SYSTEM AND METHODS FOR ADJUSTABLE EDGE COOLING MEANS FOR SLOT GLASS DRAWDOWN

Apparatuses and methods are described for controlling the width and thickness of glass during glass sheet production. The apparatuses and methods employ a gas cooling mechanism that is designed to extract heat from molten glass during the drawdown process to reduce width attenuation and generate more uniform glass. In some examples, a nozzle of a glass forming apparatus includes a first nozzle portion with a first glass forming surface, and a second nozzle portion opposite the first nozzle portion, where the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The nozzle also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion. Gas, such as air, is delivered to each of the first cavity and the second cavity to cool molten glass as it is drawn between the first and second glass forming surfaces.

FIELD OF THE DISCLOSURE

The present disclosure relates to the production of glass sheets and, more particularly, to apparatus and methods for controlling the uniformity of glass during glass sheet production.

BACKGROUND

Glass sheets are used in a variety of applications. For example, they may be used in glass display panels such as in mobile devices, laptops, tablets, computer monitors, and television displays. Glass sheets may be manufactured by a slot drawdown process whereby molten glass is drawn through a slot to form a glass sheet. For a variety of applications, the close control of the width and thickness of manufactured glass can be important. Thermo-mechanical and glass flow conditions can be uneven across the entirety or portions of a width of a glass ribbon as it is being formed in the slot drawdown process, thereby causing variations in the width or thickness of the formed glass. These width and thickness differences in the formed glass are, in many applications, undesirable as they may result in cost and time consequences that, in many cases, can be significant. As such, there are opportunities to improve the production of glass sheets.

SUMMARY

The embodiments disclosed herein are directed to apparatus and methods for providing a cooling mechanism in glass formation apparatus during the glass formation process. The cooling mechanism may allow for the extraction of heat along a width of molten glass and, in particular, along and near either edge of the molten glass.

For example, the embodiments may control heat extraction along a width of molten glass by providing gas (e.g., air, oxygen, etc.) flow within portions of a nozzle that guides the molten glass during the drawdown process. The embodiments may, for example, increase the viscosity of the molten glass near and along the ends of the width of glass compared to more center regions of the width of glass. The embodiments may achieve the higher viscosity levels by controlling the amount of heat extracted from the molten glass as it is drawn down. For example, the embodiments may extract heat from portions of the molten glass near and along the ends of the width of glass to increase viscosity along those portions. The embodiments may extract the heat by providing higher gas flow within portions of the nozzle closer to the ends of the molten glass compared to any gas flow provided within portions of the nozzle that are closer to more center regions of molten glass.

Among other advantages, the embodiments may allow for the production of glass (e.g., ribbon) sheets with reduced width attenuation, thus allowing for the formation of glass sheets with more uniform widths. As a result, the embodiments may reduce cost and time consequences associated with generating glass with less uniform widths, including the reduction of glass waste and cost (e.g., such as when glass doesn't meet a width specification). Moreover, glass sheets, and in particular thin or ultrathin glass sheets (e.g., <200 microns thickness) can be more reliably formed. Those of ordinary skill in the art having the benefit of these disclosures may recognize other benefits as well.

In some examples, the apparatuses and methods described herein may employ a gas cooling mechanism that is designed to extract heat from molten glass during the drawdown process to reduce width attenuation and generate more uniform glass. For example, in some embodiments, a nozzle of a glass forming apparatus includes a first nozzle portion with a first glass forming surface, and a second nozzle portion opposite the first nozzle portion, where the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The nozzle also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion. Gas, such as air, is delivered to each of the first cavity and the second cavity to cool molten glass as it is drawn between the first and second glass forming surfaces.

In some embodiments, a nozzle assembly for a glass forming apparatus includes a first nozzle portion and a second nozzle portion opposite the first portion. The first nozzle portion includes a first glass forming surface, and the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The nozzle also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion.

In some embodiments, a glass forming apparatus includes a nozzle with a first nozzle portion and a second nozzle portion opposite the first portion. The first nozzle portion includes a first glass forming surface, and the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The nozzle also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion. The apparatus also includes at least one gas supply configured to deliver a gas to the first cavity and the second cavity.

