Insert Molding vs Overmolding: Guía detallada

Injection molding doesn't need any introduction as it has been catering to many industries for years. However, under the head of injection molding comes two very important terms: insert molding and overmolding.

If you are planning to start a new project and want to learn the difference between insert molding vs overmolding, the guide below is for you. So, let's read.

What is Insert Molding?

Insert molding is a process that assembles the plastic component with a metal insert. The plastic is injected into the mold. As soon as the plastic solidifies, the component and insert are assembled.

Insert molding is mostly used to create metal-attached plastic components. This process is commonly observed when creating fasteners so that they can help assist with assembling different products.

Benefits of Insert Molding

Insert molding offers various benefits, and the most important ones are discussed below:

• Injection molding is known for mass production. Hence, it offers the economics of scale when it comes to choosing the injection molding process.
• One can manufacture these components at a low cost. Moreover, the assembling process also simplifies, and the need for CNC machined components is eliminated, helping to save.
• The combination of metal and plastic materials enhances the performance of the components. The company has the benefits of both: the metal part allows the component to be made strong and stiff, and the plastic part helps reduce weight.

Limitations of Insert Molding

Insert molding has some limitations along with advantages, and these are as follows:

• Insert molding has a two-step manufacturing process; the first step requires manufacturing metal components and then the injection molding process for assembly. It increases the hassle of the process.
• The complexity of the component also increases, especially when the custom metal part is manufactured and hence the integration gets complex.

What is Overmolding?

Overmolding is a type of injection molding, but in this process, the molding takes place over another component, which is also made using moldeo por inyección.

The process combines different types of plastics to achieve functionality or aesthetics. It is used in screwdrivers for making their handles, toothbrushes or power drills.

Benefits of Overmolding

The benefits of overmolding are as follows:

• Overmolding allows designers to create components that have multiple materials, which help add properties and visual complexity.
• It doesn't require any adhesive to combine the materials because the molten materials are fused in the other part, which reduces cost and enhances durability.
• Overmolding helps mold soft seals in the components, and the seal forms a groove in the part where the o-ring can be installed.

Limitations of Overmolding

Some of the limitations of overmolding are as follows:

• Overmolded components are manufactured in two steps, which increases the manufacturing time and is expensive. It needs two tools or two-shot molds, which adds to the cost.
• The process of bonding two different materials with one another in an injection mold run leads to the chance of delamination.
• In cases where the appropriate temperatures are not maintained, this leads to a problem with bonding and durability.

Differences Between Insert Molding vs Overmolding

The section below highlights the differences between overmolding and insert molding in detail.

Proceso

Insert molding consists of injecting just one shot of molten plastic, whereas overmolding requires two shots of molten plastic to be inserted.

Speed

Insert molding takes time to mold another layer because the two pieces are manufactured separately. Hence, compared to overmolding, insert molding takes more time.

Overmolding is quick. It doesn't need two pieces to be manufactured separately, and direct molding takes place over the first product to create the second one.

Selección de materiales

Overmolding doesn't need adhesive, and the selection of the material needs to be adequate enough to create a strong component.

Similarly, insert molding also doesn't need any additional fasteners as the metal components are already present in the mold.

Coste

Insert molding can help reduce the cost of assembling and can create thousands of parts in a single day. However, overmolding is expensive as it requires double steps.

Common Applications of Insert Molding vs Overmolding

There are many applications of insert molding and overmolding as they cater to versatile industries, and some of these are discussed below:

Automóvil

In the automobile sector, the two processes allow the components to have a combination of plastic and metal parts. The process of manufacturing batteries, dash panels, handles, and knobs all use insert molding.

Cosmetics

Most of the equipment used in the cosmetics industry is made using overmolding and insert molding, as they help in enhancing the overall look of the products.

These methods help to create special surfaces of components composed of different colors. Some of the cosmetic products are makeup brushes, bottles of perfumes and even compact powders.

Electrónica

The placement of the rubber on the electrical wire is attained through insert molding. It creates coats on the electronic products and makes handling them safer.

How to Choose Between Insert Molding vs Overmolding for Your Project

When choosing between insert molding o overmolding for your projects, some of the considerations that you must keep in mind are highlighted here. It will help you make the relevant decisions.

Overmolding is suitable when thermoplastics and rubber are used, and multiple colored layers are used on the components. Moreover, the components do not need to be disassembled later on.

Insert molding is suitable where a prefabricated substrate is used, and the metals or computerized parts are contained in the substrate.

Conclusión

Understanding the differences between overmolding and insert molding is very important to make a relevant decision between the two processes and their selection. Hence, the guide above must have helped you in this regard.

If you are looking forward to having hands on the components made through the two processes, DEK can assist you.

Preguntas frecuentes

What is TPE overmolding?

TPE overmolding is a process of injecting TPE into an existing plastic part.

Is insert molding the same as 2K injection molding?

Insert molding is composed of creating a secondary component on a substrate, 2K molding is a double shot injection molding that injects different materials in a mold with multiple chambers.

What is two-shot injection molding?

The shot injection molding process involves molding multiple parts using a single tool.

What are inserts in injection molding?

The inserts are metal parts that are used for manufacturing components by having molten plastic with it using injection molding.