Study on optimisation methods for production processes of composite insulator sheath and GRP rod

Water diffusion significantly contributes to the abnormal heating in composite insulators. At the same time, the material performance shortcomings caused by the composite insulator production process can further increase water diffusion. To optimise the production process of composite insulators to prevent or reduce such abnormal heating, the fillers of the composite insulator sheath and the production of glass-fibre-reinforced plastic (GRP) rods are analysed. Based on the water absorption model of the sheath and the fibre infiltration model of the rod, it is identified that the flame retardant particle size is a factor that affects the water absorption of the sheath, whereas the epoxy resin liquid viscosity and the fibre volume fraction are factors that affect the porosity of the GRP rod. The experimental results show that the use of modified large-particle-size flame retardants can reduce the water absorption rate of the sheath, whereas low-viscosity liquids and high-fibre volume fractions can reduce the porosity of the GRP rod. The sheath and GRP rod produced using the optimised process continue to meet the standards.