Overmolding: What It is and What It Means for Products and Profits

Overmolding- What It is and What It Means for Products and Profits

Overmolding has become extremely famous amongst consumer products producers and other mass producers. The main reasons cited for their preference of overmolding are performance, aesthetics, and top efficiency and functionality of overmolded products.

In this post, these three over cited reasons for the preference of overmolding are highlighted. More than that, the answer to what it means for products and profits shall also be laid down.

What is Overmolding?

For the non-layman, overmolding may be a very technical term. But basically, overmolding is just one of the many plastic injection methods whereby plastic materials are molded over another material, mostly resin or another plastic.

With this procedure, multiple plastic parts are combined, forming not only a seamless product but also a more durable and polished one.

With this objective, overmolding incorporates high-precision techniques and high-level knowledge of the precise heat that would temper together the parts in a seamless fashion.

What is Possible With Overmolding?

What is Possible With Overmolding

Aside from performance, aesthetics, and top efficiency and functionality of overmolded products, overmolding is also popular for other reasons.

The following are the other production possibilities made possible by overmolding:

  • Better grip and feel of the product
  • Durability and increased product longevity
  • Lessened vibration and shock
  • Makes a softer product exterior
  • Generates better electrical insulation
  • Provides better UV and chemical resistance
  • Significantly reduces cost of production

Of course, there are other reasons to choose overmolding that were not listed here. For professionals who have been in the overmolding industry for long, the list goes on.

But in so far as basic knowledge on the possibilities offered by overmolding, this list is for your reference.

Explanation of Overmolding Process

Explanation of Overmolding Process

As has been mentioned, overmolding is the process of forming one, durable and uniform product by materials molded over other materials.

Overmolding is made possible by a specific level of heat and temperature so that the parts that are combined would stay intact.

There are two known types of overmolding: multiple material molding and insert molding. The latter is a more common choice in production.

In insert molding, there is already a pre-molded part which will be re-inserted in the machine for another molding.

On the other hand, multiple material molding makes use of a molding machine with at least two barrels. This allows two materials to be molded in the same plate in just a single cycle.

Materials Commonly Used in Overmolding

Materials Commonly Used in Overmolding

Just like the possibilities offered by overmolding, the materials used in the process are also virtually infinite.

Nevertheless, the following are the most common materials used in overmolding:

  • High-density polyethylene (HDPE)
  • Acrylonitrile butadiene styrene (ABS)
  • PEEK Resin
  • PEI Resin
  • PBTR Resin
  • Acetal copolymer
  • Polymethyl methacrylate acrylic (PMMA)
  • Nylon
  • Polycarbonate (PC)
  • Silicone
  • Thermoplastics

Importance of Overmolding for Product Manufacturing

From a general view, there are various benefits of overmolding for product manufacturing. One of the significant importance of overmolding is that it creates a uniform and durable product which in turn enhances product value.

Importance of Overmolding for Product Manufacturing

Most importantly, overmolding adds more functionality, aesthetics, and ergonomic value to products thanks to its ability to make a seamless fit out of various materials and parts.

In the succeeding sections, more benefits of overmolding in product manufacturing shall be discussed. As such, let us leave it with this general importance of overmolding for product manufacturing.

Benefits of Overmolding

Benefits of Overmolding

Overmolding, as have been laid down, is a popular and cost-efficient method in production. As is the case, it is right to present further some of the specific benefits of overmolding.

In this section, we look at five of overmolding’s benefits to products and producers.

Improved Product Quality:

There are many reasons why overmolding could improve product quality. First, overmolded parts have that multiple material advantage.

As such, you can expect that the finished product of overmolding is more durable, more efficient, and functional, chemical resistant, water-resistant and more.

Aside from these, it also enhances the grip and feel of finished products, hence, more ergonomics.

Enhanced Product Functionality:

Enhanced Product Functionality

Because of the multi-material advantage of overmolding plus the durable, uniform parts that it creates, expect enhanced product functionality from this production method too.

Just imagine the overlap of two materials with combined functional properties. The result is a more functional finished product.

Increased Product Durability:

One of the reasons why overmolding increases product durability is it enhances shock absorption. This is because the finished product is infused with an extra layer of plastic or resin material.

As an effect, the product just does not have greater durability but also longevity, increasing dramatically the shelf life of finished products.

Further, tests and reports also widely indicate that overmolded products have greater resistance to elements and inevitable physical impacts.

Reduced Assembly Time and Costs:

Reduced Assembly Time and Costs

This is perhaps the most upfront benefit of overmolding for producers. Note that in overmolding, multiple materials are molded in just one cycle.

As such, multi-part production and assembly is basically expedited. Because of this, the post-assembly face is entirely eliminated, thus, lessening press time, machining, and the overall operations cost of the finished product.

Overall, overmolding is a highly productive method with lots of benefits. There is no wonder as to why consumer products production and many other fields are choosing overmolding to be one of their indispensable and go-to methods in their production lines.

Applications of Overmolding

From the on-set, the applications of overmolding have been overly emphasized. It cuts across various fields but remains to be a mainstay in consumer production and automotive industries.

But there is so much more when it comes to this production method so here are the most common applications of overmolding.

Automotive Industry:

Most of the vital parts of automobiles are produced in a multi-material fashion. As such, overmolding is a key process in the production of such. Some of the automotive parts which need overmolding are gears, sensors, and fasteners.

