Made of carbonized fiber which is impregnated with PTFE dispersion. It is inert to almost all corrosive chemicals. When it is used for pumps, frictional heat is freely conducted to the stuffing box metal because of its excellent thermal conductivity, and thus no damage will be caused to the packing. It can replace PTFE asbestos packing within wide service range. It can be used to seal corrosive fluids except strong oxidizer acids, organic solvents , etc.