Overmolding VS Insert Molding

In the current industrial field, multi-material injection molding finds wide applications in producing products that meet multiple functions and aesthetic purposes. Explicitly speaking, the multi-material injection molding mainly comes in two forms, namely the Overmolding VS Insert Molding.
Since these two molding technologies bear some similarities while some key differences also exist. Therefore, it is visionary for you to learn relevant information about insert molding and overmolding before choosing.
Today, this is a piece of good news. This guide explains Overmolding VS Insert Molding in terms of definition and differences covering benefits, applications. It will help you more easily identify which type of injection molding technologies is apt for your needs.

Definition: Overmolding VS Insert Molding

If you are going to browse the Wikipedia page on the two molding technologies, you would find them verbose and difficult to understand. So, to understand them better, Let us explains in detail down below:

What is Insert Molding?

Insert molding is a process in which an insert is to be pre-placed into a mold for injected plastic to flow around. The inserts come in various types, such as metals and different kinds of plastic. The fruit of this injection molding technology is a single piece of molded plastic that surrounds the whole insert. Such plastic is generally more solid and durable than one produced in the secondary assembly way.

What is Overmolding?

Most commonly, overmolding is a process in which a single component or product takes into shape by collectively using two or more different materials.

Differences: Overmolding VS Insert Molding

Benefits of Insert Molding

The benefit of insert molding are evident across a variety of industries. It finds wide applications in miscellaneous industries ranging from automobiles, electrical parts or components, medical instruments and devices, consumer products.


The insert molding serves as a low-cost method to decrease the part size and weight and to produce strong, durable, and reliable finished products.

Better Product Design:

The insert molding can boost component reliability, increase the strength of each component. All products produced in this technology features corrosion-resistant, strong, durable, and reliable.

Reducing Assembly Time and Labor Costs:

In the process of insert molding, the step of putting an insert into the mold can achieve using some form of automation. That spares the time and energy of technicians so that they can devote to more sophisticated and important events.

Benefits of Overmolding

In contrast, the overmolding boasts some outstanding benefits alike the insert molding as follows:

Better Product Performance:

Thermoplastic elastomers ( aka TPE) are a kind of copolymers or a physical mix of polymers composed of materials with both thermoplastic and elastomeric features. As an ideal material, the unique elastic performance makes TPE a natural barrier to protect a product and prolong its shelf life by decreasing shock, vibration, and noise.

Better Product Appealing:

The TPE comes in various colors and texture and can act as a visually attractive veneer. Moreover, the transparent TPE surface can be printed with an exclusive logo, advertisements, or instructions.

Lower Product Costs:

Overmolding is effective in that it enhances product properties in several aspects. Hence, it can curtail production costs to some degree extent.

All these molding technologies have benefits that are conducive to help cut your project budget. Meanwhile, the quality of your products will not suffer loss. These two injection molding technologies have their respective uniqueness.

The insert molding may be helpful in adding logos, advertisements. In this way, the whole manufacturing cost will witness a great decrease. While, the overmolding may be conducive to glut parts together.

If you want to satisfy your targeted customers, you can use these two methods singly or collectively according to circumstances. Besides, you should also take the external environment and the concrete needs into consideration to determine which type of methods is more suitable.

Applicable Materials: Overmolding VS Insert Molding

Overmolding Materials

使用的材料在overmolding技术求进步d on the compatibility, adhesion, and other factors, such as the thickness of the overmolding material, the softness of the material itself, etc.

  1. HDPE.

高密度聚乙烯(AKS HDPE)或聚乙烯是由单体乙烯产生的热塑性聚合物。此类材料具有高强度密度比和可回收特性。HDPE广泛适用于塑料瓶,土工膜,塑料木材等的生产。

2. PMMA (Acrylic)

Polymethyl methacrylate ( aka PMMA) is a transparent thermoplastic often used in sheet form. It serves as a substance to alternate lightweight or shatter-resistant glass.

3. POM

Polyoxymethylene ( aka POM) is an engineering thermoplastic, which is applicable in precision components needing high stiffness, low friction, and excellent dimensional stability.

POM features a high strength, hardness and rigidity under −40 °C. Although it is opaque white intrinsically, it can come into being in any colors.

It is popular in the automotive and consumer electronics industry, such as small gear wheels, ball bearings, ski bindings, fasteners, guns, knife handles, etc.

Insert Molding Materials

The materials used in insert molding technology depend on the mold and other elements, such as the wall thickness of the shaped product.

The main focus relies on the sustainable running of the machine in the course of molding.

  1. Thermoplastics:

Such materials are eco-friendly and resistant to chemicals. The following are the main kinds of thermoplastic materials in the market:

a. Polyethylene.

b. Polystyrene.

c. Nylon.


Thermosets are much similar to thermoplastics. But they are not eco-friendly, because they can not be used for many times.

The following are the main types of thermosets materials in the market:

a. Phenolic.

b. Epoxy.

3. Elastomers:

Such materials are elastic and recyclable.

They are very eco-friendly materials and are great for home appliances and automotive product manufacturing.

a. Natural Rubber.

b. Polyurethane.

Applications: Overmolding VS Insert Molding

Applications of Overmolding

Overmoldeding finds wide applications in multiple industries. Overmolding is not only applicable in large amounts of private products, such as toothbrushes, but also many higher-value products, such as plastic engine components. When it is used in the hospital, it can make products more stable, clean, and moisture-resistant. When it is used in the automobile industry, it can spare the efforts to conduct additional assembly steps that would need using adhesives.

The following are the concrete applicable fields:

  • Plastic or metal components equipped with a soft-grip handle.
  • Medical appliances.
  • Appliance Knobs.
  • Automotive components.
  • Encapsulated electronic devices.
  • Electrical parts.
  • 控件。
Overmoulding application
Overmolding application
overmolding application

Applications of Insert Molding

The insert molding finds a wide applications in the various industries.
注塑技术是最好的设计ing smaller products. The products in small sizes often find a place in commercial uses that require additive manufacturing and laser sintering.

It is also popular in developing compact products. In contrast, the products in the overmolding way are much larger. Therefore, Overmolding takes a much longer time to produce a product.

The following are some concrete applications:

  • Automotive sector.
  • Consumer goods.
  • Medical industry.
  • Electronics.
  • 航天。
  • Tube valves.
  • 控件。
  • Electrical components.
insert molding applications
Insert molding applications (2)
Insert molding application


This article mainly gives a brief introduction to the differences between insert molding and overmolding. If you want to learn other information, please leave your message below or contact us directly.

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