Process for producing glass tubes and use thereof
A process for producing glass tubes is provided that includes: applying a glass melt onto the outer surface of a rotating cylindrical shaping body to form thereon a hollow glass melt body; and withdrawing the hollow glass melt body over the shaping body toward a front end for forming a glass tube; w...
Gespeichert in:
1. Verfasser: | |
---|---|
Format: | Patent |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | A process for producing glass tubes is provided that includes: applying a glass melt onto the outer surface of a rotating cylindrical shaping body to form thereon a hollow glass melt body; and withdrawing the hollow glass melt body over the shaping body toward a front end for forming a glass tube; wherein the shaping body is coated with platinum or a platinum alloy in regions that are in contact with the glass melt. The glass melt has a composition in wt.-% of: SiO2 71.0 to 77.0; B2O3 9.0 to 12.0; Na2O 5.5 to 8.0; K2O 0.0 to 2.0; Al2O3 6.5 to 8.0; CaO 0.0 to 1.5; BaO 0.0 to 2.0; Li2O 0.0 to 0.5; ZrO2 0.0 to 5.0. The glass composition provides enhanced devitrification characteristics so that glass tubes can be drawn using a Danner mandrel that is coated with platinum or a platinum alloy. |
---|