In some embodiments, a glass forming apparatus includes a nozzle with a first nozzle portion and a second nozzle portion opposite the first portion. The first nozzle portion includes a first glass forming surface, and the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The nozzle also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion. The apparatus also includes at least one gas supply configured to deliver a gas to the first cavity and the second cavity. The apparatus further includes a thermal camera configured to detect a temperature of molten glass that flows between the first glass forming surface and the second glass forming surface. The apparatus further includes a processor configured to receive a signal from the thermal camera identifying a temperature of the molten glass, and determine a pressure for the gas based on the temperature. The processor is also configured to transmit a signal to the at least one gas supply to cause the at least one gas supply to provide the gas at the determined pressure.

In some embodiments, a method by a glass forming apparatus includes providing a first gas flow at a first pressure through a passageway of a first portion of a nozzle of a glass forming apparatus. The method also includes providing a second gas flow at a second pressure through a passageway of a second portion of the nozzle. Further, the method includes providing molten glass between the first and second glass forming surfaces to produce a glass ribbon. In some examples, the method further includes generating a laser beam towards molten glass that has flowed between the first and second glass forming surfaces.

In some embodiments, a method by one or more processors includes transmitting a first signal to cause a delivery of air flow at a first pressure through a cavity of a nozzle of a glass forming apparatus. The method also includes receiving a second signal that identifies a temperature of molten glass at a first edge of the molten glass. Further, the method includes determining a second pressure of air flow based on the first pressure and the temperature of the molten glass at the first edge. The method also includes transmitting a third signal to cause the delivery of the air flow at the second pressure through the cavity of the nozzle.

In some embodiments, a non-transitory computer readable medium stores instructions that, when executed by one or more processors, cause the one or more processors to perform a method that includes transmitting a first signal to cause a delivery of air flow at a first pressure through a cavity of a nozzle of a glass forming apparatus. The method also includes receiving a second signal that identifies a temperature of molten glass at a first edge of the molten glass. Further, the method includes determining a second pressure of air flow based on the first pressure and the temperature of the molten glass at the first edge. The method also includes transmitting a third signal to cause the delivery of the air flow at the second pressure through the cavity of the nozzle.

DETAILED DESCRIPTION

The present application discloses illustrative (i.e., example) embodiments. The disclosure is not limited to the illustrative embodiments. Therefore, many implementations of the claims will be different than the illustrative embodiments. Various modifications can be made to the claims without departing from the spirit and scope of the disclosure. The claims are intended to cover implementations with such modifications.

At times, the present application uses directional terms (e.g., front, back, top, bottom, left, right, etc.) to give the reader context when viewing the Figures. The claims, however, are not limited to the orientations shown in the Figures. Any absolute term (e.g., high, low, etc.) can be understood as disclosing a corresponding relative term (e.g., higher, lower, etc.).

Referring toFIG.1, glass forming apparatus20includes a cavity24that is bounded on its longitudinal sides by walls25and26. The walls25and26terminate at their upper extent in opposed longitudinally extending overflow weirs27and28, respectively. The walls25and26are integral with a nozzle60that includes pair of opposed and downwardly inclined glass forming surfaces32. The pair of opposed and downwardly inclined glass forming surfaces32terminate at a slot34of nozzle60. Molten glass is delivered into cavity24by means of a delivery passage38that is in fluid communication with the cavity24. The molten glass is directed to the slot34by walls25,26and the pair of opposed and downwardly inclined glass forming surfaces32.

FIG.1illustrates one nozzle portion61of nozzle60. Each nozzle portion61may, in some examples, include cold fingers (not illustrated) to extract heat from corresponding portions of the molten glass as the glass ribbon is being formed. For example, one or more cold fingers may be embedded into the nozzle portion61of nozzle60to extract heat from the molten glass through an adjacent portion of a corresponding downwardly inclined glass forming surface32. Each cold finger may be manufactured from material that facilitates heat conductivity (e.g., thermal conduction), such as a metal. Further, each nozzle portion61may include one or more cavities63. The cavities63may extend into the nozzle portion61in a direction towards a corresponding glass forming surface32.

