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 overlaid with a thin, pliable, rubber-like thermoplastic elastomer (TPE) exterior layer or other materials using either a single-shot (insert molding) or two-shot (multiple-shot molding) technique.
Increasingly popular with manufacturers, you may find overmolding to be a great option for your next project when you consider the significant advantages it provides.
Manufacturers that want to add a soft-touch exterior to their products that enhances grip or “feel” and that provides a stylish appearance attractive to consumers are prime candidates for overmolding. Overmolding also reduces shock and vibration, dampens sound, provides electrical insulation, and improves chemical/UV resistance — which increases product longevity. Overmolding also lowers production costs despite improving product viability and customer satisfaction.
Here's a more in-depth look at its distinct advantages:
Better product performance
A primary reason to design and manufacture a product or part using overmolding is improved product performance.
TPE is an ideal material for creating a soft, non-slip grip for any number of products where tactile sensitivity is not just comfortable but critical, as in the case of medical products such as surgical instruments.
Plus, a TPE surface can act as an environmental barrier to protect a product and extend its shelf life by reducing shock, vibration and noise — key benefits of overmolding.
Increased shelf appeal
Overmolding helps a product stand out from the competition, since TPE can be used to create a visually attractive surface. TPE comes in a wide range of colors, and it can be engineered for different finishes. Clear TPE surfaces that may carry a corporate logo, message or operation instructions can also be overmolded on patterned or customized substrates.
Lower production costs
Overmolding is rare in that it adds value in several ways yet also lowers production costs.
How? Overmolding reduces the number of manufacturing steps involved. In the automotive market, for example, it can eliminate the need for injection molding and assembly for components (such as gaskets or bumpers), as well as secondary finishing operations (priming, painting or coating).
Is overmolding right for your project?
Overmolding is appropriate for many applications, but several factors must be weighed before determining if it's the best solution, including:
- Product design
- Materials selection
- Injection molding tooling quotes and equipment budgets
- Labor costs
- Production volume
Partnering with an experienced custom injection molder — especially one with scientific molding expertise, like Kaysun — will help you navigate the pros and cons of using overmolding on your project, and collaboratively guide you to the best decision for your application and bottom line.
To learn more about how overmolding can improve performance and aesthetics while lowering production costs, read our Overmolding Fundamentals whitepaper. Click the button below to access your free copy today!