Study On Surface Performance Improvement Of Insulating Materials Based On Plasma Jet Spraying Technology

In areas with large temperature difference between morning and evening,condensation is prone to occur inside outdoor electrical equipment.Condensation is easy to cause creepage phenomenon,cause equipment failure,and bring hidden dangers to the safe and stable operation of the power system.In this paper,by using atmospheric pressure plasma jet technology,epoxy resin and silicone rubber insulation materials for surface hydrophobic modification,From the perspective of practical engineering application,determine a set of optimum parameters of the hydrophobic modified gas flow,and explore the plasma in the insulation material after deposition hydrophobic film on the surface of the sample,the change of the surface physical and chemical properties,electrical properties.Firstly,a set of plasma jet spraying equipment was designed and set up.The surface of epoxy resin and silicone rubber was modified by plasma jet with high frequency AC power supply.The water contact angles of samples modified by two hydrophobic monomers were compared.Combined with the economic cost,a modified scheme using Ar as the working gas and hexamethyl-disilazane(HMDSN)as the precursor monomer was determined.Secondly,the influence of the working gas flow rate,the gas flow into the precursor monomer and the treatment time on the hydrophobic effect was explored.Through the measurement of water contact Angle before and after reconstruction,and combined with economic analysis,the optimal hydrophobic treatment condition parameters were obtained: The flow rate of Ar in the working gas is 3L/min,and the flow rate of Ar in the monomer HMDSN is 50 m L /min,and the processing time is 180 s.The surface morphology of the plasma deposited films was observed by AFM,and it was found that after plasma hydrophobic treatment,the surface treated area of the sample was covered with uneven particles,which increased the surface roughness of the sample.The changes of chemical groups on the surface of the material before and after hydrophobic modification were investigated by Fourier transform infrared spectroscopy.It was found that a large number of silica methyl,methyl and silica oxygen groups were deposited on the surface of the sample after plasma jet modification,and these hydrophobic groups greatly improved the hydrophobicity of the sample.The influence of natural aging on the hydrophobicity of the sample was tested within 60 days,and it was found that although the water contact Angle decreased,it still remained superhydrophobic.Finally,the influence of hydrophobic modification by plasma jet on the electrical properties of epoxy resin and silicone rubber samples was investigated.It was found that the surface conductivity of the modified epoxy resin and silicone rubber samples increased,while the volume conductivity remained basically unchanged.The surface flashover discharge of epoxy resin and silicone rubber samples before and after modification was carried out in atmospheric environment and condensation environment,respectively.It was found that with the increase of modification time,the surface flashover voltage values first increased and then decreased.The surface flashover voltage of epoxy resin and silicone rubber samples can be increased by 23.7%and 58.3%,respectively,in atmospheric environment,and by 32.1% and 40%,respectively,in condensation state.By testing the changes of surface potential of the samples before and after modification,it was found that the initial surface potential of the modified epoxy resin and silicone rubber samples decreased,and with the increase of plasma modification time,the initial potential first decreased and then increased,and the attenuation rate of surface charge was at first fast and then slow.In summary,after the hydrophobic modification by plasma jet,the insulation performance of the sample is also improved,which verifies the engineering feasibility of hydrophobic modification by plasma jet,which has a certain reference for the application of plasma to improve the condensation problem of outdoor power equipment.