Process for drying optical waveguide preforms

Claim 1

In the method of forming a glass article comprising the steps of depositing on a starting member a coating of glass soot to form a porous soot preform, removing the starting member from the preform to leave an aperture having an inlet at one end of the preform and an exit at the other end of the preform, disposing the preform in a furnace having a heated consolidation zone, introducing a drying gas stream into the aperture inlet, and moving the preform relative to the heated consolidation zone to cause the soot particles of the preform to fuse into a dense glass layer, the improvement wherein: the soot preform is moved relative to the heated consolidation zone in a direction such that consolidation proceeds from the aperture inlet end to the aperture exit end of the preform, thereby to provide an article exhibiting a reduced water gradient from the drying gas inlet end to the drying gas outlet end thereof.