More than 400 billion plastic caps and closures are used annually around the world—including more than 100 billion in the United States—according to speakers at the IntertechPIRA conference "The Future of Caps and Closures" in Atlanta, Ga., June 20–21, 2007 (www.intertechusa.com).
If we include the metal screw closures and crowns for bottles; double-seam steel and aluminum can ends; the singular heat-seal liddings and snap overcaps on plastic tubs, trays, and cups; and zippers and slides appeari…