Think of the car manufacturing process and you will most likely jump straight away to metal being moulded, shaped and manipulated into the right shape to fit its intended purpose. However, plastic is becoming more and more popular as a material used in automotive manufacturing, thanks to its strength, versatility and durability. Plus, it is inexpensive, attractive and easy to manipulate, making it an ideal automotive manufacturing choice for many reasons.
Several different types of plastic can be used in car manufacturing via plastic moulding techniques; however, three key ones are polypropylene, polyurethane and polyvinyl chloride, or PVC. These polymers are all used for major components in automotive injection moulding and are made into a wide variety of car engine and component applications. The versatility of these plastics also helps extend the scope of car design potential, as it can be moulded into pretty much any shape, size or thickness to match exact specifications.
Inside and out
It’s not just the smaller details of a car, such as the gauges, switches, vents, door handles and seat belts that can be made from plastic. Many components inside the engine, under the bonnet and around the car’s exterior are now being made from plastic instead of metal too. These include such things as the oil dipstick handle, cabling, the screw top of the windscreen washer bottle, the fuel tank and its cover.
Plastic is lighter than steel and other metals, and helps keep the overall weight of the engine down to improve the car’s performance. Other exterior components made from plastics include window trims, wheel liners and covers, mud guards, air deflectors and car bumpers. Bumpers made from plastic offer highly effective energy absorption Most headlight casings are made from polycarbonate plastic. This is a strong plastic that can cope with harsh road conditions and is easy to clean – crucial for optimal road safety when driving after dark, or in rain, snow or sleet when visibility is low.
Inside the car, plastic is taking over too, with many car seats now being made from plastic, or a material derived from a polymer. Other interior areas made from plastics and polymers include ceiling fabric, headrests, child seats, seat belts and air bags, as well as cup holders, side pillars, glove box covers and sun visors. Dashboards are increasingly being made solely from plastic too, thanks to its light weight, resistance to corrosion, design flexibility and ease to keep clean. Then, there are the numerous buttons, handles, casings and sockets required to run a modern-day vehicle that all benefit from being made out of plastic.
The rise of plastics in car manufacture has many other benefits aside from performance and weight reduction. A lighter car will consume less fuel, making it cheaper to run with fewer trips required to the petrol station. Plastic is heat resistant, easy to maintain and has a pleasingly sleek finish – not forgetting the fact that it is easier to keep free from lingering odours. Plastic won’t rust if it gets scratched and is relatively inexpensive to repair. It offers excellent flexibility and resilience. It is easy to recycle, allowing eco-minded people to do their bit towards preserving resources, cutting down on carbon emissions and reducing greenhouse gases. Not forgetting, of course, that plastics have very good thermal insulation properties, which means that they can help to reduce noise by a significant degree – a characteristic that is more and more sought after for modern vehicles.
Finally, plastic is playing a major role in enhancing the safety of the modern automobile. Windscreens now come with a thin layer of plastic sandwiched between the layers of glass to render it shatterproof. ABS, or acrylonitrile butadiene styrene is a strong plastic used in air bags and the parts of a car’s safety systems designed to absorb impacts in the event of a collision or vehicle rolling. ABS and other plastics made from high-strength polyamides are extremely strong and absorb energy easily. Staying with safety considerations, using plastic also helps to lower production costs, enabling automotive companies to plough a higher percentage of their profits into safety enhancements and research into new technologies to produce even lighter, stronger and safer automotive materials.