Steel, brass, aluminum, or plastic subcomponents are often incorporated into rubber over-molded parts. These subcomponents are commonly termed “inserts”, as they are inserted into the mold. Typical metal inserts include screw machine parts, metal stampings, and powdered metal shapes.

The production of molded rubber parts containing inserts involves considerable preparation before and after molding. Steps may include cleaning and etching of the insert surfaces, masking and unmasking, application of adhesives, and de-flashing. Careful design of the insert can help to ensure a durable finished part while minimizing production costs.

Our chemist and engineers work together to design a process to ensure proper adhesion between the substrate and rubber material. In many applications we achieve bond strength that exceeds the tear strength of the rubber material.

Robinson Rubber has developed several different ways to test rubber to bonded parts. Sometimes these tests are destructive and can be done with a hydraulic press that applies or records pressure applied. Depending on the application and the direction of force versus the direction of the bond, we can work with you to develop periodic testing that can reduce or eliminate the possibility of parts failing in application.