Overmolding is a special plastic molding process, it’s a two-step injection molding process of adding an additional layer of material over an molded part to enhance a product’s features. First, a plastic component is produced using plastic injection molding process. After the part has cooled, it is placed into an overmolding tool where it is then coated with molten thermoplastic (TPE) or rubber (typically a rigid plastic). If properly selected, the TPE overmolding design will permanently form a strong bond with the plastic that is maintained in the end-use environment. The use of primers or adhesives is no longer required to achieve an optimum bond between the two materials. Overmolding process makes the process faster and more cost-effective, it has been widely employed in plastic design.

Overmold materials (typically plastic) start off in pellet form. These pellets are mixed with additives like colorants, foaming agents, and other fillers. They’re then heated to their melting point and injected into the mold tooling as a liquid. There are some limitations on what materials are suitable for overmolding. The most used are as following:

• HDPE
• ABS
• PMMA (Acrylic)
• Acetal Copolymer (POM)
• PEEK
• PEI
• PBTR

Overmolding is a value-added injection molding method for improving plastic and metal substrate performance and aesthetics. The products manufacturerd by two-shot molding process are widely used in many fields of industry such as medical, automotive, military industry and more.

Our company is a professional manufacturer of plastic injection molding and overmolded parts in China. The company is mainly engaged in the R & D, design and manufacturing of plastic injection mould/two-shot molding, as well as component assembly business, and is committed to providing customers with high-quality comprehensive services in overmolded part design, overmolding electronics and more injection molding plastic products assembly. The options of our two-shot injection molding creates are endless, we have the ability to use the materials and colors you want to make your parts look and function perfectly.

We also have extensive knowledge of plastic materials including thermoplastics and exotic resins to help you choose the suitable materials for your injection overmolding part. The various materials we use, the precise capabilities of our overmolding machine, and our plastic injection mold design services make our overmolding process extremely customizable. We can meet all your plastic needs.