Apparatus and method for controlling glass ribbon properties

Abstract

Apparatus and methods for manufacturing glass articles include a thickness control device configured to flow a fluid toward a glass ribbon, the thickness control device including at least one pivotable fluid discharge conduit configured to flow the fluid therethrough, wherein rotation of the pivotable fluid discharge conduit changes the orientation of the fluid flow relative to the glass ribbon.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63 / 447,116, filed February 21, 2023, the contents of which are herein relied upon and incorporated by reference in their entirety.

[0002] The present disclosure relates generally to apparatus and methods for controlling glass ribbon properties, and more particularly to apparatus and methods for controlling glass ribbon thickness. [Background technology]

[0003] In the production of glass articles, such as glass sheets for display applications, including televisions and handheld devices such as phones and tablets, glass articles can be manufactured from glass sheets formed from drawing a glass ribbon from a forming body. As the glass ribbon is drawn from the forming body, the ribbon thickness can vary across its width. Such thickness variations can result in undesirable glass sheet thickness variations or process upsets, particularly with an increase in ribbon width and / or a decrease in average ribbon thickness. Therefore, solutions to address these issues are desirable. Summary of the Invention

[0004] Embodiments disclosed herein include an apparatus for manufacturing a glass article. The apparatus includes a forming apparatus configured to accommodate a glass ribbon. The apparatus also includes a thickness control device configured to channel a fluid toward the glass ribbon. The thickness control device includes at least one pivotable fluid discharge conduit configured to channel the fluid therethrough. Rotation of the pivotable fluid discharge conduit changes the orientation of the fluid flow relative to the glass ribbon.

[0005] Embodiments disclosed herein also include a method of manufacturing a glass article. The method includes flowing a glass ribbon through a forming apparatus. The method also includes flowing a fluid toward the glass ribbon from at least one pivotable fluid discharge conduit of a thickness control device. Rotation of the pivotable fluid discharge conduit changes the orientation of the fluid flow relative to the glass ribbon.

[0006] Additionally, embodiments disclosed herein include a thickness control device configured to channel a fluid toward the glass ribbon. The thickness control device includes at least one pivotable fluid discharge conduit configured to channel the fluid therethrough. Rotation of the pivotable fluid discharge conduit changes the orientation of the fluid flow relative to the glass ribbon.

[0007] Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description which follows, and in part will become readily apparent to those skilled in the art from that description, or may be learned by practicing the disclosed embodiments as described herein, including the following detailed description, claims, and accompanying drawings.

[0008] It is to be understood that both the foregoing summary and the following detailed description represent embodiments intended to provide an overview or framework for understanding the nature and features of the claimed embodiments. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the present disclosure and, together with the description, serve to explain its principles and operation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an exemplary fusion downdraw glass making apparatus and process. [Figure 2] FIG. 1 is a schematic cross-sectional view of a glass ribbon. [Figure 3] FIG. 3 is an exploded view of a portion of the glass ribbon of FIG. 2. [Figure 4]1 is a schematic top view of a thickness control device according to an embodiment disclosed herein. [Figure 5] FIG. 5 is a schematic side view of the thickness control device of FIG. 4. [Figure 6A] 1 is a schematic end view of a pivotable fluid discharge conduit according to an embodiment disclosed herein; FIG. [Figure 6B] 1 is a schematic end view of a pivotable fluid discharge conduit according to an embodiment disclosed herein; FIG. [Figure 7] FIG. 2 is a schematic top view of a thickness control device positioned relative to a glass ribbon according to embodiments disclosed herein. [Figure 8] FIG. 2 is a schematic end view of a thickness control device positioned relative to a glass ribbon according to embodiments disclosed herein. [Figure 9] FIG. 8 is an exploded view of a portion of the glass ribbon of FIG. [Figure 10] FIG. 10 is an exploded view of a portion of the glass ribbon of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0011] Ranges can be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, for example, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0012] Directional terms used herein, e.g., up, down, right, left, front, back, top, bottom, are made solely with reference to the drawings depicted and are not intended to imply absolute orientations.

