Method for manufacturing an article comprising a refractory dielectric body
US5000771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1989 |
| Grant date | Mar 19, 1991 |
| Priority date | — |
| Expiry date | Dec 29, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B37/01446
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
To attain high strength optical glass fibers, the glass preforms, from which the fibers are drawn, must generally be free of surface imperfections such as bubbles, and air lines. It has been discovered that these imperfections can be removed quickly and cleanly by contacting the preform surface with a substantial portion of the electrically conducting plasma region (the plasma fireball) extending from a plasma torch. Significantly, the surface material is substantially removed by vaporization, due to the extremely high plasma temperature (>9000.degree. C. at the plasma center) of the isothermal plasma torch. Though the temperatures in the tail of the plasma fireball are substantially less than at the plasma center, the temperatures are generally still several thousand degrees centigrade. These tail temperatures typically are sufficiently high to cause vaporization of most refractory dielectrics making the inventive method applicable to the fabrication of a wide variety of articles comprising refractory dielectric bodies. Advantageously, selective etching, according to one aspect of the inventive method, is used to remove fiber preform eccentricity and to fabricate optical fiber pre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.