Plastic injection moulding and the benefits for the automotive industry


Plastic injection moulding and the benefits for the automotive industry

Authored By: SDI Plastics

When most people think of the production of automobiles and manufacturing, a few words come to mind, being, rubber, aluminium, glass, fibreglass and steel. Steel is used in manufacturing with nearly every car on the road today. If we take a closer look at steel, this is predominantly used on the frame of the car, because of its strength, it is also used to manufacture door panels, the chassis of the car, support beams, exhaust pipes and mufflers in the car.

Having said that, when looking to the future, more and more consideration is being given to plastics. Plastics are becoming the preferred choice in the automotive industry, and are challengers to the traditional steel options, because of their prominence in car manufacturing. Plastics have the flexibility to be pressed into shape without breaking or cracking, whilst also being strong enough to hold its structure in place. It is with this versatility, durability and lightweight characteristics of plastics, that make them the ideal materials to use for many different parts in the automotive industry.

Plastics, in one form or another, today comprise almost 50% of car parts. Many of the hundreds of plastic components in a car are items with which the driver or passengers will have direct contact with, such as the dashboard, door handles, pipes and air vents to name a few. For automotive parts, automakers prefer injection moulding, which uses special equipment to fill custom made moulds with liquid plastics that harden into the final component.

In the automotive industry, consistency, safety, and quality are of the utmost importance, and as a result, plastic injection moulding plays a vital role in the manufacturing process to meeting these objectives.

Interestingly, plastic injection moulding makes many advances when new technology emerges. Along with this advancement, the industry constantly explores new options, especially when it comes to materials, for creating car parts, which are then used in car manufacturing. Its effectiveness is something from which we can all benefit. When technology is constantly evolving, it is safe to say that injection moulding can only improve to produce better parts.


What are the potential benefits of plastic injection moulding?

Plastic injection moulding can produce more parts, which are identical, in less time than metal because it is much easier to work with. Plastic car parts and components are also extremely durable, withstanding road hazards, extreme weather conditions, the constant use of being turned, pushed, or pulled, and exposure to extreme heat inside the engine compartment. While metal can corrode or rust, plastic is impervious to these forces.

One of the most significant advantages to date, is the light weight of plastic parts over metal parts. Lightweight plastic components contribute to increased fuel efficiency without sacrificing power. This is critical for meeting government fuel-efficiency regulations and consumer demand for environmentally friendly vehicles.

A few advantages of plastic injection moulding in automotive applications are:
  1. Repeatability.
  2. Scalability.
  3. Material accessibility.
  4. Surface finish and high precision.
  5. Rapid prototyping with rapid tooling.

Plastic injection moulding enables the more natural production of critical automotive parts. It aids in cost control and project timeline development. Regardless of the vehicle design, injection moulding can mass produce identical components consistently in a short time. For example, the automotive industry benefits significantly from injection moulding, particularly in making repetitive parts such as, engine hoses and tubes, knobs, door handles, clips, and engine housing covers, amongst many other things. Injection moulding therefore, is a highly repeatable process with good design and finishing.

Manufacturers can use a variety of polymers for various applications in the automotive industry, including polypropylene, acrylic, ABS, acetal, nylon, polycarbonate, and more. It also provides a variety of colour options, excellent designs with high precision and finish for the automotive industry, as well as provides a competitive edge and enables performance and suitability. The ability to produce rapid prototyping to articulate the final product prior to production is also a key advantage.

The production benefits of plastic injection moulding in the automotive industry are exceptional, with the concept of lightweighting. The term ‘lightweighting’ may refer to moving from traditionally-used materials for lighter based materials, reducing the actual amount of material used, and/or optimising the design of a part or system for a combination of these practices.

The automotive industry has been using lightweighting for some time to reduce vehicle mass and improve fuel efficiency, not to compromise on safety and functionality. Lighter car parts have lower material costs and low energy use in the manufacturing process, providing many environmental benefits. Lighter parts additionally promote greater fuel efficiency as it takes less energy to move a lighter weight vehicle, ultimately reducing carbon emissions and being kinder to the planet.


Plastic injection moulding is becoming an increasingly important solution for the automotive industry. Injection moulders have been critical in lowering the cost of the production of vehicles, through moving away from using heavy metals and offering new material options, mass production and a cost effective option for manufacturing parts. Lightweighting, mass production, precision manufacturing and producing on quality are all combined factors that make injection moulding a popular and preferred method of manufacturing for the automotive industry.

SDI Plastics, as a full service plastic injection moulding company specialising in the automotive industry. Our team specialise in product design and innovation, prototyping, toolmaking and injection moulding manufacturing. If you are looking for a trusted partner, please contact our talented team on (07) 3807 8666 to discuss your manufacturing requirements.

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