engleski

Processing of Short Fibre - Thermosetting Matrix Composites

The fundamental aspects of the processing of thermosetting matrix composites with short fibres in compression moulding technologies are presented. The reaction kinetics and the rheology of compounds based on unsaturated polyester matrices have been characterized as a function of different processing variables (temperature and shear rate). The effects of the filler (calcium carbonate) and the reinforcement (glass fibres) on the curing kinetics of unsaturated polyester resins were studied by differential scanning calorimetry (d.s.c.) and the rheological properties of the compounds were analysed using parallel-plate rheometry. The results of the d.s.c. characterization were used to develop an empirical kinetic model accounting for diffusion control effects, while d.s.c. and rheological measurements were combined to obtain correlations between viscosity, extent of reaction, temperature and shear rate. The complete chemorheological model was verified through rheological tests performed at different heating rates and angular frequencies. The model developed in this work has been integrated into a general processing model for the description of the moulding behaviour of thermosetting matrix compounds for automotive applications. Excellent agreement between model predictions and experimental results has been obtained.

thermoset moulding compounds; reaction kinetics; rheology; model

nije evidentirano