Advances in Polymer Technology, Vol.25, No.1, 51-62, 2006
Influence of postcuring conditions on the processing characteristics of epoxy components
Reactive molding technologies, especially the automated pressure gelation (APG) method, are commonly used in the production of a wide range of medium and high voltage electrical equipment, including switch gears, voltage and current transformers, sensors, and bushings. In such products, not only very good electrical insulation properties but also high mechanical and thermal performance are required. In order to achieve these, a suitable manufacturing process has to be established. Therefore, the use of optimal process parameters, such as mold temperature, filling time, filling velocity, initial temperature of internal parts, gelation time, as well as appropriate product design is key factors for better quality components derived from minimized shrinkage and crack avoidance. The simulation approach for analyzing the filling and curing stages of reactive molding manufacturing processes has been successfully utilized for some time, providing useful information about thermal conditions during the production. In this paper, the principles of a newly developed structural analysis are rationalized and described. A novel simulation procedure for stress and shrinkage calculations, as well as the simulation results, is presented. Based on the achieved results, the influence of various postcuring conditions is analyzed. (C) 2006 Wiley Periodicals, Inc.