Method and apparatus for producing glass articles with reduced electrostatic attraction

Abstract

A method and apparatus for manufacturing a glass article includes flowing a glass ribbon through an enclosure having first and second sidewalls. The glass ribbon has first and second opposing major surfaces extending in a length and width direction. Ions are directed from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon, and / or electrodes direct particles away from at least one of the first and second opposing major surfaces of the glass ribbon, thereby reducing a density of particles on the major surfaces of a glass article formed from the glass ribbon.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Patent Application No. 63 / 243,429, filed September 13, 2021, the contents of which are relied upon and incorporated herein by reference in its entirety. [Technical field]

[0002] The present disclosure relates generally to methods and apparatus for manufacturing glass articles, and more particularly to methods and apparatus for manufacturing glass articles having reduced electrostatic attraction. [Background technology]

[0003] In the manufacture of glass articles, such as glass sheets for display applications, including televisions and portable devices such as phones and tablets, the glass articles may be manufactured from a ribbon of glass that flows continuously through an enclosure. During this process, particles, such as dust or small pieces of glass, may adhere to the glass ribbon, resulting in undesirable surface particles on the resulting glass article. Such particle adhesion may occur as a result of electrostatic attraction between the particles and the ribbon. Summary of the Invention [Problem to be solved by the invention]

[0004] It would therefore be desirable to mitigate the adhesion of such particles. [Means for solving the problem]

[0005]

[0006] Embodiments disclosed herein include an apparatus for manufacturing a glass article. The apparatus includes a housing with a first sidewall and a second sidewall, the housing forming an enclosure for an atmosphere and a glass ribbon. The glass ribbon has first and second opposing major surfaces extending in a lengthwise and widthwise direction, and the housing has first and second sidewalls configured to extend in a lengthwise and widthwise direction along at least a portion of the first and second opposing major surfaces. The apparatus also includes an ionization source configured to direct ions into the housing and toward at least one of the first and second opposing major surfaces of the glass ribbon, and / or an electrode configured to direct particles away from at least one of the first and second opposing major surfaces of the glass ribbon. The apparatus is configured to manufacture a glass article, and a density of particles having a diameter of less than about 212 μm on the major surface of the glass article is less than about 0.008 per square centimeter.

[0006] The embodiments disclosed herein also include a method of manufacturing a glass article. The method includes flowing a glass ribbon having first and second opposing major surfaces extending in a length and width direction through an enclosure into an atmosphere. The enclosure includes a first sidewall and a second sidewall, the first and second sidewalls extending in a length and width direction along at least a portion of the first and second opposing major surfaces. The method also includes directing ions from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon within the enclosure and / or using electrodes to repel particles away from at least one of the first and second opposing major surfaces of the glass ribbon. Additionally, the method includes forming a glass article from at least a portion of the glass ribbon, wherein a density of particles having a diameter of less than about 212 μm on the major surface of the glass article is less than about 0.008 per square centimeter.

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

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

[0009] [Figure 1] Schematic of an exemplary fusion downdraw glass manufacturing equipment and process [Diagram 2] FIG. 1 is a schematic side perspective view of an example glass manufacturing apparatus and process including an ionization source configured to direct ions into an enclosure according to embodiments disclosed herein; [Diagram 3] FIG. 1 is a schematic side perspective view of an example glass manufacturing apparatus including a glass separation apparatus and process according to embodiments disclosed herein, and further including an ionization source configured to direct ions into the vicinity of the glass separation apparatus; [Figure 4] FIG. 1 is a schematic cutaway side perspective view of glass ribbon processing using an exemplary ionization source and enhancer according to embodiments disclosed herein; [Diagram 5] FIG. 1 is a schematic cutaway side perspective view of glass ribbon processing using an exemplary ionization source and enhancer according to embodiments disclosed herein; [Figure 6] FIG. 1 is a schematic cutaway side perspective view of glass ribbon processing using an exemplary ionization source according to embodiments disclosed herein; [Figure 7]FIG. 1 is a cross-sectional perspective view of a glass ribbon treatment using an exemplary ionization source according to embodiments disclosed herein; [Figure 8A] FIG. 1 is a perspective view of an example glass manufacturing apparatus and process including electrodes according to embodiments disclosed herein; [Figure 8B] FIG. 1 is a perspective view of an example glass manufacturing apparatus and process including electrodes according to embodiments disclosed herein; [Figure 9A] FIG. 1 is a perspective view of an example glass manufacturing apparatus and process including electrodes according to embodiments disclosed herein; [Figure 9B] FIG. 1 is a perspective view of an example glass manufacturing apparatus and process including electrodes according to embodiments disclosed herein; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers 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 the embodiments set forth herein.

