Method for preparing a primary preform by etching and collapsing a deposited tube
US10730784B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2016 |
| Grant date | Aug 4, 2020 |
| Priority date | — |
| Expiry date | Jul 25, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B37/01869
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An exemplary method for preparing a primary preform by etching and collapsing a deposited tube includes mounting a deposited tube on a lathe and introducing the deposited tube into a central aperture of a furnace mounted on the lathe, wherein the furnace and the deposited tube are movable in axial direction with respect to each other, and creating within the furnace a hot zone that moves in translation back and forth over the length of the deposited tube during one or more cycles, wherein (i) during at least one cycle at least part of the outside of the deposited tube is etched by supplying a fluorine-containing etching gas to an annular region between the outer surface of the deposited tube and the central aperture of the furnace, and (ii) during at least one cycle the deposited tube is collapsed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.