Process for devices for the production of internally-hardened glass tubes as well as their use

US6595029B1 · kind B1 · utility

Assignee

• Schott Spezialglas GmbH · DE

Inventors

• Erhard Dick · Mitterteich, DE
• Erich Fischer · Altdorf, DE
• Roland Fuchs · Mitterteich, DE

Key dates

• Filing date: Sep 15, 2000
• Grant date: Jul 22, 2003
• Expiry date: May 9, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S65/09
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the production of internally-hardened glass tubes, in which in a tube-drawing process for the production of glass tubes that is known in the art, a coated drawing tool, for example in the process according to Danner a coated mandrel or in the process according to Vello or in A-drawing process a coated needle, is used, whose coating releases coating material upon contact with the inside surface of the tube that is produced and accumulates on the inside glass surface. The chemical resistance is increased by this internal hardening. The invention also relates to devices for implementing this process and uses of the tubes that are produced according to these processes.