Heated edge director for glass flow stability

Abstract

There is provided a system for controlling the shape of molten glass, the system comprising: a feeder; a burner configured to generate a flame; and an edge guide. The feeder defines an interior space and a slot proximate a bottom portion of the feeder. The interior space is connected to the slot, and the interior space receives molten glass such that the molten glass exits the feeder at the slot. An edge guide is positioned relative to the slot. Each edge guide includes a body portion defining a first interior cavity and a contact portion configured to contact molten glass. The edge guide is positioned such that the contact portion is at least partially immersed within the molten glass and such that the contact portion controls the shape of the molten glass. Heat from the generated flame causes the molten glass proximate the edge director to have a first viscosity that is greater than a second viscosity proximate a central portion of the molten glass.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 623386, filed on January 22, 2024, the content of which is relied upon herein and incorporated herein by reference in its entirety. Technical field

[0003] Embodiments generally relate to heated edge guides for maintaining the stability of glass flow. Background art

[0004] Slot - drawing techniques are used for ultra - thin glass forming, such as for mobile phone products. Notably, the formed slot - drawn sheet is vulnerable to edge - flow instability, leading to process challenges in manufacturing. The production of some ultra - thin glass products uses water - cooled cold fingers to actively cool the edges of the slot to improve edge - flow stability. However, where these water - cooled cold fingers are used, thickness repeatability and consistency have been an issue.

[0005] Alternative heat - removal methods have been used, such as misted spray cooling (MSC), radiant cooling pads (RCP), internal cooling channels. While these methods are more consistent than methods using water - cooled cold fingers, these methods attempt to actively cool the slot to improve edge - flow stability, but this poses a risk of devitrification of the molten glass. This devitrification typically results in inclusions in the glass, which may lead to a risk of breakage of the resulting glass product and may also lead to irregularities in glass thickness and other glass properties. Heat removal generally limits the available glass compositions with a compatible liquidus viscosity. Summary of the invention

[0006] In various embodiments, an edge guide is provided that contacts molten glass to assist in controlling the shape of the molten glass. The edge guide can be at least partially immersed in the molten glass by a few millimeters (e.g., less than about 1 mm, less than about 3 mm, less than about 5 mm, etc.) to obtain sufficient wetting such that the molten glass travels vertically along the edge guide and then departs from the edge guide due to a pulling force (e.g., due to a downstream roller, roll gap, etc.).

[0007] The edge guide is actively heated, and the edge guide can be heated using an internal oxy - hydrogen burner that generates heat that is transferred to the molten glass. The heat transferred to the molten glass can reduce glass attenuation and improve the edge - flow stability of the molten glass by increasing the viscosity of the center of the molten glass when supported and reheated at the edge.

[0008] A burner or other heat source can be utilized to heat the edge guide. In some embodiments, the heat generated can be adjusted (e.g., by increasing or decreasing the size of the flame), thereby allowing the viscosity of the portion of the molten glass at the edge of the molten glass to be adjusted. In some embodiments, the heat at the edge guide can be controlled to a temperature of up to about 1200 degrees Celsius. By heating the edge guide, the edge guide can assist in adjusting the viscosity of some portions of the molten glass. Compared to current slot drawing methods, the edge guide can enable the glass to be formed at a relatively lower viscosity. In some embodiments, the forming viscosity of the molten glass can be maintained between about 50 kilopoise and about 500 kilopoise, within a narrower range, or at about 100 kilopoise. However, the forming viscosity can be adjusted as needed by adjusting the temperature at the edge guide or by changing other properties of the edge guide.

[0009] In some embodiments, the edge guide can be removable to increase its ease of use. In some embodiments, the edge guide may be separable relative to the burner, thereby allowing the removal and replacement of the edge guide. This can improve the simplicity of maintenance and increase the efficiency of use, as it allows the molten glass to continue flowing even when the edge guide is being replaced and makes it easy to remove any inclusions that may accumulate on the edge guide. The use of the edge guide can reduce the temperature gradient across the width of the molten glass, thereby resulting in a reduction in the residual stress retained in any final glass product formed.

[0010] Since the thickness at the edge of the molten glass is similar to the center sheet thickness, the cooling distribution may be more uniform across the width of the molten glass. This may result in lower residual stress, which can help avoid sheet breakage when cutting the sheet. As described above, heat removal at the slot is another potential source of non-uniform cooling distribution, resulting in residual stress generation in the molten glass during drawing. Therefore, when using an edge guide, heat removal techniques can be avoided. The absence of heat removal at the edge of the slot also makes the system compatible with lower liquidus glass compositions. In the case of performing heat removal, since the forming temperature is below the liquidus temperature, heat removal techniques may limit the range of glass compositions that can be used, resulting in devitrification of the glass at the edge over time. This devitrification causes inclusions to appear in the glass, thereby damaging the final glass product formed and potentially distorting the glass shape and other properties.

[0011] Systems and methods using the edge guides of the various embodiments described herein can provide several other potential advantages. The edge guides can help improve the edge flow stability at the edges of the molten glass. This stability can be improved in terms of the left - right movement of the molten glass (e.g., glass deflection), and the stability can also be improved in terms of the change in the width of the glass sheet. By providing improved stability, the quality region of the molten glass can be increased, thereby allowing the formation of a final glass product with improved properties. For example, a final glass product with a greater width can be made, a glass product with a reduced thickness can be made, and / or the glass product can have a reduced thickness variation. Additionally, the edge guides can assist in reducing glass attenuation, such that the width of the molten glass can be increased, and this reduction in glass attenuation can lead to an increase in the width of the quality region. In some embodiments, the positioning of the edge guides can be controlled to adjust the properties of the molten glass flow. For example, the positioning of the edge guides relative to the glass root can be adjusted and / or the immersion depth of the edge guides can potentially be adjusted.

[0012] The various example edge guides described herein can be used to assist in forming glass with a very small thickness (about 2 millimeters or less). The final glass product formed using the edge guides can be used in flexible mobile devices, such as smartphones with foldable screens, other electronic devices with foldable screens, and other applications that require thin foldable glass.

[0013] In an example embodiment, a system for controlling the shape of molten glass is provided. The system includes a feeder that defines an internal space and a slot near the bottom portion of the feeder. The internal space is configured to receive molten glass such that the molten glass exits the feeder at the slot. The system also includes a burner configured to produce a flame. Additionally, the system includes one or more edge guides positioned relative to the slot. Each edge guide includes a body portion that defines a first internal cavity and a contact portion configured to contact the molten glass. The edge guides are positioned such that the contact portion is at least partially immersed in the molten glass and thus controls the shape of the molten glass. When a flame is produced by the burner, the heat from the flame is configured to cause the molten glass near the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass near the central portion of the molten glass.

[0014] In some embodiments, the heat from the flame can be emitted through the first internal cavity towards the contact portion and into the molten glass that contacts the edge guide. In some embodiments, controlling the shape of the molten glass can increase the quality region of the molten glass. The quality region of the molten glass can have a thickness within a specific range of less than about 0.5 millimeters over a width of at least about 120 millimeters.

[0015] In some embodiments, each edge guide may include an exhaust portion attached to the body portion. The exhaust portion may define a second internal cavity and an outlet. The second internal cavity and the outlet are in fluid communication with each other. Additionally, in some embodiments, the body portion may extend at least partially along a first axis, the exhaust portion may extend at least partially along a second axis, and the first axis may be offset at an acute angle relative to the second axis.

[0016] In some embodiments, an edge guide among the edge guides may be configured to be replaced by raising the temperature level at the edge guide, moving the edge guide away from the molten glass, removing any excess molten glass from the edge guide, preheating the replacement edge guide, and moving the replacement edge guide toward the molten glass until the replacement edge guide is at least partially immersed in the molten glass.

