PRODUCTION UNIT FOR GLASS PREFORM FOR OPTICAL FIBER

摘要

PURPOSE:To reduce weight error by measuring weight increase of a target member with each traverse of the respective burners, estimating weight increase based on all the memorized data and controlling the speed of the last traverse. CONSTITUTION:Combustion burners 3 and 3' for production of fine glass particles are traversed from (A) to (B) to generate the fine glass particles in a flame 4 by flame hydrolysis and the generated fine glass particles are deposited on the surface of a target member 1. One of two burners 3 and 3' is traversed in one direction to form one layer 2 of the fine glass particles on the surface of the target member 1 and the other of the burners 3 and 3' is then traversed to form the second layer. Weight increase in next traverse is estimated by a computer 7 using data about weight increase in each traverse and the traverse speed is determined in accordance with the difference between the estimated value and the target value to obtain a fine glass particle-deposited layer low in its weight error from the target value. A composite material composed of the target member 1 and the fine glass particle-deposited layer 2 is then heat treated, thus affording the objective glass preform for an optical fiber.