Our customer needed to produce an industrial electronics enclosure in large quantity, that featured two overmolded threaded brass inserts into which fasteners could be threaded for mounting the component. The part required a glass-filled resin for strength, but still needed to be molded within critical flatness tolerances.
Since the product required high volume production, we created a fully automated process for the part using a transaxial robot to load the two brass inserts into the injection mold. The inserts were preheated before inserting into the mold to achieve a perfect match with the elevated mold temperatures. The preheating process minimized warpage and unwanted stresses which can occur in the plastic part if a cold insert was overmolded. The insert molding process produces a robust thread feature within a plastic part without the need for unscrewing mechanisms.