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Compressed Non-Asbestos (CNA)
Non-Asbestos Gaskets & Seals
Non-asbestos materials are heat-resistant and chemical-resistant substitutes for asbestos sealing materials. They provide similar strength and resistance characteristics as asbestos materials while eliminating the toxic hazards associated with asbestos fibers. These alternative materials incorporate carbon-based or organic materials as the reinforcing fibers in gaskets.
CNA gasket material is comprised of three major elements: fiber, filler and a binder. Whether mineral, synthetic or organic, fiber is the base component that provides the material with its tensile strength, compression and other mechanical properties. Such fibers include aramids (Kevlar®), cellulose, ceramic or fiberglass.
An elastomer binder is added that links the materials together and provides added flexibility to the gasket material. While EPDM, neoprene, nitrile, and SBR are the most common rubber binders, any elastomer can be used depending on specific characteristics needed for the application.
Adding fillers can moderate cold flow and help to regulate creep. Since at least half of the gasket material is made up of filler, such as clay, mica, powdered graphite or silica, it also reduces the material cost.
Compressed non-asbestos gasket materials have excellent heat resistance, seal performance and torque retention. Gaskets fabricated from CNA materials are used in many environments that transfer acids, air, chemicals, fuels, gases, oils, solvents, steam and water.
Web Seal can recommend the best compressed non-asbestos material for your specific sealing application.