| 摘要 |
PURPOSE:To make the production of a glass tube having excellent out of round ness and straightness possible by sintering tubular gel while rotating the same around the tube axis in the stage of producing the glass tube by a sol-gel method. CONSTITUTION:The sol having high homogeneity is produced by mixing 900ml ethyl silicate, 730ml 0.02N hydrochloric acid and 900g pulverous powder silica, agitating vigorously the mixture and subjecting the mixture to ultrasonic irradia tion, centrifugal sepn. and filtration. The pH value of the sol is adjusted to 5 by adding 0.1 N aq. ammonia to the sol and thereafter the sol is filtered and the filtrate is put into a cylindrical vessel made of PP, by which the sol is rotated at a high speed of 1,000rpm around the tube axis to form the gel. The resultant tubular gel 1 is dried for 2 weeks at 60 deg.C and thereafter the gel is heated to 1,300 deg.C by a heating element 3 while the gel is rotated at lnpm around the tube axis in an annular furnace 2. The sintered body of th fused glass tube having the excellent straightness and out of roundness is thus pro duced. |
