Method for processing surface of insert in vacuum pouring and APG process by using semi-conductive rubber

Abstract

The invention relates to a method for processing the surface of an insert in a vacuum pouring and APG process by using semi-conductive rubber. The method is implemented by the following steps: preparing the semi-conductive rubber, wherein the semi-conductive rubber is prepared by the following steps that: 100 parts of chloroprene rubber, 3 to 5 parts of graphitized carbon black, 3 to 5 parts of epoxy resin, and 10 to 15 parts of QS toughened agent are mixed at a normal temperature to obtain a mixture, 100 parts of methylbenzene, 150 to 200 parts of butanone, and 150 to 200 parts of ethanediolare added into the mixture, and the mixture is stirred and dissolved; washing the insert; drying the insert in the air; sealing the insert; adjusting the viscosity of the semi-conductive rubber; measuring the viscosity to obtain a measured value of between 400 to 600 cp; coating the insert for the first time; drying the insert in the air; coating the insert for the second time; placing the insertin a drying oven to cure for 1.5 to 2 hours at the temperature of 130+ / -5 DEG C; and taking out the insert and covering the insert for preservation and later use. The method has the advantages of ensuring that a buffer layer is arranged between the insert and an epoxy material, preventing knurling point discharge, eliminating coronas, and simultaneously preventing a gap from being generated between the insert and the epoxy material due to large difference of coefficients of thermal expansion of the insert and the epoxy material so that quality of an insulating part is improved.

Description

Technical field [0001] The present invention relates to a vacuum casting process and an APG process, in particular to a surface treatment method of an insert in the above process. Background technique [0002] The vacuum casting process refers to the process of mixing thermosetting resin, filler, curing agent, etc., into a mold by gravity, and thermosetting molding under a vacuum state. [0003] APG process refers to the automatic pressure gelation process (automatic pressure gelation process), which mixes thermosetting resin with fillers, curing agents, etc. under vacuum, and then uses pressure to inject the processed material into a mold for thermosetting molding. [0004] Insulation parts of medium and high voltage electrical equipment are generally embedded with inserts. These inserts are made of copper or aluminum. They are used as electrodes or connectors in the insulating parts. Due to the need to increase the bonding force between the inserts and the epoxy parts, they are gen...

AI Technical Summary

Problems solved by technology

[0004] The insulators of medium and high voltage electrical equipment are generally embedded with inserts. These inserts are made of copper or aluminum and are used as electrodes or connectors in the insulation. Due to the need to increase the bonding force between the inserts and epoxy parts, generally inserts Knurling treatment on the surface of the parts. If in a high electric field (above 110kV), the knurled tip may generate tip discharge. At the same time, during the curing process, due to the different thermal expansion coefficients of the metal part and the epoxy material, the shrinkage rate during curing is inconsistent, which can lead to insulation parts. There is a gap around the inner insert, which makes the insulation have defects such as poor electrical performance or air leakage