[0017] In some embodiments, the contact portion may define a guide slot or a concave, convex, flat, ridged, multi-jointed, or curved shape. In some embodiments, the edge guide may be positioned between about 1 millimeter and about 5 millimeters below the slot. In some embodiments, the edge guide may include a first edge guide and a second edge guide, the molten glass may define a first edge and a second edge, and the first edge guide may be at least partially immersed in the molten glass proximate the first edge, and the second edge guide may be at least partially immersed in the molten glass proximate the second edge.

[0018] Additionally, in some embodiments, the burner may include a burner tip that emits a flame, and the burner may be water-cooled. Further, in some embodiments, each edge guide among the edge guides may be attached to a drain port. In some embodiments, the system may further include a burner assembly that includes a burner, a drain port, and an outer tube extending from the drain port to proximate the burner tip. The body portion may extend upward along an inclination angle between the burner and the contact portion, the outer tube may be configured to receive water at a portion between the burner tip and the drain port, and the drain port may be positioned at a height lower than the contact portion. Additionally, in some embodiments, the burner may be configured to generate steam, the steam condenses to form byproduct water, and the byproduct water may flow to at least one of the outlet or the drain port.

[0019] In another exemplary embodiment, a method for controlling the shape of molten glass is provided. The method includes causing molten glass to flow downwardly from a slot of a feeder. The method further includes positioning one or more edge guides relative to the slot. Each of the edge guides includes a body portion defining a first internal cavity and a contact portion. Additionally, the method includes generating a flame at a burner such that heat from the flame causes the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass. The edge guide is positioned such that the contact portion is at least partially immersed in the molten glass and thereby controls the shape of the molten glass.

[0020] In some embodiments, positioning the edge guide relative to the slot can cause the contact portion to be at least partially immersed in the molten glass. Additionally, in some embodiments, positioning the edge guide relative to the slot can increase a mass region of the molten glass, and the mass region of the molten glass can have a thickness within a specific range of less than about 0.5 millimeters over a width of at least about 120 millimeters.

[0021] In some embodiments, the edge guide can include a first edge guide, and the method can further include raising a temperature level at the first edge guide, moving the first edge guide away from the molten glass, removing any excess molten glass from the first edge guide, preheating a replacement edge guide, and moving the replacement edge guide toward the molten glass until the replacement edge guide is at least partially immersed in the molten glass.

[0022] In some embodiments, the contact portion can define a guiding slot or a concave, convex, flat, ridged, multi-jointed, or curved shape. In some embodiments, the contact between the contact portion and the molten glass can reduce the viscosity of the molten glass. In some embodiments, the edge guide can be positioned between about 1 millimeter and about 5 millimeters below the slot of the feeder.

[0023] In some embodiments, each of the edge guides can include an exhaust portion attached to the body portion. The exhaust portion can define a second internal cavity and an outlet, and the first internal cavity, the second internal cavity, and the outlet are in fluid communication with each other. The body portion can extend at least partially along a first axis (which can be a central axis or a longitudinal axis of the body portion), the exhaust portion can extend at least partially along a second axis (which can be a central axis or a longitudinal axis of the exhaust portion), and the first axis can be offset at an acute angle relative to the second axis.

[0024] In another exemplary embodiment, an edge guide for controlling the shape of molten glass is provided. The edge guide includes a body portion defining a first internal cavity and a contact portion configured to contact the molten glass. The edge guide is positioned such that the contact portion is at least partially immersed in the molten glass and thereby controls the shape of the molten glass. The edge guide is configured to be positioned relative to a burner such that when a flame is generated by the burner, heat from the flame is configured to cause the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass.

[0025] In another exemplary embodiment, a system for controlling the shape of molten glass is provided. The system includes a feeder that defines an internal space and a slot proximate a bottom portion of the feeder, wherein the internal space is connected to the slot and wherein the internal space is configured to receive molten glass such that the molten glass exits the feeder at the slot. The system further includes a burner configured to generate a flame. Additionally, the system includes one or more edge guides positioned relative to the slot, and each edge guide includes a body portion defining a first internal cavity and a contact portion configured to contact the molten glass. When a flame is generated by the burner, heat from the flame travels through the first internal cavity toward the contact portion and into the molten glass flowing over the contact portion of the edge guide. The heat from the flame is configured to cause the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass. Additionally, the contact portion of the edge guide affects the shape of the molten glass such that, over a width of at least about 120 millimeters, the difference between the maximum thickness and the minimum thickness of the molten glass is about 0.5 millimeters or less.

[0026] In another exemplary embodiment, a glass sheet made by a particular process is provided. The process includes flowing molten glass downwardly from a slot of a feeder. The process further includes positioning one or more edge guides relative to the slot, wherein each edge guide of the edge guides includes a body portion and a contact portion. The body portion defines a first internal cavity. The contact portion is configured to contact the molten glass to control the shape of the molten glass, and the edge guide is positioned such that the contact portion is at least partially immersed in the molten glass and such that the contact portion controls the shape of the molten glass. The process further includes generating a flame at a burner such that heat from the flame is configured to cause the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass.

[0027] In another exemplary embodiment, a glass sheet made by a specific process is provided. The process includes flowing molten glass downwardly from a slot of a feeder. The process further includes positioning one or more edge guides relative to the slot. Each of the edge guides includes a body portion and a contact portion. The body portion defines a first internal cavity. Additionally, the contact portion is configured to contact the molten glass, wherein the edge guide is positioned such that the contact portion is at least partially immersed in the molten glass and thereby controls the shape of the molten glass. The process further includes generating a flame at a burner such that heat from the flame causes the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass. The process further includes cutting the molten glass to remove a portion of the molten glass at a region proximate an edge of the molten glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Reference will now be made to the accompanying drawings, which are not drawn to scale, and in which:

[0029] Figure 1 is a schematic view illustrating an example system including an edge guide in accordance with some embodiments discussed herein;

[0030] Figure 2A is a perspective view illustrating an example edge guide assembly in accordance with some embodiments discussed herein;

[0031] Figure 2B is an illustration of an example edge guide in an edge guide assembly in accordance with some embodiments discussed herein Figure 2A in an enhanced view;

[0032] Figure 3A is a schematic view illustrating an outer tube of an example edge guide and burner assembly in accordance with some embodiments discussed herein, wherein the edge guide is separated from the outer tube;

[0033] Figure 3B is an illustration of an example edge guide in accordance with some embodiments discussed herein Figure 3A partially received within an outer tube of a burner assembly;

[0034] Figure 4A is a cross-sectional view illustrating an example edge guide received within an outer tube of a burner assembly in accordance with some embodiments discussed herein;

[0035] Figure 4B is an illustration of an example edge guide and an outer tube in accordance with some embodiments discussed herein Figure 4A in a front cross-sectional view;

[0036] Figure 4CIs a schematic diagram illustrating various contact portions that can be used in an edge guide according to some embodiments discussed herein;

[0037] Figure 5 Is a bottom perspective view of a glass sheet having an edge guide formed only at one edge of the molten glass according to some embodiments discussed herein;

[0038] Figure 6 Is a graph illustrating the variation of the molten glass thickness with the lateral position on the molten glass of two different glass sheets according to some embodiments discussed herein, where the first glass sheet is formed without using any edge guide, and where the second glass sheet is formed with an edge guide only on one edge of the molten glass;

[0039] Figure 7 Is a bottom perspective view of a glass sheet having edge guides formed on two edges of the molten glass according to some embodiments discussed herein;

[0040] Figure 8 Is a graph illustrating the variation of the molten glass thickness with the lateral position on the molten glass of two different glass sheets according to some embodiments discussed herein, where the first glass sheet is formed without using any edge guide, and where the second glass sheet is formed with edge guides on two edges of the molten glass;

[0041] Figure 9A Is a graph illustrating the retardation levels at different lateral orientations along the width of the molten glass under three different operating conditions according to some embodiments discussed herein;

[0042] Figure 9B Is a graph illustrating the variation of the temperature at the contact portion of the edge guide over time with the adjustment of the hydrogen level, oxygen level, and mass flow rate according to some embodiments discussed herein;

[0043] Figure 10 Is a flowchart illustrating an example method of using one or more edge guides according to some embodiments discussed herein; and

[0044] Figure 11 Is a flowchart illustrating an example method for replacing one or more edge guides according to some embodiments discussed herein. Detailed Description

[0045] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings, which show some, but not all embodiments. Like reference numerals generally refer to like elements throughout. For example, reference numerals 108, 508, and 708 all refer to molten glass. Additionally, unless otherwise specifically noted, any connection or attachment can be a direct or indirect connection or attachment.

