Lightweight Metal CVD Coated Nonwovens Work Well, Cost Less Published Oct. 19, 2012 By Heyward Burnette, AFRL/RXOB Materials and Manufacturing WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- The Air Force Research Laboratory and Conductive Composites Company have developed a continuous commercial reel-to-reel process for metal chemical vapor deposition (CVD) coated nonwoven composites, used for electrical conductivity and electromagnetic shielding. Coated nonwovens are as light and conductive as carbon nanotube (CNT) sheets, and cost only a fraction of the price. Work on this project was done through a Small Business Innovation Research program. The Nickel CVD coated nonwovens produced by Conductive Composites are ultra lightweight, conductive, and highly effective at broadband electromagnetic shielding. Ductile and uniform coatings are applied in a continuous process that offers excellent control. Currently, coated nonwovens offer the highest specific shielding performance of any composite material. Incorporation of these materials on Department of Defense platforms is expected to result in significant cost savings and performance benefits for technologies and systems. The state of the art in the conductive nonwoven market is to use a chopped metal coated fiber (nickel or nickel copper), disperse it into a binder, and then produce a nonwoven. This process results in two engineering disadvantages; the fibers are insulated from one another by the binder, which limits conductivity, and conductivity and shielding effectiveness are increased only by increasing caliper and areal weight. The new, commercial process solves both of these challenges. During Conductive Composites' process, a finished nonwoven is continuously coated by chemical vapor deposition (CVD) with a thin film of nickel. The nickel is able to uniformly coat all surfaces throughout the nonwoven, and substrates up to an inch thick can be coated uniformly throughout. Coating every external surface creates a continuous film of conductive nickel on all exposed areas. The continuous surface coating of the CVD process makes a better shield than the insulated sub-surfaces of traditional coated fiber nonwovens. CVD-coated nonwovens enable performance levels in conductivity and shielding and provide possibilities for production of sheet, roll, or tape material formats. The materials provide the capability to design conductivity and shielding effectiveness in thin sheet nonwoven-based and composite laminate materials.