The importance of carbon fibres as a reinforcement material in energy-saving lightweight composites is well accepted. Fast and reliable, i.e. automated, linear-density- and tensile testing of carbon fibres thus becomes increasingly important. Due to the special properties of carbon fibres an automatic handling of individual filaments has been considered to be problematic. TEXTECHNO in Mönchengladbach realizes an automated test of linear-density- and tensile properties on such carbon filaments in their automatic fibre test system FAVIMAT+ with ROBOT.
For such automatic testing of carbon fibres the filaments are first inserted into a magazine. The magazine storage of the ROBOT system can take up to 20 magazines with 25 fibres each. The linear-density-, tensile-, as well as elastic properties are then tested fully automatically. The vibroscopic linear-density test as well as the tensile- and elasticity test are performed in the FAVIMAT+ single-fibre tester on exactly the same fibre section and clamping the fibre only once. In comparison to the testing of laminated rovings this method has a big advantage: First results are already available after a few minutes and not only after several hours.
Also without the automation described above the FAVIMAT+ is employed successfully by producers and users of carbon fibres as well as in research institutes. It is a universal tester, suitable for all types of fibres. Its excellent length- and force resolution (down to 0.1 µN) make it an interesting testing instrument also for other applications as for instance tensile tests on nano nonwovens. In the vibroscopic linear-density test, the instrument automatically determines the resonance frequency of the basic transversal oscillation under a well-defined tension and oscillating length. Taking the density of the tested material into account, the effective cross-section can easily be determined. Here, the precision is in general better than a determination by optical means. The measuring principle can be extended to a complete vibrational analysis for the determination of further parameters such as the bending stiffness.Back to Overview