Method and apparatus for forming a glass ribbon

Abstract

The glass forming apparatus includes a cooling tube positioned adjacent a path of travel of the glass ribbon. The cooling tube includes a central portion including a first sidewall extending along a tube axis surrounding a central chamber. The cooling tube includes end portions including second sidewalls surrounding end chambers. The end portions extend along the tube axis and are attached to the central portion. The cooling tube receives a cooling fluid within the central chamber and the end chambers. A sleeve extends along the tube axis and circumferentially surrounds the end portions. The sleeve includes a sleeve wall radially spaced from the second sidewall and an insulating material positioned between the sleeve wall and the second sidewall. A method of forming a glass ribbon using the glass forming apparatus is provided.

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 Patent Application No. 63 / 373,611, filed August 26, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] TECHNICAL FIELD The present disclosure relates generally to an apparatus and method for forming a glass ribbon, and more particularly to a method for forming a glass ribbon using cooling tubes. [Background technology]

[0003] It is known to produce glass ribbons using forming devices. Conventional forming devices are known to operate by drawing a quantity of molten material downward as a glass ribbon from a glass ribbon-forming device. The glass ribbon can cool as it travels along its travel path. However, while the center portion of the glass ribbon cools, the terminal portions of the glass ribbon may cool more than desired. This can cause supercooled terminal portions, which can lead to high stresses within the glass ribbon and make the glass ribbon more susceptible to breakage. In addition, the supercooled terminal portions of the glass ribbon can cause the transition walls to be cooler, leading to excessive condensation. Summary of the Invention [Means for solving the problem]

[0004] The following presents a simplified summary of the present disclosure in order to provide a basic understanding of some aspects that are described in the detailed description.

[0005] Methods of forming glass using cooling tubes are enumerated. The cooling tubes are hollow and filled with a cooling fluid. The cooling tubes are positioned adjacent to a glass ribbon and function to extract heat from the glass ribbon. In an embodiment, the cooling tubes include a non-constant diameter, and a central portion of the cooling tube includes a larger diameter than the end portions of the cooling tube. In this manner, the central portion of the cooling tube can extract more heat from the glass ribbon than the end portions. In an embodiment, a sleeve including an insulating material can surround the end portions to further reduce heat extraction by the end portions. In this manner, the center of the glass ribbon can cool faster than the ends of the glass ribbon.

[0006] In an embodiment, the glass forming apparatus may include a cooling tube positioned adjacent to a path of travel of the glass ribbon. The cooling tube may include a central portion including a first sidewall extending along a tube axis surrounding a central chamber. The cooling tube may include end portions including second sidewalls surrounding end chambers. The end portions may extend along the tube axis and may be attached to the central portion. The cooling tube may receive a cooling fluid within the central chamber and the end chambers. The cooling tube may include a sleeve extending along the tube axis and circumferentially surrounding the end portion. The sleeve may include a sleeve wall radially spaced from the second sidewall. An insulating material may be positioned between the sleeve wall and the second sidewall.

[0007] In an embodiment, the central portion can include a first outer diameter that is greater than the second outer diameter of the distal portions.

[0008] In an embodiment, the first outer diameter can be in the range of about 40 mm to about 65 mm.

[0009] In embodiments, the second outer diameter can be in the range of about 10 mm to about 40 mm.

[0010] In an embodiment, the central chamber can include a first chamber diameter and the distal chamber can include a second chamber diameter that is smaller than the first chamber diameter.

[0011] In an embodiment, the thickness of the first sidewall can be equal to the thickness of the second sidewall.

[0012] In an embodiment, the sleeve wall may comprise stainless steel.

[0013] In an embodiment, the insulating material may include at least one of ceramic fibers or zirconia.

[0014] In an embodiment, the insulating material may include air.

[0015] In an embodiment, the first sidewall can include a first coating and the second sidewall can include a second coating, and the emissivity of the second coating can be different from the emissivity of the first coating.

[0016] In an embodiment, the glass forming apparatus may include a cooling tube positioned adjacent to a path of travel of the glass ribbon. The cooling tube may include a central portion including a first sidewall extending along a tube axis surrounding a central chamber. The cooling tube may include end portions including second sidewalls surrounding end chambers. The end portions may extend along the tube axis and may be attached to the central portion. The cooling tube may receive a cooling fluid within the central chamber and the end chambers. The cooling tube may include a sleeve extending along the tube axis and circumferentially surrounding the end portions. The sleeve may include a sleeve wall radially spaced from the second sidewall. The sleeve may include a first support protrusion attached to the second sidewall and extending radially between the sleeve wall and the second sidewall. The first support protrusion may extend along the tube axis. The sleeve may include an insulating material positioned between the first sleeve wall and the second sidewall. The insulating material may surround the first support protrusion.

[0017] In an embodiment, the sleeve can include a second support protrusion extending radially between the sleeve wall and the second sidewall. The second support protrusion can extend along the tube axis. The first support protrusion and the second support protrusion can be circumferentially spaced apart within a range of about 60 degrees to about 90 degrees about the tube axis.

[0018] In an embodiment, a thermal insulating material can be positioned between the first support protrusion and the second support protrusion. The thermal insulating material can include at least one of ceramic fiber or zirconia.

[0019] In an embodiment, the first outer diameter of the central portion can be equal to the sleeve outer diameter of the sleeve.

[0020] In an embodiment, the first outer diameter of the central portion can be greater than the second outer diameter of the distal portion.

[0021] In an aspect, a method of forming a glass ribbon using a glass forming apparatus includes moving the glass ribbon along a travel path in a travel direction past cooling tubes. The method includes flowing a cooling fluid through the cooling tubes. The cooling tubes can include a central portion positioned adjacent a central region of the glass ribbon and end portions positioned adjacent edge portions of the glass ribbon. The end portions can be surrounded by a sleeve including insulating material. The method can include extracting heat from the glass ribbon passing through the cooling tubes such that heat extraction from the central region is greater than heat extraction from the edge portions.

[0022] In embodiments, the sleeve can include a first support protrusion extending radially between the sleeve wall and the end portion. The first support protrusion can extend along the length of the sleeve.

[0023] In an embodiment, the central portion can include a first outer diameter that is greater than the second outer diameter of the distal portions.

[0024] Additional features and advantages of the embodiments disclosed herein are set forth in the following detailed description, and in part will be apparent to those skilled in the art from the description, or may be learned by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings. It is to be understood that both the foregoing summary and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and characteristics of the embodiments disclosed herein. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various aspects of the present disclosure and, together with the description of the invention, serve to explain its principles and operation.

