Companies Partner to Produce Novel PEEK-Based Battery Insulators

Welch Fluorocarbon (Dover, NH) has developed a process for producing custom-fit battery insulators for pacemakers using Vestakeep PEEK film made by Evonik Industries (Parsippany, NJ). This technique yields thin-walled, molded liners suitable for the limited space available inside current pacemakers.

To save space and accommodate low wall-thickness tolerances, batteries are often manually encapsulated within polyimide adhesive strips or parylene conformal coatings--a task that requires considerable effort, according to the companies. And although custom-fit insulators provide an alternative option, their required thin walls, low tolerances, and long flow paths typically eliminate the possibility of injection molding as a processing method.

In an effort to solve this insulation conundrum, Welch Fluorocarbon has created a thermoforming process that enables the fabrication of these components from amorphous PEEK film. The Vestakeep film is completely melted and then molded in a vacuum, which enables the production of low-stress parts, according to the companies. Optimized for this process, the film is low stress and flows little upon melting.

Suitable for use as battery insulators in pacemakers, the film boasts good chemical resistance, including to metallic lithium. It also features tribiological and electrical properties, stability at high continuous working temperatures, and high mechanical and flame resistance.

By employing the Vestakeep PEEK film in combination with this new process, Welch Fluorocarbon reports that it can manufacture battery insulators at extremely low tolerances and with wall thicknesses measuring less than 25 µm.