Influence of fillers on silicone rubber for outdoor insulation

HV outdoor insulating systems such as line and station insulators, surge arresters and bushings, using silicone rubber for outdoor insulation have become very popular. This paper presents the mechanical behavior and electrical behavior of silicone rubber blend with different fillers. Various loadings of alumina trihydrate (ATH) and silica are added to silicone rubber and their performance are evaluated. Different types of silica such as fumed silica and precipitated (ppt) silica are studied. It was found the type of different silica filler makes difference in mechanical properties and dielectrical properties. And it was also found silane treatment of precipitated silica have great influence on the performance. The test results show that the more addition of ATH, the better the erosion resistance is achieved, but will result in declined mechanical properties.