PROCESS FOR CUTTING HOLLOW GLASSWARE

摘要

In a process for cutting hollow glassware, especially hollow glassware (3) with a rounded cross-section, an upper (36) and a lower (37) stress region on either side of an intended cut are produced thermally in the glass at a temperature slightly below its softening temperature by two laser beams (33, 34) substantially symmetrically to the intended cut. A crack inducing point (13) brought briefly into contact with the glass surface between the stress regions (36, 37) is used to make an initial crack on a section of the cut line which extends to form a high-grade cut around the entire circumference, thus obviating the need for subsequent grinding of the separation surface. The initial crack may also be made by focussing the laser beams (39, 40) in the area be tween the stress regions (35, 36). It is also possible to use only one laser beam to produce a single stress region, and in this case the initial crack is made substantially in the middle of the single stress region.