Mapping of the fluid distribution in impregnated reinforcement textiles using Magnetic Resonance Imaging: Application and discussion

In this study, the local fluid concentration during in-plane impregnation of various reinforcement fabrics was mapped employing Magnetic Resonance Imaging (MRI). Repeated MRI scans during intermittent injection allowed the development of meso-scale dry spots to be tracked individually. The dry spots were found to be stationary and to decrease in size during impregnation. Changes in local fluid concentration within fibre bundles, reflecting the micro-scale void content, indicate that, behind the flow front, a zone of partial saturation travels through the specimen. For each type of specimen, this has a characteristic width. 3D maps of the fluid content in the specimens provided qualitative verification of models for the impregnation behaviour of specific fabrics. The results show the potential of MRI to provide unique 3D information on the local fluid content and the formation and development of dry spots.