[0046] Figure 1 FIG. is a schematic diagram illustrating an example system 100 that includes edge guide assemblies 112A, 112B, where system 100 is configured to control the shape of molten glass 108. System 100 also includes a feeder 104. Feeder 104 defines an internal space and a slot 106 proximate a bottom portion of feeder 104. The internal space is configured to receive molten glass 108, and the internal space is in fluid communication with slot 106 such that molten glass 108 exits the feeder at slot 106. Molten glass 108 moves downwardly due to the force of gravity, where molten glass 108 extends between a first edge 108A and a second edge 108B.

[0047] System 100 also includes a first edge guide assembly 112A and a second edge guide assembly 112B. The edge guide assemblies 112A, 112B will be described in more detail herein with reference to Figures 2A to 2B and other figures. Each of the edge guide assemblies 112A, 112B includes an edge guide positioned relative to slot 106. The edge guide of edge guide assembly 112A is immersible in the molten glass proximate first edge 108A, and the edge guide of edge guide assembly 112B is immersible in the molten glass proximate second edge 108B. In some embodiments, the edge guide may extend into the molten glass 108 at edges 108A, 108B by about 0 millimeters to about 10 millimeters or so. However, in other embodiments, the edge guide may extend into the molten glass 108 a different distance. Although some heat generated within the edge guide may travel through the solid portion of the edge guide by conduction, some heat or a portion of the flame may travel through the internal space of the edge guide and exit through the outlets in the directions indicated by arrows D1, D2. The outlets are oriented such that the direction is at least partially angled away from the molten glass 108. By doing so, the heat transferred to the molten glass can be better controlled. The heat generated by the flame may be configured to cause the molten glass 108 proximate the edge guide assemblies 112A, 112B to have a first viscosity that is greater than a second viscosity of the molten glass 108 proximate a central portion of the molten glass 108. Thus, the heat from the flame can result in a viscosity gradient across the width of the molten glass.

[0048] The edge guides of the edge guide assemblies 112A, 112B can be positioned at a distance A below the slot 106 of the feeder 104. The distance A can be measured from the highest point of the edge guide to the bottommost part of the slot 106. In some embodiments, the distance A can be greater than zero millimeters but less than about 5 millimeters below the slot 106. Additionally, in some embodiments, the distance A can be greater than about 1 millimeter but less than about 5 millimeters below the slot 106. By adjusting the vertical positioning of the edge guide assemblies 112A, 112B, the viscosity of the molten glass can be significantly changed, and this change in viscosity can result in a significant change in the lateral force acting on the molten glass. Positioning the edge guide assemblies 112A, 112B at a distance A less than about 5 millimeters below the slot 106 can result in the molten glass having a desired level of viscosity and lateral force. Additionally, by positioning the edge guide assemblies 112A, 112B at a distance A less than about 5 millimeters below the slot 106, the flow properties of the molten glass may be more desirable. Additionally, the edge guides of the edge guide assemblies 112A, 112B can each be positioned such that the tip of the edge guide is positioned at a distance A' away from the edge of the slot when measured horizontally. In some embodiments, the distance A' can be about 15 millimeters, but in other embodiments the distance A' can be different.

[0049] As the molten glass 108 moves downward, the molten glass 108 may tend to cool, where the molten glass 108 eventually solidifies to form a solidified processed glass sheet. The molten glass or the processed glass sheet can extend through the gap between the two rollers 110. The rollers 110 can be positioned at a distance B below the slot 106. In some embodiments, the distance B can be about 1.5 meters. However, in other embodiments, the rollers can be positioned at different distances from the slot 106. In Figure 1 the illustrated embodiment, two rollers 110 are provided, and the rollers 110 extend across the entire width of the molten glass 108. However, in other embodiments, a different number of rollers 110 can be used. For example, four rollers can be used, where two rollers are positioned near the first edge 108A of the molten glass 108, and where the other two rollers are positioned near the second edge 108B of the molten glass 108, with no rollers positioned within the central portion of the molten glass. Eventually, one or more cutters 107 can be used to cut the processed glass sheet. In Figure 1In the illustrated embodiment, the cutter 107 is a laser cutter configured to emit a laser 107A toward the glass sheet being processed. The cutter 107 may also be configured to remove material adjacent to the first edge 108A and the second edge 108B, and this may be beneficial because the properties of the glass (e.g., thickness) at these edges 108A, 108B may be different relative to the central portion of the molten glass 108. Once cut, the processed glass sheet may be processed in other ways to help form the final glass product 105.

[0050] Figure 2A An example edge guide assembly 212 including an edge guide 202 and a burner 218 is illustrated. The edge guide 202 includes a body portion 216A, an exhaust portion 216B, and a contact portion 216C. In Figure 2A it, the body portion 216A includes an inner tube 216, and the inner tube 216 may be received within the inner space of an outer tube 214 such that an effective seal is formed between the inner tube 216 and the outer tube 214, wherein the outer surface of the inner tube 216 is attached to the inner surface of the outer tube. The body portion 216A defines an inner cavity extending through the outer tube 214 and the inner tube 216. Portions or all of the contact portion 216C are configured to contact the molten glass and are configured to control the shape of the molten glass. The exhaust portion 216B is attached to the body portion 216A, wherein the exhaust portion 216B defines a second inner cavity and an outlet 216D.

[0051] As Figure 2BAs shown in the enhanced view, the burner 218 can be positioned such that it will produce a flame that will be emitted into the edge guide 202. The burner 218 can define a burner tip 218A that produces the flame. The burner 218 can extend into the outer tube 214 and partially into the inner tube 216 such that the burner tip 218A is positioned within the internal space of the inner tube 216. The burner 218 can be configured to emit oxygen and hydrogen at the burner tip 218A. Additionally, in some embodiments, a water source can be configured to discharge water into the outer tube 214 to assist in cooling the burner 218. When a flame is produced by the burner 218, heat from the flame is emitted through the internal cavity within the edge guide 202 and discharged from the outlet 216D. More specifically, some of the heat from the flame is emitted by convection through a first internal cavity defined at the body portion 216A towards the contact portion 216C and then through a second internal cavity defined at the exhaust portion 216B until the heat is discharged from the outlet 216D. Additionally, some of the heat can also be emitted via conduction through the solid portion of the edge guide 202 such that the heat is conducted to the molten glass flowing on the edge guide 202 near the contact portion 216C. In the edge guide 202, the body portion 216A defines a first axis A1 that generally extends through the center of the body portion 216A, the exhaust portion 216B defines a second axis A2 that generally extends through the center of the exhaust portion 216B, and the axes A1, A2 are angularly offset from each other by an angle 2. In some embodiments, the angle 2 can be an acute angle such that when the edge guide 202 is in use, any heat or flame emitted from the outlet is directed away from the molten glass, as Figure 1 shown by the arrows D1, D2.

