Plastic Injection Overmolding Manufacturer

FCE is an expert in providing customers with high-quality precision plastic injection overmolding parts. It has rich experience in precision injection molding and molds. With its superb technical level, we can provide high-quality overmolding services to meet all industry recognized standards. As a company in China, certified by ISO 9001 and IATF 16949, we know the characteristics of various plastic materials very well. We will provide you with professional overmolding services, From reviewing your design to delivering high-quality molds and plastic parts.

What is overmolding?

Overmolding is a unique injection molding process that combines two or more components together. It is the best practice for the production of multi-color and multi-layers products.

Overmolding process and characteristics

Compared with bonding with third-party materials, the secondary molding process makes the process faster and more cost-effective. Therefore, it has been widely used in plastic structure design. During overmolding, the surface of soft and hard segments is softened, the molecular diffusion of outer elastomer and engineering plastics must be compatible with each other, that is, they cannot reject each other’s molecules. With the increase of molecular mobility, the molecules of the two materials diffuse each other, resulting in melting adhesion. Finally, a cohesive bond is formed in the surface layer network.

Overmolding process is used in many industries, including medical, aerospace, national defense, electronics and automobiles. Overmolding can be used for aesthetic or functional purposes, depending on end use requirements. Many types of thermoplastic materials can be re molded, including soft plastics such as polyurethane and TPE, and hard plastics such as nylon and polycarbonate. In key defensive injection molding and high-end electrical connector molding applications, overmolding is widely used to strengthen, protect and improve products, and reduce costs by reducing labor and materials.

Classification of overmolding

There are three kinds of overmolding: Insert molding, Two-shot Molding and Co-Injection Molding.

Insertion molding: the most commonly used overmolding method to inject soft elastomer to hard engineering plastic at present. Insertion molding has the characteristics of minimum hardware configuration and investment. In the insertion design, the hard segments have been pre separated and put into the tool, and the elastomer is injected again. The advantage of insertion molding is small thermal expansion and contraction, while the disadvantage is that it requires independent mold and substrate inventory, which often needs to be prepared several days or weeks ago.

Two-shot Molding: This process requires two injection molding machines and expensive and complex molds with many gates and sliders (rows). The hard segment is first injected, and then led to the elastomer injection molding machine by the mold, where the injection molding of the elastomer to the hard segment substrate is completed.

Co-Injection Molding: In co injection molding, hard substrate and elastomer are simultaneously injected into the same mold, and the elastomer migrates to the outer layer. Compatibility between materials is critical and must be carefully controlled. Co-injection molding is very expensive and difficult to control. It is also the least used of the three secondary molding methods.

In order to ensure the effective operation of overmolding process, the mold must have strict tolerance. This dual injection process also requires the selection and use of compatible materials to achieve excellent mechanical and chemical combination. Our technicians are very familiar with many different products of overmolding. With our experience and technical background, we can help customers reduce working hours from the cost of assembling products, while making significant improvements in quality, integrity and reliability. FCE is your real one-stop shop for overmolding parts.

Ask for quotation or contact us to provide professional overmolding injection service for your project.