ソーカー内で発生するガラス壜の亀裂現象

抄録

In the process of cleansing there appeared minute cracks on the surface of bottles after they were steeped in soakers; the phenomenon which is likely to occur after many hours of steeping.
The experiments concerning this matter gave following results:
(1) As it was expected, the cracks occur generally in the soakers containing the solution of alumium compounds.
(2) The trend was found that the cracks appear more frequently on carbon-sulpher amber than mangan brown bottles.
(3) Comparing the difference in the composition between the carbon amber and mangan brown bottles it was found that, in general, the former was rich in SiO₂ and contained a small amount of SO₃, while the latter was rich in Fe₂O₃, MnO and Al₂O₃.
(4) In the powder test of durability against acid and alkali the mangan brown bottles gave the better results than those of carbon amber.
(5) The outbreak of cracks can be prevented effectively when the bottles are turned out from a lehr in which they are kept in contact with the current of CO₂, and SO₂.
(6) By scraping test it was observed that there existed a trend of producing cracks as far as 0.1-0.2mm from glass surface, which, however, decreased toward the middle.
(7) The presence of Be, Zn, and Al ions in the soaker solution was found to prevent the reduction of bottle weight, but to promote the outbreak of cracks.