Electrical insulating properties of nano-composites according to additive

The use of a filler material in epoxy composite materials is an essential condition for reducing the unit cost of production and reinforcing the mechanical strength. However, the dielectric strength of insulators decreases rapidly due to interactions between the epoxy resin and filler particles. In contrast to existing composite materials, nano-composite materials have superior dielectric strength, mechanical strength and enduring chemical properties due to an increase in bond strength of the polymer and nanomaterial. It has been reported that nano-fillers provide new characteristics different from properties of the polymer material. In this study, to improve the insulation capability of epoxy resin used in the insulation of a power transformer apparatus and many devices mold. To accomplish this, the addition amount of nano-SiO₂ to epoxy resin was changed and the epoxy/SiO₂ nano composite materials were made, and the fundamental electrical properties of them were investigated using a physical properties and analysis breakdown test. Using allowable breakdown probability, the optimum breakdown strength for designing electrical apparatus was determined. As the result, it was found out that the electrical characteristics of the nano-SiO₂ content specimens were superior to the virgin specimens. The 0.4 [wt%] specimens showed the highest electrical properties among the specimens examined with an allowable breakdown probability of 20%, which indicates stable breakdown strength in insulating machinery design.