Insert molded plastic is a type of plastic made from the process of injection molding. The plastic material is injected into a cavity or mold and surrounds some type of an inset that is placed in the same mold before the plastic is melted. This particular molding process was originally created to encapsulate wire-plug connections inside electrical cords. There are now many uses for insert molded plastic materials such as threaded fasteners, bifurcations and other types of electrical components that need to be encapsulated.
Insert molding, overmoldingInsert molding is the process that creates insert molded plastic products. The process uses a specific mold that opens as it cools to release the finished product. Additional work, such as circuit testing or die cutting, may be needed.
Automatic moldAn automatic mold is a mold that can repeatedly go through the molding cycle without any assistance from an operator.
A-side, stationary sideThe A-side, or stationary side, of a mold is the half that mounts to a fixed part on the molding press. The A-side of the mold does not contain the ejector pins to make the visual side of the mold.
Ejector pin, ejector sleeveAn ejector pin is a sleeve, blade or pin that pushes the finished material out of a mold. The pins are attached to an ejector plate that is actuated by a press or auxiliary air cylinders.
Ferris State University provides an animation of how an ejector sleeve works.