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The Complete Guide to the Different Types of Automotive Molding

Have you ever wondered how the latest styles of automobiles came to be?

The next time you drive or ride in a car, you’ll notice much of the interior consists of plastic. The molding around the entertainment center, the steering wheel, and more all consist of plastic.

Take a look at the exterior. The headlights and bumpers? In many models, they consist of, you guessed it, plastic.

But plastic automotive molding is relatively new.

Automobiles before the 1970s used metal for everything. This made them heavy and clunky.

It wasn’t until the 1940s and 1950s when the plastics started booming. By the 1970s, vehicles started using lightweight plastic for decorative elements. It wasn’t until the 1980s that some exterior elements started to use plastics.

The 2000s welcomed the use of plastics for structural parts making vehicles lighter and more fuel-efficient.

Today, automotive molding is an efficient way to manufacture plastic components for vehicles. Here are the types and advantages of automotive molding.

How Automotive Molding Works

Injection molding is one of the most popular processes of automotive molding. Its uses range from forming car parts and cell phones to toys and storage containers.

Injecting molding uses an injection machine to create a plastic or foam molding. To use it, you feed plastic powder or granular into the machine which heats it into molten plastic.

Once melted, the plastic enters an injector which pushes it into a shaped cavity. It fills the cavity and sits until it cools and hardens. After it hardens, you can remove it from the metal cavity and use it for its intended purpose.

A similar process works with most polymers, resins, foams, and silicone rubber. The process and machine used will change a little depending on the size of the part you’re molding and material used.

Structural automotive foam, which you can find inside the door and side panels, uses a foam mold. Resin is the primary material, but other plastics can work as well. It’s even lighter than most plastics and can be just as durable.   

Injection Molding Uses

In the automotive world, injection molding can quickly create many parts for a vehicle. And your limits go beyond just interior decor and plastic bumpers.

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If you pop open your vehicle’s hood, you’ll find many metal and plastic automobile components. The plastics you’ll find here are very durable and robust, such as ABS plastics, PET plastics, and nylon.

Common plastic parts include oil pans, head covers, and tubes.

Injection molding created most of the components you find inside your vehicle. Your compartments, dashboard, air vents, and more all consist of plastic. And to make those parts, automotive molding played an important part.

The exterior of your vehicle may have more plastic than you originally thought. Durable plastics make up fenders, grilles, door panels, headlight housing, and more. Of course, this depends on the type and age of the vehicle.

Other uses of automotive molding include:

  • Interior trim
  • Door handles
  • Rails
  • Side molding
  • Wheel trim
  • Vents
  • Mudflaps
  • Window moldings
  • Car mats
  • Engine caps
  • And more

Plastic automotive moldings are popular choices for anything that doesn’t endure intense heat or friction.

Automotive Molding Advantages

What are the advantages of automotive molding?

The biggest advantage of automotive molding is its ability to quicken the process of making parts. While you can create metal components with molds, it often costs more and takes longer than plastic or foam.

Durable Materials

Plastics are strong and durable materials. But injection molding increases the strength and durability of these plastics.

Automotive molding lets you add other materials to continue improving the durability of the plastics. Glass fibers are a common material that strengthens plastic components. Oil pans found on trucks and SUVs are plastics reinforced with glass fibers and other materials to improve durability.

Automotive molding can create parts with a lot of detail and complex geometry. Adding ribs, corrugation, and curves to a part is another way to improve strength and reduce cost.

Improved Efficiency

As mentioned above, automotive moldings create lightweight plastic parts. These parts are much lighter than traditional metal components. Replacing heavy metal parts with durable plastics reduces a vehicle’s weight and improves fuel efficiency.

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This will depend on the type of vehicle. Some vehicles like trucks and machinery will use more metal components on the exterior compared to a small commuter car.

Affordable and Repeatable

The initial costs of automotive moldings are expensive. However, injection molding is scalable meaning the more parts you create will lower the cost. Manufacturers who need to produce mass amounts of parts will benefit the most.

With automotive molding, you can maintain consistency with all parts. Since the molds consist of durable metal, they are reusable. This ensures all parts made with that mold are consistent and identical.

The entire process is repeatable. This saves time and energy from having to create new molds or making parts by hand. Create thousands of plastic-based automotive parts in a small amount of time.

Insert & Overmolding

Another form of injection molding that improves the durability of plastics is overmolding. Also known as 2-shot molding, overmolding mixes the plastic with a 2nd material.

This process improves performance and the product’s aesthetics. Strength and beauty are 2 important features in the automotive world.

But the benefits of overmolding don’t end there. Overmolding vehicle components can protect from electric shock, water, dust, and other metals.

Insert molding is very similar to overmolding. Both use a mold and plastic or resin materials. The main difference is insert molding typically covers or forms around another part.

This second part can consist of metal or other durable plastic. The advantages of insert molding include affordability and more diversified uses of plastics in the automotive industry.

The Importance of Automotive Molding

Automotive molding plays an important roll in the manufacturing process of vehicles. By cutting vehicle weight and improving fuel efficiency, it will continue to play an important roll in automotive innovation. The automotive molding will continue saving manufacturing time and money for years to come.

Want to learn more about the automotive industry’s innovations? Check out our latest articles in our Auto News and Reviews sections.