[0052] Figure 2A The edge guide assembly 212 includes a burner assembly 211, where the burner assembly 211 includes a burner 218, an outer tube 214, and a drain port 222. By inserting the inner tube 216 of the edge guide 202 into the outer tube 214 of the burner assembly 211, the edge guide 202 can be removably attached to the burner assembly 211. The body portion 216A of the edge guide 202 is angled 1. When the burner 218 is a hydrogen-oxygen burner, steam or water can be produced as a by-product of combustion. When steam is produced, it may eventually condense into water. A portion of this steam or water can be pushed through the edge guide 202 and discharged from the outlet 216D. Other portions of this steam or water can be pushed in the opposite direction and thus move backward towards the drain port 222. Due to the angled 1. The drain port 222 can be positioned at a height lower than the contact portion 216C. In some embodiments, the internal space of the outer tube 214 can include water therein to assist in cooling the burner 218. In this case, due to the inclination of the edge guide 202, the water for cooling the burner 218 generally stays at a position between the burner tip 218A and the drain port 222. Although the burner 218 is utilized in the Figures 2A to 2B illustrated embodiment, other heat sources can also be used. For example, in some embodiments, an electric heater or some other heat source can be used instead of the burner 218 and other burners described herein.

[0053] In some embodiments, the edge guide assembly 212 can be mounted to the mounting bracket 226, and the positioning of the edge guide assembly 212 is adjustable. For example, the joint 223 can be adjusted relative to the arm 228 to move the edge guide 202 along the axis B1, the edge guide 202 can be rotated about the X axis (as indicated by the arrow B2) by rotating the arm 228 relative to the ball-and-socket joint 224, the edge guide 202 can be moved up and down along the axis B3 (which can be parallel to the Y axis) using the ball-and-socket joint 224, the edge guide 202 can be moved along the axis B4 (which can be parallel to the X axis) by moving the ball-and-socket joint 224 relative to the mounting bracket 226, or the edge guide 202 can be rotated about the Y axis (as indicated by the arrow B5) by rotating the ball-and-socket joint 224 relative to the mounting bracket 226. However, the edge guide assembly 212 can also be moved in other ways. Additionally, in other embodiments, the arrangement of the edge guide assembly 212 may be different. In some embodiments, an actuator can be used to automatically move the edge guide assembly 212, and this can be beneficial for reducing the exposure of human operators to hot molten glass and improving the safety of the edge guide assembly 212. By allowing adjustment of the positioning of the components of the edge guide assembly 212, the X, Y, and Z positioning of the edge guide assembly can be adjusted, the distance between the edge guide and the slot can be adjusted, the positioning of the edge guide relative to the center thickness plane of the molten glass can be adjusted, the immersion depth can be adjusted, the entry angle of the edge guide into the attenuation zone of the molten glass can be adjusted, etc.

[0054] Figures 3A to 3B is a schematic diagram illustrating an exemplary edge guide 302 and outer tube 314 of a burner assembly. In Figure 3A it, the edge guide 302 is separated from the outer tube 314, while in Figure 3BIn it, the edge guide 302 is partially received within the outer tube 314. The outer tube 314 may generally define a circular cross-sectional shape and an internal space that also has a circular shape, where the outer tube 314 defines an outer diameter of approximately 14 millimeters and an inner diameter of approximately 10 millimeters. Additionally, the outer tube 314 defines an outer surface 315A and an inner surface 315B. The outer tube 314 defines a length C. In some embodiments, the length C may be approximately 300 millimeters, but in other embodiments the length C may have other values.

[0055] The edge guide 302 includes an inner tube 316. The inner tube 316 may generally define a circular cross-sectional shape and an internal space that also has a circular shape, where the inner tube 316 defines an outer diameter of approximately 10 millimeters and an inner diameter of approximately 6 millimeters. The inner tube 316 defines an outer surface 317A and an inner surface 317B. The outer surface 317A of the inner tube 316 may be attached to the inner surface 315B of the outer tube 314, and in some embodiments, an effective seal may be formed between the surfaces 315B, 317A. The outer tube 314 may overlap the inner tube 316 by an overlap length E. In some embodiments, the overlap length E may be approximately 25 millimeters, but in other embodiments, the overlap length E may have other values. The outer tube 314 may be positioned relative to the inner tube 316 such that the outer tube 314 is positioned at a distance D from the tip of the contact portion 316C when measured in the length direction of the body portion 316A (e.g., horizontally in FIG. 3). In some embodiments, the distance D may be approximately 50 millimeters, but in other embodiments, the distance D may have other values. Additionally, as Figure 3A shown, in some embodiments, the inner tube 316 may define a length G of approximately 75 millimeters (e.g., the distance D plus the overlap length E), but in other embodiments the length G may be different.

[0056] The edge guide 302 includes an exhaust portion 316B that is attached to the inner tube 316 at the body portion 316A of the edge guide 302 such that the internal space of the body portion 316A is in fluid communication with the internal space of the exhaust portion 316B and an outlet 316D located at the end of the exhaust portion 316B. Different from some other embodiments described herein, the exhaust portion 316B is positioned at a distance F from the contact portion 316C of the edge guide 302. The distance F can be measured along the length direction of the body portion 316A (e.g., horizontally in FIG. 3) from the center of the exhaust portion 316B to the most tip of the contact portion 316C. In some embodiments, the distance F can be about 25 millimeters. However, in other embodiments, the distance F can have other values. Additionally, in some embodiments, the distance F can be zero, as illustrated in the figures and exemplified by other embodiments described herein. The distance F can be selected to adjust the distance from the flame to the exhaust portion 316B and to adjust the distance from the exhaust portion 316B to any molten glass. Although the exhaust portion 316B is illustrated as having a smaller diameter than the body portion 316A, in some embodiments, the size of the exhaust portion 316B can be greater than or equal to the size of the body portion 316A.

[0057] Similar to Figures 2A to 2B the edge guide 202, the body portion 316A of the edge guide 302 extends at least partially along a first axis, a portion of the exhaust portion 316B extends at least partially along a second axis, and the first axis is offset at an acute angle with respect to the second axis.

[0058] As Figures 3A to 3B shown, in some embodiments, the edge guide can be easily replaced without damaging the overall forming platform. For example, the edge guide can be replaced without replacing or otherwise adjusting the slot assembly, the heating chamber, or the burner assembly. The replacement can also be performed while the molten glass is still flowing, thus avoiding interruptions in the upstream processes such as glass melting and clarification.

[0059] Figure 4AA cross-sectional illustration shows another example edge guide 402. The edge guide 402 includes a body portion 416A which includes an inner tube 416. Additionally, the burner assembly may include an outer tube 414. The outer tube 414 is configured to receive the inner tube 416 of the edge guide 402 within the inner space of the outer tube 414. The outer tube 414 has an outer surface 415A and an inner surface 415B, and the inner tube 416 also has an outer surface 417A and an inner surface 417B. The outer surface 417A of the inner tube 416 is generally in contact with the inner surface 415B of the outer tube 414, and the surfaces 417A, 415B may be attached together to form a seal. The surfaces 417A, 415B may be attached together using an adhesive, but in other embodiments the adhesive may be omitted and the surfaces 417A, 415B may be attached together in other ways. Figure 4A A contact portion 416C is shown in Figure 4A , where the contact portion is generally hemispherical, but contact portions having other shapes may also be used, such as Figure 4C shown.

