Process Monitoring during Injection Moulding of Thermosetting Materials

Abstract

The continuing advance of technology is placing increasing demands on existing material systems while at the same time calling for weight reductions. In this context, thermoset moulding compounds display excellent thermomechanical properties, even at high service temperatures of more than 300°C. These properties are significantly influenced by parameters such as injection speed, mould temperature and geometry-dependent shear rates in the injection moulding process. A whole range of sensors are available for online monitoring of flow and cure characteristics. Since, in most cases, manufacturers distribute the sensors together with the appropriate software and hardware, purchase costs for the different systems are very high. The aim of the present investigation, conducted within the FiberSet research and development project, which was funded by the German Federal Ministry of Education and Research (BMBF), was to compare these sensor systems for thermoset processing in injection and compression moulds and to permit appropriate analysis. Based on the findings obtained, an assessment of the industrial suitability of various sensor systems was made with reference to predefined criteria.