[0013] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring its steps to be performed in a particular order, or that any apparatus require a particular orientation. Thus, where a method claim does not actually recite the order in which its steps must be followed, or where any apparatus claim does not actually recite an order or orientation for individual components, or where the claim or the specification otherwise specifically states that the steps are to be limited to a particular order, or where no particular order or orientation for the apparatus components is recited, no order or orientation is intended to be inferred in any sense. This applies to all possible implicit bases for interpretation, including logical considerations regarding the arrangement of steps, operational flow, component order, or component orientation, the plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described herein.

[0014] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" element includes aspects having two or more such elements unless the context clearly dictates otherwise.

[0015] As used herein, the term "particles" refers to any type of particle that may be present on a surface, such as glass particles and dust particles.

[0016] An exemplary glass manufacturing apparatus 10 is shown in FIG. 1 . In some examples, the glass manufacturing apparatus 10 may include a glass melting furnace 12, which may include a melting vessel 14. In addition to the melting vessel 14, the glass melting furnace 12 may optionally include one or more additional components, such as heating elements (e.g., combustion burners or electrodes) that heat the raw materials and convert the raw materials into molten glass. In further examples, the glass melting furnace 12 may include thermal management devices (e.g., insulating components) that reduce heat loss from the vicinity of the melting vessel. In still further examples, the glass melting furnace 12 may include electronic and / or electromechanical devices that facilitate melting of the raw materials into a glass melt. Still further, the glass melting furnace 12 may include support structures (e.g., support chassis, support members, etc.) or other components.

[0017] Glass melting vessel 14 is typically constructed of a refractory material, such as a refractory ceramic material, e.g., a refractory ceramic material including alumina or zirconia. In some examples, glass melting vessel 14 may be constructed from refractory ceramic brick. Specific embodiments of glass melting vessel 14 are described in more detail below.

[0018] In some examples, the glass melting furnace can be incorporated as a component of a glass manufacturing apparatus for producing glass substrates, e.g., continuous lengths of glass ribbon. In some examples, the glass melting furnace of the present disclosure can be incorporated as a component of a glass manufacturing apparatus, including a slot draw apparatus, a float bath apparatus, a downdraw apparatus such as a fusion process, an updraw apparatus, a press rolling apparatus, a tube drawing apparatus, or any other glass manufacturing apparatus that would benefit from embodiments disclosed herein. By way of example, FIG. 1 schematically illustrates a glass melting furnace 12 as a component of a fusion draw glass manufacturing apparatus 10 for fusion drawing a glass ribbon for subsequent processing into individual glass sheets.

[0019] Glass manufacturing apparatus 10 (e.g., fusion downdraw glass manufacturing apparatus 10) may optionally include upstream glass manufacturing apparatus 16 disposed upstream relative to glass melting vessel 14. In some examples, a portion or all of upstream glass manufacturing apparatus 16 may be incorporated as part of glass melting furnace 12.

[0020] As shown in the illustrated example, the upstream glass manufacturing apparatus 16 can include a storage bin 18, a raw material feed device 20, and a motor 22 connected to the raw material feed device. The storage bin 18 can be configured to store a quantity of raw material 24, as indicated by arrow 26, which can be fed to the melting vessel 14 of the glass melting furnace 12. The raw material 24 typically includes one or more glass-forming metal oxides and one or more modifiers. In some examples, the raw material feed device 20 can be powered by the motor 22 such that the raw material feed device 20 feeds a predetermined amount of raw material 24 from the storage bin 18 to the melting vessel 14. In a further example, the motor 22 can power the raw material feed device 20 to introduce the raw material 24 at a controlled rate based on a level of molten glass sensed downstream of the melting vessel 14. The raw material 24 in the melting vessel 14 can then be heated to form molten glass 28.

