PRODUCTION OF FIBRES WITH REDUCED SHOT FORMATION

FOR CANADA Spray drying process and apparatus for producing fibres, especially polycrystalline inorganic fibres such as alumina, from viscous aqueous sols or solutions, optionally with the use of a linear organic polymer spinning aid such as polyethylene oxide. The preferred atomiser is a rotating disc atomiser which may have grooves in the disc vanes. The interior of the atomiser may be supplied with cold humid air to prevent premature solidification of the feed liquid which leads to shot formation. Hot air for drying the fibres is preferably introduced tangentially on to the interior wall of the drying chamber and away from the atomiser, and in the same direction as fibres are formed from the atomiser. Fibres having mean diameters above 1 micron and less than 5 microns and virtually free from shot (non-fibrous material) can be produced.