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The use of innovative higher-performance highly reactive resin systems requires an enhancement of the established method of fiber impregnation (open bath) towards closed resin-injection pultrusion (CIP), due to the short pot life of the resin systems. The result is that the open bath is developed into a closed injection and impregnation chamber ("ii-chamber"). In this study, three parameters—resin viscosity, opening angle and opening factor at the injection point on the ii-chamber—are varied, each in three stages. For each set of parameters, a pultrusion trial is conducted and the process pressures in the ii-chamber and pultrusion die measured. This enables direct feedback via the process conditions of the as yet uncured composite. The data obtained are used to validate a newly developed simulation model. The model is based on Darcy's law, which has been extended to take fiber movement into account and thus represent the resulting pressure increase in the die. The flexible ii-chamber and die concept enhance our understanding of the processes taking place in the die system. The sensitivity of the process pressures can be shown for the three influencing variables. The experiment shows that of the three influencing variables investigated, viscosity has the greatest sensitivity to pressure development. In general, it can be said that over the length of the pultrusion die system, the pressure level increases across the three measuring points. [ABSTRACT FROM AUTHOR]

Investigates the pulling force modelling and analysis in conventional pultrusion and resin injection pultrusion (RIP) of vinylester resin. Background on the study of pulling force in pultrusion; Model of pulling force for the injection die in RIP; Comparison of different types of resistance stress in the injection die; Schematic of the heat transfer analysis for pultrusion.

Offers information on a study which determined the pulling force distribution in pultrusion. Theoretical background; Data and methods used; Findings and discussion.

Pulling force modeling and analysis in conventional pultrusion and Resin Injection Pultrusion (RIP) of vinylester resin were carried out in this study. Based on the friction coefficient value of liquid resin, an analytical model was developed to predict the resistance force in the injection die. A thermal expansion-polymerization shrinkage model and a friction coefficient model, combined with the temperature and resin conversion profiles along the die, were used to predict the resistance stress in the heating die, and to determine the composite separation point from the die wall. The simulation results were verified by the experimental data in the conventional pultrusion and RIP processes. The comparison shows that the models and the simulation tool developed in this study are capable of predicting the pulling force in the entire die with good agreement. [ABSTRACT FROM AUTHOR]