Anaheim, Calif. — Jeff Hrivnak made a rational case on utilizing specialty polymers instead of metal in a presentation at the UBM Advanced Manufacturing expo in Anaheim.
In discussing material substitution issues, he outlined the benefits of polymers including a material's performance and the total cost of ownership. Hrivnak is global business manager for health care at Solvay's Specialty Polymers business unit in Alpharetta, Ga.
In one example, Hrivnak described conversion of a large portion of a program from steel to plastic. The program had 200 parts per stock keeping unit and needed about 200 SKUs per year. Steel parts were $98 each with annual production at $3.9 million. Injection molded reusable plastic parts would cost $23 each. One-time purchasing of molds was about $2 million, and production of the plastic parts would be about $920,000 per year with tooling cost being recovered in eight months. After the amortization, the user would save $3 million per year per 200 SKUs for the remainder of the program's life.
For conversion of a surgical hip retractor, Hrivnak showed how an Ixef polyarylamide single-use retractor and an AvaSpire polyaryletherketone reusable retractor could attain the stiffness of a steel retractor. The size of the plastic ribs was modified and tested until the Ixef PARA single-use design and the AvaSpire PAEK reusable design achieved 125 percent and 75 percent, respectively, of the metal retractor's stiffness. In another design iteration, a large handle was added to improve ergonomics with the rigidity of the thicker handle providing stiffness required at the back end of the retractor. SolidWorks simulation software was used for mechanical testing.
Separately, Hrivnak discussed how Legacy Medical Solutions LLC of North Andover, Mass., transforms sheets of Solvay's Radel polyphenylsulfone into steam-sterilizable instrument trays for orthopedic surgeries. A thermoformed tray of Radel PPSU can go through as many as 1,000 steam sterilizations.
“A surgery for a hip or knee implant may require up to 12-14 cases,” Hrivnak said. “With a modular design, they can validate one.”
At the expo, Solvay displayed Legacy's large-format tray measuring 23.5 by 15 by 5.6 inches and being composed of a thermoformed transparent lid and an opaque base tray that secures with a metal clamping system.
Joel Hughes, Legacy president, said in a statement that an anodized aluminum tray can fade after one sterilization cycle if treated with high pH cleaners, “but the trays we make with Radel PPSU retain their fresh appearance thanks to the material's superior chemical and heat resistance.”
Hrivnak noted that Solvay increased capacity of its Marietta, Ohio, facility including for more production of Radel PPSU.