[0025] These and other features, aspects, and advantages will be better understood when the following detailed description is read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram of an exemplary embodiment of a glass forming apparatus according to an aspect of the present disclosure. [Figure 2] 2 is a perspective cross-sectional view of the glass forming apparatus taken along line 2-2 of FIG. 1 according to an embodiment of the present disclosure. [Figure 3] 3 is a cross-sectional view of the cooling tube taken along line 3-3 of FIG. 1 according to an embodiment of the present disclosure. [Figure 4] 1 is a cross-sectional view of a cooling tube including a sleeve according to an aspect of the present disclosure. [Figure 5] FIG. 5 is an end view of the cooling tube taken along line 5-5 of FIG. 4 according to an embodiment of the present disclosure. [Figure 6] 10A-10C are end views of additional embodiments of cooling tubes according to aspects of the present disclosure. [Figure 7] 10A-10C are perspective views of additional embodiments of cooling tubes according to aspects of the present disclosure. [Figure 8] 8 is a cross-sectional view of the cooling tube taken along line 8-8 of FIG. 7 according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] The embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments are shown. Wherever possible, the same reference numerals are 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 those embodiments set forth herein.

[0028] As used herein, the term "about" means that quantities, sizes, compositions, parameters, and other quantities and characteristics are not or need not be exact, but may be approximate and / or larger or smaller as necessary to reflect tolerances, conversion factors, rounding, measurement error, and the like, as well as other factors known to those skilled in the art.

[0029] Ranges may be expressed herein as from "about" one value and / or to "about" another value. When such a range is expressed, an embodiment includes from the one value to the other value. Similarly, it will be further understood that when values ​​are expressed as approximations, by use of the pre-modifier "about," the 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.

[0030] Directional terms used herein, such as above, below, right, left, front, back, top, bottom, upper, lower, etc., are intended to represent the state as depicted with respect to the figures and are not intended to imply absolute orientation.

[0031] Unless expressly stated otherwise, it is in no way intended that any method set forth herein be construed as requiring the performance of its steps in a particular order or as requiring a particular orientation with respect to any apparatus. Thus, where a method claim does not actually recite the order in which its steps are to be followed, or where any apparatus claim does not actually recite an order or orientation with respect to individual components, or where the claim or the specification does not otherwise specifically state that the steps are limited to a particular order, or does not recite a particular order or orientation with respect to the apparatus components, no order or orientation is intended to be inferred in any respect. This is true with respect to all implicit fundamentals considered in providing interpretation, including logical matters regarding the arrangement of steps, operational flow, component order, or component orientation, the obvious meaning derived from grammatical constructions or punctuation, and the number or type of aspects described herein.

[0032] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. That is, for example, reference to "a" element includes aspects having one or more of such elements unless the context clearly dictates otherwise.

[0033] The words "exemplary" and "example," as well as various variations thereof, are used herein to mean serving as an example, instance, or embodiment. Any aspect or design described herein as "exemplary" or "example" is not to be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided merely for purposes of clarity and understanding and are not intended to limit or restrict in any way the subject matter of the present disclosure or relevant portions thereof. It is contemplated that many additional or alternative examples of varying scope may be presented, but may be omitted for purposes of brevity.

[0034] As used herein, the terms "comprising" and "including" and variations thereof, unless otherwise indicated, should be construed as synonymous and open-ended. A list of elements following the transitional phrase "comprising" or "including" is an open-ended list, as there may be other elements than those specifically recited in the list.

[0035] As used herein, the terms "substantial," "substantially," and variations thereof are intended to indicate that a described feature is equal to or approximately equal to a value or description. For example, a "substantially planar" surface is intended to indicate a flat or nearly flat surface. Furthermore, "substantially" is intended to indicate that two values ​​are equal or approximately equal. The term "substantially" can refer to values ​​within about 10% of each other, for example, within about 5% of each other, or within about 2% of each other.

[0036] Modifications may be made to the present disclosure without departing from the scope or spirit of the claimed subject matter. Unless otherwise specified, "first" or "second," etc., are not intended to imply any temporal, spatial, or ordering. Rather, such terms are merely used as identifiers or names for features, elements, items, etc. For example, a first end and a second end generally correspond to end A and end B or two different ends.

[0037] The present disclosure relates to glass forming apparatuses and methods for producing glass ribbons. The methods and apparatus for producing glass ribbons from glass materials are described below using exemplary embodiments. As illustrated in FIG. 1 , in an embodiment, an exemplary glass forming apparatus 100 can include a glass melting and delivery apparatus 102 and a glass ribbon forming device 101 designed to produce a glass ribbon 103 from a quantity of molten material 121. The glass ribbon 103 can include a central region 152 positioned between opposing edge portions (e.g., edge beads) formed along a first outer edge 153 and a second outer edge 155 thereof, and the thickness of the edge portions can be greater than the thickness of the central portion. The glass ribbon 103 can include the central region 152 positioned between a first edge portion 179 and a second edge portion 181. The first edge portion 179 can include the first outer edge 153 and a portion of the glass ribbon 103 inward from the first outer edge 153. The second edge portion 181 may include the second outer edge 155 and a portion of the glass ribbon 103 inward from the second outer edge 155. Further, in embodiments, the individual glass ribbons 104 may be separated from the glass ribbon 103 along the separation path 151 by a glass separator 149 (e.g., a scribe, notch wheel, diamond tip, laser, etc.).

[0038] In an embodiment, the glass melting and delivery apparatus 102 may include a melting tank 105 adapted to receive batch material 107 from a storage bin 109. The batch material 107 may be introduced by a batch delivery device 111 powered by a motor 113. In an embodiment, an optional controller 115 may operate the motor 113 to introduce a desired amount of the batch material 107 into the melting tank 105, as indicated by arrow 117. The melting tank 105 may heat the batch material 107 to provide molten material 121. In an embodiment, a melt level probe 119 may be used to measure the level of the molten material 121 in a standpipe 123, and the melt level probe 119 may communicate the measurement information to the controller 115 via communication line 125.

