Process monitoring of moulding compounds by ultrasonic measurements in a compression mould

Current research addresses ultrasonic quality sensor utilisation for inline cure monitoring, to control and analyse compression moulding. In this inve stigation, an ultrasonic impulse transmission method was applied to directl y monitor changes in the mechanical properties of moulding compounds throug hout the whole cure cycle. These measurements were performed during the pro cessing using transducers which were designed to operate at elevated temper ature and pressure in a compression mould. Measurements of ultrasound veloc ity and variation of attenuation coefficient of longitudinal waves were per formed following the cure cycle. Ultrasonic measurements were used to inves tigate the influence of different types of moulding compounds, artificial w eathering at elevated temperatures, filler volume, moisture content as well as amount of hardener on the curing process. (C) 2000 Elsevier Science Ltd . All rights reserved.