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

[0012] Directional terms used herein (e.g., up, down, right, left, front, back, upper, bottom) are made solely with reference to the depicted figures and are not intended to imply absolute directions.

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

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

[0015] As used herein, the term "cooling mechanism" refers to a mechanism that results in an increase in heat transfer from an area compared to conditions in which such cooling mechanism is absent. The increase in heat transfer can occur by at least one of conduction, convection, and radiation.

[0016] As used herein, the term "enclosure" refers to an enclosure in which the glass ribbon is formed and which generally cools from a relatively high temperature to a relatively low temperature as it travels through the enclosure. Although embodiments disclosed herein are described with reference to a fusion downdraw process in which the glass ribbon flows down the enclosure in a generally vertical direction, such embodiments are also applicable to other glass forming processes, such as float, slot-draw, updraw, and press rolling processes, where the glass ribbon may flow through the enclosure in various directions, such as a generally vertical or generally horizontal direction.

[0017] An exemplary glass manufacturing apparatus 10 is shown in FIG. 1. In some examples, the glass manufacturing apparatus 10 can include a glass melting furnace 12, which can include a melting vessel 14. In addition to the melting vessel 14, the glass melting furnace 12 can optionally include one or more additional components, such as a heating element (e.g., a combustion burner or an electrode) that heats the raw materials and converts the raw materials into molten glass. In a further example, the glass melting furnace 12 can include a thermal management device (e.g., an insulating component) that reduces heat loss from the vicinity of the melting vessel. In yet another example, the glass melting furnace 12 can include electronic and / or electromechanical devices that facilitate melting of the raw materials into a glass melt. Furthermore, the glass melting furnace 12 can include a support structure (e.g., a support chassis, a support member, etc.) or other components.

[0018] The glass melting vessel 14 is typically constructed of a refractory material, such as a refractory ceramic material including alumina or zirconia. In some instances, the glass melting vessel 14 may be constructed of refractory ceramic bricks. Particular embodiments of the glass melting vessel 14 are described in more detail below.

[0019] In some examples, the glass melting furnace can be incorporated as a component of a glass manufacturing apparatus to produce glass substrates, such as continuous lengths of glass ribbons. In some examples, the glass melting furnace of the present disclosure may be incorporated as a component of a glass manufacturing apparatus, including a slot draw apparatus, a float bath apparatus, a downdraw apparatus such as a fusion process, an updraw apparatus, a press rolling apparatus, a tube drawing apparatus, or any other glass manufacturing apparatus that would benefit from the aspects disclosed herein. By way of example, FIG. 1 illustrates a schematic of a glass melting furnace 12 as a component of a fusion downdraw glass manufacturing apparatus 10 for melting and drawing glass ribbons for subsequent processing into individual glass sheets.

[0020] The glass manufacturing system 10 (e.g., the fusion downdraw system 10) may optionally include an upstream glass manufacturing apparatus 16 positioned upstream relative to the glass melting vessel 14. In some examples, some or all of the upstream glass manufacturing apparatus 16 may be incorporated as part of the glass melting furnace 12.

[0021] As shown in the illustrated example, the upstream glass manufacturing apparatus 16 may include a storage bin 18, a raw material delivery device 20, and a motor 22 connected to the raw material delivery device. The storage bin 18 may be configured to store a quantity of raw material 24, which may be fed to the melting vessel 14 of the glass melting furnace 12, as indicated by arrow 26. The raw material 24 typically includes one or more glass-forming metal oxides and one or more modifiers. In some examples, the raw material delivery device 20 may be powered by the motor 22 such that the raw material delivery device 20 delivers a predetermined quantity of the raw material 24 from the storage bin 18 to the melting vessel 14. In a further example, the motor 22 may power the raw material delivery device 20 to introduce the raw material 24 at a controlled rate based on a level of molten glass sensed downstream of the melting vessel 14. The raw material 24 in the melting vessel 14 may then be heated to form molten glass 28.