[0039] Additionally, in embodiments, glass melting and delivery apparatus 102 may include a first conditioning station including a fining tank 127 positioned downstream from and coupled to melting tank 105 through a first connecting conduit 129. In embodiments, molten material 121 may be gravity fed from melting tank 105 through first connecting conduit 129 to fining tank 127. For example, in embodiments, gravity may drive molten material 121 from melting tank 105 through the internal passage of first connecting conduit 129 to fining tank 127. Additionally, in embodiments, gas bubbles may be removed from molten material 121 within fining tank 127 by various techniques.

[0040] In embodiments, the glass melting and delivery apparatus 102 may further include a second conditioning station including a mixing chamber 131, which may be positioned downstream of the fining vessel 127. The mixing chamber 131 may be used to provide a uniform composition of the molten material 121, thereby reducing or eliminating non-uniformities that may otherwise be present in the molten material 121 exiting the fining vessel 127. As shown, the fining vessel 127 may be coupled to the mixing chamber 131 through a second connecting conduit 135. In embodiments, the molten material 121 may be gravity fed from the fining vessel 127 through the second connecting conduit 135 to the mixing chamber 131. For example, in embodiments, gravity may drive the molten material 121 from the fining vessel 127 through the internal passage of the second connecting conduit 135 to the mixing chamber 131.

[0041] Further, in embodiments, the glass melting and delivery apparatus 102 may include a third conditioning station including a delivery chamber 133, which may be positioned downstream of the mixing chamber 131. In embodiments, the delivery chamber 133 may be conditioned to deliver the molten material 121 into the inlet conduit 141. For example, the delivery chamber 133 may act as an accumulator and / or a flow controller to regulate and provide a consistent flow of the molten material 121 to the inlet conduit 141. As shown, the mixing chamber 131 may be coupled to the delivery chamber 133 through a third connecting conduit 137. In embodiments, the molten material 121 may be gravity fed from the mixing chamber 131 through the third connecting conduit 137 to the delivery chamber 133. For example, in embodiments, gravity may drive the molten material 121 from the mixing chamber 131 through the internal passage of the third connecting conduit 137 to the delivery chamber 133. Additionally, as shown, in embodiments, a delivery pipe 139 may be positioned to deliver molten material 121 to the glass ribbon forming device 101, for example, to an inlet conduit 141 thereof. The glass ribbon forming device 101 may include a trough (e.g., trough 201 shown in FIG. 2 ) extending along a trough axis 140 between an inlet end 142 and an opposite end 143 thereof and facing the inlet end 142. The inlet end 142 is the end of the trough 201 closest to the inlet conduit 141 that receives the molten material 121. The opposite end 143 is the end furthest from the inlet conduit 141.

[0042] Illustratively, the glass ribbon forming device 101 shown and disclosed below can be provided to melt and draw molten material 121 from a bottom edge, defined as the root 145, of a forming wedge 209 to produce a glass ribbon 103. For example, in embodiments, the molten material 121 can be delivered to the glass ribbon forming device 101 from an inlet conduit 141. The molten material 121 can then be formed into a glass ribbon 103 based in part on the configuration of the glass ribbon forming device 101. For example, as shown, the molten material 121 can be drawn from a bottom edge (e.g., root 145) of the glass ribbon forming device 101 along a drawing path extending in a direction of travel 154 of the glass forming apparatus 100. In embodiments, edge directors 163, 164 can direct the molten material 121 from the glass ribbon forming device 101 to partially define a width 180 of the glass ribbon 103. In an embodiment, the width 180 of the glass ribbon 103 extends between a first outer edge 153 of the glass ribbon 103 and a second outer edge 155 of the glass ribbon 103. The glass forming apparatus 100 may include cooling tubes 171 positioned adjacent a travel path of the glass ribbon 103 (e.g., travel path 221 in FIG. 2 ). For example, the cooling tubes 171 may include a central portion 173 positioned adjacent a central region 152 of the glass ribbon 103 and end portions 175, 177 positioned adjacent edge portions 179, 181 of the glass ribbon 103. The cooling tubes 171 may be substantially hollow and filled with a cooling fluid that reduces the temperature of an outer surface of the cooling tubes 171. In this manner, the cooling tubes 171 may extract (e.g., absorb, accept, etc.) heat from the glass ribbon 103, thereby reducing the temperature of portions of the glass ribbon 103 adjacent the cooling tubes 171.

[0043] In embodiments, the width 180 of the glass ribbon 103 extending between the first outer edge 153 of the glass ribbon 103 and the second outer edge 155 of the glass ribbon 103 can be greater than or equal to about 20 millimeters (mm), such as greater than or equal to about 50 mm, such as greater than or equal to about 100 mm, such as greater than or equal to about 500 mm, such as greater than or equal to about 1000 mm, such as greater than or equal to about 2000 mm, such as greater than or equal to about 3000 mm, such as greater than or equal to about 4000 mm, although embodiments can provide other widths less than or greater than the aforementioned widths. For example, in embodiments, width 180 is in the range of about 20 mm to about 4000 mm, e.g., in the range of about 50 mm to about 4000 mm, e.g., in the range of about 100 mm to about 4000 mm, e.g., in the range of about 500 mm to about 4000 mm, e.g., in the range of about 1000 mm to about 4000 mm, e.g., in the range of about 2000 mm to about 4000 mm, e.g., in the range of about 3000 mm to about 4000 mm, e.g., about 20 mm The thickness may be in the range of about 1000 mm to about 3000 mm, for example, in the range of about 500 mm to about 3000 mm, for example, in the range of about 1000 mm to about 3000 mm, for example, in the range of about 2000 mm to about 3000 mm, for example, in the range of about 2000 mm to about 2500 mm, and all ranges and subranges therebetween.

[0044] FIG. 2 illustrates a cross-sectional perspective view of glass ribbon forming device 101 taken along line 2-2 in FIG. 1. In an embodiment, glass ribbon forming device 101 may include a trough 201 oriented to receive molten material 121 from inlet conduit 141. For illustrative purposes, the cross-hatching of molten material 121 has been removed from FIG. 2 for clarity. Glass ribbon forming device 101 includes a pair of weirs 203, 204 that define an opening 224 in trough 201. Glass ribbon forming device 101 includes a bottom surface 225 that may be substantially planar and may extend at least partially between inlet end 142 and opposite end 143 (e.g., as shown in FIG. 1 ). Bottom surface 225 may at least partially define trough 201; e.g., bottom surface 225 extends along the bottom of trough 201, and the pair of weirs 203, 204 extend along opposite sides of trough 201. The glass ribbon forming device 101 may further include a forming wedge 209 including a pair of downwardly inclined converging surface portions 207, 208 extending between opposite ends of the forming wedge 209. The pair of downwardly inclined converging surface portions 207, 208 of the forming wedge 209 may converge along the travel direction 154 to meet along the backbone 145 of the glass ribbon forming device 101 (e.g., at the bottom edge of the forming wedge 209 where the downwardly inclined converging surface portions 207 and 208 meet). A drawing plane 213 of the glass forming apparatus 100 may extend through the backbone 145 along the travel direction 154. In embodiments, the glass ribbon 103 may be drawn in the travel direction 154 along the drawing plane 213. As shown, the drawing plane 213 may bisect the forming wedge 209 through the backbone 145, although in embodiments, the drawing plane 213 may extend in other directions relative to the backbone 145. In an embodiment, the glass ribbon 103 may travel along an advance path 221 that may be coplanar with the drawing plane 213 in the advance direction 154 .

