预制棒芯棒电炉延伸的积热现象及外径控制技术

使用电炉加热延伸光纤预制棒或芯棒,延伸开始阶段和结束阶段的外径控制比较困难,影响着棒体延伸精度和利用率。本文从棒体加热软化的角度分析,提出加热延伸中棒体轴向上不同部位,因空间、时间以及材质差异等因素导致热量吸收累积的程度不同。棒体拉伸的锥头外型因黏度变化而变化,导致延伸外径控制困难。本文分析积热现象的影响原理,提出相应的外径控制技术方案。

Using electrical furnace to heat and stretch the optical fiber preform or core rods,it is difficult to control the diameter during the start and finish period,and influence the stretching accuracy and use ratio.In this paper,from the point of view of heating and softening of the rod,it is pointed out that different parts of the rod in the axial direction during heating and stretching have different degrees of heat absorption and accumulation,due to factors such as space,time and material differences.The cone shape of the rod body is changed due to the viscosity change,which makes it difficult to control the extended outer diameter.In this paper,the influence principle of heat accumulation phenomenon is analyzed,and the corresponding technical scheme of outer diameter control is put forward.