Insert molding can best be described as injection molding a plastic material around an insert of a different material or substrate. This process is commonly used for a wide variety of products in practically all market segments. The inserts are can be made from many different types of materials and geometric shapes. Some examples of insert molding are; fasteners, electrical connectors, terminals, filters, bushings, bearings, and component strengthening.
Linear Shuttle Press
Imperial Plastics utilizes Linear Shuttle presses. In this type of insert molding the mold has one cavity half and two core halves which are secured to a table and shuttle back and forth. The inserts are loaded in the core half of the mold. This process is used for higher volume parts and or where the inserts cannot be held securely in place in a horizontal machine and is also typically used for smaller parts.
Rotary Shuttle Press
Imperial Plastics also utilizes Rotary Shuttle presses. The Rotary Table design can have up to 4 core halves mounted to a rotary table which rotates each cycle either 90 or 180 degrees. This method is typically reserved for medium to smaller parts requiring multiple inserts which require more time to load into the mold thereby keeping the overall cycle time to a minimum which in turn is the most cost effective method of insert molding in most applications.
Standard Injection Press
Conventional horizontal injection molding machines can be utilized for insert molding as well. An operator or robotics place the insert in the molding cavity and then the press is closed up and the plastic material is filled in around the insert.