[0045] Additionally, the molten material 121 may flow into and along the trough 201 of the glass ribbon forming device 101 in the flow direction 156. The molten material 121 may then overflow the trough 201 by flowing through the openings 224, over the corresponding weirs 203, 204, and downwardly over the outer surfaces 205, 206 of the corresponding weirs 203, 204. Each stream of molten material 121 may then flow along the downwardly sloping converging surface portions 207, 208 of the forming wedges 209 and be drawn from the backbone 145 of the glass ribbon forming device 101 where the streams converge and fuse into the glass ribbon 103. The glass ribbon 103 may then be drawn along the travel direction 154. In embodiments, the glass ribbon 103 comprises one or more states of material based on its vertical location, i.e., distance from the backbone 145. For example, the glass ribbon 103 may include a viscous molten material 121 at a first location and an amorphous solid (eg, a glass ribbon) in a vitreous state at a second location.

[0046] The glass ribbon 103 includes a first major surface 215 and a second major surface 216 facing in opposite directions that define a thickness 212 (e.g., average thickness) of the glass ribbon 103. In embodiments, the thickness 212 of the glass ribbon 103 can be less than or equal to about 2 millimeters (mm), less than or equal to about 1 millimeter, less than or equal to about 0.5 millimeters, such as less than or equal to about 300 micrometers (μm), less than or equal to about 200 micrometers, or less than or equal to about 100 micrometers, although other thicknesses can be provided in further embodiments. For example, in embodiments, the thickness 212 of the glass ribbon 103 can be in the range of about 20 micrometers to about 200 micrometers, in the range of about 50 micrometers to about 750 micrometers, in the range of about 100 micrometers to about 700 micrometers, in the range of about 200 micrometers to about 600 micrometers, in the range of about 300 micrometers to about 500 micrometers, in the range of about 50 micrometers to about 500 micrometers, in the range of about 50 micrometers to about 700 micrometers, in the range of about 50 micrometers to about 600 micrometers, in the range of about 50 micrometers to about 500 micrometers, in the range of about 50 micrometers to about 400 micrometers, in the range of about 50 micrometers to about 300 micrometers, in the range of about 50 micrometers to about 200 micrometers, in the range of about 50 micrometers to about 100 micrometers, in the range of about 25 micrometers to about 125 micrometers, including all ranges and subranges of thickness therebetween. Additionally, the glass ribbon 103 may include one or more of a variety of compositions, such as soda-lime glass, borosilicate glass, aluminoborosilicate glass, alkali-containing glass, alkali-free glass, aluminosilicate, borosilicate, boroaluminosilicate, silicate, glass-ceramic, or other glass-containing materials.In embodiments, the glass ribbon 103 may include one or more of lithium fluoride (LiF), magnesium fluoride (MgF), calcium fluoride (CaF), barium fluoride (BaF), sapphire (AlO), zinc selenide (ZnSe), germanium (Ge), or other materials. In embodiments, none of the glasses listed above are fusion drawn, or some or all may be fusion drawn.

[0047] In embodiments, a glass separator 149 (see FIG. 1 ) can separate the glass ribbon 104 from the glass ribbon 103 along a separation path 151 to provide a plurality of individual glass ribbons 104 (i.e., a plurality of glass sheets). In embodiments, a lengthwise portion of the individual glass ribbons 104 can be wound onto a storage roll. The individual glass ribbons can then be processed into a desired application, such as a display application. For example, the individual glass ribbons can be used in a wide variety of display and non-display applications, including, but not limited to, liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light-emitting diode displays (OLEDs), plasma display panels (PDPs), micro LED displays, mini LED displays, organic light-emitting diode lighting, light-emitting diode lighting, augmented reality (AR), virtual reality (VR), touch sensors, photovoltaic cells, flip phones, or other applications.

[0048] FIG. 3 illustrates a cross-sectional view of cooling tube 171 as viewed along line 3-3 in FIG. 1. In an embodiment, cooling tube 171 can include a central portion 173, an end portion 175, and a second end portion 177, with central portion 173 positioned between end portion 175 and second end portion 177. In an embodiment, central portion 173, end portion 175, and second end portion 177 can extend along a tube axis 301. Central portion 173 includes a first sidewall 303 that surrounds a central chamber 305 that extends along tube axis 301. In an embodiment, central portion 173 can be cylindrical such that first sidewall 303 can include a substantially circular cross-sectional shape. Central chamber 305 can be hollow such that cooling tube 171 can receive cooling fluid 307 therein. For example, cooling fluid 307 may be provided by a fluid source 309 (e.g., a pump, cartridge, liquid reservoir, etc.) that may be in fluid communication with cooling tube 171. By being in fluid communication, fluid source 309 may be attached to cooling tube 171 (e.g., via tubing, conduits, pipes, etc.) such that cooling fluid 307 may be delivered from fluid source 309 to central chamber 305. In an embodiment, cooling fluid 307 may include a liquid, for example, water.

