The shielding materials for emf blocking are mainly inorganic fibers. The types of fibers currently used are listed as follows.
Silicon carbide fiber
It's electrical resistivity is 103 - 107Ω·cm, the dielectric constant is 6.5 - 9.0 in 10GHz.
Nanometer granules of graphite powder or ethylene carbon black powder
It is effective when combined with epoxy resin between 4 - 12GHz. There are 15% granules.
Magnetic metal
Superfine fiber, whisker or particles of magenetic metal. It is combined with matrix to form composite material.
Carbon fiber
The carbon fiber is modified in surface. The electrial resistivity of carbon fiber is 10-2Ω·cm, which is the strong reflector of radar electromagnetic wave.