[0022] The glass manufacturing apparatus 10 may also optionally include a downstream glass manufacturing apparatus 30 located downstream relative to the glass melting furnace 12. In some instances, a portion of the downstream glass manufacturing apparatus 30 may be incorporated as part of the glass melting furnace 12. In some cases, the first connecting conduit 32, discussed below, or other portions of the downstream glass manufacturing apparatus 30 may be incorporated as part of the glass melting furnace 12. The elements of the downstream glass manufacturing apparatus, including the first connecting conduit 32, may be formed from a precious metal. Suitable precious metals include platinum group metals selected from the group of metals consisting of platinum, iridium, rhodium, osmium, ruthenium, and palladium, or alloys thereof. For example, the downstream components of the glass manufacturing apparatus may be formed from a platinum-rhodium alloy including about 70% to about 90% by weight platinum and about 10% to about 30% by weight rhodium. However, other suitable metals may include molybdenum, palladium, rhenium, tantalum, titanium, tungsten, and alloys thereof.

[0023] The downstream glass production apparatus 30 may include a first conditioning (i.e., processing) vessel, such as a fining vessel 34, located downstream of the melting vessel 14 and coupled thereto by the first connecting conduit 32 described above. In some examples, the molten glass 28 may be gravity fed from the melting vessel 14 to the fining vessel 34 by the first connecting conduit 32. For example, gravity may pass the molten glass 28 through the internal path of the first connecting conduit 32 from the melting vessel 14 to the fining vessel 34. However, other conditioning vessels may be located downstream of the melting vessel 14, such as between the melting vessel 14 and the fining vessel 34. In some embodiments, a conditioning vessel may be used between the melting vessel and the fining vessel to either further heat the molten glass from the primary melting vessel to continue the melting process or to cool the molten glass to a temperature lower than that of the molten glass in the melting vessel before entering the fining vessel.

[0024] The bubbles can be removed from the molten glass 28 in the fining vessel 34 by a variety of techniques. For example, the raw material 24 can include a polyvalent compound (i.e., a fining agent), such as tin oxide, that undergoes a chemical reduction reaction when heated and releases oxygen. Other suitable fining agents include, but are not limited to, arsenic, antimony, iron, and cerium. The fining vessel 34 is heated to a temperature above the melting vessel temperature, thereby heating the molten glass and the fining agent. The oxygen bubbles created by the temperature-induced chemical reduction of the fining agent rise through the molten glass in the fining vessel, where gases in the molten glass created in the melting furnace can diffuse or incorporate into the oxygen bubbles created by the fining agent. The enlarged bubbles can then rise to the free surface of the molten glass in the fining vessel and then be expelled from the fining vessel. The oxygen bubbles can also cause mechanical mixing of the molten glass in the fining vessel.

[0025] The downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as a mixing vessel 36 for mixing the molten glass. The mixing vessel 36 may be located downstream of the fining vessel 34. The mixing vessel 36 may be used to provide a homogenous glass melt composition, thereby reducing codes of chemical or thermal inhomogeneity that may otherwise be present in the fined molten glass exiting the fining vessel. As shown, the fining vessel 34 may be coupled to the mixing vessel 36 by a second connecting conduit 38. In some examples, the molten glass 28 may be gravity fed from the fining vessel 34 to the mixing vessel 36 by the second connecting conduit 38. For example, gravity may pass the molten glass 28 through the internal path of the second connecting conduit 38 from the fining vessel 34 to the mixing vessel 36. It should be noted that although the mixing vessel 36 is shown downstream of the fining vessel 34, the mixing vessel 36 may be located upstream of the fining vessel 34. In some embodiments, downstream glass manufacturing equipment 30 may include multiple mixing vessels, such as a mixing vessel upstream of fining vessel 34 and a mixing vessel downstream of fining vessel 34. These multiple mixing vessels may be of the same design or of different designs.

[0026] The downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as a delivery vessel 40, which may be disposed downstream of the mixing vessel 36. The delivery vessel 40 may condition and deliver the molten glass 28 into the downstream forming apparatus. For example, the delivery vessel 40 may function as an accumulator and / or flow control device to condition and / or provide a constant flow of the molten glass 28 to the forming body 42 via an outlet conduit 44. As shown, the mixing vessel 36 may be coupled to the delivery vessel 40 by a third connecting conduit 46. In some examples, the molten glass 28 may be gravity-fed from the mixing vessel 36 to the delivery vessel 40 by the third connecting conduit 46. For example, gravity may drive the molten glass 28 from the mixing vessel 36 to the delivery vessel 40 through an internal passage of the third connecting conduit 46.