[0060] The edge guide 402 also includes an exhaust portion 416B. The exhaust portion 416B is attached to the body portion 416A at the inner tube 416. The body portion 416A may define an internal cavity within the surfaces 415B, 417B, and may also define another internal cavity in the exhaust portion 416B which is in fluid communication with the internal cavity of the body portion 416A such that heat, fluid, flame, other materials, etc. can flow to an outlet 416D at the end of the exhaust portion 416B. The exhaust portion 416B extends at an angle 3 with respect to the longitudinal direction of the inner tube 416. The angle 3 can have a wide variety of values. In some embodiments, the angle 3 can have a value between about 0 degrees and about 90 degrees. Additionally, the exhaust portion 416B may extend towards the right side of the edge guide 402 in Figure 4A (e.g., the range of the angle 3 can be a value between 0 degrees and about -90 degrees).

[0061] Figure 4AAlso illustrated is a burner 418 within the edge guide 402. The burner 418 may extend longitudinally through the center of the body portion 416A. In some embodiments, the burner 418 may generally be defined as having a cylindrical shape or a prismatic shape, but the burner 418 may also have other shapes. The burner 418 may extend to a burner tip 418A, and the burner 418 may be configured to emit a flame at the burner tip 418A. The burner 418 may extend partially into the internal space defined by the inner tube 416, but there may be a space 421 between the burner 418 and the inner surface 417B of the inner tube 416. This space 421 may allow some substances (such as vapor or water that may be produced as a by-product of combustion) to flow, such that the vapor or water may flow back to the drain 222 (see Figure 2A ). In Figure 4A , this space 421 extends circumferentially around the burner 418, but in other embodiments, the space 421 may have a different shape.

[0062] Figure 4B The front cross-sectional view of Figure 4A further illustrates in detail the edge guide 402 of Figure 4B . As Figure 4B can be seen, both the outer tube 414 and the inner tube 416 generally have a circular shape with a common center point. The exhaust portion 416B is attached to the body portion 416A, and the end of the exhaust portion 416B generally extends at an angle 4 relative to the horizontal plane. This angle 4 can have various values. In some embodiments, the angle 4 can have a value between about 0 degrees and about 90 degrees. Additionally, the exhaust portion 416B may extend towards the right side of the edge guide 402 in Figure 4B (for example, the range of the angle 4 can be a value between 90 degrees and about 180 degrees).

[0063] In some embodiments, the edge guide 402 may generally include materials such as silica, fused silica, platinum (e.g., platinum alloy), nickel (e.g., nickel alloy), quartz, Inconel alloy, or other similar materials. The material of the edge guide 402 may be configured to assist in wetting the molten glass when the material comes into contact with the molten glass.

[0064] The contact portion utilized on the edge guide 402 may be shaped as needed to interact with the molten glass. The contact portion may contact the molten glass at a short distance below the slot of the feeder to reduce the tensile tension caused by the attenuation of the molten glass before the molten glass reaches a higher viscosity at the center to reduce lateral attenuation. Figure 4CSchematic diagrams of various contact portions that can be used. For example, a slotted contact portion 425A can be provided. The slotted contact portion 425A includes portions 427A', 427A" that extend further than the end surface 427A. The surface 427A defines a flat shape, and its taper angle is similar to that of the flat contact portion 425F. In some embodiments, the end surfaces of portions 427A', 427A" can also define a flat shape, and its taper angle is similar to the taper angle of the surface 427A. However, in other embodiments, the surface 427A can define a convex curvature, a concave curvature, or some other shape, and portions 427A', 427A" can still protrude further from the surface 427A. In the case of using the slotted contact portion 425A, the molten glass may tend to stay in the slot formed between portions 427A', 427A".

[0065] Another contact portion that can be used is the concave contact portion 425B. For this concave contact portion 425B, the end surface 427B has a three-dimensional concave curvature. The end surface 427B has a concave shape along curves A3 and A4, where curves A3, A4 are perpendicular to each other at the intersection point. The end surface 427B is usually inclined at an angle.

[0066] A hemispherical contact portion 425C can also be used. For the hemispherical contact portion 425C, the end surface 427C has a hemispherical shape, where the end surface 427C defines a three-dimensional convex curvature.

[0067] As another example, a convex contact portion 425D can be used. For the convex contact portion 425D, a side view is illustrated. The convex contact portion 425D includes an end surface 427D that defines a two-dimensional convex curvature.

[0068] A concave contact portion 425E can also be used. For the concave contact portion 425E, a side view is illustrated. The concave contact portion 425E includes an end surface 427E that defines a two-dimensional concave curvature.

[0069] In addition, a flat contact portion 425F can be used. For the flat contact portion 425F, a side view is illustrated. The flat contact portion 425F includes an end surface 427F that is flat and defines a taper angle with respect to the top and bottom surfaces of the flat contact portion 425F 5. Taper angle 5 can have a variety of values. For example, the taper angle 5 can be a value greater than 0 degrees but less than about 10 degrees, greater than 0 degrees but less than about 8 degrees, greater than 0 degrees but less than about 6 degrees, greater than 0 degrees but less than about 4 degrees, etc.

[0070] Another contact portion 425G that can be used is also illustrated. As indicated by the arrow inside the contact portion 425G, heat from a burner or another heat source can travel through the interior space of the contact portion 425G by convection. When it reaches the end surface 427G, part of this heat can travel through the end surface 427G by conduction, so that heat is transferred to the molten glass flowing on the end surface 427G. Additionally, part of the heat can travel through the interior space by convection and be discharged through the outlet 416D' from the exhaust portion 416B'. The contact portion 425G is unique in that it has a plurality of corner bends 419A, 419B, and the end surface 427G can have an increased surface area in contact with the molten glass. In some embodiments, the end surface 427G can be flat, curved, concentrically curved, concave, convex, slotted, or can have some other shape. The end surface 427G can define a cone angle similar to a cone angle of 5.

[0071] Figure 4C Another contact portion 425H is illustrated, where the contact portion 425H terminates at two flat end surfaces 427H, 427H' on opposite sides of a vertically oriented ridge 431. The end surfaces 427H, 427H' extend straight up and down, but in some embodiments, the end surfaces 427H, 427H' can be inclined at an angle. Additionally, although in Figure 4C the ridge 431 extends straight up and down, in other embodiments the ridge 431 can be inclined at an angle.

[0072] The contact portions 425A - 425H are only examples of potential contact portions that can be used, and other contact portions can also be used.

[0073] Figure 5is a bottom perspective view of an exemplary glass sheet being formed, where an edge guide 502 is positioned at only one edge of the molten glass 508. Similar to other edge guides described herein, the edge guide 502 includes a body portion 516A having an inner tube 516 that is receivable within an outer tube 514 of a burner assembly. The edge guide 502 has a corner bend proximate a contact portion 516C, and an exhaust portion 516B is attached to the body portion 516A proximate the contact portion 516C. The exhaust portion 516B ultimately terminates at an outlet 516D. The contact between the contact portion 516C and the molten glass 508 can reduce the viscosity of the molten glass 508 near the first edge 508A. However, the heating of the molten glass 508 can be controlled such that the viscosity of the molten glass 508 does not decrease too much. In some embodiments, the viscosity of the molten glass 508 can be maintained at a level between about 50 kilopoise and about 500 kilopoise, between 60 kilopoise and about 400 kilopoise, between about 70 kilopoise and about 300 kilopoise, between about 80 kilopoise and about 250 kilopoise, between about 90 kilopoise and about 200 kilopoise, or about 100 kilopoise. The forming viscosity can be adjusted as needed by adjusting the temperature at the edge guide or by changing other properties of the edge guide. By controlling the viscosity, the wetting properties of the molten glass 508 at the edge guide 502 can be controlled as needed.

[0074] The molten glass 508 extends downward from the slot 506. The molten glass 508 extends downward between a first edge 508A and a second edge 508B. The edge guide 502 is positioned such that its proximity to the first edge 508A is partially immersed within the molten glass 508, and in Figure 5 which, no edge guide 502 is positioned proximate the second edge 508B. In some embodiments, the edge guide 502 can be positioned a certain distance below the slot 506. The edge guide 502 is positioned at a first region 528A proximate the slot 506. As the molten glass 508 flows downward into a second region 528B, the width of the molten glass 508 (e.g., from left to right) tends to decrease. However, the lateral position change of the first edge 508A tends to be much smaller than the lateral position change of the second edge 508B, and this tends to show that the edge guide 502 aids in increasing the width of the molten glass 508. From Figures 7 to 8 what is illustrated and the results described herein, this is more apparent.

[0075] The edge guides described herein can control the shape of the molten glass such that the mass region of the molten glass increases, where the mass region of the molten glass has a thickness within a specific range. Figure 6It is a graph 630 illustrating the variation of the thickness of molten glass with the lateral position on the molten glass of two different glass sheets, where the first glass sheet is formed without using any edge guide, and where the second glass sheet is formed with an edge guide only on one edge of the molten glass.

[0076] In graph 630, the first plotting line 632 illustrates the thickness distribution without using an edge guide. The first plotting line 632 extends between an end region 632A and an end region 632B. Both end regions 632A, 632B have a thickness of approximately 2.5 millimeters. However, in the central portion of the first plotting line 632, the thickness is approximately 1.5 millimeters. In the case where the thickness of the final glass product must be maintained within + / - 0.1 millimeter of the target thickness, only approximately 70 millimeters of the glass can fall within this target thickness range.

[0077] Additionally, the second plotting line 634 illustrates the thickness distribution in the case of using an edge guide only on one edge as Figure 5 shown. The second plotting line 634 extends between an end region 634A and an end region 634B, where the end region 634A corresponds to the edge of the molten glass in the case of using an edge guide, and where the end region 634B corresponds to the edge of the molten glass in the case of not using an edge guide. Similar to the end regions 632A, 632B of the first plotting line, the thickness of the end region 634B of the second plotting line is about 2.5 millimeters. However, the end region 634A of the second plotting line 634 is about 1.25 millimeters, which is very similar to the thickness at other central portions of the second plotting line 634. In the central portion of the second plotting line 634, the thickness ranges between approximately 1.1 millimeters and approximately 1.5 millimeters. In the case where the thickness of the final glass product must be maintained within + / - 0.1 millimeter of the target thickness, approximately 85 millimeters of the glass can fall within this target thickness range. Thus, even using only one edge guide tends to improve thickness uniformity.

[0078] It is worth noting that the second plotting line 634 has other differences relative to the first plotting line 632. For example, the second plotting line 634 spreads out over a greater width, and this is due to the addition of the edge guide. Additionally, most of the second plotting line 634 has a smaller thickness relative to the first plotting line 632.

[0079] Figure 7Is a bottom perspective view of an exemplary glass sheet being formed, where a first edge guide 702 is positioned at a first edge 708A of molten glass 708, and where a second edge guide 702' is positioned at a second edge 708B of molten glass 708. In some embodiments, the edge guides 702, 702' may be positioned a certain distance below the slot 706. Similar to other edge guides described herein, the first edge guide 702 includes a body portion 716A having an inner tube 716 configured to be received within an outer tube 714 of a burner assembly. The first edge guide 702 has a corner bend near the contact portion 716C, and an exhaust portion 716B is attached to the body portion 716A near the contact portion 716C. The exhaust portion 716B ultimately ends at an outlet 716D. Similar to other edge guides described herein, the second edge guide 702' includes a body portion 716A' having an inner tube 716' configured to be received within an outer tube 714' of a second burner assembly. The second edge guide 702' has a corner bend near the contact portion 716C', and an exhaust portion 716B' is attached to the body portion 716A' near the contact portion 716C'. The exhaust portion 716B' ultimately ends at an outlet 716D'.

[0080] The contact between the contact portions 716C, 716C' and the molten glass 708 can reduce the viscosity of the molten glass 708. However, the heating of the molten glass 708 can be controlled such that the viscosity of the molten glass 708 does not decrease too much. In some embodiments, the viscosity of the molten glass 708 can be maintained at a level between about 50 kilopascals and about 500 kilopascals, between 60 kilopascals and about 400 kilopascals, between about 70 kilopascals and about 300 kilopascals, between about 80 kilopascals and about 250 kilopascals, between about 90 kilopascals and about 200 kilopascals, or about 100 kilopascals. The forming viscosity can be adjusted as needed by adjusting the temperature at the edge guide or by changing other properties of the edge guide. By controlling the viscosity, the wetting properties of the molten glass 708 at the edge guide 702 can be controlled as needed.

[0081] The molten glass 708 extends downward from the slot 706. The molten glass 708 extends downward between a first edge 708A and a second edge 708B. The first edge guide 702 is positioned such that it is partially immersed in the molten glass 708 near the first edge 708A, and the first edge guide 702 is positioned such that it is partially immersed in the molten glass 708 near the second edge 708B. The immersion depths of the edge guides 702, 702' can have different values. For example, the immersion depth can be between about 0 mm and about 10 mm, between about 0 mm and about 8 mm, between about 0 mm and about 6 mm, between about 0 mm and about 4 mm, etc. Both of the edge guides 702, 702' are positioned at a first region 728A close to the slot 706. When the molten glass 708 flows downward into the second region 728B, the width of the molten glass 708 (e.g., from left to right) tends to decrease. However, the width of the molten glass 708 is significantly greater than the width of the molten glass formed without edge guides or with only one edge guide.

[0082] As Figure 7 shown, there may be some deviation in the width of the glass from the first edge 708A to the second edge 708B according to the distance from the slot 706. For example, at the first region 728A (which is close to the slot 706), the width of the glass from the first edge 708A to the second edge 708B can be greater than the width of the glass from the first edge 708A to the second edge 708B at the second region 728B (which is positioned at a greater distance relative to the first region 728A away from the slot 706).

[0083] Although the edge guides 502, 702, 702' generally extend in a longitudinal direction parallel to the central plane formed by the molten glass 508, 708, in other embodiments, the edge guides can be positioned and / or oriented in different ways. Additionally, although each of the edge guides 502, 702, 702' contacts the molten glass only at the edges of the molten glass, other edge guides that contact other parts of the molten glass (such as the sides and / or central part of the molten glass) can also be utilized.

[0084] The edge guides described herein can control the shape of the molten glass such that the mass area of the molten glass increases, where the mass area of the molten glass has a thickness within a specific range. Figure 8 is a graph 836 illustrating the variation of the glass thickness with the lateral position on the glass of two different glass sheets, where the first glass sheet is formed without using any edge guides, and where the second glass sheet is formed with edge guides on both edges of the molten glass.

[0085] In Chart 830, the first plotting line 838 illustrates the thickness distribution without using edge guides. The first plotting line 838 extends between an end region 838A and an end region 838B. Both end regions 838A, 838B have a thickness of approximately 2.5 millimeters. However, in the central portion of the first plotting line 838, the thickness is approximately 1.5 millimeters. In the case where the thickness of the final glass product must be maintained within + / - 0.1 millimeter of the target thickness, only approximately 75 millimeters of the glass can fall within this target thickness range.

[0086] Additionally, the second plotting line 840 illustrates the thickness distribution in the case of using edge guides at both edges of the molten glass as Figure 7 shown. The second plotting line 840 extends between an end region 840A and an end region 840B. Different from the end regions 838A, 838B of the first plotting line 838, the thicknesses of the end regions 840A, 840B of the second plotting line 840 are both about 1.5 millimeters. In the central portion of the second plotting line, the thickness ranges between a thickness of approximately 1.3 millimeters and a thickness of approximately 1.5 millimeters. In the case where the thickness of the final glass product must be maintained within + / - 0.1 millimeter of the target thickness, in fact all 142 millimeters of the glass represented by the second plotting line 840 fall within this thickness range. Therefore, the second plotting line 840 demonstrates that the edge guides can significantly improve the thickness uniformity within the glass. However, in other embodiments, the thickness can deviate from the target thickness by less than 0.25 millimeter over a width of at least 120 millimeters, the thickness can deviate from the target thickness by less than 0.1 millimeter over a width of at least 120 millimeters, or the thickness can deviate by other amounts. In some embodiments, using edge guides at both edges of the molten glass can make the thickness near the edges of the molten glass less than the thickness at the central portion of the molten glass. Additionally, in some embodiments, using edge guides can cause the edges of the processed glass sheet to terminate with a very small radius.