In some examples a cooling gas, such as air or oxygen, is provided to one or more cavities63. For example, one end of a tube (e.g., plastic air tube) may be inserted into a cavity63, and the other end of the tubes receive gas from a gas supply (e.g., air supply). The gas proceeds through the tube into the cavity63, and extracts heat during the glass ribbon44formation process. In some examples, glass forming apparatus20includes one or more gas supply devices (not illustrated inFIG.1). Each gas supply device may provide gas to one or more cavities63. In some examples, the cavities63are positioned to align with edges48, such that they allow for cooling of edges of the molten glass. In some examples, the cavities are positioned within 160 millimeters of an end of slot34(e.g., and substantially aligned with edges48of the glass ribbon44).

Further, each cavity63may have a predetermined diameter, which can be determined based on a targeted (e.g., predetermined) amount of heat extraction. In some examples, the cavities63have a diameter smaller than 2 millimeters, such as when producing ultrathin glass sheets (e.g., less than 200 microns in glass thickness). Moreover, each cavity63may extend into nozzle portion61up to a predetermined distance from the corresponding downwardly inclined glass forming surface32. For example, a cavity63may extend until a few millimeters (e.g., 2 to 10 mm) from the corresponding downwardly inclined glass forming surface32. In some examples, the distance from the corresponding downwardly inclined glass forming surface32is determined empirically, and based on heat transfer properties and algorithms.

FIGS.2A and2Billustrate views of an exemplary nozzle assembly200. For example, and with reference toFIG.2A, nozzle assembly200includes a nozzle202with a first nozzle portion204and a second nozzle portion206. Molten glass210is provided between a first glass forming surface212of first nozzle portion204and a second glass forming surface214of second nozzle portion206, and flows through slot270to product a glass ribbon272. In addition, the first nozzle portion204is supported by a first cradle portion220of a cradle assembly218, and the second nozzle portion206is supported by a second cradle portion222of the cradle assembly218. Each of the first cradle portion220and the second cradle portion222include a gas flow passageway. For example, first cradle220includes a first gas flow passageway230, and second cradle portion222includes a second gas flow passageway232.

Each of the first gas flow passageway230and second gas flow passageway232may be configured to receive a gas, such as air, and provides the gas to cavities (e.g., such as cavities63) of the nozzle202(the cavities are not illustrated inFIG.2A). For example, as illustrated inFIG.2A, gas supply250provides a gas, such as air, through a gas tube252to first gas flow passageway230. Gas supply250may provide the gas at a pressure, and the gas may flow through the gas tube252, through the first gas flow passageway230, and into one or more cavities of first nozzle portion204.

In some examples, gas tubes252are manufactured from a metal or a metal oxide, such as alumina. In some examples, the initial part of a gas tube252connected to the gas supply (and, in some examples, coming from a gas flowmeter64as described herein) may be made out of metal with a diameter of 5-10 mm, to facilitate the passage of the gas towards a relatively hot environment as well as to increase mechanical stability. The final part of the gas tube250(with a length of 100-150 mm in some examples) needs to be small enough to pass through openings in the cradle assembly218. These openings may be smaller (e.g., 2-3 mm) to minimize mechanical weakening of the cradle assembly218. Connection of the gas tube250to the openings can be made by welding or brazing with a lower melting point alloy, for example.

FIG.2Billustrates a cavity284of first nozzle portion202. Cavity284includes an opening282, and extends towards and first glass forming surface212. In this example, gas provided by gas supply250extracts heat from cold finger280, thereby increasing the amount of heat cold finger280extracts from the molten glass. In some examples, first nozzle portion202includes one or more cavities284adjacent a first distal end290of the slot270, and second nozzle portion204includes one or more cavities284adjacent a second distal end (not illustrated) opposite the first distal end290of the slot270.

