Non-destructive Testing of Carbon Fiber Nonwoven Using Novel Anisotropic Eddy Current Analysis

With an exponentially growing Carbon Fiber (CF) market the recycling of those material gains traction quickly. One way is to reuse the reclaimed CF as nonwoven in semifinished products. In this study an eddy current testing method is investigated for the characterization of the properties of a CF-nonwoven. A novel anisotropic sensor is used to evaluate the orientation of the carbon fibers in the nonwoven. In addition, the fiber areal weight (FAW) and the fiber volume content (FVC) of the CF-nonwoven mixed with thermoplastic fibers (TF) was measured. The measured orientation of the CF in the nonwoven, was validated via mechanical testing after consolidation and showed good correlation. The results obtained by eddy current testing for the FAW measured as nonwoven was deviating 6,5%. Furthermore the CF volume content of the nonwoven containing CF and TF can be determined with about 4,7 % deviation with eddy current testing. The paper was presented at the ECCM20 on June 29, 2022.