UPCOA has a strong background in over-molding both liquid silicones, thermoplastic urethanes (TPU’s) and thermoplastic elastomers (TPE’s).

Insert molding (sometimes called over-molding) consists of placing a metallic or non-metallic substrate into the mold and injecting the elastomer around it. Each elastomer requires a different method of bonding to the substrate.

The two best bonding methods are chemical or mechanical. Chemical bonding involves applying an adhesive to the insert to join the silicone and metal. In mechanical bonding, locks consisting of holes or grooves are machined or molded into the insert, allowing the silicone to flow into the locking area creating the bond. The strength of the bond is also affected by several factors: interface temperature, cleanliness of the insert, and melting temperature of the TPE or TPU.

UPCOA is skilled in high volume bonds using robotic pick equipment and reel-to-reel applications as well as lower volumes where inserts can be hand loaded.