Referring back toFIG.1, the molten glass flows through slot34to form the glass ribbon44. Pulling rolls46are located downstream of the slot34and engage side edges48at both sides of the glass ribbon44to apply tension to the glass ribbon44. The pulling rolls46may be positioned sufficiently below the root34that the thickness of the glass ribbon44is essentially fixed at that location. The pulling rolls46may draw the glass ribbon44downwardly at a prescribed rate that establishes the thickness of the glass ribbon as it is drawn though slot34.

In some examples, glass forming apparatus20includes a laser generator12that is configured to generate and emit a laser beam13. In an embodiment, the laser beam13is directed to molten glass below (e.g., just below) slot34, where the laser beam energy provided by laser beam13is provided across the molten glass. As illustrated in the aspect ofFIG.1, the laser beam13can be directed by laser generator12to the molten glass via, for example, reflecting apparatus14. Although one laser generator12generating a laser beam13towards reflecting apparatus14is illustrated, in some examples, laser beam control system10may employ additional laser generators12and/or reflecting apparatus14. For example, control system10may employ a second laser generator12to direct a laser beam to the molten glass via reflecting apparatus14. As another example, laser beam control system10may employ a second laser generator12to direct a laser beam to the molten glass flowing from slot34via a second reflecting apparatus14.

Further, reflecting apparatus14can include a reflecting surface15that is configured to receive the laser beam13generated and emitted by the laser generator12and reflected onto at least predetermined portions of the molten glass. Reflecting apparatus14may be, for example, a mirror configured to deflect a laser beam from laser generator12. Reflecting apparatus14may therefore function as a beam-steering and/or scanning device. InFIG.1, the laser beam13is illustrated as being advanced by reflecting apparatus14as reflected laser beams17to a plurality of portions (e.g., preselected portions) of the molten glass.

The reflecting surface15in one example can comprise a gold-coated mirror although other types of mirrors may be used in other examples. Gold-coated mirrors may be desirable under certain applications to provide superior and consistent reflectivity relative to infrared lasers, for example. In addition, the reflectivity of gold-coated mirrors is virtually independent of the angle of incidence of laser beam13and, therefore, the gold-coated mirrors are particularly useful as scanning or laser beam-steering mirrors.

The reflecting apparatus14in the embodiment illustrated inFIG.1may also include a regulating mechanism16(e.g., a galvanometer or polygon scanner) configured to adjust an orientation of the reflecting surface15of the reflecting apparatus14relative to the receipt of the laser beam13and a location of a preselected portion of the molten glass. For example, reflecting apparatus14can rotate or tilt reflecting surface15to direct laser beam13to a predetermined portion of the molten glass as reflected laser beams17, for example.

According to one example, the regulating mechanism16can comprise a galvanometer that is operatively associated with the reflecting surface15so that the reflecting surface15can be rotated by the galvanometer along an axis in relation to the glass ribbon44. For example, the reflecting surface15can be mounted on a rotating shaft18that is driven by a galvanometer motor and rotated about axis18aas shown by double arrow19.

In some examples, glass forming apparatus20includes one or more control computers (e.g., processors) that, in some examples, is configured to control laser generator12to direct laser beam13towards reflecting apparatus14.

Further, in some examples, glass forming apparatus20may include one or more gas flow meters, one or more thermal cameras, and/or one or more gas supply devices. The one or more processors may be communicatively coupled (e.g., via wired or wireless connection) to the one or more gas flow meters, the one or more thermal cameras, and/or the one or more gas supply devices. Each gas flow meter may be configured to measure a pressure of the gas provided to the cavities63from an air supply device, and the thermal cameras may be directed to nozzle portion61and configured to detect a temperature of the molten glass, e.g., within cavity24. The one or more control computers may receive gas pressure readings from the air flow meters, and may further receive temperature readings from the thermal cameras. In some examples, as described herein, the one or more control computers may receive a temperature from a thermal camera, and determine a gas pressure based on the received temperature. Further, the one or more processors may transmit a signal to a gas supply device to adjust its gas pressure output to the determined gas pressure.

