Solvay Develops Innovative Design Concepts For Production Of Sterilization Cases And Trays

Solvay Contracts with Promolding BV to Create Less Costly and More Efficient Designs Using Radel PPSU Resin

Alpharetta, GA - Solvay Specialty Polymers has contracted with polymer design, engineering, and injection molding firm Promolding BV, the Netherlands, to generate several original design concepts for the manufacturing of sterilization instrument cases and trays using Radel polyphenylsulfone (PPSU) resin instead of stainless steel or aluminum. These concepts were unveiled March 21 at the American Academy of Orthopedic Surgeons (AAOS) in Chicago and are being shared globally with case and tray manufacturers and medical OEMs.

The first concept takes advantage of the cost efficiencies of injection molding versus thermoforming, which has been the standard manufacturing method for this application since the mid-1990s. Responding to growing cost pressures from medical OEMs, this injection molding concept uses just five molded components to build full DIN, ¾ DIN, or ½ DIN cases.

High hole count, which is facilitated by injection molding and difficult to achieve after thermoforming, reduces surface area to avoid wet-pack and further lowers overall case weight versus metal. Snap-fit features allow quick assembly, and unlike thermoforming, a matte surface finish can be readily achieved to reduce glare from operating room lights. The use of colored resins allows for branding opportunities without the added cost of anodizing metal, and material transparency offers another design option.

The second concept offers an innovative strategy for positioning and securing instruments in the inner tray. Instruments are first laid in a pin-bed for positioning. The surface topography is then computer scanned and replicated using automated CNC equipment onto the surface of a honeycomb insert which has been molded or extruded from Radel PPSU. The honeycomb structure provides exceptional strength in the vertical direction for supporting large instruments, while inserts with varying cell sizes can be used to accommodate smaller instruments.

This system speeds time-to-market after instrument design is complete, with future instrument modifications easily incorporated without the need to reconfigure brackets or rebuild the tool. Radel PPSU is the material of choice for sterilization cases and trays because of its toughness, excellent chemical resistance, and ability to withstand repeated disinfection and autoclaving – over 1,000 cycles – while maintaining its toughness and impact resistance.

Solvay Specialty Polymers has been granted design protection for these concepts in North America, Europe, and China, thus allowing customers to use Radel PPSU in these designs at no charge. Solvay Specialty Polymers is a global leader in the development of sulfone polymer technology, launching Udel polysulfone nearly 45 years ago. In addition, Solvay’s experience as a key materials supplier in the healthcare field spans more than 20 years. The company is a leading manufacturer of high-performance plastics, offering a broad range of materials for healthcare instruments and medical devices. More recently, Solvay has successfully introduced its line of Solviva Biomaterials and offers them for use in a range of implantable devices.