Reduced surface resistivity (Carbon Fibre, Steel Fibre)
  ESD protection (Steel Fibre)
  EMI shielding (Steel Fibre)
  Improved mechanical strength, stiffness and dimensional stability
(Carbon Fibre, Glassfibre, Mineral, Talc)
  Improved wear/anti-friction properties
(Aramid, Molydenum Disulfide, PTFE, Silicon)
  Reduced tendency to warp (Glass beads, Mineral, Talc)