METHOD FOR MANUFACTURING GLASS PREFORM

摘要

PROBLEM TO BE SOLVED: To reduce the number of foreign matter mixing into a glass particulate deposit or sticking to the surface of the deposit. SOLUTION: The method for manufacturing a glass preform by a VAD (vapor-phase axial deposition) process or OVD (outside vapor deposition) process comprises storing the glass particulate deposit in an isolation chamber, introducing clean gas into the isolation chamber and keeping the time for storage in the isolation chamber within 4 to 8 hours during the time after the fabricated glass particulate deposit is heated at a high temperature and before the transparent glass is formed. COPYRIGHT: (C)2004,JPO