A method of forming a glass ribbon includes flowing a molten glass into a caster having a width (W.sub.cast) and a thickness (T.sub.cast) to form a cast glass, cooling the cast glass in the caster to a viscosity of 10.sup.8 Poise or more, conveying the cast glass from the caster, volumetrically heating the cast glass to an average viscosity of 10.sup.6 Poise or less using a gyrotron microwave heating device, and drawing the cast glass into a glass ribbon having a width (W.sub.gr) that is less than or equal to the width (W.sub.cast) of the caster and a thickness (T.sub.gr) that is less than the thickness (T.sub.cast) of the caster.

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.

Methods for manufacturing glass articles having a target effective coefficient of thermal expansion CTE.sub.Teff averaged over a temperature range comprise selecting a glass core composition having an average core glass coefficient of thermal expansion CTE.sub.core that is greater than the target effective CTE.sub.Teff and a glass clad composition having an average clad glass coefficient of thermal expansion CTE.sub.clad that is less than the target effective CTE.sub.Teff; and manufacturing a glass laminate comprising a glass core layer formed from the glass core composition and two or more glass cladding layers fused to the glass core layer, each of the two or more glass cladding layers formed from the glass clad composition such that a ratio of a thickness of the glass core layer to a total thickness of the two or more glass cladding layers is selected to produce the glass laminate having an effective coefficient of thermal expansion CTE.sub.eff that is within ±0.5 ppm/° C. of the target effective CTE.sub.Teff.

Apparatus for manufacturing glass including a forming body configured to form a glass ribbon and a glass scoring apparatus positioned below the forming body. The glass scoring apparatus includes a frame, a cross-member assembly and a movable scoring unit coupled thereto. At least four drive assemblies are mounted on the frame, each drive assembly including a threaded shaft, a drive motor coupled to the threaded shaft and configured to rotate the threaded shaft, and a ball nut assembly engaged with threads of the threaded shaft and coupled to the cross-member assembly such that rotation of the threaded shafts by the drive motors causes the cross-member assembly to vertically rise or lower. Multiple scoring devices are provided to enable bidirectional scoring of the glass ribbon.

A melting apparatus is disclosed, the melting apparatus including a melting vessel with a back wall, a front wall, a first side wall, a second side wall and a longitudinal centerline extending therebetween and a width between the first and second side walls orthogonal to the centerline. The melting vessel further includes a first feed screw including a first axis of rotation and a second feed screw including a second axis of rotation, the first axis of rotation positioned between the longitudinal centerline and the first side wall and the second axis of rotation positioned between the longitudinal centerline and the second side wall. The positions of either one or both the first and second axes of rotation are located from a respective side wall a distance that is equal to or less than about 15% of the width of the melting vessel.

A method of controlling a flowrate of molten material at a downstream location in a glass manufacturing process can include mixing the molten material at an upstream location positioned upstream from the downstream location relative to a flow direction of the molten material with a shaft including a plurality of protrusions. The method can also include measuring a torque of the shaft, measuring a level of the molten material at the upstream location, and calculating a viscosity of the molten material at the upstream location based on the measured torque and the measured level. In addition, the method can include estimating the flowrate based on the calculated viscosity, and controlling the flowrate at the downstream location based on the estimated flowrate.

A method for producing thing glass strips is provided that avoids camber defects. The method includes using a glass strip forming device that has a drawing device; drawing, using the drawing device, the thin glass strip away from the glass strip forming device; measuring, using a measuring device, variables that are dependent on a differing length of edges of the thin glass strip at at least two measurement locations spaced apart transversely to a longitudinal extension of the thin glass strip; determining a difference or a quotient of the variables. The difference or the quotient is used to determine a control variable by which the glass strip forming device is controlled so as to counteract a difference in velocities of the thin glass strip between the two opposite edges.

A glass manufacturing apparatus can include a first elongated member, a second elongated member, and an elongated anvil member aligned with a space disposed between the first elongated member and the second elongated member. Methods can include rotating the first elongated member and the second elongated member while the elongated anvil member contacts a first major surface of the glass ribbon. In another embodiment, a glass manufacturing apparatus can include a first and second row of suction cups, and an elongated anvil member. The elongated anvil member can be engaged with a first major surface of the glass ribbon between the first and second row of suction cups that are attached to the first major surface of the glass ribbon. The glass manufacturing apparatus is configured to produce a score line on the second major surface of the glass ribbon along the elongated anvil member.

A slot orifice design that delivers glass ribbon at a uniform temperature and flow across the slot orifice width is provided. The slot orifice design can include a transition section, a pressure tank, and a slot extension.

Embodiments of glass forming apparatuses are disclosed herein. In one embodiment, a glass forming apparatus may include a forming body defining a draw plane extending from the forming body in a draw direction. An actively-cooled thermal sink may be positioned below the forming body in the draw direction and spaced apart from the draw plane. An infrared-transparent barrier may be positioned between the actively-cooled thermal sink and the draw plane. The infrared-transparent barrier may comprise an infrared-transparent wall positioned proximate the actively-cooled thermal sink or an infrared-transparent jacket positioned around the actively-cooled thermal sink.