[0049] First sidewall 303 may include an outer surface 315 and an inner surface 317. Outer surface 315 may include a radially outer surface of central portion 173, and inner surface 317 may include a radially inner surface of central portion 173, with inner surface 317 circumferentially surrounding and bounding central chamber 305. In an embodiment, central portion 173 may include a first outer diameter 321 measured between opposite sides of first sidewall 303 at outer surface 315 and perpendicular to tube axis 301. First outer diameter 321 may be in the range of about 40 millimeters (“mm”) to about 130 mm, or in the range of about 40 mm to about 65 mm, or may be about 51 mm. In an embodiment, central portion 173 may include a first chamber diameter 325 measured between opposite sides of first sidewall 303 at inner surface 317 and perpendicular to tube axis 301. First chamber diameter 325 may be within a range from about 35 mm to about 55 mm, or may be about 45 mm. In an embodiment, first sidewall 303 may include a first wall thickness 329 measured between outer surface 315 and inner surface 317. In an embodiment, first wall thickness 329 may be within a range from about 2 mm to about 4 mm, or may be about 3 mm. In an embodiment, first sidewall 303 may include a rigid and hard material that is limited to deformation, such as a stainless steel material. First sidewall 303 may be free of holes or openings between outer surface 315 and inner surface 317 such that cooling fluid 307 cannot exit central portion 173 through first sidewall 303.

[0050] The end portion 175 can extend along the tube axis 301 and can be attached to the central portion 173, for example, by welding. In an embodiment, the end portion 175 can extend between a first end that can be in fluid communication with the fluid source 309 and a second end that is attached to the central portion 173. The end portion 175 can include a second sidewall 333 that surrounds an end chamber 335 that extends along the tube axis 301. In an embodiment, the end portion 175 can be cylindrical such that the second sidewall 333 can include a substantially circular cross-sectional shape. The end chamber 335 can be hollow such that the cooling tube 171 can receive the cooling fluid 307 into the end chamber 335 and the central chamber 305. For example, the end chamber 335 can be in fluid communication with the fluid source 309 and the central chamber 305 such that the cooling fluid 307 can flow from the fluid source 309, through the end chamber 335, and into the central chamber 305. Second sidewall 333 can include an outer surface 345 and an inner surface 347. Outer surface 345 can include a radially outer surface of terminal portion 175, and inner surface 347 can include a radially inner surface of terminal portion 175, with inner surface 347 circumferentially surrounding and defining terminal chamber 335.

[0051] In an embodiment, the distal portion 175 can include a second outer diameter 351 measured between opposite sides of the second sidewall 333 at the outer surface 345 and perpendicular to the tube axis 301. The second outer diameter 351 can be in the range of about 12 mm to about 40 mm, or can be about 25 mm. In an embodiment, the distal portion 175 can include a second chamber diameter 355 measured between opposite sides of the second sidewall 333 at the inner surface 347 and perpendicular to the tube axis 301. The second chamber diameter 355 can be in the range of about 10 mm to about 40 mm, or in the range of about 15 mm to about 25 mm, or can be about 20 mm. In an embodiment, the second sidewall 333 can include a second wall thickness 359 measured between the outer surface 345 and the inner surface 347. The second wall thickness 359 can be in the range of about 2 mm to about 4 mm, or can be about 3 mm. In embodiments, central portion 173 can include a first outer diameter 321 that can be larger than a second outer diameter 351 of end portion 175. In embodiments, second chamber diameter 355 can be smaller than first chamber diameter 325. In embodiments, first sidewall 303 and second sidewall 333 can include the same thickness. In embodiments, second sidewall 333 can include a rigid and hard material that is limited to deformation, such as a stainless steel material. Similar to first sidewall 303, second sidewall 333 can also be free of holes or openings between outer surface 345 and inner surface 347 such that cooling fluid 307 cannot exit end portion 175 through second sidewall 333. Thus, due to the difference in their respective outer diameters, the central portion 173 can include a larger surface area than the end portions 175, and therefore the central portion 173 can extract more heat from the central region 152 of the glass ribbon 103 than the end portions 175, 177 can extract from the edge portions 179, 181 of the glass ribbon 103.

[0052] In an embodiment, second end portion 177 can be substantially similar to or identical to first end portion 175. For example, second end portion 177 can extend along tube axis 301 and can be attached to central portion 173. That is, first end portion 175 can be attached to one side of central portion 173 and second end portion 177 can be attached to the opposite side of central portion 173, with central portion 173 and first and second end portions 175, 177 extending coaxially along tube axis 301. Second end portion 177 can include a third sidewall 365 that is substantially identical in material, shape, size, and function to second sidewall 333. For example, third sidewall 365 can be hollow and can enclose a second end chamber 367 that extends along tube axis 301. The second end chamber 367 can be in fluid communication with the central chamber 305 such that the cooling tubes 171 can receive the cooling fluid 307 into the end chambers 335 and pass it through the central chamber 305 and the second end chamber 367. Thus, in this manner, the method can include flowing the cooling fluid 307 through the cooling tubes 171. By flowing the cooling fluid 307 through the cooling tubes 171, the method can include extracting heat from the glass ribbon 103 passing through the cooling tubes 171 such that heat extraction from the central region 152 can be greater than heat extraction from the edge portions 179, 181.

[0053] In embodiments, the first sidewall 303 can include a first coating 371, and the second sidewall 333 can include a second coating 373. For example, the first coating 371 can cover none, some, or all of the exterior surface 315 of the first sidewall 303. Additionally or alternatively, the second coating 373 can cover none, some, or all of the exterior surface 345 of the second sidewall 333. In embodiments, the second coating 373 can cover none, some, or all of the third sidewall 365 of the second end portion 177. In embodiments, the emissivity of the second coating 373 can be the same as or different from the emissivity of the first coating 371. The emissivity of a coating is its effectiveness at emitting or accepting energy as thermal radiation, for example, the ratio of thermal radiation from a surface to that from an ideal black surface. In embodiments, the first coating 371 and / or the second coating 373 can include, for example, a nickel alloy-based coating. In embodiments, the first coating 371 and / or the second coating 373 can include a dark or neutral tint. The tint or surface color can affect radiation absorption, with white or neutral colors absorbing less radiation than dark or black colors. For example, when the emissivity of the first coating 371 and the emissivity of the second coating 373 are different, the first coating 371 can include a dark tint and the second coating 373 can include a neutral tint. Alternatively, when the emissivity of the first coating 371 and the emissivity of the second coating 373 are different, the first coating 371 can include a neutral tint and the second coating 373 can include a dark tint. In this manner, the first coating 371 and the second coating 373 can provide different amounts of heat extraction from the regions of the glass ribbon 103 adjacent the cooling tube 171. In an embodiment, the first coating 371 of the central portion 173 can include an emissivity of about 0.9, and the end portions 175, 177 can be free of a coating (e.g., the second coating 373) such that they can include an emissivity of about 0.7 (e.g., for stainless steel).

