Dielectric analysis as a low-complexity methodology for tracking prepreg out-time and its effects on the curing cycle

Abstract

The final properties of advanced composite parts manufactured from prepregs are strongly dependent on the combination of raw materials' properties and manufacturing parameters. Therefore, monitoring techniques that can characterize the prepreg cure advancement and the effects of this advancement on the curing process are of great interest to composite industries. In the present work, dielectric analyses were performed using a previously developed simple and low-cost device, as a successful alternative to track prepreg out-time and the specificities of aged prepregs curing process. The findings point out that, despite the temperature and humidity influence in the measurements, models for estimating prepreg out-times can be developed based on dielectric analyses results. Also, the dielectric properties can signalize the necessity of cure parameters adjustments, which might lead to the extension of prepreg out-time limits without significant detriment to the performance of the final part.