Anaheim, Calif. — Teknor Apex Co. has launched a next-generation series of medical-grade thermoplastic elastomer compounds for producing seals and gaskets for medical devices, as well as parts for consumer health wearables.
The latest Medalist-brand compounds are an outgrowth of development at the Pawtucket, R.I.-based company and have been optimized in three ways, said Ross van Royen, senior market manager in the TPE division.
He discussed the new TPEs at the Feb. 11-13 Medical Design & Manufacturing West show in Anaheim.
"We came up with enhancements to the materials so they resist chemicals in lotions and disinfectants much better," van Royen said. "They also can bond to a broader range of substrates and the bond strength is better."
The TPE compounds hold up well to chemicals in sunscreens and moisturizers, as well as bleaches, peroxide, acids and alcohols generally found in disinfectants used in wipe-down environments at room temperature, van Royen said.
Medalist TPEs bond with substrate mainstays like polycarbonate and ABS, as well as copolyester, to form the grips and handles of home health care items and surgical tools, along with the buffering trim of wearables.
The compounds also are excellent alternatives to liquid silicones used in over-molding, van Royen said, noting that silicone is generally molded independently and then assembled into the part, while TPE materials can be two-shot manufactured into parts.
"Completed parts come out of the machine," van Royen said. "You eliminate the step where you put a primer on, then the adhesive on, and then you assemble it. There's no secondary step where you're manually gluing parts together, which shortens the cycle time and reduces assembly labor."
Tooling costs are higher for two-shot molding compared to the single-shot process with manual assembly, but the investment makes sense for high-volume runs where the cost of the machine can be amortized over more parts, van Royen said.
The compounds make suitable trim to buffer the engineered plastics in wearables that can be easily bumped or dropped.
"Protecting devices is a common application, and other times it's used for pure aesthetics," van Royen said. "It just looks better and the touch-feel aspect is more pleasing."
Medalist TPEs also can be used for medical devices that undergo ethylene oxide sterilization or gamma sterilization.