Overmolding and insert molding are two different injection molding processes that have the same purpose, which is to combine two different materials in a single mold. So, what is the difference between overmolding and insert molding? Let’s take a look at each of these injection molding methods.
Overmolding – What is It?
Overmolding is an injection molding process that involves the use of two shot or multiple shot injection molding operations, which will allow you to combine one plastic material with the other material. In general, overmolding will involve the use of two injection molding shots, which include the primary and the secondary shots.
First, you will need to perform the primary injection molding shot within the mold and let the primary injection-molded product to form after it cools down. After getting the first injection-molded part, you will need to perform another injection mold around the first-injection molded part, which often has lower thickness compared to the primary shot. Both the primary and secondary injection-molded shots will then cool down and form a bond to unify them as a single injection-molded product.
Insert Molding – What is It?
Insert molding is a single-shot injection molding process that involves inserting a certain material piece inside the mold before you begin the injection molding operation. For instance, if you are going to produce a screwdriver using an insert molding process, which consists of a metal piece and a plastic handle, you will need to insert the metal material piece inside the mold first. Then, you can start the single-shot injection molding process to create the plastic handle, which will cover the upper part of the metal piece material.
In insert molding, the metal part and the plastic mold injection part will bind with each other, and they will become a single unified product after the insert molding process is complete. So, you don’t need to take these parts into the assembly process further.
Key Differences between Overmolding and Insert Molding
Although they look like a similar process, insert molding is different from overmolding. There are some aspects that differentiate between these two injection molding processes.
Here are the key differences between overmolding and insert molding:
- The use of insert vs. no insert. Insert molding uses inserts as a means of delivering the additional part for the injection-molded product, which will get inserted into the mold before the molding operation. Meanwhile, overmolding doesn’t use any insert but instead combines two or multiple injection molding shots with different materials and colors.
- One injection molding vs. multiple injection molding shots. Insert molding will only use one injection molding shot, whereas overmolding will use at least two injection molding shots. The injection molding process in insert molding will cover a part of the inserted material.
- Cheaper vs. more expensive production costs. Insert molding only involves one injection molding shot, which means fewer materials for you to use. Meanwhile, overmolding requires at least two injection molding shots, meaning more materials for you to use. So, the insert molding process can be much cheaper than the overmolding process.
- Different completion speed. Generally, the insert molding process will be completed in much faster time, as it only involves a single shot injection molding. Meanwhile, because of overmolding’s two-shot injection molding process, it will be completed at a much slower rate.
- Complexity of the process. The insert molding process is much simpler to perform than the overmolding process. With overmolding, you will need to prepare different materials with different colors, which can be complicated to do, as you will need to find the materials that are compatible with each other.
Benefits of Overmolding in Manufacturing
You can use overmolding to combine different materials with different colors and create injection-molded products in a wide range of applications. Here are some benefits of overmolding in manufacturing:
- Freely choose your material combinations. With overmolding, you can choose between two or more material combinations to create your injection-molded products. This can help you create a lot of product variations, which can help with your marketing strategy.
- Best for sealing and waterproofing. Overmolding is also best to use for sealing and waterproofing. You can combine a plastic material with silicone or rubber to create a strong sealing for your injection-molded product.
- Compact and lightweight design. Overmolding is an injection molding process that allows you to create injection-molded products with compact and lightweight design. You can also add certain features to the products, such as a soft grip, ergonomic handle, and so on.
- Creating non-corrosive injection-molded products. You can also use overmolding to create injection-molded products that have excellent corrosion-resistance properties. So, you can ensure that these products can work for the long-term without causing unnecessary problems for the customers.
- Color variations. Another important benefit of overmolding is that you can also use various colors in your injection molding process to create injection-molded products with different color variations. Again, it can also benefit your business marketing strategy, as it can help make the products appear more appealing for your customers.
Benefits of Insert Molding in Manufacturing
With its simple operation, insert molding can provide plenty of benefits in your manufacturing production. Here are some benefits of insert molding in manufacturing:
- Simple process. Insert molding is much simpler when compared to overmolding. It is similar to the regular injection molding process, with the only difference being that you will need to add an insert before you start the injection molding operation.
- Cut down on assembly costs. Insert molding is also a better choice for you if you want to cut down on assembly costs, as you can just combine the two parts together during the insert molding process. So, there will be no need for you to assemble the parts again later.
- Durable products. You can also create various durable products with insert molding, which will be good for long-term use.
- Variety of material combinations. Most insert molding processes use the combination of metal and plastic materials, with the metal being the insert and the plastic being the primary injection-molded part. However, there are plenty of material combinations you can use for this type of injection molding process.
Conclusion
Both insert molding and overmolding have their own uses, and each process has their benefits. Insert molding is generally much simpler and more affordable when compared to overmolding, but this process has more limitations and restrictions in the materials and designs you can apply.
So, you can pick the one that fits best with your manufacturing needs and requirements, including your available budget.