Interfacial bonding enhancement of the RTV recoating with sandwiched contaminant by plasma jet

Abstract

Room temperature vulcanised (RTV) silicone rubber is widely used in electrical power system, applied to the glass or porcelain insulator surface to enhance insulation. RTV coatings get contaminated after long-term operation and need to be recoated. Contaminants accumulate and embed into the surface of base RTV coating, forming a hard-to-remove inorganic transition layer. Such sandwiched contaminant layer destroys the adhesion between original and reapplied silicone rubber coating greatly. Authors’ study innovatively reports a method to enhance interfacial bond properties of the RTV recoating with sandwiched contaminant layer, by using an atmospheric-pulsed discharge plasma jet (APPJ) for surface treatment. Water boiling test and 180-degree peel test were conducted to evaluate interfacial bond properties macroscopically. Scanning electron microscopy (SEM) was applied to observe the cross-section of recoating interface, while Fourier-transform infrared spectroscopy (FTIR) to detect chemical changes of contaminant layer, giving out microscopic and theoretical explanation.