Impact of Fumed Silica on the Insulation Performance of Anti-Pollution Flashover Coatings

Figure 1

Volume Resistivity: The Core Indicator of Insulation Barrier Capability

Volume resistivity is a critical parameter measuring a material’s ability to block the passage of electric current; a higher value indicates stronger insulation performance.

According to the test data in Figure 1:

• The blank sample had a volume resistivity of 17×10¹²Ω⋅m, meeting only basic insulation requirements;
• The competing product, with the addition of conventional fillers, saw its volume resistivity increase to 3700×10¹²Ω⋅m, significantly enhancing its insulation barrier capability;

However, the anti-pollution flashover coating containing HB-132 achieved a volume resistivity of 6800×10¹²Ω⋅m, which is 400 times that of the blank sample and 1.84 times that of the competing product.

This difference stems from the nano-scale particle size and high specific surface area characteristics of HB-132. When fully dispersed in room temperature vulcanized (RTV) silicone rubber, it forms a continuous “insulation barrier network” within the coating, thereby significantly increasing the material’s volume resistivity and enhancing overall resistance characteristics.

HB-132 Properties and Functional Applications

Dielectric Strength: A Direct Reflection of Breakdown Resistance

Dielectric strength represents a material’s ability to resist breakdown under an electric field and is a core performance indicator for insulation materials in high-voltage environments.

The test results in Figure 1 show:

• The blank sample had a dielectric strength of 18.0 kV/mm, falling at the lower limit of the standard;
• The competing product’s dielectric strength increased to 21.3 kV/mm, showing enhanced breakdown resistance;
• The HB-132 group achieved a dielectric strength of 23.0 kV/mm, representing a 27.8% improvement over the blank sample and a 7.9% improvement over the competing product.

The high dispersibility of HB-132 ensures its uniform distribution within the silicone rubber. This effectively alleviates electric field concentration, suppresses electric field concentration and partial discharge, and delays insulation aging, making it suitable for equipment protection at higher voltage levels.

Electrical Erosion Resistance: The Guarantee of Long-term Insulation Stability

Resistance to electrical erosion reflects a material’s anti-aging capability under the action of corona and partial discharge; a higher TMA grade indicates better long-term insulation stability.

In the test data from Figure 1, the resistance to electrical erosion for the blank sample, the competing product, and the HB-132 group all reached TMA 2.5 level, meeting the basic industry requirements.

Experimental results demonstrate that the HB-132 model exhibits excellent performance in both volume resistivity and dielectric strength, far exceeding standard requirements and significantly surpassing market competitors, highlighting its outstanding potential in the field of high-voltage insulation protection.

Against the backdrop of increasingly stringent requirements for external insulation protection in power systems, the adoption of anti-pollution flashover coatings modified with high-performance fumed silica such as HB-132 will provide more reliable material assurance for the safe and stable operation of the power grid.

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