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Silicone Anti-Pollution Flashover Coating for Power Insulators

High-Performance Insulation Protection for Polluted Power Systems

This silicone anti-pollution flashover coating is designed to improve the external insulation performance of power insulators exposed to pollution, salt mist, fog and moisture. Tested performance includes 110° average hydrophobicity, 25.1 kV/mm dielectric strength, and a 2.20× anti-pollution flashover voltage ratio. It is suitable for AC and DC power systems operating from -50°C to 100°C, including substations, transmission lines and power plants.

What Is Silicone Anti-Pollution Flashover Coating?

Silicone anti-pollution flashover coating is an insulating protective coating applied to the surface of electrical insulators to reduce the risk of pollution-related flashover. The supplied test data shows a volume resistivity of 3.56 × 10¹⁵ Ω·cm and a dielectric strength of 25.1 kV/mm.

How Does the Coating Prevent Pollution Flashover?

The coating maintains a highly hydrophobic surface that helps reduce the formation of continuous conductive water films under polluted and humid conditions. Its tested average contact angle was 110.0°, with a minimum contact angle of 99.0°, corresponding to HC1 in the reported hydrophobicity test.

How Effective Is It Against Pollution Flashover?

The artificial wet-pollution test recorded 23.5 kV for coated insulators versus 10.7 kV for uncoated insulators. The resulting coated-to-uncoated voltage ratio was 2.20, exceeding the reported requirement of 2.0.

Does the Coating Improve Wet Flashover Performance?

Yes, the supplied comparison test shows a higher wet flashover voltage for the coated specimen. The measured values were 52.9 kV for the coated insulator and 49.9 kV for the uncoated insulator.

What Are the Electrical Insulation Properties?

The coating provides high electrical resistance and dielectric performance for external insulation protection. The reported volume resistivity is 3.56 × 10¹⁵ Ω·cm, relative dielectric constant is 2.5, dielectric loss tangent is 0.27%, and dielectric strength is 25.1 kV/mm.

Is the Coating Resistant to Tracking and Erosion?

The tested coating achieved TMA 4.5 in the reported tracking and erosion test. The maximum measured etching depth was 0.5–0.7 mm, while the requirement stated in the test sheet was to exceed TMA 2.5.

How Strong Is the Adhesion?

The coating demonstrated Grade 1 adhesion, exceeding the stated requirement of Grade 2 or better. Grade 1 adhesion was also reported after the oil-resistance evaluation.

Is It Resistant to Transformer Oil and Corrosive Chemicals?

The test report states that the coating showed no detachment, wrinkling or foaming under transformer-oil exposure. Under acidic, alkaline and saline reagents, the reported result showed no detachment or efflorescence.

What Temperature Range Can It Handle?

The product is specified for ambient temperatures from -50°C to 100°C. The application range covers various voltage levels as well as AC and DC systems operating in polluted environments.

Where Is the Coating Used?

The coating is intended for electrical insulation equipment exposed to pollution, fog and moisture. Typical applications listed in the product data include transformer substations, transmission-line insulators, power-plant booster stations, chemical plants, steel plants, electric railways and mines.

Is It Suitable for High-Voltage Equipment?

The product data states that the coating is widely used on equipment rated 500 kV and above. The reported over-voltage breakdown test showed no breakdown at positive polarity levels of 337–374 kV and negative polarity levels of -336 to -372 kV.

Does It Resist UV, Ozone and Environmental Aging?

The product is specified as resistant to ozone, ultraviolet radiation and environmental aging, with the product description stating that peeling and cracking do not occur. The supplied technical sheet also reports a 3,000-hour salt spray test with no electrical scratching or erosion damage observed on the coating surface.

How Long Does the Coating Take to Dry and Cure?

The reported skin-drying time is 26 minutes at room temperature. The reported curing time at room temperature is 23.4 hours, compared with the stated maximum requirement of 72 hours.

What Coating Thickness Is Recommended?

The recommended coating thickness is not less than 0.3 mm. The application should produce a complete coating without defects or dripping.

How Is the Coating Applied?

The coating can be applied by spraying or brushing in suitable weather conditions. The supplied instructions recommend applying it to a clean and dry insulator surface after removing dust, wax and grease.