For example,FIG.3illustrates portions of exemplary control system10that includes laser power control55and control computer52. Each of laser power control55and control computer52can include one or more processors, one or more field-programmable gate arrays (FPGAs), one or more application-specific integrated circuits (ASICs), one or more state machines, digital circuitry, or any other suitable circuitry. In some embodiments, one or more of laser power control55and control computer52may be implemented in any suitable hardware or hardware and software (e.g., one or more processors executing instructions stored in memory). For example, a non-transitory computer readable medium such as, for example, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), flash memory, a removable disk, CD-ROM, any non-volatile memory, or any other suitable memory, may store instructions that may be obtained and executed by any one or more processors of laser power control55and control computer52to execute one or more of the functions described herein.

Laser power control unit55can control the operation of the laser generator12so that the pulse energy, beam width, power level, and/or wavelength of a laser beam13generated at laser generator12and directed towards reflecting apparatus14comprises preselected values. In addition, laser power control unit55can control the time intervals during which the laser generator12generates the laser beam13. Control computer52is communicatively coupled to laser power control55and can control the operation of the laser power control unit55to cause laser generator12to generate, during preselected time intervals, a laser beam13having preselected wavelength and power characteristics.

Additionally, the control computer52may be operatively associated with the reflecting apparatus14to control the functioning of the regulating mechanism16, and in a particular example where a galvanometer is employed, the motor of the galvanometer. Accordingly, the control computer52can be capable of adjusting the attitude and positioning of the reflecting surface15relative to the receipt of the laser beam13by the reflecting surface15and the locations of preselected portions of the molten glass.

For example, control computer52may configure regulating mechanism16to adjust (e.g., tilt or rotate), for preselected time periods, the reflecting surface15of the reflecting apparatus14in a plurality of varying attitudes relative to the receipt of the laser beam13and the reflection of the laser beam at the reflecting surface15of the reflecting apparatus14. Consequently, the laser beam13can be directed onto a plurality of preselected portions of the molten glass during respective preselected time periods, as illustrated by the reflected laser beams17inFIG.1, for example, thereby providing laser beam energy to the molten glass to control the thickness of the molten glass.

In some examples, control system10further includes one or more thermal cameras62, one or more gas flow meters64, and one or more gas supplies68. Further, control computer52, may be communicatively coupled to the one or more thermal cameras62, one or more gas flow meters64, and one or more gas supplies68. Each thermal camera62may be directed to a portion of nozzle60. In some examples, control computer52is configured to adjust the direction of a thermal camera62. For example, control computer52may transmit a signal to a thermal camera62to adjust its field of view in the horizontal, or vertical, directions.

Further, control computer52may be configured to receive a signal from a gas flow meter identifying a current gas pressure from a gas supply68. Based on the current gas pressure and a temperature received from a thermal camera62, control computer52may determine an adjusted gas pressure for the gas supply68. Control computer may generate and transmit to the gas supply68a signal identifying the adjusted gas pressure and, in response gas supply68may adjust the gas pressure to the adjusted gas pressure. In some examples, to determine the adjusted pressure, control computer52applies an algorithm to the current gas pressure and the temperature to determine the adjusted gas pressure. The algorithm may be based on empirical experiments, or on heat transfer properties and algorithms, for example.

FIG.4illustrates an exemplary cradle assembly400, which may be an example of the cradle assembly218ofFIGS.2A and2B. Cradle assembly400includes a front portion402and a back portion404opposite the front portion402. Each of the front portion404and back portion406may include a plurality of gas flow passageways that allow for the flow of a gas, such as air.

For example, front portion402includes entrance openings410A and corresponding exit openings410B, as well as entrance openings412A and corresponding exit openings412B. Between each entrance opening410A,412A and corresponding exit opening410B,412B is a gas flow passageway. For example, a gas tube, such as gas tube252, may be inserted through an entrance opening410A,412A, proceed through a gas flow passageway, and come out of a corresponding exit opening410B,412B.

Similarly, back portion404includes entrance openings414A and corresponding exit openings414B, as well as entrance openings416A and corresponding exit openings416B. Between each entrance opening414A,416A and corresponding exit opening414B,416B is a gas flow passageway. For example, a gas tube, such as gas tube252, may be inserted through an entrance opening414A,416A, proceed through a gas flow passageway, and come out of a corresponding exit opening414B,416B.

