| 摘要 |
PURPOSE:To eliminate or diminish the bubbles existing in a formed quartz glass without deforming the shape of the formed product, by heating and softening the quartz glass formed product, and applying the uniform external pressure to the surface of the product. CONSTITUTION:A pressure vessel 1 made of high tensile steel, is lined and insulated with porous fused quartz refractories 2. The pressure vessel 1 contains tubular carbon heaters 3 and a container 4 to hold the bubble-containing quarz glass 5 to be treated. The heaters 3 are electrified to raise the temperature in the oven, and the oven is pressurized with argon gas, and cooled maintaning the pressurized state. The heating rate, treating temperature, treating pressure, treating time, etc. depend upon the character, shape and dimensions of the quartz glass to be treated, or the structure of the oven and the treating method: however, it is necessary to set the pressure to 1-300MP and the temperature to the level at which the quartz glass becomes fluid, e.g. about 1,000-2,000 deg.C. |
