Insert molding, or “overmolding” is one of several plastic injection molding processes that can be used to combine different materials within a single part. Unlike two-shot injection molding, this process uses pre-existing parts, usually metal or a more rigid plastic, to form the substrate around which the more flexible plastic polymer is injected. For example, USB drives are often made using this process, with the plastic component that gives the drive its size, shape, color, and texture molded around the metal piece that houses the electronic components.
Benefits of Overmolding:
Overmolding allows you to combine multiple materials into a single part. Once molded, the bond between these two materials is much more durable than if they were to be combined in separate stages of the manufacturing process, so they won’t separate if the part is dropped or damaged. This feature makes plastic parts much more versatile, as you can easily add metal components, plastics of different textures and rigidity, and even plastics of different colors to achieve the desired effect.
Products made with overmolding:
- Toothbrushes
- Tape dispensers
- USB drives
- Medical devices, like defibrillators and pacemakers
- Cosmetics packaging
- Electrical wires
- Automotive paneling
- Bowling pins