Further, entrance openings410A and414A, and corresponding exit openings410B and414B, are located near a first end420of the cradle assembly400. Opposite first end420is second end422. Entrance openings412A and416A, and corresponding exit openings412B and416B, are located near the second end422of the cradle assembly400.

It may be desirable to minimize air leaks between the cradle and the nozzle to avoid perturbation in the attenuation zone. In some examples, the openings on the front side (e.g., entrance openings410A, exit openings410B) can advantageously be offset by a distance, such as half the pitch distance, from the openings on the back side ((e.g., entrance openings414A, exit openings414B), in order to provide increased spatial resolution.

In addition, in some examples, the openings located farther from the center of the cradle assembly400(e.g., closer to first end420and second422), can be bored at a larger diameter than those closer to the center of the cradle assembly400to provide an outlet for the air flow coming out of the tubes. In some examples, the openings are bored at an angle versus the cooled surface such as to orient air extraction away from the center of the cradle assembly400. Also, in some examples, cradle assembly400can include an insulating material, such as a fiber based insulating material, to insulate the areas of the cradle assembly from the opening closest to the center of the cradle assembly to the center of the cradle assembly400, to minimize unnecessary air flow that could impact the temperature of the slot.

FIG.5is a chart500illustrating glass changes in sheet widths during the glass formation process when air flows (e.g., air flow pressure) to a nozzle, such as nozzle assembly200, are applied (e.g., increased, or decreased) at various times. The air flow may be provided by, for example, gas supply250via one or more gas tubes252. In this chart, first line502identifies changes in the width of a right side of a glass sheet, while second line504identifies changes in the width of a left side of a glass sheet. Third line506identifies the overall width of the glass sheet, and fourth line508identifies changes in pulling force (e.g., by pulling rolls46due to increased viscosity of the forming glass).

For example, at first flow rate change520, air flow pressure is increased from 0 liters per min (l/min), to 8 l/min. As indicated by first line502, second line504, and third line506, the widths of the forming glass increase. In addition, the pulling force increases. At second flow rate change522, the air flow pressure is decreased back to 0 l/min. First line502, second line504, and third line506each indicate that the glass sheet widths then decrease, as well as the required pulling force, as indicated by the fourth line508.

Similarly, at third flow rate change524, the air flow pressure is once again increased to 8 l/min. Again, the widths of the forming glass increase, as indicated by first line502, second line504, and third line506, and the pulling force also increases, as indicated by fourth line508. At fourth flow rate change526, the air flow pressure is increased from 8 l/min to 10 l/min. The widths of the forming glass further increase, as indicated by first line502, second line504, and third line506, and the pulling force also further increases, as indicated by fourth line508. At fifth flow rate change528, the air flow pressure is decreased from 10 l/min to 0 l/min, and as a result, the widths of the forming glass decrease, as indicated by first line502, second line504, and third line506. In addition, the pulling force decreases, as indicated by fourth line508.

For a given design, heat extraction depends on air flow (as illustrated inFIG.5), which can accurately be controlled by a flowmeter, such as a gas flow meter64. An exemplary mass flowrate may range from 0 to 10 l/min, for example. Considering an environment where the hot zone is above 1100 Celsius, and air temperature in the jet may be below 100 Celsius, the power extracted can be up to 50 Watts, which is sufficient to generate a noticeable effect on glass viscosity. The flow density near the ends of the forming glass are relatively low and thus does not take much temperature reduction to significantly increase viscosity.

For example, at a temperature of 1100 Celsius, viscosity may be near 1.77×105Poise. As another example, at a temperature of 1125 Celsius, viscosity may be near 1.10×105Poise. An exemplary viscosity ratio may be 1.61 (viscosity/temperature).

