Glass forming devices can comprise a first outer surface of a first wall, a second outer surface of a second wall, and a heater. Glass forming methods can comprise flowing a first stream of molten material over a first outer surface of the first wall and flowing a second stream of molten material over a second outer surface of the second wall. Methods can further comprise drawing a glass ribbon. Methods can also comprise heating the first wall with the heater to heat an inner portion of the first stream of molten material contacting the first outer surface of the first wall to maintain a viscosity of the inner portion of the first stream of molten material below the liquidus viscosity of the first stream of molten material.

A tinted glass composition and glass article including the same, the composition including: about 45 mol % to about 80 mol % SiO.sub.2; about 6 mol % to about 22 mol % Al.sub.2O.sub.3; 0 mol % to about 25 mol % B.sub.2O.sub.3; about 7 mol % to about 25 mol % of at least one alkaline earth oxide selected from MgO, CaO, SrO, BaO, and combinations thereof; about 0.5 mol % to about 20 mol % CuO; 0 mol % to about 6 mol % SnO.sub.2, SnO, or a combination thereof; 0 mol % to about 1.0 mol % C; 0 mol % to about 5 mol % La.sub.2O.sub.3; and 0 mol % to about 10 mol % PbO, and that is substantially free of alkali metal.

An alkali-free glass of the present invention includes as a glass composition, in terms of mass %, 55% to 70% of SiO.sub.2, 15% to 25% of Al.sub.2O.sub.3, 0% to 5% of B.sub.2O.sub.3, 3% to 10% of MgO, 7% to 20% of SrO, and 0% to 5% of BaO, is substantially free of an alkali metal oxide, and has a strain point of more than 720° C.

Provided is a method comprises: continuously forming an elongated, glass film having marginal portions from molten glass into a given shape having two marginal portions, in width-directional opposite edge regions thereof, wherein the glass film having marginal portions has the marginal portions, and an effective portion formed in a width-directional central region of the glass film having marginal portions; annealing the glass film having marginal portions; continuously forming resin tapes on the glass film having marginal portions at positions adjacent to and away by a given distance from the respective marginal portions, to extend in a length direction of the glass film having marginal portions; and continuously removing each of the marginal portions from the glass film having marginal portions, along a position between the marginal portion and a corresponding one of the resin tapes, or at a given width-directional position within the corresponding resin tape.

A method of predicting the gravity-free shape of a glass sheet and a method of managing the quality of a glass sheet based on the gravity-free shape of the glass sheet. The initial shape of a glass sheet is determined. When the glass sheet is flattened, values of stress at a plurality of locations in the glass sheet are obtained. A shape that the glass sheet will have when the flattened glass sheet is deformed such that the values of stress are zero is predicted as a stress-induced shape and a gravity-free shape of the glass sheet is predicted by combining the initial shape and the stress-induced shape. Quality management is performed on glass sheets based on gravity-free shapes thereof predicted using the method of predicting the gravity-free shape of a glass sheet.

A tempered glass sheet of the present invention is a tempered glass sheet having a compressive stress layer in a surface thereof, wherein the tempered glass sheet comprises as a glass composition, in terms of mol %, 50% to 75% of SiO.sub.2, 1% to 20% of Al.sub.2O.sub.3, 5% to 30% of B.sub.2O.sub.3, 0% to 15% of Li.sub.2O, 1% to 25% of Na.sub.2O, 0% to 10% of K.sub.2O, and 0% to 15% of P.sub.2O.sub.5, wherein the tempered glass sheet has a molar ratio [Al.sub.2O.sub.3]/[Na.sub.2O] of from 0.1 to 2.5, and wherein the tempered glass sheet satisfies the following relationship:

[SiO.sub.2]−3×[Al.sub.2O.sub.3]−[B.sub.2O.sub.3]−2×[Li.sub.2O]−1.5×[Na.sub.2O]−[K.sub.2O]+1.2×[P.sub.2O.sub.5]≥−20%.

Methods for producing a glass sheet are provided. The methods can include forming a glass ribbon from molten glass, applying a polymer precursor to at least a portion of a first or second major surface of the glass ribbon, curing the polymer precursor to form a polymer coating, and separating the glass ribbon to produce at least one glass sheet. Glass ribbons and glass sheets produced by these methods are also disclosed.

A laminated glass article includes a glass core layer and a glass cladding layer adjacent to the glass core layer. At least one of the glass core layer or the glass cladding layer is a tinted layer. The tinted layer can include a tinting agent that imparts a color to the tinted layer.

According to one embodiment, a glass-ceramic composition may include from about 60 mol. % to about 75 mol. % SiO.sub.2; from about 5 mol. % to about 10 mol. % Al.sub.2O.sub.3; from about 2 mol. % to about 20 mol. % alkali oxide R.sub.2O, the alkali oxide R.sub.2O including Li.sub.2O and Na.sub.2O; and from 0 mol. % to about 5 mol. % alkaline earth oxide RO, the alkaline earth oxide RO including MgO. A ratio of Al.sub.2O.sub.3 (mol. %) to the sum of (R.sub.2O (mol. %)+RO (mol. %)) may be less than 1 in the glass-ceramic composition. A major crystalline phase of the glass-ceramic composition may be Li.sub.2Si.sub.2O.sub.5. A liquidus viscosity of the glass-ceramic composition may be greater than 35 kP. The glass-ceramic composition may be used to form the glass clad layer(s) of a laminated glass article.

Provided is a method of manufacturing a glass sheet, which comprises a conveying step of conveying a glass sheet (G3) by holding an upper part of the glass sheet (G3) in a vertical posture. The conveying step comprises a first conveying step of conveying the glass sheet (G3) in a first direction along a direction perpendicular to a main surface of the glass sheet (G3), and a second conveying step of conveying the glass sheet (G3) in a second direction along a direction parallel to the main surface after the first conveying step. When a conveying direction of the glass sheet is changed from the first direction to the second direction, a lower part of the main surface (G3y) is supported by a roller (41) of a support portion (4) from a forward side in the conveying direction of the glass sheet (G3) conveyed in the first direction.