[0021] The glass manufacturing apparatus 10 may also optionally include downstream glass manufacturing equipment 30 disposed downstream relative to the glass melting furnace 12. In some examples, a portion of the downstream glass manufacturing equipment 30 may be incorporated as part of the glass melting furnace 12. In some instances, the first connecting conduit 32, discussed below, or other portions of the downstream glass manufacturing equipment 30 may be incorporated as part of the glass melting furnace 12. Elements of the downstream glass manufacturing apparatus, including the first connecting conduit 32, may be formed from precious metals. Suitable precious metals include platinum group metals selected from the group of metals consisting of platinum, iridium, rhodium, osmium, ruthenium, and palladium, or alloys thereof. For example, downstream components of the glass manufacturing apparatus may be formed from a platinum-rhodium alloy comprising about 70 to about 90 weight percent platinum and about 10 to about 30 weight percent rhodium. However, other suitable metals may include molybdenum, palladium, rhenium, tantalum, titanium, tungsten, and alloys thereof.

[0022] The downstream glass manufacturing apparatus 30 can include a first conditioning (i.e., processing) vessel, such as a fining vessel 34, located downstream from the melting vessel 14 and coupled to the melting vessel 14 via the first connecting conduit 32 described above. In some examples, the molten glass 28 can be gravity-fed from the melting vessel 14 to the fining vessel 34 via the first connecting conduit 32. For example, gravity can cause the molten glass 28 to pass from the melting vessel 14 through the internal path of the first connecting conduit 32 to the fining vessel 34. However, it should be understood that other conditioning vessels can be positioned downstream of the melting vessel 14, for example, between the melting vessel 14 and the fining vessel 34. In some embodiments, a conditioning vessel can be used between the melting vessel and the fining vessel, where the molten glass from the primary melting vessel is either further heated to continue the melting process or cooled to a temperature below that of the molten glass in the melting vessel before entering the fining vessel.

[0023] Gas bubbles can be removed from the molten glass 28 in the fining vessel 34 by various techniques. For example, the raw material 24 may contain a polyvalent compound (i.e., a fining agent), such as tin oxide, which, when heated, undergoes a chemical reduction reaction to release oxygen. Other suitable fining agents include, but are not limited to, arsenic, antimony, iron, and cerium. The fining vessel 34 is heated to a temperature higher than the melting vessel temperature, thereby heating the molten glass and fining agent. Oxygen bubbles generated by the temperature-induced chemical reduction of the fining agent(s) rise through the molten glass in the fining vessel, and gases in the molten glass generated in the melting furnace can diffuse or coalesce with the oxygen bubbles generated by the fining agent. The enlarged gas bubbles then rise to the free surface of the molten glass in the fining vessel and can then be expelled from the fining vessel. The oxygen bubbles can further induce mechanical mixing of the molten glass in the fining vessel.

[0024] The downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as a mixing vessel 36, for mixing the molten glass. The mixing vessel 36 may be located downstream of the fining vessel 34. The mixing vessel 36 may be used to provide a uniform glass melt composition, thereby reducing chemical or thermal inhomogeneities that may otherwise be present in the refined molten glass exiting the fining vessel. As shown, the fining vessel 34 may be coupled to the mixing vessel 36 via a second connecting conduit 38. In some examples, the molten glass 28 may be gravity-fed from the fining vessel 34 to the mixing vessel 36 via the second connecting conduit 38. For example, gravity may cause the molten glass 28 to pass from the fining vessel 34 to the mixing vessel 36 through an internal passageway of the second connecting conduit 38. It should be noted that although the mixing vessel 36 is shown downstream of the fining vessel 34, the mixing vessel 36 may be located upstream of the fining vessel 34. In some embodiments, downstream glass manufacturing equipment 30 may include multiple mixing vessels, for example, a mixing vessel upstream of fining vessel 34 and a mixing vessel downstream of fining vessel 34. These multiple mixing vessels may be of the same design, or they may be of different designs.