[0054] In embodiments, the central portion 173 may extract a greater amount of heat (and thus provide better cooling) than the end portions 175, 177 in some manner. For example, the central portion 173 may include a larger heat transfer area than the end portions 175, 177 for the same length due to including a larger outer diameter than the end portions 175, 177. Additionally or alternatively, an increased surface emissivity coating may result in increased radiation absorbed by the surface, and thus increased heat extraction. Thus, due to the central portion 173 being adjacent to the center of the glass ribbon 103 and the end portions 175, 177 being adjacent to the ends of the glass ribbon 103, the temperature drop at the center of the glass ribbon 103 may be greater than the temperature drop at the ends of the glass ribbon 103.

[0055] FIG. 4 shows a cross-sectional view of an additional embodiment of cooling tube 171 including, for example, sleeve 401. Cooling tube 171 can include, for example, central portion 173 and end portions 175, 177 and can be substantially identical to cooling tube 171 of FIG. 3. In an embodiment, first end portion 175 can be surrounded by sleeve 401 including insulating material 403. For example, in an embodiment, sleeve 401 can include first sleeve wall 405 and second sleeve wall 407. In an embodiment, first and second sleeve walls 405, 407 can include stainless steel. Sleeve 401 can extend along tube axis 301 and circumferentially surround end portion 175. For example, sleeve 401 can include first sleeve wall 405 positioned radially outward of and radially spaced apart from second sidewall 333 (e.g., having a larger diameter than second sidewall 333). The insulating material 403 may be positioned between the first sleeve wall 405 and the second sidewall 333 .

[0056] In embodiments, first sleeve wall 405 can be radially spaced from second sleeve wall 407, with insulating material 403 positioned between first sleeve wall 405 and second sleeve wall 407. In embodiments, first sleeve wall 405 is positioned radially outward of second sleeve wall 407 (e.g., has a larger diameter than second sleeve wall 407). In this manner, a gap or space can be provided between first sleeve wall 405 and second sleeve wall 407, which can be filled with insulating material 403 and extend along tube axis 301. In embodiments, sleeve 401 can extend along tube axis 301 between a first end of sleeve 401 coplanar with an end of terminal portion 175 and an opposite second end of sleeve 401 coplanar with the opposite end of terminal portion 175 and in contact with central portion 173. In this manner, the length of sleeve 401 can substantially match the length of terminal portion 175. In an embodiment, second sleeve wall 407 may contact and / or be attached to second sidewall 333 and may surround second sidewall 333 .

[0057] In embodiments, the insulating material 403 can include at least one of a ceramic fiber material or zirconia. The ceramic fiber material can include a high-strength needled insulation blanket made from cross-locked spun Fiberfrax ceramic fibers. The ceramic fiber material can include a mixture of silicon dioxide and aluminum oxide. In embodiments, the sleeve 401 can include one or more end walls, such as, for example, a first end sleeve wall 411 and a second end sleeve wall 413. The first end sleeve wall 411 can be located at a first end of the sleeve 401 and can extend in a plane perpendicular to the tube axis 301. The second end sleeve wall 413 can be located at a second end of the sleeve 401 and can extend in a plane perpendicular to the tube axis 301 and parallel to the first end sleeve wall 411. The first end sleeve wall 411 can be attached to the first and second sleeve walls 405 and 407, for example, by sealing thereto. Second end sleeve wall 413 can be attached to first sleeve wall 405 and second sleeve wall 407, for example, by sealing thereto. Thus, first sleeve wall 405, second sleeve wall 407, first end sleeve wall 411, and second end sleeve wall 413 can define a closed and sealed chamber with insulating material 403 positioned therein. In embodiments, insulating material 403 is not limited to including structural materials (e.g., ceramic fiber, zirconia, etc.), but can instead include a void. For example, the closed and sealed chamber of sleeve 401 can be substantially hollow and filled with air, which can thus act as insulating material 403. In embodiments, the closed and sealed chamber of sleeve 401 can form a vacuum by removing the air. In embodiments, the thermal conductivity of the vacuum is about 2 watts / meter. * Kelvin to about 4 watts / meter *Kelvin range. The insulating material 403 can reduce heat transfer at the end portions 175, 177, thereby reducing the transfer of thermal energy (e.g., heat flow) from the edge portions 179, 181 to the end portions 175, 177. In embodiments, the thermal conductivity of zirconia is about 1.5 watts / meter * Kelvin to about 3 watts / meter * In some embodiments, the thermal conductivity of the ceramic fiber material may be in the range of 0.11 watts per meter. * Kelvin to approximately 0.21 watts / meter * In comparison, the thermal conductivity of the central portion 173 is higher than the thermal conductivity of the insulating material 403, e.g., the thermal conductivity of the first sidewall 303 is about 15 watts per meter. * Kelvin to about 17 watts / meter * In the Kelvin range.

[0058] In an embodiment, the sleeve 401 can include a sleeve outer diameter 417, and the first outer diameter 321 of the central portion 173 can be substantially equal to the sleeve outer diameter 417 of the sleeve 401. As such, the sleeve outer diameter 417 can be measured between opposite sides of the first sleeve wall 405 and perpendicular to the tube axis 301. The sleeve outer diameter 417 can be in the range of about 40 mm to about 130 mm, or in the range of about 40 mm to about 65 mm, or can be about 51 mm. Additionally, the cooling tube 171 can include a second sleeve 421 surrounding the second end portion 177 and including a second insulating material 423. In an embodiment, the second sleeve 421 can be substantially identical to the sleeve 401 in material, shape, size, and function. For example, the second sleeve 421 can include a sleeve wall including an insulating material 403 and can include a length that substantially matches the length of the second end portion 177 and an outer diameter that substantially matches the first outer diameter 321 of the central portion 173.

[0059] 5 illustrates a cross-sectional view of cooling tube 171 including sleeve 401 taken along line 5-5 in FIG. 4. As shown, in embodiments, second sleeve wall 407 can abut and / or contact outer surface 345 of second sidewall 333. In this manner, sleeve 401 can be secured relative to end portion 175 and restricted from, for example, axial movement along tube axis 301 and / or radial movement perpendicular to tube axis 301.

