Solvay Debuts New Concepts for Sterilization Cases and Trays

Responding to OEM concerns about production costs and time to market, Solvay Specialty Polymers has teamed with a Dutch company to develop designs for sterilization instrument cases and trays made of Radel polyphenylsulfone (PPSU) resin instead of metal.

Solvay (Alpharetta, GA) will collaborate with Promolding BV (The Hague) on two original design concepts that do not use stainless steel or aluminum. One concept uses injection molding, a cost-efficient alternative to standard thermoforming. The other involves a method for positioning and securing instruments in the case’s inner tray.

Solvay introduced the design ideas at the American Academy of Orthopedic Surgeons (AAOS) conference in Chicago this past March. The injection-molding concept uses only five components to build full-DIN, ¾-DIN, and ½-DIN cases. Molding facilitates high hole counts, which reduces surface area to avoid wet-pack and produces cases that weigh less than metal ones, Solvay says.

The tray design process involves positioning instruments in a pin-bed, scanning their topography into a computer, and replicating the image with CNC equipment onto the surface of a honeycomb insert molded from Radel PPSU. The structure supports large instruments and the use of inserts for smaller instruments. Because instrument changes can be made without reconfiguring the tray’s brackets or rebuilding the tool, the process expedites time to market, Solvay says.

Promolding specializes in design, engineering, and injection molding. The partnership between Solvay and the Dutch company grew out of a successful collaboration on an aircraft serving trolley, says Jill Sanders, Solvay’s sales development manager. Radel PPSU is the “material of choice today for sterilization cases,” she says, noting that companies prefer plastics because they’re lighter than metal and allow for the use of color. “Color is important to OEMs because they appreciate the ability to have special branding,” Sanders says. Anodizing metal for color is expensive, and the color is prone to scratch off, she says.

Radel PPSU’s performance characteristics make it a “great fit” for sterilization cases, Sanders says. The material is chemical resistant and withstands disinfection and repeated autoclaving. She says Solvay is in the early stages of investigating the use of other resins in its portfolio.

AAOS attendees responded positively to the design, which Sanders says standardizes manufacturing of the trays and makes the process more efficient. “Generally speaking, people move to plastics because of the cost efficiencies,” she adds. The savings depends on the number of parts used as well as tooling and set-up costs.

Solvay is sharing the two concepts with case and tray manufacturers and device OEMs around the world. The designs are protected in North America, South America, Europe, and China, so OEM customers can use Radel PPSU to manufacture products with these concepts without charge. Solvay has shared the concepts with “the top five or six orthopedic companies” and is working “with one of the large orthopedic OEMs on a huge project,” Sanders says.

—John Conroy is a frequent contributor to MD+DI. Reach him at [email protected].