METHOD OF STRENGTHENING GLASS USING PLASMA TORCHES AND/OR ARC JETS, AND ARTICLES MADE ACCORDING TO THE SAME
Certain example embodiments relate to an improved method of strengthening glass substrates (e.g., soda lime silica glass substrates). In certain examples, a glass substrate may be chemically strengthened by creating an electric field within the glass. In certain cases, the chemical tempering may be performed by surrounding the substrate by a plasma including certain ions, such as Li + , K + , Mg 2+ , and/or the like. In some cases, these ions may be forced into the glass substrate due to the half-cycles of the electric field generated by the electrodes that formed the plasma. This may advantageously chemically strengthen a glass substrate on a substantially reduced time scale. In other example embodiments, an electric field may be set in a float bath such that sodium ions are driven from the molten glass ribbon into the tin bath, which may advantageously result in a stronger glass substrate with reduced sodium content.
1 - 20 . (canceled)
21 . An apparatus for increasing strength of a glass substrate, the apparatus comprising:
at least one plasma torch comprising at least first and second electrodes for facing at least a first major surface of a glass substrate;
means for spraying a plasma comprising replacement ions through a nozzle of the plasma torch facing the first major surface of the glass substrate via an applied asymmetric varying electric field between the two electrodes such that the plasma is sprayed proximate the first major surface of the glass substrate; and
means for providing the asymmetric varying electric field between the first and second electrodes, including increasing asymmetry between voltage half-cycles, in order to drive the replacement ions into the glass surface to a depth in the glass substrate of at least 100 micrometers in order to increase the strength of the glass substrate.
22 . The apparatus of claim 21 , further comprising:
a second plasma torch comprising third and fourth electrodes; and
means for spraying a plasma comprising replacement ions through a nozzle of the second plasma torch via an applied electric field between the two electrodes so that the plasma is sprayed proximate a second major surface of the glass substrate and replacement ions are driven into the first and second major surfaces of the glass substrate so as to increase the strength of the glass substrate.