The Effect of Surface Conductivity on the Accumulation and Dissipation of Static Electricity Charges on the Surface of Polymer Dielectrics

The results of studies of the effect of specific surface conductivity γS on the accumulation and dissipation of static electricity (SE) charges on the surface of polymer dielectrics are presented. Samples with a thickness of 1–5 mm with a specific volumetric conductivity of γV60 ≤ 10—12 Ω–1 m–1 were selected for research. It has been found that such dielectrics are characterized by the absence of a steady-state mode after voltage application, since the current flowing through the volume of the dielectric is constantly decreasing. The dependence of γS on the tangential component of constant electric field strength γS = f(Eτ) in the range Eτ = 5 × 102–5 × 105 V/m is studied. It has been found that, for dielectrics with a basic surface conductivity of γS0 < 10–12 Ω–1, a nonlinear dependence of γS = f(Eτ) is observed, and this nonlinearity increases with a decrease in γS0. It has also been found that a more pronounced nonlinearity γS = f(Eτ) is characteristic of hydrophobic dielectrics. Mathematical modeling of the accumulation and dissipation of SE charges is performed without and with taking into account the nonlinear dependence of γS = f(Eτ). It is concluded that, for dielectrics with γV60 ≤ 10–12 Ω–1 m–1, only surface conductivity can be taken into account; moreover, while γS = const for hydrophilic dielectrics, for hydrophobic dielectrics it is necessary to take into account the nonlinear dependence γS = f(Eτ).