HIGH CONDUCTIVE MULTI FILAMENT FIBER MATERIAL MADE OF INORGANIC FIBERS COATED WITH ALUMINIUM

摘要

Conductive textiles are used in applications such as battery shielding in electric vehicles, EM-shielding from 5G emission or the mounting of a solar panel. Electrical textiles can be used to build a Faraday cage to protect high sensitive electronic devices or behave as a wire or sensor. However, conductive textiles are a bottle neck in achieving the goals of the electricmobility. [9] Electric vehicles are to be produced in large quantities and offered at affordable prices. However, the current state of research does not allow such a low-cost production. Currently used metal fibers have a diameter of 2- 40 μm. The fibers are usually produced by the drawing process, the Taylor process, by melt spinning or extraction. Due to the slow and manual production processes, metal fibers with a diameter of 50 μm cost about 100 €/kg. To realize frequency shielding from 3 - 300 GHz new shielding materials are required. The decisive factor here is that simple EMI shielding by reflection is not sufficient, but for a shielding effect (SE) above 50 dB, the absorption of EM radiation supported by multiple internal reflections is of primary importance. [3,9] The aim of the presented work is to develop a low-cost conductive fiber material for electromagnetic shielding. The approach of this technology is the metallic coating of inorganic fibers in the spinning process. The conductivity is achieved by a thin aluminum sheath of only 2-4 μm. A flexible inorganic fiber is used as the core, which enables the formation of fabrics like wovens or nonwovens. These fabrics can be draped into complex geometries. The multifilament yarn production is running at a speed of up to 1000 m/min to achieve high productivity. The aluminum coating is happening in the spinning process and covers each single filament. The resulting yarns electrical resistance is 100 Ωm and its temperature resistants is up to 500 °C. Fiber and fabric design can be adapted to the requirement of different applications.