Fiberglass reinforced plastic ladder rails are traditionally produced by the pultrusion process. In this process, reinforcements are gathered systematically, impregnated with a cureable resin, formed into a shape and cured continuously by the addition of heat in a metallic die. The process has been in existence for over fifty years with little change in the basics design of the process. During the past ten years, the federal government has through the Environmental Protection Agency and through Air Quality Standards caused the operators of the pultrusion process to reassess the methods they use to handle VOC containing resins in the pultrusion process. This has evolved several different methodologies for impregnating reinforcement that minimize the contact of the impregnating resin with the atmosphere and also reducing the exposure of workers to the volatile chemicals.
USPTO Backgrounds
USPTO Backgrounds