Overmolding: Chemical and Mechanical Bonding

Chemical Bonding

This bonding process involves two chemically compatible materials that are molded together to form a strong bond with each other. It’s important to note that not all materials play well with one another. The compatibility chart below indicate whether a chemical or mechanical bond is recommended for key thermoplastic and thermoset materials.

Mechanical Interlocking

What happens when your materials are not compatible, the desired bonding strength cannot be achieved, or you want to ensure your materials don’t peel apart from repeated use? This is where designing a mechanical interlock, which physically holds the overmolded material to the substrate, makes sense. There are many ways to design these into parts (see example), so discuss the options with your manufacturer.