What Is Overmolding and Why Is It a Good Choice?

Posted by Kaysun Corporation on Jul 21, 2015 12:00:03 PM

blank.pngThinking Overmolding? Here's Why It's a Good Decision

If you’re contemplating whether to choose overmolding for your next product or part but aren’t 100 percent sure, it never hurts to think and then rethink. But to remove any shadow of doubt, here’s why overmolding will only continue to grow in popularity - and why it’s a solid choice.

What is overmolding again?

Overmolding is a unique injection molding process that results in a seamless combination of multiple materials into a single part or product. It typically includes a rigid, plastic-base component that is overlain by a thin, pliable, rubber-like thermoplastic elastomer (TPE) exterior layer or other materials. Two types of overmolding techniques used to combine the TPE layer and plastic substrate are single-shot (insert molding) and two-shot (multiple-shot molding).

Better product performance

If there was ever a reason to design and manufacture a product or part using overmolding, improved product performance definitely qualifies.

Better product performance has a lot to do with TPE. It’s an ideal material for creating a soft, comfortable non-slip grip for any number of products where “feel is everything.” A classic example is when it’s used with medical products like surgical instruments where tactile sensitivity is not just nice, but critical.

Overmolding also reduces shock and vibration, as well as noise. Additionally, it provides electrical insulation and improves chemical/UV resistance. What’s more, an exterior TPE surface can act as an environmental barrier to protect a product and extend its shelf life.

Increased shelf appeal

Another reason overmolding is likely to become even more popular is because it delivers the desired look and helps a product stand out from the competition.

Increased shelf appeal stems from the ability to use TPE to create a visually attractive surface. It comes in a wide range of colors, can be tinted, and engineered for different finishes, such as matte or gloss. Clear TPE surfaces can also be overmolded on patterned or customized substrates, which might carry a corporate logo or message.

Lower production costs

Although it’s rare for something to add value in so multiple ways with less production cost, overmolding gets it done.

Manufacturers achieve lower costs with overmolding because it reduces the number of steps involved in making the product. In the automotive market, for example, it can eliminate the need for injection molding and also assembly for components like gaskets or bumpers. Additionally, it can eliminate the need for secondary finishing operations, such as priming, painting or coating.

Complexity dictates good decision-making

With any part or product used in complex or challenging applications, there are more than a few key decisions to be made – and overmolding is no exception.

Among the considerations are product design, materials selection, injection molding equipment used in the process, mold budgets, labor costs, and production volume. Clearly, there’s a lot to overmolding but that’s why there are injection molders who excel at it.

So the question now might not be whether to design a part or product that involves overmolding, the question is when.

To learn more about all that goes into overmolding and the keys to success, click here to download our free “Overmolding” white paper.