| 摘要 |
PURPOSE:To prevent dirt and flaw of tubular gel and to produce a high-quality glass pipe in favorable mass productivity by placing tubular gel on a roller which is brought into contact with the specified liquid and drying it while rotating the tubular. CONSTITUTION:Sol obtained by hydrolyzing metallic alkoxide and fine powder of metallic oxide in the presence of an acid catalyst is introduced into a cylindri cal vessel and rotated around an axis of a pipe to obtain tubular gel 1. Then this tubular gel 1 is placed or rollers 2 provided to the inside of a drying vessel 3 and the following liquid [i.e. -(CF2CF2CF2CF2O)-] is introduced until it is brought into contact with the rollers 2 wherein vapor pressure at the temp. performing drying is lower than the component of a dispersing medium of sol, and rollers 2 are rotated and while removing dirt and a fragment of tubular gel stuck on the rollers 2, the tubular gel is dried and thereafter sintered. |
