Co-injection is the process of injecting two resins simultaneously through a single gate to form a multi-layer structure. This advanced molding technique has been used for a couple of decades with some success in specialized applications like ketchup containers, stadium beer bottles and medical vials. However, recently there has been a re-emergence of interest in co-injection technology spurred on by the development of new resins, barrier systems, controls and hardware technologies.
Co-Injection in Action
Historically, co-injection workcells have been highly specialized dedicated systems with high capital cost to start with. Now there are new solutions coming on the market, which will allow molders and moldmakers to create co-injection systems at a radically different cost because they are now able to use their installed workcell base and standard molds for the solution.