The fabrication of silica glass fibres by thermoplastic extrusion of nanosize and micron Si02 powders has been investigated. The powders were mixed with a binder system, compounded for 3h at 150 deg C and finally extruded through a die with a 500um-diameter die land. After debinding the green fibres at 500 deg C, these were sintered for 1h at 1100 deg C under air to yield glassy and crack-free silica fibres with a final diameter of 400um. The effect of the two different particle size distributions as well as the influence of varying powder loading (between 38 and 58 vol%) on the rheological properties of the feedstocks were analysed using capillary rheometry. The debinding and sintering behaviour was also investigated using mercury intrusion porosimetry, thermal gravimetric analysis and dilatometry.