[0025] The downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as a feed vessel 40, which may be located downstream from the mixing vessel 36. The feed vessel 40 may condition the molten glass 28 to be delivered to a downstream forming device. For example, the feed vessel 40 may function as an accumulator and / or flow controller to condition and / or provide a constant flow of the molten glass 28 to the forming body 42 via an outlet conduit 44. As shown, the mixing vessel 36 may be coupled to the feed vessel 40 via a third connecting conduit 46. In some examples, the molten glass 28 may be gravity-fed from the mixing vessel 36 to the feed vessel 40 via the third connecting conduit 46. For example, gravity may drive the molten glass 28 from the mixing vessel 36 to the feed vessel 40 through an internal path of the third connecting conduit 46.

[0026] The downstream glass manufacturing apparatus 30 may further include a forming apparatus 48 comprising the forming body 42 and inlet conduit 50 described above. The outlet conduit 44 may be positioned to deliver the molten glass 28 from the feed vessel 40 to the inlet conduit 50 of the forming apparatus 48. For example, in the example, the outlet conduit 44 may be nested within and spaced from the inner surface of the inlet conduit 50, thereby providing a free surface for the molten glass disposed between the outer surface of the outlet conduit 44 and the inner surface of the inlet conduit 50. The forming body 42 in the fusion downdraw glass making apparatus may include a trough 52 disposed on the upper surface of the forming body and a converging forming surface 54 that converges in the draw direction along a bottom edge 56 of the forming body 42. Molten glass delivered to the forming body trough via the feed vessel 40, the outlet conduit 44, and the inlet conduit 50 overflows the sidewall of the trough and descends along the converging forming surface 54 as a separate stream of molten glass. The separate streams of molten glass merge below and along the bottom edge 56 to produce a single glass ribbon 58 that is drawn from the bottom edge 56 in a draw or flow direction 60 by applying tension to the glass ribbon, such as by gravity, edge rolls 72, and pull rolls 82, to control the dimensions of the glass ribbon as the glass cools and its viscosity increases. The glass ribbon 58 therefore undergoes a viscoelastic transition and acquires mechanical properties that give the glass ribbon 58 stable dimensional characteristics. The glass ribbon 58 can, in some embodiments, be separated into individual glass sheets 62 by a glass separator 100 within the elastic region of the glass ribbon. A robot 64 can then use gripping tools 65 to transfer the individual glass sheets 62 to a conveyor system so that the individual glass sheets can be further processed.

[0027] FIG. 2 shows a schematic cross-sectional view of a glass ribbon 58, such as the glass ribbon 58 formed in the forming apparatus 48. FIG. 3 shows an exploded view of a portion of the glass ribbon 58 in FIG. 2, specifically, the portion of the glass ribbon 58 shown in area "A" in FIG. 2. The glass ribbon 58 includes a central region 158 (also referred to as a "quality region") and an edge region 160 (also referred to as a "bead region"). In addition, the glass ribbon 58 includes an intermediate region 156 between the central region 158 and the edge region 160. As can be seen from FIG. 3, the glass ribbon 58 has a minimum thickness T1 in the intermediate region 156 and a maximum thickness T2 in the edge region 160, where T2 is greater than T1. In addition, the glass ribbon 58 has an intermediate thickness T3 in the central region 158, where T3 is greater than T1 and less than T2.

[0028] 4 and 5 show schematic top and side views, respectively, of a thickness control device 200 according to an embodiment disclosed herein. The thickness control device 200 includes two substantially parallel pivotable fluid discharge conduits 202, each extending through a turret assembly 204. Each of the pivotable fluid discharge conduits 202 is configured to flow a fluid therethrough, and the turret assembly 204 is configured to effect at least one of vertical or horizontal rotation of the pivotable fluid discharge conduits 202, with the vertical rotation of the pivotable fluid discharge conduits 202 being generally indicated by dashed arrows in FIG. 5 and the horizontal rotation of the pivotable fluid discharge conduits 202 being generally indicated by dashed arrows in FIG. 4.

