when the sound waves incident into it, it can cause gaps in the air vibration; the viscous drag due to air friction and pore walls, so that a considerable part of the sound energy into heat energy has been consumed.Specification: Project :UnitTest resultDensity:g/c22Hardnes:sC-TYPE22Tensile:kPa400Elongation: %100compressive:kPa≤5Note://
