| 摘要 |
PURPOSE:To form a synthetic quartz glass pipe enhanced in resistant heat deformation properties in a high-temp. state by sandwiching a intermediate quartz layer incorporating many fine bubbles with outer and inner two quartz layers free from bubbles so as to making the quartz glass pipe with a three- layer structure. CONSTITUTION:A synthetic quartz glass pipe is formed by providing a quartz layer 3 incorporating many fine bubbles to the intermediate part of the quartz layers 1, 2 consisting of the outer and inner two layers substantially free from bubbles and making it to a three-layer structure. The thickness of the quartz layer 3 is preferably regulated so that it occupies 10-90% in the direction of thickness of the pipe. Further the fine bubbles have 1-1,000mum diameter and these are preferably incorporated at >=1,000 pieces per 1cm<3> volume of the glass layer. The above-mentioned synthetic quartz glass pipe is obtained by the following method. The synthetic quartz glass pipe 17 is obtained by packing synthetic quartz powder 14 into the gap 13 of the synthetic quartz pipe made to a structure of the double pipes 11, 12, heating and melting it and integrally stretching them. |
