If you can melt it, you can form it. That’s the credo at Welch Fluorocarbon in Dover, N.H., which thermoforms ultra-thin (less than 0.001-in) films into battery sleeves, vapor and corrosion barriers, pump liners, and other intricate parts for medical, aerospace, and other uses. The company uses fluoropolymers, PEEK, PEI (GE’s Ultem), and other films to meet demanding requirements for corrosion and heat resistance. Ultra-thin film forming is booming, says v.p. David Midgley, due to miniaturization, higher thermal requirements in electronics, and the arrival of advanced equipment and materials. He says formed films are less vulnerable to pinholes than coatings and are thinner and lighter than injection molded parts. Welch plans to soon offer its proprietary forming equipment for sale to others. Its vacuum formers for ultra-thin films are small, portable, modular, and dedicated to specific applications. They typically involve drape forming using male tools. Special heating systems and controls permit tight dimensional tolerances. Welch units can fully encapsulate 3D parts. Advances in extrusion of ultra-thin films is assisting growth of forming applications. Ajedium Film Group LLC, Newark, Del., is working on films of less than 1 mil in PEEK, high-temperature nylon, and nylon/polyimide blends, which have not previously been available. Cost-effective coextruded PEEK/PEI films are also emerging. Suppliers of ultra-thin fluoropolymer films for forming include Welch along with DuPont Teflon Films in Wilmington, Del., and Honeywell Specialty Films in Morristown, N.J.