Effects of resin storage aging on rheological property and consolidation of composite laminates

Abstract The ability to predict the viscosity of thermoset resin is important to understand the manufacturing process of composites and optimize the processing parameters. During resin or prepreg storage course, the cure reaction may happen and the degree of cure increases gradually. The storage aging effect reduces the fluidity of resin, and hence alters the processability of resin. In this article, the rheological properties of an epoxy resin and a bismaleimide resin used in composite autoclave process were measured and a viscosity model was established, which can predict the viscosity progression during cure for different aging degree of resin. Moreover, a computer simulation method was used to study the effects of aging degree on the composite consolidation and the processing operations. It is found that the viscosity model of aged resin can be obtained by modified dual Arrhenius model of fresh resin with the dynamic rheological measurement. The resin aging strongly alters the flowability, so influences composite consolidation. According to the simulated results, the processing parameters need to be adjusted to achieve cured composites with appropriate fiber content. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers