Abstract: A method for making a glass ribbon that includes: flowing a glass into a caster having a width (Wcast) from about 100 mm to about 5 m and a thickness (t) from about 1 mm to about 500 mm to form an a cast glass; cooling the cast glass in the caster to a viscosity of at least 108 Poise; conveying the cast glass from the caster; drawing the cast glass, the drawing comprising heating the cast glass to an average viscosity of less than 107 Poise and drawing the cast glass into a glass ribbon having a width (Wribbon) that is less than Wcast; and thereafter cooling the glass ribbon to ambient temperature. Further, the cast glass during the cooling, conveying and drawing steps is about 50° C. or higher.

Abstract: A glass tube manufacturing apparatus for manufacturing glass tubing includes a glass delivery tank with molten glass. The glass delivery tank has a bottom opening. A bell has an upper portion with an outer diameter located at the bottom opening. A heating apparatus is at least partially disposed around the bell. The heating apparatus includes a heated portion and a muffle portion located below the heated portion. A lower extended muffle structure extends downwardly from the muffle portion. The lower extended muffle structure extending about the glass tubing on all sides to manage convective airflow therethrough.

Abstract: A method for making a glass ribbon that includes: flowing a glass into a caster having a width (Wcast) from about 100 mm to about 5 m and a thickness (t) from about 1 mm to about 500 mm to form an a cast glass; cooling the cast glass in the caster to a viscosity of at least 108 Poise; conveying the cast glass from the caster; drawing the cast glass, the drawing comprising heating the cast glass to an average viscosity of less than 107 Poise and drawing the cast glass into a glass ribbon having a width (Wribbon) that is less than Wcast; and thereafter cooling the glass ribbon to ambient temperature. Further, the cast glass during the cooling, conveying and drawing steps is about 50° C. or higher.

Abstract: A method for making a glass ribbon that includes: flowing a glass into a caster having a width (Wcast) from about 100 mm to about 5 m and a thickness (t) from about 1 mm to about 500 mm to form an a cast glass; cooling the cast glass in the caster to a viscosity of at least 108 Poise; conveying the cast glass from the caster; drawing the cast glass, the drawing comprising heating the cast glass to an average viscosity of less than 107 Poise and drawing the cast glass into a glass ribbon having a width (Wribbon) that is less than Wcast; and thereafter cooling the glass ribbon to ambient temperature. Further, the cast glass during the cooling, conveying and drawing steps is about 50° C. or higher.

Abstract: A method for making a glass ribbon that includes: flowing a glass into a caster having a width (Wcast) from about 100 mm to about 5 m and a thickness (t) from about 1 mm to about 500 mm to form an a cast glass; cooling the cast glass in the caster to a viscosity of at least 108 Poise; conveying the cast glass from the caster; drawing the cast glass, the drawing comprising heating the cast glass to an average viscosity of less than 107 Poise and drawing the cast glass into a glass ribbon having a width (Wribbon) that is less than Wcast; and thereafter cooling the glass ribbon to ambient temperature. Further, the cast glass during the cooling, conveying and drawing steps is about 50° C. or higher.

Abstract: A glass tube manufacturing apparatus for manufacturing glass tubing includes a glass delivery tank with molten glass. The glass delivery tank has a bottom opening. A bell has an upper portion with an outer diameter located at the bottom opening. A heating apparatus is at least partially disposed around the bell. The heating apparatus includes a heating portion and a muffle portion located below the heating portion. A lower extended muffle structure extends downwardly from the muffle portion. The lower extended muffle structure extending about a periphery of the glass tubing to manage convective airflow therethrough.

Abstract: A bell positioning apparatus for glass tubing manufacturing includes a bell and a support connected to the bell. A bell positioning apparatus is attached to the support and configured to move the support and the bell with at least three degrees of freedom. The bell positioning apparatus includes a platform, a platform frame, and one or more frame legs. A frame leg dimensional stability apparatus maintains a temperature variation within 6.5° C. per meter of distance between each frame leg for an extended period of time, e.g. 4 hours.

Abstract: A bell positioning apparatus for glass tubing manufacturing includes a bell and a support connected to the bell. A bell positioning apparatus is attached to the support and configured to move the support and the bell with at least three degrees of freedom. The bell positioning apparatus includes a platform, a platform frame, and one or more frame legs. A frame leg dimensional stability apparatus maintains a temperature variation within 6.5° C. per meter of distance between each frame leg for an extended period of time, e.g. 4 hours.

Abstract: An apparatus for making a glass sheet using overflow fusion down-draw process comprising an inlet assembly having an elliptic cylindrical section coupled to a transition section which is, in turn, coupled to an open end of an open channel of an isopipe, and an overflow fusion down-draw process for making glass sheet. The glass melt flow has a high surface velocity profile conducive to the formation of a glass ribbon over the surface of the weirs and the wedge side surfaces with the desired mass distribution.

Abstract: An apparatus for making a glass sheet using overflow fusion down-draw process comprising an inlet assembly having an elliptic cylindrical section coupled to a transition section which is, in turn, coupled to an open end of an open channel of an isopipe, and an overflow fusion down-draw process for making glass sheet. The glass melt flow has a high surface velocity profile conducive to the formation of a glass ribbon over the surface of the weirs and the wedge side surfaces with the desired mass distribution.

Abstract: An apparatus for making a glass sheet using overflow fusion down-draw process comprising an inlet assembly having an elliptic cylindrical section coupled to a transition section which is, in turn, coupled to an open end of an open channel of an isopipe, and an overflow fusion down-draw process for making glass sheet. The glass melt flow has a high surface velocity profile conducive to the formation of a glass ribbon over the surface of the weirs and the wedge side surfaces with the desired mass distribution.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: Methods of drawing glass sheet via a downdraw process are provided. In certain aspects, the methods utilize rapid cooling below the root (70) of the forming apparatus (10). Such rapid cooling can, for example, facilitate the use of glass having a liquidus viscosity less than about 100,000 poise. In other aspects, the methods utilize slow cooling between the viscosities of 1011 poises and 1014 poises. Such slow cooling can facilitate the production of glass substrates which exhibit low levels of compaction. In further aspects, substrates are removed from the glass sheet at elevated temperatures which can facilitate increases in the production rates of downdraw machines. In still further aspects, rapid cooling below the root, slow cooling between the viscosities of 1011 poises and 1014 poises, and/or substrate removal at elevated temperatures are combined. Such combinations can facilitate economically effective utilization of downdraw equipment.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: An apparatus for making a glass sheet using overflow fusion down-draw process comprising an inlet assembly having an elliptic cylindrical section coupled to a transition section which is, in turn, coupled to an open end of an open channel of an isopipe, and an overflow fusion down-draw process for making glass sheet. The glass melt flow has a high surface velocity profile conducive to the formation of a glass ribbon over the surface of the weirs and the wedge side surfaces with the desired mass distribution.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: Methods of drawing glass sheet via a downdraw process are provided. In certain aspects, the methods utilize rapid cooling below the root (70) of the forming apparatus (10). Such rapid cooling can, for example, facilitate the use of glass having a liquidus viscosity less than about 100,000 poise. In other aspects, the methods utilize slow cooling between the viscosities of 1011 poises and 1014 poises. Such slow cooling can facilitate the production of glass substrates which exhibit low levels of compaction. In further aspects, substrates are removed from the glass sheet at elevated temperatures which can facilitate increases in the production rates of downdraw machines. In still further aspects, rapid cooling below the root, slow cooling between the viscosities of 1011 poises and 1014 poises, and/or substrate removal at elevated temperatures are combined. Such combinations can facilitate economically effective utilization of downdraw equipment.