Pilot runs, low-volume production, bridge tooling
Overmolding is a process where a single part is created using two or more different materials in combination.
There are a lot of reasons to overmold. Among the most common are the following:
As a means to break up the color (aesthetic impacts).
To provide a soft grip surface around a part of a separate material.
To add flexible areas to a rigid part.
To eliminate assembly line time. Instead of manufacturing a metal tool and a plastic handgrip separately and then joining the two together manually or with automation, you can just overmold the metal tool with a plastic handgrip and eliminate the need for assembly altogether.
To capture one part inside of another without having to use fasteners or adhesives.
With overmolding, the production of the substrate parts is a standard injection molding process involving an aluminum mold with no heating or cooling lines running through it. Cycle times are a bit longer, which allows our molders to monitor fill pressure, cosmetic concerns, and the basic quality of the parts. When the total run of substrate parts are molded, overmold tooling is then assembled to the press. The substrate parts are placed by hand into a mold where each part is overmolded with either a thermoplastic or liquid silicone rubber material.
Simply put, overmolding lets you combine multiple materials into one part. One material, usually a thermoplastic elastomer (TPE/TPV), is molded onto a second material, which is often a rigid plastic. Think about your toothbrush handle where the single piece has both rigid and rubbery components. It’s a great way to make plastic parts perform and look better.
We have a team of skilled engineers ready to support you in your product development journey from prototyping to production.