| 摘要 |
In a process for producing glass fibres with very low optical attenuation, the end of a cylindrical glass preform 1 is heated until viscous and the viscous end is then drawn out via the stage of an onion 3 to form a thin glass fibre 4. To compensate for inhomogeneities in the glass, shortly after its emergence from the onion 3, the glass fibre 4 is guided through a tempering zone of constant temperature in the form of a tubular kiln 8. The temperature in the tempering zone is some 100@C lower than in the onion 3. It may be also chosen such that the diameter of the glass fibre 4 is reduced somewhat as it passes through the tempering zone and thus a precise adjustment of the diameter is carried out. The interior of the tubular kiln 8 may be flushed with helium during the drawing process (Fig. 2). <IMAGE>
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