[0060] FIG. 6 illustrates a cross-sectional view of the cooling tube 171 along line 5-5 of FIG. 4, similar to FIG. 5, but with an additional aspect of the sleeve 401. For example, in an embodiment, the sleeve 401 is not limited to including a first sleeve wall 405 and a second sleeve wall 407. Alternatively, the sleeve 401 may include the first sleeve wall 405 but not the second sleeve wall 407. For example, the sleeve 401 extends along the tube axis 301 and circumferentially surrounds the end portion 175, and the sleeve 401 includes the first sleeve wall 405 that is radially spaced from the second sidewall 333. In this manner, the insulating material 403 can be positioned between the first sleeve wall 405 and the second sidewall 333, and the insulating material 403 can contact the outer surface 345 of the second sidewall 333.

[0061] 7-8 illustrate additional embodiments of sleeve 401. For example, FIG. 7 illustrates a perspective view of end portion 175 of cooling tube 171, with sleeve 401 surrounding end portion 175. FIG. 8 illustrates a cross-sectional view of end portion 175 and sleeve, as viewed along line 8-8 in FIG. 7. Sleeve 401 includes a first sleeve wall 405 radially spaced from second side wall 333. In embodiments, sleeve 401 can include one or more protrusions, such as first support protrusion 701, second support protrusion 703, etc. Although FIGS. 7 and 8 illustrate a total of five support protrusions spaced circumferentially about tube axis 301, any number of support protrusions can be provided.

[0062] The first support protrusion 701 can be attached to the second sidewall 333 and can extend radially between the first sleeve wall 405 and the second sidewall 333 of the end portion 175. The first support protrusion 701 can extend along the tube axis 301, for example, by extending continuously along the length of the sleeve 401 between both ends of the sleeve 401. In an embodiment, as shown in FIG. 7 , the first support protrusion 701 can extend along a first support axis 702 that is substantially parallel to the tube axis 301. In an embodiment, the first support protrusion 701 can extend radially along a first protrusion axis 705 that intersects the tube axis 301 perpendicularly. In this manner, the first protrusion axis 705 can intersect the first sleeve wall 405 and the second sidewall 333. In an aspect, the first support protrusion 701 can be attached to the first sleeve wall 405 and the second sidewall 333, such that the first sleeve wall 405, the first support protrusion 701, and the second sidewall 333 can be substantially fixed relative to one another. For example, the first support protrusion 701 can be attached to the second sidewall 333 at a radially inner end and attached to the first sleeve wall 405 at a radially outer end.

[0063] The second support protrusion 703 can be attached to the second sidewall 333 and can extend radially between the first sleeve wall 405 and the second sidewall 333. The second support protrusion 703 can extend along the tube axis 301, for example, by extending continuously along the length of the sleeve 401 between both ends of the sleeve 401. In an embodiment, as shown in FIG. 7 , the second support protrusion 703 can extend along a second support axis 704 that is substantially parallel to the tube axis 301 and the first support axis 702. In an embodiment, the second support protrusion 703 can extend radially along a second protrusion axis 709 that intersects the tube axis 301 perpendicularly. In this manner, the second protrusion axis 709 can intersect the first sleeve wall 405 and the second sidewall 333. In an embodiment, the second support protrusion 703 can be attached to the first sleeve wall 405 and the second sidewall 333, thereby substantially fixing the first sleeve wall 405, the second support protrusion 703, and the second sidewall 333 relative to one another. For example, the second support protrusion 703 can be attached to the second sidewall 333 at a radially inner end and attached to the first sleeve wall 405 at a radially outer end.

[0064] In embodiments, the support protrusions can be spaced circumferentially at substantially the same distance about the tube axis 301. For example, each of the five support protrusions in FIGS. 7-8 can be spaced apart from an adjacent support protrusion by about 60 to about 90 degrees, or about 70 to about 75 degrees, or about 72 degrees. In this manner, the first support protrusion 701 can be spaced apart from the second support protrusion 703 by about 60 to about 90 degrees, or about 70 to about 75 degrees, or about 72 degrees about the tube axis 301. In embodiments, the first and second support protrusions 701, 703 can provide structural support to the sleeve 401 and, therefore, the cooling tube 171. For example, the first and second support protrusions 701, 703 can limit movement of the sleeve 401 relative to the end portion 175 by contacting and in some embodiments being attached to the first sleeve wall 405 and the second side wall 333.

[0065] In embodiments, in addition to providing structural support to the cooling tube 171, the sleeve 401 can insulate the end portion 175. For example, the sleeve 401 can include insulating material 403 positioned between the first sleeve wall 405 and the second side wall 333. The insulating material 403 can surround the first support protrusion 701, for example, by being positioned on either side of the first support protrusion 701 relative to the first support axis 702. The insulating material 403 can also extend along the first support axis 702 along the length of the sleeve 401. In embodiments, the insulating material 403 can be positioned in the space between each of the support protrusions. For example, the insulating material 403 can be positioned between the first support protrusion 701 and the second support protrusion 703, for example, by filling substantially all of the space between the first support protrusion 701 and the second support protrusion 703. In this manner, the insulating material 403 can contact the first sleeve wall 405 radially outward, the second sidewall 333 radially inward, and the support protrusions (e.g., 701, 703) on both circumferential sides. Thus, in aspects, substantially all of the portion of the sleeve 401 between the first sleeve wall 405 and the second sidewall 333 can be occupied by either the first and second support protrusions 701, 703 or the insulating material 403.

[0066] In embodiments, as shown in FIGS. 7-8 , first and second support protrusions 701, 703 are not limited to contacting and being attached to second side wall 333. Instead, in embodiments, similar to the embodiment of sleeve 401 shown in FIGS. 4-5 , sleeve 401 can include second sleeve wall 407. Second sleeve wall 407 can be attached to support protrusions (e.g., 701, 703, etc.), and thus support protrusions (e.g., 701, 703, etc.) can be attached radially inwardly to second sleeve wall 407 and radially outwardly to first sleeve wall 405. In this manner, support protrusions (e.g., 701, 703, etc.) can extend between second side wall 333 and first sleeve wall 405 without contacting second side wall 333, but instead contacting second sleeve wall 407. The sleeve 401 can be attached to the end portion 175 in substantially the same manner as illustrated and described above with respect to Figures 4-5, for example, the second sleeve wall 407 can be configured to receive the end portion 175 with the second sleeve wall 407 in contact with the second side wall 333.

