| 摘要 |
PURPOSE:To realize the suitable exfoliation of the glass bead from a crucible without using any repellent, by cooling the glass bead while supporting the crucible with a supporter which is heated up to a level between the ambient temperature and the freezing point of the glass bead. CONSTITUTION:An aluminum plate held at about 500 deg.C is used for a supporter, and a crucible made of the platinum-alloy which is cooled right at a temperature C under the freezing point is put on the aluminum plate to be cooled down. Thue the heat of the crucible is absobed more to the supporter since the crucible touches the supporter to be cooled more quickly than the glass bead. As a result, the temperature change D of the crucible is more sudden than the temperature change E of the glass bead. However, the crucible absorbs the heat from the supporter to retard the coling speed when the crucible is cooled down to a level near the temperature M of the supporter. On the other hand, the glass bead is cooled down as it was, and accordingly the temperature change F becomes slower than the change G. Owing to such different of the temperature change, the exfoliation can be carried out in a suitable way between the crucible and the glass head. |
