METHOD AND DEVICE FOR INCREASING STRENGTH IN MOUTH PART OF GLASS WARE

摘要

PURPOSE:To form a compressive stress layer on the surface in the mouth part of glass ware to increase the strength in the mouth part by subjecting the mouth edge of the glass ware to a calcination treatment by a burner flame then applying the flame from the mouth to the body part thereby relieving the abnormal strain and stress generated by the calcination. CONSTITUTION:Glass ware 6 after cracking-off is placed on a receiving base 1 and is fed to a calcination zone after preheating. While the glass 6 is rotated, a strong flame f1 of a narrow width is applied from a calcination burner 7 to the mouth edge 6a from the position slightly higher than the edge 6a, by which the rough cut surface is subjected to a calcination treatment. The glass ware is then moved into a relieving zone where the flame f2 from a relieving burner 8 is applied to the same level as the level in the abnormal stress and strain zone in the mouth 6b of the glass ware or slightly lower than the same. The uneven strain and stress in the peripheral direction of the mouth 6b is thus decreased and the strength of the mouth 6b is increased.