Optimization of tracking resistance, erosion resistance and hydrophobicity for outdoor insulation materials

In additional to excellent weathering resistance, an outstanding outdoor high voltage insulation material must possess good tracking and erosion resistance, good hydrophobicity and fast recovery of hydrophobicity after arcing activity. Moreover, the material should retain good processability. It is shown that the optimum balance of all these properties can be achieved by a specially formulated silicone compound with no alumina trihydrate (ATH) and a polyolefin copolymer with medium level of ATH and a surface modifier.