Materials: Self-Bonding LSR Optimizes Overmolding with Specialty Copolyester

An innovative self-bonding liquid silicone rubber (LSR) technology fromMomentive Performance Materials (U.S. office in Waterford, N.Y.) has been designed to optimize the properties of medical grade Tritan—the proprietary amorphous copolyester from Eastman Chemical, Kingsport, Tenn., without the need for primers.

Silopren LSR 47x9 series takes advantage of the lower Tg of Tritan. Its ability to cure at relatively low temperatures in a single-step molding process creates a sweet spot that can shorten cycle times and reduce input costs. Unlike other medical polymers, Tritan complements Silopren LSR’s chemical resistance—reportedly creating a dynamic duo with no material compromise for applications that demand compatibility with powerful disinfectants and solvents.

 With what is said to be the first commercially available process of its kind, molders can use Silopren LSR 47x9 LSRs to provide strong in-mold adhesion with transparent and opaque Tritan—without the need for primers. So, it’s said to be more efficient than ever to add a soft touch to the Tritan advantages of chemical resistance, impact strength and durability, clarity and color retention, and design flexibility. The process is ideal for applications that require handling comfort, waterproofing, durability, aging stability, and other properties. This includes such applications as: respiratory devices; sealing elements; gaskets for joints in housings and hardware; vibration reduction; and, membranes and lenses for electronic device housings.