Chat with us, powered by LiveChat


Welcome To ETCN - Top china CNC machining service provider
Customise by Drawing
CNC Machining Services
Metal Processing
Helpful Links


Learn the Benefits of Overmolding!

Unlock the potential of overmolding with ETCN! Our comprehensive guide will teach you all about this injection molding process. With a better understanding, you can maximize your capabilities and create unique products with an optimal combination of materials that’ll stand out.

  • Discover All You Need to Know with ETCN's Overmolding Guide

Are you curious about the benefits of overmolding? Get all the information you need with ETCN’s comprehensive guide. From understanding what overmolding is, to learn which materials and methods are best suited for your project, discover how to make your parts stand out. With our detailed instructions and clear explanations, you’ll have no trouble getting on top of this process in no time. Get started now with ETCN!


Comprehensive List of Standard Specifications for Overmolding Service

Material CombinationsThe types of materials that can be combined using overmolding, such as plastic with rubber or metal with plastic
Tooling Lead TimeThe time required to create a custom mold for overmolding
Injection Molding Tonnage CapacityThe maximum clamp force that can be applied during injection molding
Injection Molding Shot Size CapacityThe maximum volume of material that can be injected into the mold during injection molding
Overmolded AreaThe specific area or areas of the part that will be overmolded
Tolerance LevelThe level of accuracy that can be achieved in part dimensions
Surface FinishThe smoothness and texture of the finished product's surface
Color OptionsThe range of colors available for the finished product
FunctionalityThe specific functional purpose of the overmolded area, such as providing grip or improving durability
Production VolumeThe expected volume of parts to be produced per run or per year
PriceThe cost of the overmolding service per unit or per run
what is Overmolding?
  • What is Overmolding?

Overmolding is a manufacturing process that involves combining multiple materials to create a single part or product. This process typically involves molding one material (often a rigid plastic) over another (usually a softer material like rubber or silicone) to achieve the desired look, feel, or function.

Overmolding is often used in producing items like tools, toys, and electronic devices, as it creates parts with aesthetic appeal and enhanced functionality.

Custom Overmolding Parts Display

Exceeding your Expectations: Overmolding Service

At ETCN, we proudly offer our clients the advantages of Overmolding. Get an injection molding process that combines multiple materials into a single part or product, and see the benefits for yourself! Our Overmolding service helps you to create parts and products with excellent function, durability, compatibility, and aesthetic appeal. Let us help you exceed your expectations with our exceptional services – get in touch today to learn more!

2023 Professional Guide

What is Overmolding?

Overmolding is a manufacturing process commonly used to produce complex parts and products. This process involves two or more materials where a substrate is covered, partially or entirely, with a rubber-like material, usually thermoplastic elastomer (TPE), to create a final product that is both visually and functionally appealing.

Definition of Overmolding

Overmolding is the process of fusing two or more materials to create a single, final product. The process is typically used to produce parts and products that combine different materials to achieve the desired aesthetics, texture, and functionality. Overmolding uses various materials, including plastics, rubber, and metal.

Overmolding Process Basics

The overmolding process involves several steps, starting with creating a substrate that needs to be covered with another material. Once the substrate is produced, an injection molding machine makes the over-molded part. The substrate is first placed into the mold. Then, the overmolding material is injected into the mold, covering and fusing with the substrate. After the material cools and hardens, the part is removed from the mold and is ready for any necessary finishing touches.

Benefits of Overmolding

Overmolding offers several benefits over traditional manufacturing processes. The process creates a seamless bond between two or more materials, resulting in a final product that is more durable, more robust, and more aesthetically pleasing. Additionally, overmolding can help reduce the number of parts in a product, ultimately reducing assembly time and costs.

Applications of Overmolding

Overmolding is widely used in various industries, including automotive, medical, and consumer products. It is often used to produce grips, handles, and buttons on electronic devices and to create soft-touch components on medical devices. Overmolding is also essential in making automotive interior parts, like steering wheels and gear shifters.

Differences between Overmolding and Insert Molding

Although similar in concept, overmolding and insert molding are different processes. Overmolding involves molding one material over another material or substrate, while insert molding involves placing an insert before injecting the material. Another key difference is that overmolding allows for a broader range of part geometries than insert molding, as the substrate acts as a base.

How Does Overmolding Work?

Overmolding is a manufacturing process that involves the creation of a single part or product from multiple materials. It combines rigid plastic with a softer material like rubber or silicone, resulting in a final product that offers improved functionality, appearance, and durability.

Step-by-Step Overmolding Process

The overmolding process involves several stages. First, the substrate material is prepared, often by washing and drying it thoroughly. Next, the first material or substrate is placed into the mold. The second material is then injected into the mold to overmold the first material. The two materials are then bonded via a chemical or mechanical bond, resulting in a final product.

Types of Overmolding

Overmolding can be divided into two types: two-shot and insert molding. Two-shot overmolding involves molding two materials in one single process. Insert molding, on the other hand, consists of the insertion of an object into the plastic before setting it with a softened material like rubber.

Overmolding Materials

The most common materials used in overmolding are thermoplastic elastomers (TPE), thermoset rubbers, and silicone. TPE and thermoset rubbers are known for their flexibility, durability, and resistance to chemicals and heat. Silicone is known for its softness and biocompatibility.

Choosing Overmolding Materials

When choosing overmolding materials, several factors should be considered. These include the functional requirements of the final product, the environment in which it will be used, and the cost. Material compatibility must also be considered to ensure chemical bonding between the two materials.

Overmolding on Different Substrates

Overmolding is a versatile process, enabling manufacturers to over mold many substrates. Materials that can be over-molded include metals, plastics, glass, and textiles. Overmolding offers a range of benefits, such as improved aesthetics, cushioning, grip, and durability. As such, it has applications in various industries, including automotive, medical, and consumer products.

Types of Molds Used in Overmolding

Overmolding is a manufacturing process that creates one part by combining two or more materials into a single component. This process involves using a mold, a tool that shapes the material into the desired form. Depending on the materials used and the desired outcome, different types of molds may be used in the overmolding process.

The most common types of molds used in overmolding are insert molds, family molds, and multi-shot molds. Insert molds incorporate pre-manufactured components into the mold to create a finished product. On the other hand, family molds produce multiple parts in a single mold, making production more efficient. Multi-shot molds are used for complex parts that require more than one material to be molded simultaneously.

Overview of the Injection Molding Process

Injection molding is the core process used in overmolding. It is a process that creates complex plastic parts by injecting molten material into a mold. The process starts with melting the plastic material, followed by the injection of the molten material into the mold cavity. Once the material has cooled and solidified, the mold is opened, and the part is ejected.

Two-Shot Molding and Injection Molding Machine

Two-shot molding, or multi-material overmolding, is a technique used in overmolding that involves using two different materials. This technique is performed on a single injection molding machine, combining two other materials into one part. The result is a more complex part with unique characteristics that cannot achieve through traditional overmolding.

An injection molding machine is used in the overmolding process to heat and inject the molten material into the mold. The device consists of the hopper, the injection unit, and the clamping unit. The hopper stores the plastic material, the injection unit melts and injects the material into the mold, and the clamping team holds the mold in place during the injection process.

Different Types of Molds Used in Overmolding

As mentioned earlier, different types of molds are used in the overmolding process. The most common types of molds include insert, family, and multi-shot molds.

Insert molds are used when one or more components must be inserted into a plastic part during molding. Family molds are used when multiple factors are required for a single mold, which increases efficiency and reduces costs. Multi-shot molds are used when complex features require more than one material to be molded simultaneously.

Tool and Machine Requirements for Overmolding

Specific tool and machine requirements must be met to succeed over the mold. The mold must be designed to accommodate the materials being used, and the device must be selected based on the size and complexity of the part. Additionally, the materials must be compatible to ensure proper adhesion during the overmolding process.

Common Problems Encountered during Overmolding and Their Solutions

One of the most common problems encountered during overmolding is material compatibility. If the materials used in the overmolding process are incompatible, the resulting part may have poor adhesion, which can lead to failure.

Another common problem is warping, which occurs when the part cools unevenly, causing it to warp or bend. To prevent warping, the cooling time for the position should be carefully monitored and adjusted as needed.

Finally, sink marks may appear on the finished part if the mold is incorrectly designed. Sink marks result from uneven cooling and can be minimized by adequately creating the mold and controlling the cooling time and temperature.

In conclusion, overmolding is a versatile process that combines two or more materials to create a single part. Manufacturers can produce complex parts with unique characteristics that cannot be achieved through traditional molding processes using the appropriate molds, machines, and materials. However, it is essential to be aware of common problems and solutions to ensure the success of the overmolding process.

Choosing the Right Plastic for Overmolding

Overmolding is a popular manufacturing process due to its numerous benefits. However, choosing the choosing is essential to achieve the desired results. Is important. The success of your overmolding project heavily depends on selecting suitable materials.

Types of Resin Used in Overmolding and Their Properties

Regarding overmolding, two plastics commonly used are thermoplastic elastomers (TPE) and thermoplastic polyurethane (TPU). TPE and TPU have unique properties that make them suitable for specific applications. TPEs are softer and more flexible, while TPUs are more resilient and abrasion resistant. 

Critical Parameters to Consider When Selecting Overmold Material

Before choosing a material for overmolding, it is essential to consider various parameters such as the application requirements, molding processes, part design, end-use environment, and material compatibility. These parameters should be evaluated in-depth to ensure the final product meets the desired functionality, durability, and stiffness requirements.

TPE Overmolding and its Advantages

TPE overmolding is popular due to its ability to create soft-touch grips and ergonomic features that ensure comfort and ease of use. TPEs are also easy to mold and recycle, making them an eco-friendly option. Furthermore, TPEs offer excellent chemical resistance and a low compression set, making them ideal for applications that require resistance to oils, solvents, and harsh environments.

Surface Texture and Coefficient of Friction

The surface texture of over-molded parts can be critical in providing a positive tactile effect, enhanced slip resistance, and aesthetic appearance. Various surface finishes, such as textured, glossy, matte, and soft-touch, can be achieved through overmolding. Additionally, the coefficient of friction of the over-molded part impacts the grip, feel, performance, and behavior of elements in various environments.

Optimizing your Overmolding Project for Maximum Efficiency

The efficiency of your overmolding project can be maximized by considering various factors such as part design, molding processes, material selection, and tooling. Properly optimizing these factors can improve product functionality, reduce manufacturing costs, shorten lead times, and improve overall quality. Additionally, partnering with experienced overmolding manufacturers can help you gain insights and identify opportunities for continuous improvement. 

In conclusion, overmolding is a versatile and efficient manufacturing process that offers numerous design and functional benefits. Choosing the suitable plastic, evaluating critical parameters, optimizing your process, using TPEs, and paying attention to texture and friction help ensure your overmolding project’s success.

Benefits and Challenges of Overmolding

Overmolding is a manufacturing process that has gained popularity in recent years, particularly in producing tools, toys, and electronic devices. One of the main benefits of overmolding is that it allows for the creation of parts with enhanced functionality and improved aesthetics. By combining two or more materials into a single piece, overmolding can produce a product with a softer and more comfortable grip, better shock absorption, and more attractive design features.

Advantages of Overmolding and Insert Molding

Overmolding is a process that can be used to create various products, from small electronic components to more comprehensive industrial tools. One of the most significant advantages of overmolding is that it allows for creating a single part with creating a single piece with different properties in different areas of the region. For example, an over-molded tool handle could have a soft rubber grip for comfort, with a more rigid plastic base for durability.

Insert molding is a similar process that involves inserting a pre-manufactured component (such as a metal insert) into a mold and then overmolding the piece with plastic or rubber. Insert molding allows for the creation of parts with enhanced strength, durability, and improved functionality.

Challenges of Overmolding

While overmolding and insert molding offer numerous benefits, there are also challenges associated with these processes. One key challenge is the need to ensure that the two materials being combined have compatible properties. For example, the bonding process between the materials must be strong enough to prevent delamination or separation of the layers.

Another challenge is the equipment cost needed to perform overmolding and insert molding. These processes require specialized machinery and molds, which can be expensive to purchase and maintain.

Overmolding: Misconceptions and the Future of Plastic Molding Process

There are many misconceptions surrounding overmolding and insert molding. One common misconception is that these processes are only suitable for producing small components. Overmolding and insert molding can create parts of all sizes, from tiny electronic components to extensive industrial tools.

Another misconception is that overmolding is a complex and time-consuming process. While it is true that overmolding requires specialized equipment and expertise, advances in technology have made the process faster and more efficient.

Looking to the future, overmolding and insert molding is likely to continue to play a significant role in the plastic molding industry. As manufacturers seek to produce parts with enhanced functionality and improved aesthetics, these processes offer a cost-effective and reliable solution.


Overmolding and insert molding are two manufacturing processes that allow for creating parts with enhanced functionality, improved aesthetics, and better strength and durability. While these processes have specific associated challenges, their benefits outweigh the costs. Overmolding and insert molding will likely become increasingly important in producing a wide range of plastic and rubber products as technology advances.

Frequently Asked Question

Q: What is overmolding?

A: Overmolding is a process where two or more materials are molded together to create a single, integrated part. This process is commonly used in the manufacturing of complex plastic parts.

Q: How is overmolding different from insert molding?

A: Overmolding and insert molding are similar because they merge multiple materials. However, overmolding typically involves setting plastic over plastic, whereas insert molding involves inserting a pre-molded component into a mold and then setting plastic around it.

Q: What are some typical applications of overmolding?

A: Overmolding is commonly used in manufacturing products such as handles, grips, and seals. It can also be used in electrical applications where a part must be insulated and conductive.

Q: What is the overmolding process?

A: The overmolding process begins by molding the base material, followed by the overmolding material. The two materials are then bonded together using heat and pressure. Cycle times for overmolding can vary depending on the complexity of the part being produced.

Q: How are overmolding and insert molding used in product design?

A: Overmolding and insert molding are commonly used in product design to incorporate multiple materials and create complex shapes. Proper manufacturing process evaluation is needed to ensure the invention can be efficiently produced using overmolding.

Q: What materials are commonly used in overmolding?

A: Overmolding materials can range from thermoset rubbers to thermoplastic elastomers. The selection of material is essential as it can affect the bonding strength between the two materials.

Q: How does the overmolding process work?

A: The overmolding process works by injecting the base material into a mold, followed by the overmolding material. The two materials are bonded using heat and pressure to create a single, integrated part.

Q: What is the evaluation process for determining the best overmolding type?

A: The evaluation considers the part design, required material properties, manufacturing process, and cycle times. This process helps determine the best overmolding type for a specific application.

Q: Can the overmolding process be used for multiple material molding?

A: Yes, the overmolding process can be used to combine more than two materials. This allows even more complex parts to be created with unique material properties.

Q: What are some design considerations for using overmolding?

A: When designing for overmolding, it’s essential to consider factors such as material selection, wall thickness, and draft angles. Additionally, overmolding can be used to absorb vibration and improve product performance.

Contact ETCN

Scroll to Top