Automotive Industry

Some smaller gears are also created with the combination of metal and plastics, hence, the dependence on overmolding.

Consumer Electronics Industry:

By just looking at the internal pieces of your small appliances and cords, you can already see the multiplicity of materials used to create them.

Consumer Electronics Industry

The multiple plastic and rubber parts of consumer electronics like wires, chargers, and adapters are made possible by overmolding.

Healthcare Industry:

This is another field which reaps the benefits of overmolding. Most of the high-end medical facilities and equipment are now produced through overmolding. The reason for this is that overmolded plastics and rubbers are easier to disinfect and sterilize.


As such, you would see in hospitals nowadays that cables, wirings, and equipment such as defibrillators, pacemakers, equipment for colonoscopy, medical imaging and sensors are now encased in medicine grade plastic casings which are made through overmolding. 

Aerospace and Defense Industry:

Aerospace and Defense Industry

The aerospace and defense industry is now advancing to lightweight, high insulation technologies. These two key words already allude to the benefits of overmolding.

These fields are dependent on composite polymers, other plastics, and resins. Overmolding, specifically injection molding, are now mainstays in the production of parts and equipment used in aerospace and defense.

Challenges in Overmolding

Challenges in Overmolding

Overmolding is not a perfect process nor an industry. It also has its fair share of imperfections and challenges encountered. The following are the most common limitations in overmolding as a process.

Material Compatibility:

Compared to conventional single molding, you would need two different materials in overmolding. The problem with this is that not all materials are compatible with each other.

If you are in a trial-and-error mode, material incompatibility adds to the costs of developing the design or the finished product. For instance, some specific elastomers have difficulty bonding with other plastics.

Thus, make sure that you know the proper mix and match of materials to avoid unnecessary costs.

Design Considerations:

Overmolding is beneficial for uniformly designed products at a bulk quantity. Hence, you must be wary of some design considerations. The more geometrical your designs are, the more that you should just resort to single molding.

Note that the more intricate the design is, the longer the press time, hence, greater costs if you overmold.

Tooling and Equipment Limitations:

You also must know that overmolding requires some specified tool and equipment. Most of this equipment is hard to find and most start-up companies may have a difficulty in accessing them.

Thus, aside from the previously mentioned limitations, this is also one of the most important challenges to bear in mind.

Impact of Overmolding on Profits

Impact of Overmolding on Profits

Given everything that we have covered, the impact of overmolding on your profits should also be emphasized. As a general take, the following are the most immediate effects of overmolding on company profits.

Reduction in Production Costs:

This aspect has been overemphasized. The shorter lead time, mass production, and shorter press time in overmolding allows you to lessen the overall cost of production.

The lack of need to still go through post-molding assembly is one of the main reasons which will upend your profits through overmolding.

Improved Product Performance:

Of course, the high functionality, durability, and high performance of the finished products of overmolding lead to greater profitability.

This is another benefit of overmolding which is also obvious. And at an expedited bulk production, you can sell improved products with evolved performance at a higher value.

Increased Consumer Appeal:

The ergonomics, better grip and handle, softer exteriors, high shock absorption, and overall aesthetics due to the different finishes that can be incorporated in overmolded products are some of the major reasons of raising consumer appeal among these products.

Whether you admit it or not, aesthetics is an important marketing strategy. The fact that overmolding can insert your desired aesthetics in your product designs without compromising functionality is already determinative of more cash in the bag.

Is Overmolding Right for Your Project?

Is Overmolding Right for Your Project

While we have said time and again that there are a lot of possibilities which come from overmolding, the project at hand is still determinative if it is an appropriate process or not.

When considering overmolding, the following factors should be kept in mind:

Product Design:

If you need uniform mold designs or product designs at a bulk, then overmolding is right for your project. Otherwise, it is expensive.


The overmolding appropriate materials have been listed here. While they are not exclusive and a more thorough list could still be searched, it only emphasizes that not all product materials are overmolding friendly.

Thus, if the material at hand is not in any of the lists, then you should not consider overmolding at all.

Tooling and Equipment Costs:

Note that overmolding still needs tooling and works on equipment. Again, if you are not working on a bulk order or if you are working on a specific design with lots of geometrics, then overmolding is not right for your project.

Labor Costs:

Labor Costs

Drawing from tooling, equipment, and project design, labor costs are also tough to consider. This includes maintenance of the equipment, coming up with mold designs, molding materials together to get the geometry right and more.

If you are on a tight budget but want intricacy in your finished product, you might forego overmolding for a while.

Production Volume:

Time and again, if you are not working on a large product volume requiring uniform design and parts, overmolding might not be the best solution to expedite the production and to capitalize on cost-efficiency.


Overmolding is a popular production process and all for the right reasons. Although it might not be applicable to all projects, large producers and companies could really cut costs using overmolding.

Aside from the glaring cost benefits, it also enhances finished products. This is in terms of durability, longevity, functionality, and added aesthetics and ergonomics.

With all things considered, overmolding means better, more cost-efficient production and end products which could generate you more profit.

Prototyping Using Overmolding From Kemal

Prototyping Using Overmolding From Kemal

If you are looking for efficient prototyping using overmolding, you can check the services of Kemal Manufacturing.

They offer state of the art prototyping, with high precision techniques, and top of the line tooling and equipment. Most importantly, they provide competitive and reasonable pricing for your prototyping needs.



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