Patent ID: 9309139
Filing Date: 2016-04-12
CPC Classification: C03B,Y02P

Claim Text:
1. A method for making display quality glass sheets comprising: (I) melting batch materials in a furnace to produce molten glass; (II) fining the melted batch materials in a finer; (III) forming a glass ribbon from the fined, molten glass; and (IV) separating glass sheets from the ribbon; wherein: (a) the furnace has an internal surface, a portion of which contacts molten glass; (b) said portion of the internal surface that contacts molten glass comprises ZrO 2 as its major constituent; (c) the melting of step (I) comprises employing a plurality of electrodes to pass electrical current through the molten glass; (d) each of the plurality of electrodes comprises molybdenum as its major constituent; (e) molten glass leaves the furnace and enters the finer at a rate R, where at steady state, R satisfies the relationship: (f) at steady state, the glass sheets produced in step (IV) are characterized by: (i) the glass making up the glass sheets is an alumina-silicate glass; (ii) the average content of ZrO 2 in the glass sheets satisfies the relationship: where [ZrO (iii) the average content of MoO 3 in the glass sheets satisfies the relationship: where [MoO (iv) prior to removal of any unacceptable glass sheets, a population of 50 sequential sheets has an average level of solid defects plus gaseous defects of a size greater than 100 microns that is less than or equal to 0.012 defects per pound of glass, where each of the glass sheets has a thickness that is less than or equal to 2.0 millimeters and a weight of at least 10 pounds.