[0067] By providing differential cooling of the glass ribbon 103 from the cooling tubes 171, several benefits can be achieved. For example, the cooling tubes 171 can extract more heat from the central region 152 than from the edge portions 179, 181. Therefore, damage to the edge portions 179, 181, which may be associated with overcooling of the edge portions 179, 181, can be avoided. Furthermore, the buildup of condensation, which also results from overcooling of the edge portions 179, 181, can be reduced, thus reducing the potential for damage to the glass ribbon 103. The cooling tubes 171 can be further supported by sleeves 401, e.g., support protrusions (e.g., 701, 703, etc.), which can limit sagging or deformation of the cooling tubes 171 over time. Additionally, in embodiments, the insulating material 403 can be selected from several materials based on their thermal conductivity to achieve a desired amount of cooling from the end portions 175, 177 of the glass ribbon 103. In this manner, the thermal conductivity at the end portions 175 , 177 of the glass ribbon 103 can be different, eg, less than, the thermal conductivity at the center portion 173 of the glass ribbon 103 .

[0068] In embodiments, modeling was performed to determine the temperature change as a result of heat extraction based on different types of cooling tube 171. For example, compared to a cooling tube having a constant diameter of about 50 mm along its entire length, cooling tube 171 of FIG. 3 (e.g., central portion 173 including a diameter of about 50 mm and end portions 175, 177 including a diameter of about 25 mm) had a relative temperature increase of about 1.5° C. in central region 152 and a relative temperature increase of about 17° C. in each of edge portions 179, 181. Thus, central region 152 was cooled to a lower temperature than edge portions 179, 181. In yet another example, compared to a cooling tube having a constant diameter of about 50 mm along its entire length, the cooling tube 171 of FIG. 4 (e.g., the central portion 173 included a diameter of about 50 mm, the end portions 175, 177 included a diameter of about 25 mm, and the sleeve 401 included insulating material 403) had a relative temperature increase of about 4° C. in the central region 152 and a relative temperature increase of about 29° C. in each of the edge portions 179, 181. Again, the central region 152 cooled to a lower temperature than the edge portions 179, 181. Thus, the non-uniform cooling tube 171 can generate differential cooling along the width of the glass ribbon 103.

[0069] While various aspects have been described in detail with respect to certain illustrative and specific examples thereof, it should be understood that the present disclosure should not be considered as limited thereto, as many modifications and combinations of the features of the present disclosure are possible without departing from the scope of the following claims.

Claims

1. 1. A glass forming apparatus comprising: a cooling tube positioned adjacent the path of travel of the glass ribbon; Including, The cooling tube is a central portion including a first sidewall surrounding a central chamber and extending along the tube axis; a terminal portion including a second sidewall surrounding a terminal chamber, the terminal portion extending along the tube axis and attached to the central portion, the cooling tube configured to receive a cooling fluid within the central chamber and the terminal chamber; a sleeve extending along the tube axis and circumferentially surrounding the end portion, the sleeve including a sleeve wall radially spaced from the second side wall and an insulating material positioned between the sleeve wall and the second side wall; Including, Glass forming equipment.

2. 10. The glass forming apparatus of claim 1, wherein said central portion includes a first outer diameter that is greater than a second outer diameter of said end portions.

3. 3. The glass forming apparatus of claim 2, wherein the first outer diameter is in the range of about 40 mm to about 65 mm.

4. 3. The glass forming apparatus of claim 2, wherein the second outer diameter is in the range of about 10 mm to about 40 mm.

5. 5. The glass forming apparatus of claim 1, wherein the central chamber includes a first outer chamber diameter and the terminal chamber includes a second outer chamber diameter that is smaller than the first outer chamber diameter.

6. 6. The glass forming apparatus of claim 1, wherein the thickness of the first sidewall is equal to the thickness of the second sidewall.

7. 7. The glass forming apparatus of any one of claims 1 to 6, wherein the sleeve wall comprises stainless steel.

8. 8. A glass forming apparatus according to any one of claims 1 to 7, wherein the insulating material comprises at least one of ceramic fibre or zirconia.

9. 8. A glass forming apparatus according to any one of claims 1 to 7, wherein the insulating material comprises air.

10. 10. The glass forming apparatus of claim 1, wherein the first sidewall includes a first coating and the second sidewall includes a second coating, the emissivity of the second coating being different from the emissivity of the first coating.

11. 1. A glass forming apparatus comprising: a cooling tube positioned adjacent the path of travel of the glass ribbon; Including, The cooling tube is a central portion including a first sidewall surrounding a central chamber and extending along the tube axis; a terminal portion including a second sidewall surrounding a terminal chamber, the terminal portion extending along the tube axis and attached to the central portion, the cooling tube configured to receive a cooling fluid within the central chamber and the terminal chamber; a sleeve extending along the tube axis and circumferentially surrounding the end portion; Including, The sleeve is a sleeve wall radially spaced from the second side wall; a first support protrusion attached to the second side wall and extending radially between the sleeve wall and the second side wall, the first support protrusion extending along the tube axis; an insulating material positioned between the first sleeve wall and the second side wall, the insulating material surrounding the first support protrusion; Including, Glass forming equipment.

12. 12. The glass forming apparatus of claim 11, wherein the sleeve includes a second support protrusion extending radially between the sleeve wall and the second side wall, the second support protrusion extending along the tube axis, and the first support protrusion and the second support protrusion being circumferentially spaced apart within a range of about 60 degrees to about 90 degrees about the tube axis.

13. 13. The glass forming apparatus of claim 12, wherein the insulating material is positioned between the first support protrusion and the second support protrusion, the insulating material comprising at least one of ceramic fiber or zirconia.

14. 14. The glass forming apparatus of any one of claims 12-13, wherein the first outer diameter of the central portion is equal to the outer sleeve diameter of the sleeve.

15. 15. The glass forming apparatus of claim 14, wherein the first outer diameter of the central portion is greater than the second outer diameter of the end portions.

16. 1. A method of forming a glass ribbon using a glass forming apparatus, comprising: moving the glass ribbon along an advancing path in an advancing direction past cooling tubes; flowing a cooling fluid through the cooling tubes, the cooling tubes including a central portion positioned adjacent a central region of the glass ribbon and end portions positioned adjacent edge portions of the glass ribbon, the end portions being surrounded by a sleeve comprising an insulating material; and extracting heat from the glass ribbon passing through the cooling tubes such that heat extraction from the central region is greater than heat extraction from the edge portions; A method comprising:

17. 17. The method of claim 16, wherein the sleeve includes a first support protrusion extending radially between a sleeve wall and the end portion, the first support protrusion extending along the length of the sleeve.

18. 18. The method of any one of claims 16-17, wherein the central portion comprises a first outer diameter that is greater than a second outer diameter of the distal portions.

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