Understanding the Different Types of Plastic Injection Molding

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Injection molding is a cost-effective technique to manufacture a high volume of similar goods by injecting molten materials into a mold. Although the method is most frequently used with thermoplastic and thermosetting polymers, it may also be applied with metals, glassware, elastomers, and confections.

This article will dive into the types of plastic injection molding, their definitions, and their specific applications.

Metal Injection Molding

Niche industries may use metal over plastic in injection molding to achieve certain product specifications. This process is especially vital for electronics and digital goods production processes. Since many markets demand components with complex shapes, metal injection molding is quickly becoming one of the more prevalent manufacturing techniques.


Overmolding makes it feasible to make a component out of two or more polymers. A substrate (typically the initial material) is covered with secondary materials — such as overmold materials — to achieve unique product requirements for each item.

Overmolded goods are commonly used to make everyday items, such as attachments for tools or personal care products.

Insert Molding

Although this procedure is comparable to overmolding, insert molding has more material restrictions since it uses sub-materials to fill in the spaces between the pieces, increasing its strength. You may combine two or more components to make a single product by adding your selected polymer to the insert.

Insert molding parts are generally durable because they reduce the need for extra pieces, which might make the product bulkier yet less useful.

Gas-Assisted Injection Molding

This injection molding technique shields the formed components against damage or distortion after the cooling process. To retain its flawless finish, it processes pieces by injecting gas into an injection mold filled with plastic.

Gas-assisted injection molding is ideal for components requiring hollow sections, as this process can achieve said sections without adding to the cost.

Thin Wall Molding

Thin wall molding is the best method for producing components with incredibly thin walls and reducing fractures on the molded product. Since it may be utilized for tiny pieces, this process is highly accurate. Electronics, medical equipment, tubes, and other items frequently use this technique.

Thermoplastic Injection Molding

The electronics and automotive industries rely heavily on thermoplastic polymers for various purposes because they have the benefit of being conductive and strong. Thermoplastic injection molding features a reduced risk of component damage and shrinks resistance. Moreover, its high adaptability and sustainability make it a good method for companies with rigorous standards for design and functionality.

Liquid Silicone Injection Molding

High-end medical equipment and auto parts can benefit greatly from this technique since silicone is highly resistant to extreme temperatures. When creating a component, the material is injected using a heated mold. Then, a cold material is injected to chill the material and form the part.

Hot Runner Molding

Hot runner molds use heat as their primary agent. This technique is used for plastic resins that need to be heated inside or outside to materialize. It uses two heat-resistant plates that can handle small to big pieces.

Cold Runner Molding

Cold runner molding often requires three plates, unlike hot running molding. This process is preferred among manufacturers, and numerous businesses have recognized the benefits this approach offers for production. With robotic runners removal aid, cycle times for this system are significantly faster.

Need Assistance in Your Manufacturing Needs?

Molding industry experts can provide you with resources to make the most of the types of plastic injection molding to satisfy your design requirements. With Integral Manufacturing, we offer solutions that meet your demands and exceed your expectations!

To provide our clients with the best overall injection molding services, we have a wide variety of design, engineering, modeling, prototyping, testing, and production capabilities.

Find out more about Integral Manufacturing’s services here. Ready to get started? Send us an email, and we will be delighted to assist you!