[0027] The downstream glass manufacturing apparatus 30 may further include a forming apparatus 48 including the forming body 42 and inlet conduit 50 described above. The outlet conduit 44 may be positioned to deliver the molten glass 28 from the delivery vessel 40 to the inlet conduit 50 of the forming apparatus 48. For example, the outlet conduit 44 may be nested within and spaced from the inner surface of the inlet conduit 50, thereby providing a free surface of molten glass located between the outer surface of the outlet conduit 44 and the inner surface of the inlet conduit 50. The forming body 42 of the fusion downdraw glass manufacturing apparatus may include a trough 52 located on the upper surface of the forming body 42 and a converging forming surface 54 that converges in the draw direction along a bottom edge 56 of the forming body 42. The molten glass delivered to the forming body trough via the delivery vessel 40, the outlet conduit 44, and the inlet conduit 50 overflows the sidewall of the trough and descends along the converging forming surface 54 as a separate stream of molten glass. The separate streams of molten glass merge beneath and along the bottom edge 56 to produce a single glass ribbon 58 that is drawn from the bottom edge 56 in a draw or flow direction 60 to control the dimensions of the glass ribbon as the glass cools and the glass becomes more viscous, such as by applying tension to the glass ribbon, such as by gravity, edge rolls 72, and pull rolls 82. Thus, the glass ribbon 58 undergoes a viscoelastic transition and acquires mechanical properties that give the glass ribbon 58 stable dimensional properties. The glass ribbon 58 can be separated into individual glass sheets 62 by a glass separator 100 in the elastic region of the glass ribbon, in some embodiments. The individual glass sheets 62 can then be transferred by a robot 64 using grippers 65 to a conveyor system, after which the individual glass sheets can be further processed.

[0028] 2 illustrates a schematic perspective view of an example glass manufacturing apparatus 10 and process including an ionization source 300 configured to direct ions 302 into an enclosure 200 according to embodiments disclosed herein. Specifically, in the embodiment illustrated in FIG. 2, the glass ribbon 58 flows lengthwise between first and second sidewalls 202 of the enclosure 200 below the bottom edge 56 of the forming body 42. The enclosure 200 may generally be separated from a forming body enclosure 208 by a separation member 206, where the enclosure 200 is downstream relative to the forming body enclosure 208 with respect to a draw or flow direction 60 of the glass ribbon 58. Additionally, FIG. 2 illustrates multiple ionization sources 300, each directing ions 302 between the first and second sidewalls 202 of the enclosure 200 toward first and second opposing major surfaces of the glass ribbon 58. In particular, a first subset of the plurality of ionization sources 300 directs ions 302 along the length of a first major surface of the glass ribbon 58, and a second subset of the plurality of ionization sources 300 directs ions 302 along the length of a second major surface of the glass ribbon 58.

[0029] 3 shows a schematic side perspective view of an example glass manufacturing apparatus 10 including a glass separation apparatus 100 and process according to embodiments disclosed herein, and further including an ionization source 300 configured to direct ions 302 in the vicinity of the glass separation apparatus 100. The glass separation apparatus 100 includes a first portion 102 extending along a first major surface of the glass ribbon 58 and a second portion 104 extending along an opposing second major surface of the glass ribbon 58. The first portion 102 of the separation apparatus 100 includes a scoring device 106 (e.g., a scoring wheel, etc.), and the second portion 104 of the separation apparatus 100 includes a nosing 108. During the separation process, the scoring device 106 can impart score lines along the first major surface of the glass ribbon 58 and can bend against the nosing 108 to facilitate separation of the individual glass sheets 62 from the glass ribbon 58. The robot 64 can then transfer the individual glass sheets 62 using a gripping tool 65, as described above. As further shown in FIG. 3, each of the first and second portions 102, 104 of the separation apparatus 100 includes an ionization source 300 that directs ions 302 toward first and second opposing major surfaces of the glass ribbon 58.

