| 摘要 |
PURPOSE:To remove strain in a short time with low cost of installation and a small floor space by heating only the vicinity of the welding part at a specific temperature higher than the slowly cooling point of glass while rotating a welded body consisting of both a funnel and a neck made of glass. CONSTITUTION:A welded body having glass strain on the welded part caused by welding of a funnel to a neck is rotated, for instance, at the speed of 4-5times/ min. While rotating the welded body consisting of the funnel and the neck, the welded part 12 is heated by a heating means 13, for instance, an electric coil or the like. Said heating is perfomed at a temperature higher than the slowly cooling point of the glass of the funnel 10 and the neck 11 (for instance, 465 deg.C for funnel glass and 466 deg.C for neck glass) at 20-100 deg.C for 2-6min. Thereby, the strain removing time can be shortened while contributing to save energy. |
