METHOD FOR PRODUCING A TUBE OF GLASS

摘要

The present invention relates to a method for producing a quartz glass tube through a hollow cylinder. The cylinder is partially softened in a heating region in which the cylinder is moved at a relative supply speed Va while being rotated with respect to a rotation axis, and a softened part is radially expanded under the application of a centrifugal force and/or the application of internal overpressure applied to a hollow cylinder bore, so a deformed region is formed. The tube is continuously formed to have a larger outer diameter D_2 than the diameter D_1 of a hollow cylinder. To produce a hollow cylinder in a glass tube having a large outer diameter and high dimensional stability through a single forming step or as few forming steps as possible, radial expansion of the softened part is performed at a position-dependent radial expansion speed Vr, and a profile has a maximum value Vr,max which is twice lower than the supply speed Va according to the deformed region.