| 摘要 |
PURPOSE:To suppress formation of large particles, to improve yield of gel drying process and to produce glass tubes having improved surface state in good productivity, by adding a pH adjustor to a rotating cylindrical tube and then feeding sol. CONSTITUTION:A cylindrical tube 1 is rotated around the tubular axis, a pH adjustor such as ammonia water, etc., is fed from a hole 8 at the tubular end face to the tube and then sol 10 is added from the same hole. Since the ammonia water has smaller specific gravity than the sol, the ammonia water tends to exist the inside of the tube. The ammonia water is uniformly taken in the sol layer fed next and formation of large particles are eliminated. Since pH adjustment is carried out in rotation of the cylindrical tube by this method, the sol can be directly advanced from the sol container to rotary gelatinization. High-purity glass tubes can be produced in a short time in high yield by this method. |
