| 摘要 |
<p>The present invention relates to a mandrel for producing glass tubes or rods, particularly for the Vello process, the A-drawing process and preferably for the Danner process. The mandrel comprises a body (1) of a ceramic composite material, and an external metal material jacket (2) surrounding at least a portion of said body, wherein the ceramic composite material has a substantially similar thermal expansion coefficient as the metal material of said jacket. Alternatively the mandrel comprises a self-supporting metal material jacket (22).</p> |
