Electrification properties of FRP and surface treatment of glass fiber

Glass-fiber reinforced plastics (GFRP) are often used in high voltage insulation systems. It is very important for applying GFRP at higher voltage to study the electrification properties of the material. We have observed the surface charge distribution of GFRP blocks by the dust figure method after applying dc electric field. The distribution is directly influenced by the texture of glass cloth. In order to study further the electrification phenomena, we have made observed surface charges of a well devised specimen using the dust figure method and also measured the volume resistivity of GFRP and its components, the surface resistivity of glass plates, and the interface resistivity of glass/epoxy resin. From the experimental results, it is concluded that electric charges generated in GFRP are transported by the external electric field along glass fibers, especially the interface of the glass/epoxy resin. It is confirmed that the surface and interface resistivity are strongly affected by the surface treatment (with coupling agent) of glass fibers.