Conduction mechanism in PE-CB composites suitable for low voltages and high currents

Carbon black (CB) particles can form conducting passageways or quantum mechanical tunnels only in the boundaries of PE crystal grains or in the amorphous region in HDPE-CB composite PTC materials suitable for low voltages and high currents. The percolation model was modified using considering the effective volume fraction of the conductive component. The effective volume fractions of CB at various temperatures were calculated based on the temperature dependence of the specific volume of polyethylene (PE) and the temperature dependence of the PE unit cell parameters. The temperature dependence of the specimen resistance was then calculated using the modified percolation model.