[0030] In certain exemplary embodiments, the ionization source 300 may include a corona discharge ionizer, a soft x-ray ionizer, or a nuclear ionizer, as known to those skilled in the art. FIG. 4 illustrates a schematic cutaway side perspective view of a glass ribbon 58 being processed using an exemplary ionization source 300 and enhancer 400, according to embodiments disclosed herein. Specifically, FIG. 4 illustrates two ionization sources 300, each directing ions 302 toward first and second major surfaces of the glass ribbon 58. The ionization source 300 of FIG. 4 includes a corona discharge ionizer including a conductive emitter 304 housed within an insulating material 306. The conductive emitter 304 directs the ions 302 toward the major surfaces of the glass ribbon 58. The insulating material 306 may include, for example, a ceramic conduit circumferentially surrounding the conductive emitter 304. The ceramic conduit may comprise, for example, a thermally and electrically insulating ceramic material such as boron nitride, silica, silicon nitride, alumina, aluminum silicate, aluminum nitride, or MACOR® machinable glass-ceramic.

[0031] 4, enhancer 400 is positioned above ionization source 300 and configured to flow a fluid 402, such as a gaseous fluid, toward a major surface of glass ribbon 58. Specifically, enhancer 400 cooperates with ionization source 300 to increase the flow rate of ions 302 toward a major surface (i.e., at least one of a first opposing major surface and a second opposing major surface) of glass ribbon 58. Although enhancer 400 is shown positioned directly above ionization source 300, embodiments disclosed herein include embodiments in which enhancer 400 is positioned elsewhere, such as below and / or to the side of ionization source 300.

[0032] In one particular exemplary embodiment, enhancer 400 may include an air knife, such as those used in the glass processing industry, known to those skilled in the art.

[0033] FIG. 5 illustrates a schematic cutaway side perspective view of a glass ribbon 58 being processed using an example ionization source 300′ and enhancer 400 according to embodiments disclosed herein. Specifically, FIG. 5 illustrates two ionization sources 300′, each directing ions 302 to a first and second major surface of the glass ribbon 58. The ionization source 300′ of FIG. 5 is similar to that shown in FIG. 4, except that the ionization source 300′ further includes a heat shield and cooling enclosure 308 surrounding the insulating material 306. The heat shield and cooling enclosure 308 may include a cooling mechanism through which a cooling fluid (not shown) flows. The cooling fluid may include a gas, such as air, and / or a liquid, such as water.

[0034] FIG. 6 illustrates a schematic cutaway side perspective view of a glass ribbon 58 being processed using an exemplary ionization source 300″ according to embodiments disclosed herein. Specifically, FIG. 6 illustrates two ionization sources 300″, each directing ions 302 to first and second major surfaces of the glass ribbon 58. The ionization source 300″ of FIG. 6 includes a soft x-ray ionizer with a soft x-ray photoionizer 310, a soft x-ray photoeye 312, and a hot radioluminescent cover 314, as known to those skilled in the art. The ionization source 300″ further includes a heat shielding and cooling housing 308 circumferentially surrounding the soft x-ray photoionizer 310 and the soft x-ray photoeye 312. The heat shielding and cooling housing 308 may include a cooling mechanism through which a cooling fluid (not shown) flows. The cooling fluid may include a gas, such as air, and / or a liquid, such as water.

[0035] The thermal insulation material 306 and / or the heat shielding and cooling enclosure 308 may facilitate operation of the ionization source 300, 300', 300" in a high temperature environment, such as a temperature of at least about 200°C, such as at least about 250°C, even such as at least about 300°C, even such as at least about 350°C, or even such as at least about 400°C, including from about 200°C to about 500°C.

[0036] Accordingly, embodiments disclosed herein include those in which ions 302 are directed toward at least one of the first opposing major surface and the second opposing major surface of the glass ribbon 58 in an atmosphere within the enclosure 200 having a temperature of at least about 200°C, such as at least about 250°C, further such as at least about 300°C, further such as at least about 350°C, and even such as at least about 400°C, including from about 200°C to about 500°C.

[0037] The embodiments disclosed herein may include ionizers that use alternating current (AC) or direct current (DC) power sources to generate the voltage required for ionization, as known to those skilled in the art. Additionally, the embodiments disclosed herein may include commercially available ionizers, such as, for example, the L12645, L9873, or L14471 soft x-ray photo ionizers available from Hamamatsu, the Gen4 Super Ion Air Knife, Gen4 Standard Ion Air Knife, Gen4 Ionizing Bar, Gen4 Ion Air Cannon, or Gen4 Ionizing Point Corona Discharge Ionizer available from Exair, or the Linear Alpha Ionizer, Mini Ionizer, or Ion Air Source Nuclear Ionizer available from NRD.

