Medical Device Link.

MATERIALS

This ankle clamp is another metal to metal/plastic–hybrid conversion. It illustrates one way to remove cost from an application. The difficult-to-machine titanium components for this orthopedic ankle clamp have been replaced by a plastic application. The components have been redesigned and adapted so that they can be molded into their net shape without further secondary machining steps. The joining components of the assembly are still metal parts. Again, the requirements for the application are repeated steam sterilization and chemical resistance.

Return to Article: Material Selection: The Right Resin for Your Design

In this case, the big advantage of replacing metal with plastic is cost. When compared with machining each piece of titanium into its net shape, building a tool and molding a final part to net shape was significantly less expensive. The process for these components is injection molding; the material chosen for the application is polyphenylsulfone (PPSU). The molded parts are assembled with metal parts for the final configuration.