Composite Insulator Injection Molding And Online Monitoring Research

As composite insulators has a series of advantages, such as light weight, easy maintenance, easy to install, high mechanical strength and good anti pollution performance, it’s widely used in electricity transmission equipment. A large number of ultra high voltage(UHV) composite insulators is used in UHV power transmission and substation equipment. As a key component of the transmission equipment, its quality directly affects the security and stability of the power system. To reduce scrap rate and improve the production efficiency and product quality, necessary research should be done on UHV composite insulator production process.This paper introduces the technological process and die structure of silicone rubber composite insulator injection molding. The mould heating system is analyzed by ANSYS. According to the analysis results, the distribution of the heating rods is optimized to make the mold temperature distribution become more uniform.The liquid silicone rubber(LSR) used in the composite insulators production is analyzed by differential scanning calorimetric(DSC). The isothermal DSC curve and non-isothermal DSC curve during the reaction process of the LSR are obtained by DSC. Then the curing reaction starting temperature, peak temperature and peak temperature of the LSR are determined by the non-isothermal DSC curve. Reaction model of the LSR is established according to the DSC curve. By further processing, the activation energy,the reaction frequency factors and the reaction order of the LSR are obtained.In order to find out the relationship between the LSR viscosity and the temperature and shear rate, the rheological curves of LSR at different temperatures are measured.The dielectric constants of LSR with different curing time are measured to study the relationship between the dielectric constant and the curing time.Moldfiow database is established according to the LSR reaction model. The reaction injection molding process of LSR is simulated by Moldflow to analysis the effect of injection speed and mold temperature on the injection pressure, clamping force and the LSR’s viscosity and curing degree.The ultrasonic online monitoring system is set up based on ultrasonic probe, ultrasonic data acquisition card and Labview. Then the curing process of LSR at different temperatures is monitored by the system. The monitoring results show that the ultrasonic attenuation and velocity change along with the curing time of LSR. It shows that the LSR with different amount of bubbles have different monitoring signal.