Low-volume injection molding isn’t limited to just simple parts. At Proto Labs, we have the ability to manufacture complicated parts using side-actions, hand-loaded inserts, overmolding, and have now started beta testing our insert molding process.
Instead of a mold that produces a final part using two separate shots like overmolding, insert molding generally consists of a preformed part—often metal—that is loaded into a mold, where it is then overmolded with plastic to create a part with improved functional or mechanical properties.
One way insert molding is leveraged is with threaded inserts, which reinforce the mechanical properties of plastic parts’ ability to be fastened together, especially over repeated assembly. Self-tapping screws work well with softer plastics, but they can become easily worn and/or cross threaded, and fail to perform well, which results in damaged parts that need to be replaced.