FIG.6is a chart600illustrating the cooling impact at various portions along a slot during the glass formation process when providing air near one end of a slot. Chart600displays a slot602, along with lines representing temperatures at various distances from slot center604. As illustrated, the temperature drops more significantly near the end606of the slot602than near the center604. For example, the difference in temperature is greater at distances greater than 160 mm from the slot center604, than at distances less than 160 mm from the slot center604. In some examples, cavities are bored into nozzle portions within a predetermined distance, such as within 160 mm, from a slot end606. By increasing the number of nozzle cavities through which air is provided, heat extraction (and thus cooling) can be increased. In addition, the areas of heat extraction along the slot can be controlled by positioning cavities to receive gas adjacent those areas.

FIGS.7A and7Billustrate an embodiment of a nozzle assembly700.FIG.7Aillustrates a cross section view, andFIG.7Billustrates a top view. Nozzle assembly700includes a first glass forming surface702of a first nozzle portion701, and a second glass forming surface704of a second nozzle portion703. Second glass forming surface704is opposite the first glass forming surface702. Further, nozzle assembly700includes a first wall712coupled to first glass forming surface702, and a second wall714coupled to second glass forming surface704. Between first wall712and second wall714is molten glass720, which is guided by first wall712, second wall714, first glass forming surface702, and second glass forming surface704to a slot730, to produce glass ribbon740.

Further, first nozzle portion701includes a plurality of first cavities750, and second nozzle portion701includes a plurality of second cavities760. Each of the plurality of first cavities750and plurality of second cavities760may receive a gas, such as from gas supply250. As indicated inFIG.7B, the plurality of first cavities750may be offset from the plurality of second cavities760, as indicated by dashed line770.

In some examples, cradle assembly700is manufactured out of a platinum alloy. In some examples, gas tubes made of metal may provide the gas from the gas supply. In some examples, the gas tubes are manufactured out of alumina.

FIG.8illustrates an exemplary method that may be performed by a glass forming apparatus, such as glass forming apparatus20. Beginning at step802, a first flow of gas is provided to a first cavity of a first portion of a nozzle of the glass forming apparatus. For example, gas supply250may provide gas, such as air, to a cavity63of first nozzle portion202of a glass forming apparatus. The first nozzle portion202includes a first glass forming surface, such as first glass forming surface212. At step804, a second flow of gas is provided to a second cavity of a second portion of the nozzle. The second portion includes a second glass forming surface. For example, gas supply204may provide the gas to another cavity63of second nozzle portion204, which includes a second glass forming surface214. Further, and at step806, molten glass is provided between the first and second glass forming surfaces to produce a glass ribbon. The method then ends.

FIG.9illustrates an exemplary method that may be performed by one or more computing devices, such as control computer52. Beginning at step902, a first signal is transmitted to cause the delivery of air flow at a first pressure through a cavity of a nozzle of a glass forming apparatus. For example, control computer52may transmit a signal to gas supply250to provide a gas at a first pressure through a cavity63of a nozzle202. The method also includes receiving a second signal that identifies a temperature of molten glass at a first edge of the molten glass. For example, control computer52may receive a signal from a thermal camera62that identifies a temperature of molten glass at or near molten glass edge48, and just below slot34. Further, the method includes determining a second pressure of air flow based on the first pressure and the temperature of the molten glass at the first edge. For example, the control computer52may apply an algorithm to the first pressure and the temperature to determine the second pressure. The method also includes transmitting a third signal to cause the delivery of the air flow at the second pressure through the cavity of the nozzle. For example, the control computer52may transmit another signal to the gas supply250to provide the gas at the second pressure through the cavity63of the nozzle202. The method then ends.

In some examples, a nozzle assembly for a glass forming apparatus includes a first nozzle portion, where the first nozzle portion includes a first glass forming surface. The assembly also includes a second nozzle portion opposite the first nozzle portion, where the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. Further, the assembly includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion.

In some examples, the assembly further includes a first cradle portion coupled to the first nozzle portion, and a second cradle portion coupled to the second nozzle portion. The first cradle portion includes a first gas flow passageway, and the second cradle portion includes a second gas flow passageway.

In some examples, the assembly the first gas flow passageway is configured to deliver a gas to the first cavity, and the second gas flow passageway is configured to deliver the gas to the second cavity. In some examples, the gas is air.

