Uniflon 50 is a non-asbestous sheet sealing material from biaxially orientated PTFE ideally adapting to flange surfaces. Enhanced compressibility for better adaptation to surface of the flange achieved by the incorporation of hollow glass microspheres as the inorganic filler. The sheet is specifically designed to seal off flange joints from glass, ceramic or plastic materials, whether uneven or distorted. Uniflon 50 is suitable for all chemical media across the pH range 0 to 14, with exception of molten alkali metals, fluorine gas and hydrogen fluoride. The sheets can be simply cut.