Mapping of the fluid distribution in impregnated reinforcement textiles using Magnetic Resonance Imaging: Methods and issues

Magnetic Resonance Imaging techniques were found to be suitable for mapping the fluid distribution in impregnated textile fabrics. They allowed the state of impregnation of E-glass and carbon fibre fabrics of different architectures with a test fluid (engine oil) to be identified and dry spots to be detected. An Ultra-Short Echo-Time technique was found to be relatively robust to signal loss caused by relaxation processes, which are related to the dispersion of the fluid in the fabric and local discontinuities in magnetic susceptibility. On a 3 T scanner, 3D images of specimens with dimensions of 140 mm × 90 mm × 4.7 mm at an isotropic resolution of 0.5 mm were acquired at scan times of 21 min. However, radio-frequency eddy currents may be induced if the fabrics are conductive and result in partial cancellation of the signal, rendering it undetectable inside the sample.