Computer-implemented methods and apparatus are provided for predicting/estimating (i) a non-equilibrium viscosity for at least one given time point in a given temperature profile for a given glass composition, (ii) at least one temperature profile that will provide a given non-equilibrium viscosity for a given glass composition, or (iii) at least one glass composition that will provide a given non-equilibrium viscosity for a given time point in a given temperature profile. The methods and apparatus can be used to predict/estimate stress relaxation in a glass article during forming as well as compaction, stress relaxation, and/or thermal sag or thermal creep of a glass article when the article is subjected to one or more post-forming thermal treatments.

An apparatus for making a glass ribbon can include a heating plane including a heat footprint facing the surface of an edge director. A projection of the heat footprint in a resultant direction of the heating plane within the heat footprint can intersect the surface of the edge director. In further embodiments, a fusion draw method of making a glass ribbon can include radiating heat within a heat footprint of a heating plane toward a surface of an edge director. At least a portion of the heating plane within the heat footprint can face the surface of the edge director so that the surface of the edge director is intersected with heat radiating from the heat footprint of the heating plane.

Disclosed herein are methods for making a thin film device and/or for reducing warp in a thin film device, the methods comprising applying at least one metal film to a convex surface of a glass substrate, wherein the glass substrate is substantially dome-shaped. Other methods disclosed include methods of determining the concavity of a glass sheet. The method includes determining the orientation of the concavity and measuring a magnitude of the edge lift of the sheet when the sheet is supported by a flat surface and acted upon by gravity. Thin film devices made according to these methods and display devices comprising such thin film devices are also disclosed herein.

A glass substrate for a high-frequency device, which contains SiO.sub.2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na.sub.2O/(Na.sub.2O+K.sub.2O) in the range of 0.01-0.99, and the glass substrate having a total content of alkaline earth metal oxides in the range of 0.1-13% in terms of mole percent on the basis of oxides, wherein at least one main surface of the glass substrate has a surface roughness of 1.5 nm or less in terms of arithmetic average roughness Ra, and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

A system includes an overflow distributor (200) including a weir (245, 247). The system further includes a thermal exchange unit positioned in proximity to the weir. The thermal exchange unit (300) includes a tubular focusing member (310) and a thermal member (330) disposed at least partially within a lumen of the focusing member. The focusing member extends distally beyond a distal end of the thermal member by a distance It. In an embodiment the thermal exchange unit comprises several focusing members and thermal members to control a thermal profile of a glass stream flowing over the weir, particularly of a portion of the glass stream in contact with the weir.

An apparatus for downwardly drawing a glass ribbon includes a forming vessel including an upper portion including a pair of outside surfaces and a forming wedge portion including a pair of downwardly inclined forming surfaces converging along a downstream direction to form a bottom edge. An edge director is provided that includes a flow directing portion formed from a portion of a frustoconical or conical shape.

A method of forming a glass sheet comprises: (a) forming a ribbon of glass from molten glass with a pair of forming rollers; (b) reducing horizontal temperature variability of the ribbon of glass to be 10° C. or less across 80 percent of an entire width of the ribbon of glass before the ribbon of glass cools to a glass transition temperature; (c) controlling a cooling rate of the ribbon of glass while the ribbon of glass moves vertically downward within a setting zone such that the ribbon of glass has a first average cooling rate before the ribbon of glass cools to the glass transition temperature and a second average cooling rate after the ribbon of glass cools to the glass transition temperature, the first average cooling rate being less than the second average cooling rate; and (d) separating a glass sheet from the ribbon of glass.

Scratch and damage resistant laminated glass articles are disclosed. According to one aspect, a laminated glass article may include a glass core layer formed from an ion exchangeable core glass composition and includes a core glass elastic modulus E.sub.C and at least one glass clad layer fused directly to the glass core layer. The at least one glass clad layer may be formed from an ion exchangeable clad glass composition different than the ion exchangeable core glass composition and includes a clad glass elastic modulus E.sub.CL. The laminated glass article may have a total thickness T and the at least one glass clad layer may have a thickness T.sub.CL that is less than 30% of the total thickness T. E.sub.C may be at least 5% greater than E.sub.CL.

Scratch and damage resistant laminated glass articles are disclosed. According to one aspect, a laminated glass article may include a glass core layer formed from core glass composition and includes a core glass elastic modulus E.sub.C and at least one glass clad layer fused directly to the glass core layer. The at least one glass clad layer may be formed from an ion exchangeable clad glass composition different than the core glass composition and includes a clad glass elastic modulus E.sub.CL. The laminated glass article may have a total thickness T and the at least one glass clad layer may have a thickness T.sub.CL that is greater than or equal to 30% of the total thickness T. E.sub.C may be at least 5% greater than E.sub.CL.

In a method of manufacturing a glass film, in a cutting step, a crack (CR) formed in a non-product portion (Gc1, Gc2) along a longitudinal direction of a glass film (G2) is guided by a guiding member (17a, 17b) so as to propagate to an outer end portion (Gd) of the non-product portion (Gc1, Gc2) in a width direction.