Patent ID: 8640498
Filing Date: 2014-02-04
Classification: C03B,C03C

Abstract:
1. A method for producing alkali-free glass sheets by a downdraw process comprising: (A) selecting, melting, and fining batch materials so that the glass making up the sheets comprises SiO (i) a Σ[RO]/[Al (ii) a MgO content greater than or equal to 1.0 mole percent; (B) producing the glass sheets from the melted and fined batch materials; wherein: (a) on an oxide basis, the glass making up the glass sheets comprises at most 0.005 mole percent As (b) on an oxide basis, the glass making up the glass sheets comprises at most 0.005 mole percent Sb (c) SnO (d) the glass making up the glass sheets has a liquidus viscosity that is greater than or equal to 100,000 poise.