In the automotive sector, injection molding is one of the main methods manufacturers use to form plastic parts. However, it's difficult to list the plastic parts in a car produced using injection molding, so we'll take a look at some of the main ones.
(1) Components under the hood
Over the past two decades or so, manufacturers have transitioned to plastic for many under-hood components that were previously made of metal. For these applications, strong polymers such as ABS, nylon and PET are common. However, automotive injection molding manufacturers now use injection molding to make parts such as cylinder head covers and oil pans. This method is less weight and cost than metal parts.
(2) External components
Injection molding is an established process for many automotive exterior components, including fenders, grilles, bumpers, door panels, floor rails, lamp shades, and more. The splash guard is a good example of the durability of injection molded parts. Additionally, the parts that protect the car from road debris and minimize splashing are often made of rubber or other durable and flexible materials.
(3) Internal components
Manufacturers also use automotive plastic injection molding to produce many automotive interior parts. They include instrument assemblies, interior surfaces, dashboard panels, door handles, glove boxes, air vents, and more. In addition, they use injection molding to produce decorative plastic components.
In many cases, molded plastic can be used as a substitute for metal. Previously, automotive injection molding manufacturers used only metal to make things like brackets, trunk lids, seat belt modules and airbag containers. Today, injection molding is the preferred production method for these plastics. On the other hand, manufacturers can sometimes replace molded plastic parts with 3D printed plastic auto parts. This is especially the case in prototyping, where there is less need for extreme durability or a smooth surface finish. Many moldable plastics can be used as 3D printer filament or as a 3D printer powder for nylon. Some professional and high-temperature 3D printers can also print reinforced composites for high-strength parts.
For one-off prototypes, especially non-mechanical parts, 3D printing can be a cost-effective alternative to molding. Since there is no mold cost, the production price is not that high. In some cases, manufacturers may even 3D print auto parts for a handful of end-uses. They might use 3D printing to make fluid handling components such as valves (usually not injection molding). Another option, however, is to use S3D printing to make parts such as bumpers, trim and windbreakers, which are sometimes injection-molded.