In some example, the assembly includes a first tube coupled to the first gas flow passageway. The first tube is configured to receive a gas from a gas supply, and provide the gas to the first gas flow passageway. In addition, a second tube is coupled to the second gas flow passageway. The second tube is configured to receive the gas from the gas supply, and provide the gas to the second gas flow passageway.

In some examples, the nozzle assembly includes a first plurality of cavities substantially parallel to the first cavity, and a second plurality of cavities substantially parallel to the second cavity.

In some examples, an apparatus includes a nozzle. The nozzle includes a first nozzle portion, where the first nozzle portion includes a first glass forming surface. The nozzle also includes a second nozzle portion opposite the first nozzle portion, where the second nozzle portion includes a second glass forming surface opposite the first glass forming surface. The apparatus also includes a first cavity within the first nozzle portion, and a second cavity within the second nozzle portion. Further, the apparatus includes at least one gas supply configured to deliver a gas to the first cavity and the second cavity. In some examples, the gas is air.

In some examples, the nozzle further includes a first cradle portion coupled to the first nozzle portion, and a second cradle portion coupled to the second nozzle portion. The first cradle portion includes a first gas flow passageway, and the second cradle portion comprises a second gas flow passageway.

In some examples, the first gas flow passageway is configured to deliver a gas to the first cavity, and the second gas flow passageway is configured to deliver the gas to the second cavity.

In some examples, the apparatus also includes a first tube coupled to the first gas flow passageway. The first tube is configured to receive a gas from a gas supply, and provide the gas to the first gas flow passageway. The apparatus further includes a second tube coupled to the second gas flow passageway. The second tube is configured to receive the gas from the gas supply, and provide the gas to the second gas flow passageway.

In some examples, the nozzle also includes a first plurality of cavities substantially parallel to the first cavity, and a second plurality of cavities substantially parallel to the second cavity.

In some examples, the apparatus includes at least one gas flow meter configured to detect a pressure of the gas delivered to the first cavity and the second cavity.

In some examples, the apparatus includes at least one processor configured to generate and transmit a signal to the gas supply to cause the gas supply to deliver the gas at a pressure.

In some examples, the apparatus includes a thermal camera configured to detect a temperature of molten glass after flowing between the first glass forming surface and the second glass forming surface.

In some examples, the apparatus includes at least one processor. The at least one processor is configured to receive a temperature from the thermal camera, and determine a pressure for the gas based on the temperature. The at least one processor is also configured to transmit a signal to the gas supply to cause delivery of the gas at the pressure.

In some examples, a method by a glass forming apparatus includes providing a first flow of gas to a first cavity of a first portion of a nozzle of a glass forming apparatus, wherein the first portion comprises a first glass forming surface. The method also includes providing a second flow of gas to a second cavity of a second portion of the nozzle, wherein the second portion comprises a second glass forming surface. Further, the method includes providing molten glass between the first and second glass forming surfaces to produce a glass ribbon. In some examples, the gas is air.

In some examples, the method also includes receiving a first signal, the first signal received from a first gas flow meter and identifying a first pressure of the first flow of gas. The method further includes receiving a second signal, the second signal received from a thermal camera and identifying a first temperature of the molten glass. The method also includes determining a first adjustment value based on the first pressure and the first temperature. Further, the method includes transmitting a third signal, the third signal transmitted to adjust the first pressure based on the first adjustment value.

In some examples, the method includes receiving a fourth signal, the fourth signal received from a second gas flow meter and identifying a second pressure of the second flow of gas. The method further includes receiving a fifth signal, the fifth signal received from the thermal camera and identifying a second temperature of the molten glass. The method also includes determining a second adjustment value based on the second pressure and the second temperature. Further, the method includes transmitting a sixth signal, the sixth signal transmitted to adjust the second pressure based on the second adjustment value.

In some examples, the first temperature is a temperature near a first end of the molten glass, and the second temperature is a temperature near a second end of the molten glass.

In some examples, the method includes transmitting a first signal to cause the first flow of gas to the first cavity of the first portion of the nozzle. The method also includes transmitting a second signal to cause the second flow of gas to the second cavity of the second portion of the nozzle.

The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this disclosure. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this disclosure.