Plastic Injection Molding in the Automotive Industry

While the automotive industry is traditionally associated with metal and steel, plastic is increasingly important in the manufacture of cars and trucks. There are several reasons for this. For one thing, plastics are much sturdier than they have been in the past and, in some cases, are even more durable than their metal counterparts. More importantly, however, your customers have different expectations of their automobiles than car buyers did in the past, especially as it relates to comfort and fuel efficiency. Parts manufactured through the process of automotive plastic injection molding often meet these expectations far more effectively than metal parts could.

What Are the Benefits of Using Plastic?

Plastic is used in the passenger compartment and has been for some time, in applications such as entertainment systems, interior finishes, and convenience features. It has a key role to play in reducing cabin noise and improving handling performance. These are functions necessary to the comfort of the vehicle occupants, which has become a significant concern of consumers. However, more parts necessary to the function of the vehicle itself are being made out of plastic as well.

Plastic car parts are extremely durable, able to stand up equally well to road hazards, inclement weather conditions, and the constant abuse of being turned, pushed, or pulled, as well as exposed to extreme heat inside the engine compartment. While metal is susceptible to corrosion or rust, plastic is impervious to these forces. It is easier to work with than metal, meaning that more parts may be produced in less time using injection molding.

One of the biggest advantages of plastic parts is that they are extremely lightweight compared to metal. Lightweight plastic parts help to improve fuel efficiency without sacrificing power. This is critical to meeting fuel-efficiency regulations imposed by the government as well as the consumers’ demand for eco-friendly vehicles. As internal combustion engines give way to electric vehicles, lightweight plastic parts continue to be of utmost importance.

What Happens During Prototyping and Production?

The automotive plastic injection molding process involves pushing melted plastic material into a mold. The finished piece is removed from the mold once the plastic has had a chance to cool. When it comes to automotive manufacturing, plastic injection molding applications are nearly limitless.

However, before plastic injection molding can be used to produce parts on a grand scale, a prototype must be designed and tested. A prototype allows you to ensure that the part meets your specifications and to fine-tune it if necessary. At Special Tool and Engineering, we offer full-run production capabilities in addition to design and prototype testing services.

What Are the Processes of Overmolding and Insert Molding?

While many automotive parts can be made with plastic injection molding, not all parts can be made entirely of plastic. Overmolding and insert molding are processes that can produce parts made of more than one material.

Overmolding is used to produce parts that need to be in contact with different surfaces at the same time. Examples include many pieces found inside the vehicle’s cabin. The process often starts with a hard plastic material, such as polycarbonate or acrylonitrile butadiene styrene. Then a thermoplastic elastomer, urethane, or other soft thermoplastic material is overmolded onto the harder material.

In automotive or aftermarket applications, sometimes bushings, nuts, filters, screws, or other components made of ceramic or metal need to be included in the part. These are added via a process of insert molding. This creates a part made of two different materials blended together seamlessly by placing the metal or ceramic parts into the mold prior to injecting the melted plastic.

A Leader in Automotive Plastic Injection Molding

As a full-service supplier, Special Tool & Engineering has been offering design, engineering, and complete tool manufacturing for over 20 years. During that time, we have established longstanding relationships with the nation’s major original equipment manufacturers. Contact us today to discuss your manufacturing needs!

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