PURPOSE: In producing glass by sol-gel method, in drying process of gel, to shorten drying period by enlarging opening area of dryer and to prevent cracks and breakage by supplying steam at the initial stage of drying.
CONSTITUTION: Ethyl silicate, etc., are used as raw materials to prepare a sol solution, which is gelatinized to produce wet gel. Then, the wet gel is put in a dryer having a large opening area, dried and at the initial stage of drying, the dryer is supplied with steam for a fixed period to prevent abrupt drying of the gel. As a means to supply steam, a method wherein unnecessary gel smaller than the wet gel is put in both the sides of the wet gel or a method wherein an alcohol solution is added to the wet gel are proper. Then the dried gel is sintered to give high-quality glass suitable as a jacket pipe for optical fiber, etc.
TOKI MOTOYUKI
IKEJIRI MASAHISA
MORI TEIICHIROU
UCHIYAMA SHOICHI
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