Measurement method for migration of hydrophobicity of surface of polyolefin insulator

Abstract

The invention provides a measurement method for migration of hydrophobicity of the surface of a polyolefin insulator. The method comprises the following steps of sample pretreatment, contamination solution preparation, sample contamination, contamination degree check and characterization of migration of hydrophobicity. A certain area of the surface of a polyolefin insulator sample is cleaned withabsolute ethyl alcohol, and then flushed with deionized water; powdered sodium chloride serves as a salt component for preparation of the contamination solution, powdered diatomite or kaolin serve asan ash component, and ethyl alcohol or methyl alcohol or propyl alcohol or a mixture thereof serves as a dispersing agent; the contamination solution directly contaminates the surface of the sample through brush application by a clean banister brush or with a spraying method; by comparing the weight difference of the sample before and after contamination, the contamination weight per unit area iscalculated to check the contamination grade; 96 hours after migration, a static water contact angle of the sample is measured, and a spray method is used for determining the hydrophobicity level. Themeasurement method is also applicable to the measurement of migration of hydrophobicity of various insulators such as porcelain, glass, silicone rubber and epoxy, and has the advantages of simple steps, simplified operation, short drying time of contaminated samples and the like.

Description

technical field [0001] The invention relates to a method for measuring hydrophobic migration on the surface of polyolefin insulators, belonging to the field of insulator material detection. Background technique [0002] Hydrophobic migration refers to the phenomenon that the hydrophobicity of the surface of the insulator penetrates the dirt layer attached to the umbrella cover, making the surface of the dirt layer hydrophobic. In heavily polluted areas, the problem of pollution flashover of insulators has always been a major threat to the safe operation of power systems, and the hydrophobic migration characteristics can make insulators have better anti-pollution flashover performance. In addition, as the running time increases, the gradual aging of the insulator and the continuous deposition of pollution will reduce or even lose the hydrophobicity of the insulator surface, resulting in a decrease in its pollution resistance. Therefore, hydrophobic migration, as a key parame...

AI Technical Summary

Problems solved by technology

[0004] Practical applications have found that the existing hydrophobicity migration test technology has certain limitations, such as: (1) Not wide applicability: this technology is feasible for testing the hydrophobicity migration of porcelain, glass and silicone rubber insulator materials, and is applicable to polyolefin insulators During the water-based migration test, it was found that the water and sewage liquid formed droplets on the surface of the polyolefin, which could not spread evenly and form a uniform and continuous pollution layer, so the test could not be completed

(2) The pollution degree check is not direct and the operation is cumbersome: in order to check the pollution degree of the sample, it is generally necessary to prepare another sample. In water, test the conductivity, and confirm the contamination degree of the sample according to the relationship between salinity and volume conductivity. There are many operation steps and large errors.

(3) After the polyolefin insulator sample is polluted, the water volatilizes slowly and the drying time is longer, generally 6-8h