[0029] The turret assembly 204 may be assembled and operated according to methods known to those skilled in the art and may effect rotation of the pivotable fluid discharge conduit 202 via a drive mechanism 206, which in certain exemplary embodiments may include a precision-adjustable micrometer drive in mechanical communication with the turret assembly 204. The turret assembly 204 may also be manually adjusted to effect rotation of the pivotable fluid discharge conduit 202.

[0030] And, while FIG. 4 shows a thickness control device 200 having two substantially parallel fluid discharge conduits 202, embodiments disclosed herein include thickness control devices having a greater or lesser number of fluid discharge conduits, for example, one fluid discharge conduit, or at least three substantially parallel fluid discharge conduits, such as three, four, or five substantially parallel fluid discharge conduits.

[0031] 6A and 6B show schematic end views of pivotable fluid exhaust conduits 202 and 202′ according to embodiments disclosed herein. Specifically, FIG. 6A shows a schematic end view of fluid exhaust conduit 202 having a single internal bore 212 extending therethrough, while FIG. 6B shows a schematic end view of fluid exhaust conduit 202′ having substantially parallel dual bores 212A and 212B extending therethrough. And, while FIGS. 6A and 6B show fluid exhaust conduits 202 and 202′ having a single bore and dual bores extending therethrough, respectively, embodiments disclosed herein include fluid exhaust conduits having at least three internal bores extending therethrough, for example, fluid exhaust conduits having three, four, or five internal bores extending therethrough.

[0032] In certain exemplary embodiments, the fluid exhaust conduit 202 or 202′ comprises a refractory material capable of withstanding temperatures of at least about 1200° C. For example, the fluid exhaust conduit 202 or 202′ may comprise a refractory ceramic material such as alumina, mullite, or zirconia.

[0033] 7 shows a schematic top view of thickness control devices 200 positioned relative to a glass ribbon 58 according to embodiments disclosed herein. Specifically, FIG. 7 shows four thickness control devices 200, two of which are positioned on opposite sides of a first end (proximal end or “bead” region 160) of the glass ribbon 58 and two of which are positioned on opposite sides of a second end (proximal end or “bead” region 160) of the glass ribbon 58. The thickness control devices 200 are each positioned to direct a fluid flow to the glass ribbon 58 via a pivotable fluid discharge conduit 202, where rotation of the pivotable fluid discharge conduit 202 changes the orientation of the fluid flow relative to the glass ribbon 58.

[0034] 8 shows a schematic end view of a thickness control device 200 positioned relative to a glass ribbon 58 according to an embodiment disclosed herein. Specifically, FIG. 8 shows two thickness control devices 200, each positioned on opposite sides of the glass ribbon 58 near the bottom edge 56 of the forming body 42. Each thickness control device 200 is positioned to direct a fluid flow to the glass ribbon 58 via a pivotable fluid discharge conduit 202, where rotation of the pivotable fluid discharge conduit 202 changes the orientation of the fluid flow relative to the glass ribbon 58.

[0035] In one particular exemplary embodiment, the fluid channeled toward the glass ribbon 58 via the pivotable fluid discharge conduits 202 comprises a gas, such as at least one gas selected from air, nitrogen, helium, or argon.

[0036] In certain exemplary embodiments, the flow rate of fluid channeled toward the glass ribbon 58 through the pivotable fluid discharge conduits 202 can be controlled, adjusted, or varied to effect a desired amount of localized cooling within a predetermined area of ​​the glass ribbon 58. Such fluid flow rate control or adjustment can be performed by a control mechanism, such as, for example, a feedback or feedforward control mechanism known to those skilled in the art.

