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OwnerFrank Buellesfeld, Markus Riedl +1inventors
InventorsFrank Buellesfeld, Markus Riedl, Paul Kissl
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The invention relates to a device and a process for producing a glass tube, preferably continuously. The device comprises a shaft (9) into which a glass melt is introduced, so that the outer profile of the glass tube (1) is determined at least in sections by the shaft, and a shaping means (10), which extends coaxially in the interior of the shaft, for determining the inner profile of the glass tube (1). The shaping means (10) is cooled and the shaft is disposed vertically. The glass melt is cast freely into the shaft (9) while forming a free meniscus. According to the invention, the shaping means (10) is cooled so that the glass melt solidifies in the shaft to form the glass tube (1). The glass passes through the temperature range which is critical for crystal formation within a very short time, so that precise glass tubes can also be produced from readily crystallising glasses. It is also possible to precisely shape glass tubes with any desired inner and/or outer profiles. Glass tubes with a comparatively low ratio of outside diameter (OD) to wall thickness (WT), in particular with a ratio OD/WT of lower than approximately 0.1*OD/[mm], can be produced by redrawing.
A device for producing a glass tube, in particular for the continuous production of a glass tube, with a shaft into which a glass melt can be introduced, so that the outer profile of the glass tube is determined at least in sections by the shaft, and with a shaping means, which extends coaxially in the interior of the shaft, for determining the inner profile of the glass tube, wherein the shaping means is cooled, wherein the shaft is disposed vertically, so that the glass melt can be cast into the shaft while forming a free meniscus, said shaping means being cooled so that the glass melt is cooled at the latter to a temperature below the softening temperature of the glass and the glass melt solidifies in the shaft to form the glass tube.
A process for producing a glass tube, in which process a molten glass is cast into a shaft in order to determine the outer profile of the glass tube and flows over a shaping means, which extends coaxially in the interior of the shaft, in order to determine the inner profile of the glass tube, wherein the shaft extends vertically, the glass melt is cast into the shaft while forming a free meniscus, and the shaping means is cooled, so that the glass melt cools at the latter to a temperature below the softening temperature of the glass and solidifies in the shaft to form the glass tube.
A glass tube, wherein a ratio of outside diameter (OD) to wall thickness (WT) is lower than or equal to 0.1*OD/[mm], wherein OD and WT denote the outside diameter and the wall thickness, respectively, of the glass tube in millimetres, and wherein the outside diameter is greater than or equal to 40 mm.
Dependencies are inferred from the claim text.