What Is the Coating Density and Solid Content?

The tested density is 1.268 g/cm³, below the stated maximum of 1.28 g/cm³. The measured solid content is 56.52%, exceeding the stated minimum of 50%.

What Is the Coating Viscosity?

At 25°C, the reported viscosity is 86 seconds when measured with a Pour-4 viscometer. The stated requirement is not less than 80 seconds.

What Are the Mechanical Strength Properties?

The coating achieved a reported shear strength of 3.856 MPa and tear strength of 18.3 kN/m. Its tensile strength was 3.863 MPa, with elongation at break of 377.8%.

Is the Coating Self-Cleaning?

The product achieved Level 2 in the reported self-cleaning test. Its hydrophobic surface is also supported by the measured contact-angle results, including a 120° average contact angle in the reported migration test.

How Long Can the Product Be Stored?

The stated storage period is 6 months when stored under dry and ventilated conditions away from direct sunlight and rain. If the storage period exceeds six months, the product should be rechecked and approved before use.

What Packaging Is Available?

The coating is supplied in sealed metal containers. Storage and transportation should be carried out in dry, ventilated conditions and away from sunlight and rain.

Key Technical Specifications

Parameter Test Result

Operating ambient temperature -50°C to 100°C

Coating thickness ≥0.3 mm

Skin drying time 26 min

Curing time 23.4 h

Density 1.268 g/cm³

Average hydrophobicity 110.0°

Minimum hydrophobicity 99.0°

Volume resistivity 3.56 × 10¹⁵ Ω·cm

Relative dielectric constant 2.5

Dielectric loss tangent 0.27%

Dielectric strength 25.1 kV/mm

Tracking & erosion TMA 4.5

Adhesion Grade 1

Wear loss 0.0662 g

Solid content 56.52%

Viscosity at 25°C 86 s

Shear strength 3.856 MPa

Tear strength 18.3 kN/m

Tensile strength 3.863 MPa

Elongation at break 377.8%

Anti-pollution flashover ratio 2.20

Self-cleaning Level 2

Salt spray test 3,000 h

The values above are taken directly from the supplied technical data sheet.

Why Choose This Anti-Pollution Insulator Coating?

The main advantage is the combination of hydrophobicity, electrical insulation, adhesion and pollution-flashover performance in one protective coating. Key reported results include 3.56 × 10¹⁵ Ω·cm volume resistivity, 25.1 kV/mm dielectric strength, Grade 1 adhesion and a 2.20× anti-pollution flashover voltage ratio.

FAQ

1. What is anti-pollution flashover coating?

It is an insulating protective coating designed for electrical insulators operating in polluted, humid or salt-mist environments. The supplied product data reports 110° average hydrophobicity and a 2.20× coated-to-uncoated anti-pollution flashover voltage ratio.

2. What voltage systems is it suitable for?

The product is specified for various voltage levels in both AC and DC systems. The supplied application data specifically notes widespread use on 500 kV and above equipment.

3. What is the recommended coating thickness?

The recommended coating thickness is at least 0.3 mm. The finished coating should be complete and free from defects and dripping.

4. How long does it take to cure?

The reported skin-drying time is 26 minutes, while the reported room-temperature curing time is 23.4 hours.

5. Can it be applied by spraying?

Yes. The supplied application instructions specify spraying or brushing as application methods under suitable weather conditions.

6. What is its dielectric strength?

The tested dielectric strength is 25.1 kV/mm, compared with the stated minimum requirement of 18 kV/mm.

7. How hydrophobic is the coating?

The reported average contact angle is 110.0°, with a minimum of 99.0° in the hydrophobicity test. The reported HC classification was HC1.

8. Does it resist salt spray?

Yes. The additional test was conducted for 3,000 hours, and the report states that no electrical scratching or erosion damage was observed on the coating surface.

9. What is the storage life?

The stated storage period is 12 months under dry and ventilated storage conditions away from sunlight and rain. Products stored longer require rechecking and approval before use.

10. Where can this coating be used?

Applications listed in the supplied product data include transformer substations, transmission-line insulators, power plants, chemical plants, steel plants, electric railways and mines. The stated operating temperature range is -50°C to 100°C.