Compressibility and Relaxation Characteristics of Bindered Non-crimp-Fabrics Under Temperature and Injection Fluid Influence

This research examines the compression, as well as short- and long-term relaxation behaviour of bindered textiles at elevated temperature levels. Experiments were conducted on a carbon fibre non-crimp fabric with epoxy resin binder in a specifically designed compressibility test rig. Expanding past research activities at room temperature [1, 2] it was found in series of loading-relaxation-unloading tests, that the test temperature level significantly influences the maximum compaction pressure during the loading stage as well as the pressure characteristics during the relaxation stage [3]. Furthermore, a significant change in the compression behaviour, well below the specified processing temperature of the binder, was found. Also, a proof-of-concept demonstrates the “in-situ”-injection capability of a novel test-rig, reproducing RTM-like conditions in a controlled laboratory environment. The findings of this work are intended to support optimizing preforming and preform handling steps for liquid composite moulding processes.