[0087] It is worth noting that the second plotting line 840 has other differences relative to the first plotting line 838 and even Figure 6 the plotting line 634 (where only one edge guide is used). For example, the second plotting line 840 spreads out over a greater width, and this is due to the use of two edge guides. In the case of using two edge guides instead of zero edge guides, the width can increase by about 40 millimeters, and in the case of using two edge guides instead of only one edge guide, the width can also increase by about 17 millimeters. Additionally, most of the second plotting line 840 has a smaller thickness relative to the first plotting line 838.

[0088] Using an edge guide may also help reduce stress in the formed glass product. Optical retardation is typically affected by the amount of stress in the glass product and the thickness of the glass product. Thus, reducing the amount of stress in the glass product may also result in a reduction in optical retardation. Figure 9A FIG. 942 is a graph illustrating the variation of optical retardation (in nanometers) with glass width (in millimeters) under three different operating conditions. Plot line 944 illustrates control data where the molten glass is allowed to freely exit the slot without any edge guide or heat removal technique. Plot line 946 uses a heat removal technique, and plot line 948 uses an edge guide as presented in various embodiments herein. The data shown in FIG. 942 shows that plot line 946 is higher in the central portion of the glass relative to plot lines 944 and 948, and this shows that using heat removal increases stress in the glass compared to other systems using edge guides and other control systems. Except for the lateral position between 0 mm and 5 mm in FIG. 942, plot line 948 generally maintains the optical retardation level at less than 30 mm. From the lateral position between about 20 mm and about 142 mm, the optical retardation level may be less than about 15 mm. In contrast, both plot lines 944 and 946 exceed these values at the central location of the plot line, showing that the central portion of the glass product formed using two edge guides tends to have less stress and higher quality.

[0089] The burner can provide an effective solution for quickly changing the temperature at the contact portion of the edge guide. Figure 9B FIG. 950 is a graph illustrating the variation of the temperature at the contact portion of the edge guide over time as the hydrogen level, oxygen level, and / or mass flow rate is adjusted. The temperature is initially maintained at around 0 degrees, and then rapidly increases to around 700 degrees Celsius at around 50 seconds. This rapid temperature increase and other sharp temperature increases show that the burner method is effective for quickly increasing the temperature of the contact portion of the edge guide. Additionally, as shown at around 275 seconds in FIG. 950, the temperature begins to rapidly decrease from 750 degrees Celsius to about 33 degrees Celsius. The initial rate of temperature decrease is large, but over time, the rate of temperature decrease becomes smaller and smaller, such that once the temperature starts to decrease, it decreases more and more slowly. This temperature decrease and other sharp temperature decreases show that the burner method is effective in quickly decreasing the temperature of the contact portion of the edge guide when necessary. Thus, the burner method can effectively allow the user to quickly adjust the temperature at the contact portion of the edge guide. However, other heat sources, such as electric heat sources, may also be used.

[0090] Figure 10FIG. 1000 is a flow chart of an example method of using one or more edge guides to control the shape of molten glass. At operation 1002, molten glass is caused to flow out of a feeder. The feeder may define an internal space and a slot proximate a bottom portion of the feeder. The internal space may be connected to the slot and may be configured to receive molten glass such that the molten glass exits the feeder at the slot. Due to gravity, the molten glass may flow downwardly from the slot of the feeder.

[0091] At operation 1004, an edge guide is positioned relative to the slot of the feeder. The edge guide may be similar to other edge guides in the embodiments described herein. Positioning the edge guide relative to the slot may result in a contact portion being at least partially immersed in the molten glass. The edge guide may be positioned between about 1 millimeter and about 5 millimeters below the slot of the feeder.

[0092] At operation 1006, a flame is generated at a burner. By doing so, heat from the flame may cause the molten glass proximate the edge guide to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass. Additionally, by generating the flame, heat from the flame may emit through a first internal cavity of the edge guide toward the contact portion of the edge guide and through a second internal cavity of the edge guide until the heat extends out of an outlet. When the contact portion of the edge guide contacts the molten glass, heat generated at the edge guide may be transferred to the molten glass flowing over the contact portion to reduce the viscosity of the molten glass.

[0093] At operation 1008, the cooled molten glass or solid glass may be cut to remove one or more portions of the molten glass at an area proximate an edge of the molten glass. The molten glass or cooled glass may be cut to remove a sheet from a remaining portion of the molten glass.

[0094] Method 1000 may result in a mass region of the molten glass having an increased size. This may cause the final glass product formed after cutting the molten glass at operation 1008 to be larger. In some embodiments, the mass region of the glass may have a thickness within a specific range of less than about 0.5 millimeters or less than about 0.2 millimeters over a width of at least about 120 millimeters.

[0095] Figure 11FIG. is a flow chart illustrating an example method 1100 for replacing one or more edge guides. At operation 1102, the temperature level at the edge guide is raised. This can be achieved by increasing the power level of a burner or some other heat source. Additionally or alternatively, the temperature level can be adjusted by changing the amount of hydrogen or oxygen emitted at the burner tip (e.g., by increasing or decreasing the amount of hydrogen emitted relative to the amount of oxygen emitted) or by changing the flow rate at the burner. At operation 1104, the edge guide is moved away from the molten glass. At operation 1106, excess molten glass is removed from the edge guide. At operation 1108, one or more replacement edge guides are preheated. In some embodiments, the replacement edge guide can be the edge guide from which any excess molten glass has been removed in operation 1106. At operation 1110, the replacement edge guide is moved towards the molten glass until the replacement edge guide is partially immersed in the molten glass. At operation 1112, the replacement edge guide can be at least partially retracted to the operating position. By retracting the replacement edge guide a certain distance, the sheet width of the molten glass can be maximized and the molten glass can still wet the replacement edge guide.

[0096] Both methods 1000 and 1100 are described only as examples and methods 1000, 1100 can be modified in various ways. Methods 1000, 1100 can be modified by adding additional operations and / or by omitting certain operations. Methods 1000, 1100 can also be modified by changing the order of operations or by performing certain operations simultaneously. In some embodiments, methods 1000, 1100 can be combined together to form a single method.

[0097] Conclusion

[0098] Many modifications and other embodiments of the teachings set forth herein will come to mind to those skilled in the art to which these embodiments pertain, which will benefit from the foregoing description and the teachings presented in the associated drawings. Accordingly, it is to be understood that the embodiments are not limited to the specific embodiments disclosed, and that the improvements and other embodiments are intended to be included within the scope of the present invention. Additionally, although the foregoing description and the associated drawings describe example embodiments in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions can be provided by alternative embodiments without departing from the scope of the present invention. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated within the scope of the present invention. Although specific terms are employed herein, they are used in a general and descriptive sense only and not for purposes of limitation.

Claims

1. A system for controlling the shape of molten glass, the system comprising: A feeder that defines an internal space and a slot near the bottom portion of the feeder, the internal space being configured to receive the molten glass such that the molten glass exits the feeder at the slot; A burner configured to generate a flame; One or more edge guides positioned relative to the slot, wherein each edge guide of the one or more edge guides comprises: A body portion that defines a first internal cavity; And A contact portion configured to contact the molten glass, Wherein the one or more edge guides are positioned such that the contact portion is at least partially immersed in the molten glass and thereby affects the shape of the molten glass, and wherein when the flame is generated by the burner, heat from the flame is configured to cause the molten glass near the one or more edge guides to have a first viscosity that is greater than a second viscosity of the molten glass near the central portion of the molten glass.