[0037] In one particular exemplary embodiment, the fluid is flowed from the thickness control device 200 toward a portion of the glass ribbon 58 having a viscosity in the range of about 80 kP to about 200 kP, such as about 120 kP to about 160 kP.

[0038] In certain exemplary embodiments, the temperature of the fluid channeled through pivotable fluid discharge conduits 202 toward glass ribbon 58 ranges from about 20°C to about 40°C.

[0039] FIG. 9 shows an exploded view of a portion of the glass ribbon 58 of FIG. 7 , and FIG. 10 shows an exploded view of a portion of the glass ribbon 58 of FIG. 9 (shown within area “C” in FIG. 9 ). Specifically, FIGS. 9 and 10 show exploded views of the glass ribbon 58 exposed to a fluid flow from a thickness control device 200. As can be seen in FIGS. 9 and 10 , the glass ribbon 58 has a maximum thickness T2 in the edge regions 160 and approximately equal minimum thicknesses T1 and T3 in the intermediate regions 156 and central region 158, respectively, with T2 being greater than T1 or T3. Furthermore, the difference in thickness between T1 and T2 of the glass ribbon 58 of FIGS. 9 and 10 is less than the difference in thickness between T1 and T2 of the glass ribbon 58 of FIG. 3 . Specifically, the dashed line in FIG. 10 represents the glass ribbon 58 of FIG. 3, and as can be seen in FIG. 10, the thickness T1 of the intermediate region 156 of the glass ribbon 58 of FIG. 3 is smaller than the thickness T1 of the intermediate region 156 of the glass ribbon 58 of FIGS. 9 and 10, and as a result, the thickness variation of the glass ribbon 58 of FIGS. 9 and 10 (i.e., the difference between the maximum thickness T2 and the minimum thickness T1) is smaller than the thickness variation of the glass ribbon 58 of FIG. 3.

[0040] Accordingly, embodiments disclosed herein include embodiments in which the variation in thickness of the glass ribbon 58 is reduced by at least about 20%, such as at least about 30%, even such as at least about 40%, and even further such as at least about 50%, such as between about 20% and about 80%, and even further such as between about 30% and about 70%, compared to a state in which fluid is not flowed from at least one pivotable fluid discharge conduit 202 of the thickness control device 200 toward the glass ribbon 58.

[0041] Such reduction in thickness variation can be achieved, for example, by targeting a portion of the glass ribbon 58 that is known to have decreased in thickness over the course of a production campaign in order to increase the relative thickness of that portion. Such targeting can include rotating or orienting the pivotable fluid discharge conduits 202 toward the targeted portion of the glass ribbon 58 to control or change the direction of fluid flow relative to the glass ribbon 58. Such targeting can also include adjusting the flow rate, temperature, and / or type of fluid channeled toward the glass ribbon 58 via the pivotable fluid discharge conduits 202 of the thickness control device 200. Such parameters can be adjusted in real time using control mechanisms, such as feedback or feedforward control mechanisms, known to those skilled in the art.

[0042] In certain exemplary embodiments, the pivotable fluid discharge conduits 202 are oriented to channel fluid toward the glass ribbon 58 within a predetermined distance of the intermediate region 156 along the width of the glass ribbon 58, such as within area "C" in Figure 9. For example, embodiments disclosed herein include embodiments in which the pivotable fluid discharge conduits 202 are oriented to channel fluid toward the glass ribbon 58 within 0.1 meters, such as within 0.05 meters, of the intermediate region 156 along the width of the glass ribbon 58.

