| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high-quality glass tube by increasing purity of the glass tube when performing piercing. SOLUTION: In a process for manufacturing the glass tube, a glass material 3 is heated and softened, and a piercing tool 30 is press-fitted into the softened part of the glass material 3 to gradually mold the glass material 3 into the glass tube 6. Here, voltage is applied to a top 31 and a heating element 41 positioned at inner and outer sides of the glass tube 6, respectively, to generate a voltage gradient in the radial direction of the glass tube 6. Preferably, electric potentials of the top 31 and the heating element 41 of the glass tube 6 are adjusted so that they serve as different poles. An apparatus for manufacturing the glass tube is equipped with the top 31 and the heating element 41 which serve as electrodes for applying voltage to the inner and outer sides of the glass tube 6, respectively. COPYRIGHT: (C)2004,JPO
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