2. The system of claim 1, wherein heat from the flame travels through the first internal cavity toward the contact portion and into the molten glass contacting the one or more edge guides.

3. The system of claim 1 or 2, wherein each edge guide of the one or more edge guides comprises an exhaust portion attached to the body portion, the exhaust portion defining a second internal cavity and an outlet, and wherein the first internal cavity, the second internal cavity, and the outlet are in fluid communication with each other.

4. The system of claim 3, wherein the body portion extends at least partially along a first axis, the exhaust portion extends at least partially along a second axis, and the first axis is offset at an acute angle relative to the second axis.

5. The system of any one of claims 1-4, wherein controlling the shape of the molten glass increases a mass region of the molten glass, the mass region of the molten glass having a thickness within a specific range of less than about 0.5 millimeters over a width of at least about 120 millimeters.

6. The system of any one of claims 1-5, wherein the edge guide of the one or more edge guides is configured to be replaced by: raising the temperature level at the edge guide, moving the edge guide away from the molten glass, removing any excess molten glass from the edge guide, preheating a replacement edge guide, and moving the replacement edge guide toward the molten glass until the replacement edge guide is at least partially immersed in the molten glass.

7. The system of any one of claims 1-6, wherein the contact portion defines a guiding slot or a concave, convex, flat, ridged, multi-jointed, or curved shape.

8. The system according to any one of claims 1-7, wherein the one or more edge guides are positioned between about 1 mm and about 5 mm below the slot.

9. The system according to any one of claims 1-8, wherein the one or more edge guides include a first edge guide and a second edge guide, wherein the molten glass defines a first edge and a second edge, wherein the first edge guide is at least partially immersed in the molten glass proximate the first edge, and the second edge guide is at least partially immersed in the molten glass proximate the second edge.

10. The system according to any one of claims 1-9, wherein the burner includes a burner tip that emits a flame, and wherein the burner is water-cooled.

11. The system according to claim 10, wherein each of the one or more edge guides is attached to a drain outlet.

12. The system according to claim 11, further comprising: a burner assembly including the burner, the drain outlet, and an outer tube extending from the drain outlet to proximate the burner tip, wherein the body portion extends upward along an inclination angle between the burner and the contact portion, wherein the outer tube is configured to receive water at a portion between the burner tip and the drain outlet, and wherein the drain outlet is positioned at a height lower than the contact portion.

13. The system according to claim 12, wherein the burner is configured to generate steam, the steam condenses to form by-product water, and wherein the by-product water flows to at least one of the outlet or the drain outlet.

14. A method for controlling the shape of molten glass, the method comprising: Causing molten glass to flow downward from a slot of a feeder; Positioning one or more edge guides relative to the slot, wherein each of the one or more edge guides includes: a body portion defining a first internal cavity; and a contact portion; and Generating a flame at a burner such that heat from the flame causes the molten glass proximate the one or more edge guides to have a first viscosity that is greater than a second viscosity of the molten glass proximate a central portion of the molten glass, wherein the one or more edge guides are positioned such that the contact portion is at least partially immersed in the molten glass and thereby affects the shape of the molten glass.

15. The method according to claim 14, wherein positioning the one or more edge guides relative to the slot causes the contact portion to be at least partially immersed in the molten glass.

16. The method according to claim 15, wherein positioning the one or more edge guides relative to the slot increases a mass region of the molten glass having a thickness within a specific range of less than about 0.5 mm over a width of at least about 120 mm.

17. The method according to any one of claims 14-16, wherein the one or more edge guides include a first edge guide, and wherein the method further comprises: Raise the temperature level at the first edge guide; Move the first edge guide away from the molten glass; Remove any excess molten glass from the first edge guide; Preheat the replacement edge guide; and Move the replacement edge guide towards the molten glass until the replacement edge guide is at least partially immersed in the molten glass.

18. The method according to any one of claims 14 - 17, wherein the contact portion defines a guiding slot or a concave, convex, flat, ridged, multi-jointed or curved shape.

19. The method according to any one of claims 14 - 18, wherein the contact between the contact portion and the molten glass reduces the viscosity of the molten glass.

20. The method according to any one of claims 14 - 19, wherein the one or more edge guides are positioned between about 1 mm and about 5 mm below the slot of the feeder.

21. The method according to any one of claims 14 - 20, wherein each edge guide of the one or more edge guides includes an exhaust portion attached to the body portion, the exhaust portion defining a second internal cavity and an outlet, and wherein the first internal cavity, the second internal cavity and the outlet are in fluid communication with each other, and wherein the body portion extends at least partially along a first axis, the exhaust portion extends at least partially along a second axis, and the first axis is offset at an acute angle with respect to the second axis.

22. An edge guide for controlling the shape of molten glass, the edge guide comprising: A body portion that defines a first internal cavity; And A contact portion configured to contact the molten glass, Wherein the edge guide is positioned such that the contact portion is at least partially immersed in the molten glass and thereby affects the shape of the molten glass, and wherein the edge guide is configured to be positioned relative to a burner such that when the flame is generated by the burner, the heat from the flame is configured to cause the molten glass near the one or more edge guides to have a first viscosity that is greater than a second viscosity of the molten glass near the central portion of the molten glass.

23. A system for controlling the shape of molten glass, the system comprising: A feeder that defines an internal space and a slot near the bottom portion of the feeder, wherein the internal space is connected to the slot and wherein the internal space is configured to receive the molten glass such that the molten glass exits the feeder at the slot; A burner configured to generate a flame; One or more edge guides positioned relative to the slot, wherein each edge guide of the one or more edge guides includes: A body portion that defines a first internal cavity; And A contact portion configured to contact the molten glass, When the flame is generated by the burner, heat from the flame travels through the first internal cavity towards the contact portion and into the molten glass flowing on the contact portion of the one or more edge guides. The heat from the flame is configured to cause the molten glass near the one or more edge guides to have a first viscosity, which is greater than a second viscosity of the molten glass near the central portion of the molten glass. And the contact portion of the one or more edge guides affects the shape of the molten glass such that, over a width of at least about 120 millimeters, the difference between the maximum thickness and the minimum thickness of the molten glass is about 0.5 millimeter or less.

24. A glass sheet, the glass sheet being made by the following process: Flowing molten glass downward from a slot of a feeder; Positioning one or more edge guides relative to the slot, wherein each edge guide of the one or more edge guides includes: A body portion that defines a first internal cavity; And A contact portion configured to contact the molten glass, wherein the one or more edge guides are positioned such that the contact portion is at least partially immersed in the molten glass and affects the shape of the molten glass; And Generating a flame at the burner such that heat from the flame causes the molten glass near the one or more edge guides to have a first viscosity, which is greater than a second viscosity of the molten glass near the central portion of the molten glass.

25. A glass sheet, the glass sheet being made by the following process: Flowing molten glass downward from a slot of a feeder; Positioning one or more edge guides relative to the slot, wherein each edge guide of the one or more edge guides includes: A body portion that defines a first internal cavity; And A contact portion configured to contact the molten glass, wherein the one or more edge guides are positioned such that the contact portion is at least partially immersed in the molten glass and affects the shape of the molten glass; And Generating a flame at the burner such that heat from the flame causes the molten glass near the one or more edge guides to have a first viscosity, which is greater than a second viscosity of the molten glass near the central portion of the molten glass; And Cutting the molten glass to remove a portion of the molten glass at a region near the edge of the molten glass.

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