Fabrication and upscaling of spinning processes for ceramic high-tech fiber production

摘要

Ceramic fibers for high-tech applications require intensive developments concerning precursor synthesis and fiber spinning. The spinning process starts at laboratory scale with only few filaments and needs to be upscaled to pilot plant and industrial scale with hundreds or even thousands of filaments. Due to the significant interaction of filaments and surrounding inert atmosphere, the behavior in the spinning tower completely changes with higher numbers of filaments. How these effects are incorporated in a model of the gas flow including its influence by the filament spinning will be described. In 2 examples for melt- and dry-spinning of ceramic fibers it will be demonstrated how characteristic properties derived from experiments on a laboratory scale can be efficiently transferred to a pilot plant scale by use of simulations. For both applications the spinning tower was built according to the conditions derived from the simulation results, and experimentally proven to work. Ceramic fibers can be grouped according to their chemical composition into oxide and non-oxide fibers. Examples are Al_2O_3, 3Al_2O_3-2SiO_2, SiO_2 for oxide and SiC, Si(B)NC and C for non-oxide ceramic fibers. Ceramic fibers are characterized by high tensile strength and stiffness, high temperature stability and a good corrosion resistance. They are used in applications like reinforcement of ceramic or metallic composites (CMC: ceramic matrix composites; MMC: metal matrix composites), insulation, filtration and catalysis.