Overmolding is a two-part process where a layer of material, usually a rubber-based liquid silicone (LSR) or thermoplastic elastomer (TPE), is molded over another component. Typically the base component part is first placed in the injection mold and the hot molding material fills the area around the inserted part. The result is an assembled product.
Over-molding or Two-shot molding:
Overmolding is a process that results in a seamless combination of multiple materials into a single part or product. In addition, it typically includes a rigid plastic base component overlaid with a soft thermoplastic elastomer. Usually, this soft plastic is TPE or TPR. Overmolding adds value in several ways. In addition, it lowers production costs. As a result, the advantages of using overmolding are numerous:
It results in a soft anti-slip grip that prevents dropping and at the same time it functions as a shock barrier to maximize product life.
We create visually attractive surfaces and branded color schemes that increase shelf appeal. In this way, a nicer design provides a competitive advantage.
Over-molding reduces the number of required manufacturing steps and associated costs.
Overmolding is extremely versatile. Common household items such as hand tools, toothbrushes, and razors may have overmolded handles for better grip. In addition, over-molding may also be used to bond gaskets or seals to a plastic cover.
In co-injection molding, we inject the hard substrate and the elastomer into the same mold. Therefore compatibility between materials is essential and it must be carefully controlled.
Co-Injection is very expensive and difficult to control. It is used least comparing with the other 2 methods. The hard and soft substrates are in a fully molten state. Therefore it provides the best bonding between soft and hard parts, the molded parts quality is also the best.
At JSK Industrial Supply we control this production technique very well. Here is what we can do for you:
We do the injection of plastic around a metal contact to make connectors or terminal blocks.
Injection of soft plastic around an electric cable to make cable splits, connectors, and grommets.
We inject plastic around printed circuit boards to make encapsulated or watertight electronics.
Overmolding of soft or hard plastic over metal parts to make a solid assembly between metal and plastic.