Formation of Capillaries and Optical Fibers with the Use of a High-Temperature Furnace with Azimuthally Inhomogeneous Temperature Field

摘要

The effect of two technological parameters-the azimuthal inhomogeneity of the wall thickness of the preform tubes and the azimuthal inhomogeneity of the temperature field of a high-temperature (HT) furnace-on the cross section ellipticity of the capillaries is investigated experimentally. SL-97-1 electron tube glass bulbs are used as the preform tubes. It is established that, when one uses an HT furnace with azimuthally homogeneous temperature field, the inhomogeneity of the wall thickness of a capillary coincides with that of the tube perform, irrespective of whether or not the preform tube is collapsed during drawing. In contrast, the ellipticity of the capillary depends on collapsing the perform tube and increases as the collapse coefficient increases. The azimuthal inhomogeneity of the temperature field leads to appreciable ellipticity of the cross sections even in capillaries drawn from preform tubes with small wall thickness inhomogeneity.