[0038] The soft x-ray ionizer can be operated, for example, at a power in the range of about 7 watts (W) to about 240 watts (W), an input AC voltage in the range of about 24 volts (V) to about 264 volts (V) (or an input DC voltage in the range of about 12 volts (V) to about 30 volts (V)), a tube voltage in the range of about 4.98 kilovolts (kV) to about 15 kilovolts (kV), and a beam angle in the range of about 130° to about 150°. The corona discharge ionizer can be operated, for example, at a power in the range of about 1 watt (W) to about 150 watts (W), an input AC voltage in the range of about 24 volts (V) to about 264 volts (V) (or an input DC voltage in the range of about 5 volts (V) to about 30 volts (V)), an output voltage in the range of about 0 kilovolts (kV) to about 60 kilovolts (kV), and a balance in the range of about ±50 volts (V).

[0039] In certain exemplary embodiments, the closest distance between the ionization source 300, 300', 300" and the glass ribbon 58 can range, for example, from about 10 millimeters to about 3,000 millimeters, such as from about 50 millimeters to about 1,000 millimeters, or even, for example, from about 100 millimeters to about 500 millimeters.

[0040] Embodiments disclosed herein may include ionization sources 300, 300', 300" that extend in various directions relative to the glass ribbon 58, such as, for example, along the width of the glass ribbon 58 or along the length of the glass ribbon 58. FIG. 7 illustrates a cross-sectional perspective view of a glass ribbon 58 being processed using an example ionization source 300 according to embodiments disclosed herein. Specifically, FIG. 7 illustrates two ionization sources 300, each directing ions 302 to first and second major surfaces of the glass ribbon 58. The ionization sources 300 may extend along the width of the glass ribbon 58, such as in the embodiments shown in FIGS. 2 or 3, and / or along the width of the glass sheet 62. The ionization sources 300 may extend along the width of the glass ribbon 58, such as in the embodiments shown in FIGS. 2 or 3. Many of the ionization sources 300 may also extend along the length of the glass ribbon 58 and / or along the length of the glass sheet 62. For example, embodiments disclosed herein include embodiments in which an outer edge region of the glass ribbon 58 and / or glass sheet 62 having a region of increased thickness relative to the remainder of the glass ribbon 58 and / or glass sheet 62 (known to those skilled in the art as a "bead region") is separated from the remainder of the glass ribbon 58 and / or glass sheet 62, and the ionization source 300 extends along the length of the glass ribbon 58 and / or glass sheet 62 proximate the separation region between the bead region and the remainder of the glass ribbon 58 and / or glass sheet 62. In such situations, the ionization source 300 may direct ions 302 onto the first and second major surfaces of the glass ribbon 58 and / or glass sheet 62.

[0041] Embodiments disclosed herein include embodiments in which a voltage difference exists between the ions 302 directed toward the glass ribbon 58 and the glass ribbon 58. Embodiments disclosed herein also include embodiments in which the voltage difference between the ions 302 and the glass ribbon 58 is reduced compared to a condition in which the ions 302 are not directed from the ionization source 300 toward at least one of the first opposing major surface and the second opposing major surface of the glass ribbon 58. For example, embodiments disclosed herein include embodiments in which the voltage difference between the ions 302 and the glass ribbon 58 is reduced by at least about 90%, such as at least about 95%, or even, such as at least about 98%, including from about 90% to about 99%, compared to a condition in which the ions 302 are not directed from the ionization source 300 toward at least one of the first opposing major surface and the second opposing major surface of the glass ribbon 58.

[0042] Given that embodiments disclosed herein include those in which the glass ribbon 58 moves (e.g., in the draw direction 60) relative to the ionization source(s) 300, such embodiments include those in which the ions 302 arrive at or near a major surface of the glass ribbon 58 in a time sufficient to reduce the voltage difference between a given surface area of ​​the glass ribbon 58 and the ions 302 by a sufficient amount (e.g., at least about 90%) before the given surface area of ​​the glass ribbon 58 moves a predetermined distance relative to the ionization source(s) 300. