By Eric Chen, Team Rapid MFG Co. ,Ltd www.teamrapidtooling.com
+86 88508730
Email:sales@teamrapidtooling.com
In manufacturing, you can add a new mold to an existing mold and combine them to create one component. This manufacturing process is called insert molding, and you can perform this process either manually or automatically. In this process, you will use an insert to perform the additional injection molding process to the already-existing mold.
In this guide, you will learn all about insert molding, which includes tips, benefits, applications, and how it works.
Knowing More about Insert Molding – What is It?
Insert molding is a type of injection molding process whereby you put a new insert part (usually from plastic materials) into the already-existing mold (usually from metal), which will become integrated into a single part. Then, you will often need to apply an overmolding process to combine the original mold and the insert part together to create the final part.
With insert molding, you can insert an additional part and integrate it with an existing mold, which can also add more features to the primary component. Other than that, insert molding is also useful for you to improve the stability of the primary component, as well as improve its durability and strength. Insert molding parts are often made with thermoplastic materials, which are easier to integrate to the existing mold than any other material types.

How Insert Molding Works in Manufacturing Production
Insert molding allows you to integrate an injection molded part into an existing mold and then combine both with overmolding to create a single component. Here’s how insert molding works in manufacturing production:
- Preparing the primary mold. First, you will need to prepare the primary mold for the primary component. This is the mold that you will use as the base for your insert mold.
- Hand/automated insert. Now that you have prepared the primary mold, you will need to put the insert into the primary mold, either by hand or by automated method. By putting the insert by hand, you will make it easier to adjust its position and ensure that it will fit best in your primary mold.
- Inject the molten materials through the insert. After putting the insert into the primary mold, it’s time for you to inject the molten materials through the insert. This process is similar to plastic molding, with the difference being that you will apply it only for the insert.
- Solidifying the insert mold. Once you’ve injected the molten materials, you will need to wait for it to solidify before you remove the insert from the primary mold. You will need to adjust the temperature of the insert during this solidification process until you get the insert mold ready.
- Removing the insert from the primary mold. After the solidification process of the insert mold, it’s time for you to remove the insert from the primary mold. Next, you will use the overmolding process to combine the primary mold and the insert mold together.
- Overmolding process. The overmolding process will ensure that the insert mold is integrated well into the primary mold. This combination will solidify both the insert mold and primary mold as one component.
The Benefits of Insert Molding in Manufacturing
What are the benefits of insert molding in manufacturing? Insert molding can provide you with plenty of advantages in your manufacturing process, such as simplifying your part assembly process, creating components with better durability and stability, and minimizing the failures in your part assembly. Here are some benefits of insert molding for your production process:
- Simplifying the part assembly process. Insert molding will help you simplify the part assembly process of your component. Instead of creating two separate parts and assembling them together, you can use insert molding to combine the primary part and the insert part together in one process. Thus, you don’t need to assemble them again later.
- Better component durability, strength, and stability. With insert molding, you will add more durability, strength, and stability for the component, as you will combine the primary part and the insert part using the overmolding process. Thus, you don’t need to use any glue to assemble the two parts together, making the component to have much better durability, strength, and stability.
- Eliminating the risk of assembly failure. When you assemble two parts together, you will often need to use a special glue for that. But, it often doesn’t make the assembled components to hold together for a long time. With insert molding, you will combine the two components together during the insert molding process and “glued” the primary component with the insert mod part by using the overmolding process. So, the risk of assembly failure can be minimized.
- Lower costs for the part assembly process. Because you will combine the insert mold part with the primary injection mold part, there will be no need for you to combine the two components separately. Thus, it will help lower the costs of the part assembly process, as you will complete the assembly process with insert molding.
- Enhanced product design. Insert molding will also allow you to improve upon the component design. By adding the insert part, you can enhance both the design and functionality of the component, adding more features to it to make the component even more usable in a wide range of applications.

Insert Molding Applications in Various Industries
Insert molding has plenty of applications across various industries, such as automotive, medical, aerospace, consumer electronics, and other industries. In various industries, manufacturers can use insert molding to create threaded parts in many of their components.
For the aerospace industry, the applications of insert molding include aircraft controls, aircraft communication parts, and other aircraft interior components, such as handles, latches, seating, and others.
For the medical industry, manufacturers can use insert molding to create various medical devices, such as implants, sutures, and various parts used in most medical devices.
For the automotive industry, you can use insert molding in various automotive parts and components, such as gears, engines, vehicle interior, and many others. Manufacturers can also replace some metal components with plastic materials using the insert molding process.
Important Tips to Get the Best Results from Your Insert Molding Process
In some cases, insert molding can be a challenging process to do. Thus, it is important for you to perform the insert molding process the right way, whether you will use the manual method (by hand) or automated method (by using robotics).
Here are some important tips to get the best results from your insert molding process:
- Make sure to pick the best insert location around the primary mold.
- Maintain the right temperature during the insert molding process to ensure a perfect solidification for the insert mold.
- It’s best to use overmolding after completing the insert molding process to ensure the best material bonding between the primary mold and the insert mold.
- Double check whether the insert you use will withstand extreme temperatures during the insert molding process.
- Selecting the best material combination is important to ensure the best bonding between the insert materials and the primary mold materials.
- Use the manual insert by hand when you perform a low-volume production and use the automated insert with robotics when you perform a high-volume production.
Conclusion
Insert molding is one of the various methods that allows you to combine one mold with another mold in manufacturing production. With insert molding, you can insert a new plastic mold into an existing mold and combine them as one component.
This method can help you simplify the product assembly process in your manufacturing production and minimize the instances of failures when you combine different parts together.