and lighting. It is also UV resistant, ensuring that the components retain their clarity and do not yellow or degrade over time due to sunlight exposure.
Polypropylene (PP):
Polypropylene (PP) is one of the most widely used plastics in the automotive industry. It is valued for its low cost, lightweight nature, and excellent chemical resistance. It is also highly versatile and can be used in both interior and exterior automotive applications.
PP is commonly found in the following automotive applications:
Bumpers
Interior trims
Door panels
Battery cases
Carpet fibers
The high impact resistance and flexibility of polypropylene make it an excellent choice for parts that require durability and toughness, such as bumpers and other exterior components that may be subjected to impacts. Its chemical resistance also makes it well-suited for use in under-the-hood applications, where it may come into contact with a variety of fluids and chemicals.
Polyamide (PA/ Nylon ):
Polyamide, also known as nylon, is a high-strength plastic that is commonly used in automotive applications that require high durability and heat resistance. Nylon is capable of withstanding high temperatures, which makes it a popular choice for engine components.
Common applications of nylon in the automotive industry include:
Engine covers
Timing belts
Fuel system components
Bearings
Air intake manifolds
Nylon’s ability to resist wear and tear, along with its strength and heat resistance, makes it ideal for use in mechanical components that are subject to high stress and temperature variations. Its relatively low coefficient of friction also contributes to its use in moving parts like gears and bearings.
Polyethylene (PE):
Polyethylene (PE) is a durable and versatile plastic that is used in various automotive applications due to its chemical resistance, toughness, and flexibility. There are different types of polyethylene, including high-density polyethylene (HDPE) and low-density polyethylene (LDPE), each with unique properties.
Polyethylene is often used in applications such as:
Fuel tanks
Fluid containers (e.g., windshield washer fluid reservoirs)
Wiring insulation
Protective covers
HDPE is particularly popular for manufacturing fuel tanks due to its ability to resist corrosion and degradation by chemicals. LDPE, on the other hand, is more flexible and is often used in applications that require a higher degree of pliability, such as wiring insulation and tubing.
Polycarbonate (PC):
Polycarbonate (PC) is a durable and transparent plastic known for its high impact resistance and heat resistance. It is often used in applications where optical clarity and strength are critical.
In the automotive industry, polycarbonate is commonly used in:
Headlight and taillight lenses
Sunroofs
Window shields
The excellent impact resistance of polycarbonate makes it a safer alternative to glass for headlamps and other glazing applications. It is also highly resistant to UV radiation, which prevents it from yellowing over time, ensuring that lenses and windows retain their clarity throughout the vehicle’s life.
Polyvinyl Chloride (PVC):
Polyvinyl Chloride (PVC) is a versatile plastic known for its excellent chemical resistance, durability, and flexibility. It is widely used in both the interior and exterior of vehicles.
PVC is often used in applications such as:
Door panels
Dashboard components
Electrical insulation
Weather-stripping
Seat covers
PVC is resistant to moisture, chemicals, and weathering, making it ideal for applications that are exposed to harsh environments. Its flexibility also allows it to be used in seals and gaskets that prevent water and air infiltration.
Polyurethane (PUR):
Polyurethane (PUR) is a versatile plastic that is available in both rigid and flexible forms. It is valued for its excellent durability, flexibility, and resistance to abrasion and chemicals.
Common polyurethane applications in the automotive industry include:
Seat cushions
Suspension bushings
Insulation panels
Seals and gaskets
Steering wheels
Flexible polyurethane is used to produce foam seat cushions, providing comfort and support for vehicle occupants. Rigid polyurethane, on the other hand, is used in structural applications such as insulation panels and in the manufacturing of parts that require strength and rigidity.
Polystyrene (PS) :
Polystyrene (PS) is a rigid thermoplastic that finds application in automotive industry mostly where thermal insulation properties are desirable and light weight is essential. As has been mentioned before, polystyrene is not utilized as often as other types of plastics, however, there are many applications involving cars.
Some common uses of polystyrene in automotive manufacturing include:
Instrument panels
HVAC components
Insulation materials
As foam material polystyrene has low density and is an insulating material Polystyrene foam plays its part as material for automotive HVAC thermal management system. Because of its stiffness and workability, it can be easily shaped, used for inner profiles especially on parts that have to be seamless and sturdy.
Polyoxymethylene (POM)
Polyoxymethylene, or POM, or acetal, is a rigid thermoplastic that has high strength and excellent wear and frictional characteristics. These properties make POM well suited to precision automotive parts that must be durable and long-lasting.
In the automotive industry, polyoxymethylene is commonly used in:
Gears
Bearings
Fuel systems
Lock mechanisms
Fasteners
The combination of a low coefficient of friction and high wear resistance makes POM suitable for applications such as gears and bearings, where moving parts are present. POM also has good dimensional stability, meaning parts produced from this material do not wear or deform after use.
Additionally, POM’s resistance to fuels and many chemicals makes it a viable material for use in fuel systems and other automotive parts that are exposed to hostile environments.
Conclusion
Plastics have significantly enhanced automotive manufacturing by providing lightweight, safe, and fuel-efficient materials that reduce environmental impact. Their adaptable properties, like the durability of ABS and the light weight of polycarbonate, enable innovative designs that meet today’s functional and performance demands.
As technology advances, the use of plastics in cars is expected to grow, guiding the automotive industry toward higher ecological performance. From structural components to interior features, plastics will play a crucial role in the future of automobiles.