[0043] Embodiments disclosed herein include those in which the glass ribbon 58 comprises a glass composition, such as an alkali-free glass composition, including 58-65 weight percent (wt%) SiO2, 14-20 wt% Al2O3, 8-12 wt% B2O3, 1-3 wt% MgO, 5-10 wt% CaO, and 0.5-2 wt% SrO. The glass ribbon 58 may also comprise a glass composition, such as an alkali-free glass composition, including 58-65 wt% SiO2, 16-22 wt% Al2O3, 1-5 wt% B2O3, 1-4 wt% MgO, 2-6 wt% CaO, 1-4 wt% SrO, and 5-10 wt% BaO. Additionally, the glass ribbon 58 may include a glass composition such as an alkali-free glass composition including 57-61 wt% SiO, 17-21 wt% AlO, 5-8 wt% BO, 1-5 wt% MgO, 3-9 wt% CaO, 0-6 wt% SrO, and 0-7 wt% BaO. The glass ribbon 58 may also include a glass composition such as an alkali-containing glass composition including 55-72 wt% SiO, 12-24 wt% AlO, 10-18 wt% NaO, 0-10 wt% BO, 0-5 wt% KO, 0-5 wt% MgO, and 0-5 wt% CaO, and in certain embodiments, may also include 1-5 wt% KO and 1-5 wt% MgO.

[0044] Although the above embodiments have been described with reference to a fusion downdraw process, it should be understood that such embodiments are also applicable to other glass forming processes, such as the float process, the slot draw process, the updraw process, the tube draw process, and the press rolling process.

[0045] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Therefore, it is intended that the present disclosure cover such modifications and variations, provided they come within the scope of the appended claims and their equivalents.

Claims

1. 1. An apparatus for manufacturing a glass article, comprising: a forming device configured to contain the glass ribbon; a thickness control device configured to channel a fluid toward the glass ribbon, the thickness control device comprising at least one pivotable fluid discharge conduit configured to channel the fluid therethrough, wherein rotation of the at least one pivotable fluid discharge conduit changes an orientation of the fluid flow relative to the glass ribbon.

2. 10. The apparatus of claim 1, wherein the forming apparatus contains a forming body configured to cause the glass ribbon to flow therefrom in a flow direction, and the thickness control device is configured to cause the fluid to flow downstream of the forming body.

3. The apparatus of claim 1 , wherein the thickness control device comprises at least two substantially parallel pivotable fluid discharge conduits.

4. The apparatus of claim 1 , wherein the thickness control device comprises a turret assembly configured to effect at least one of vertical or horizontal rotation of the at least one pivotable fluid discharge conduit.

5. The apparatus of claim 1 , wherein the fluid comprises a gas.

6. 1. A method of manufacturing a glass article, comprising: Flowing the glass ribbon into a forming device; and flowing a fluid from at least one pivotable fluid discharge conduit of a thickness control device toward the glass ribbon, wherein rotation of the at least one pivotable fluid discharge conduit changes a direction of the fluid flow relative to the glass ribbon.

7. The method of claim 6 , wherein the glass ribbon is flowed in a flow direction from a forming body and the fluid is flowed from the thickness control device downstream of the forming body.

8. The method of claim 6 , wherein the fluid comprises a gas.

9. The method of claim 6, wherein the fluid is flowed from the thickness control device toward a portion of the glass ribbon having a viscosity in the range of about 80 kP to about 200 kP.

10. 7. The method of claim 6, wherein a variation in thickness of the glass ribbon is reduced by at least about 20% compared to a condition in which fluid is not channeled toward the glass ribbon from at least one pivotable fluid discharge conduit of a thickness control device.

11. 1. A thickness control device configured to channel a fluid toward a glass ribbon, the thickness control device comprising: at least one pivotable fluid discharge conduit configured to channel the fluid therethrough, wherein rotation of the at least one pivotable fluid discharge conduit changes the orientation of the fluid flow relative to the glass ribbon.

12. The thickness control device of claim 11 , wherein the thickness control device comprises at least two substantially parallel pivotable fluid discharge conduits.

13. The thickness control device of claim 11 , wherein the thickness control device comprises a turret assembly configured to effect at least one of vertical or horizontal rotation of the at least one pivotable fluid discharge conduit.

14. A glass article produced by the method of any one of claims 6 to 9.

15. 15. An electronic device comprising the glass article of claim 14.

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