| 摘要 |
PURPOSE:To produce a thick-walled glass capillary, having excellent strength for impact or caulking and useful for connecting optical fibers, by hot-drawing a multitubular structural body having coaxially placed plural glass tubes having different diameters, thermally fusing and integrating the drawn structure. CONSTITUTION:Plural glass tubes 1-3 of different diameters in which the thermal expansion coefficient of the outermost glass tube 3 is lower than that of the adjacent inside glass tube 2 and the difference thereof is <=2X10<-6>/ deg.C are coaxially placed to form a multitubular structural body 4. The resultant multitubular structural body 4 is then inserted into an electric furnace 5, heated and drawn with draw rolls 9, thermally fused and integrated at the same time to afford the aimed glass capillary having >=5 ratio of the outside diameter to the inside diameter. |
