Overmolding and Insert Molding

Overmolding and insert molding are two variants of injection molding. The two techniques that are frequently used to create complex plastic parts with multiple materials. While both processes involve injecting molten material into a mold, they differ in the way the materials are combined.

Over Molding

What Is Overmolding?

Overmolding is a technique in which a second material is molded over a first material to create a single part with two or more materials. This technique is commonly used to create parts with soft-touch grips or to add color and texture to a part. Overmolding can also be used to create parts with multiple durometers, where the first material is a harder material and the second material is a softer material. Overmolding can be done in one or multiple shots, depending on the complexity of the part.

Benefits of Overmolding

Material selection: Overmolding typically involves using a thermoplastic elastomer (TPE) or thermoplastic vulcanizate (TPV) as the second material to create a soft-touch grip or add color to a part. However, other materials such as silicone or rubber can also be used for specialized applications. The choice of material will depend on the specific requirements of the part, such as its intended use, durability, and cost.

Less Labor-OvermoldingMulti-shot molding: Overmolding can be done in one shot, where both materials are injected into the mold at the same time, or in multiple shots, where the first material is molded first and then the second material is molded over it. Multi-shot molding allows for more complex geometries and designs, but requires a more complex molding process.

Design flexibility: Overmolding allows for greater design flexibility, as it enables designers to incorporate multiple materials and colors into a single part. This can be especially useful for creating branded or customized products that stand out from competitors.

What Is Insert Molding?

Insert molding is a technique in which a metal or plastic insert is placed into the mold cavity and then encapsulated with plastic resin to create a single part with metal or plastic components. This technique is commonly used to create parts with threaded inserts, electrical components, or metal reinforcements. Insert molding can be done in one or multiple shots, depending on the complexity of the part.

Economical Insert Molding4 Benefits of Insert Molding:

1). Enhanced part strength: Insert molding allows for metal or plastic inserts to be incorporated into the part, which can enhance its strength and durability. By integrating the insert into the molded part, the insert acts as a reinforcement that strengthens the part in specific areas where it is needed.

2). Reduced assembly time and costs: With insert molding, multiple parts can be combined into a single component, which can reduce the need for assembly and lower production costs. This is because the insert is incorporated directly into the part during the molding process, eliminating the need for additional assembly steps.

3). Improved design options: Insert molding allows for greater design flexibility and customization options. The technique enables designers to create complex geometries and combine multiple materials to create unique, innovative parts. This can help products stand out in the market and enhance their overall performance and functionality.

4). Enhanced part performance: With the ability to integrate inserts into the part, insert molding can improve the performance of the final product. Inserts can be used to add features such as threaded inserts or electrical contacts, which can enhance the functionality of the part and improve its performance.

Beska’s Overmolding and Insert Molding Services

As an injection molding manufacturer, overmolding and insert molding are two common techniques that we use to manufacture complex parts with multiple materials. Because of these two techniques, we can produce a greater variety of parts. Which processing method do you want to choose for customizing your injection molding project? Contact us now to customize your molding project!

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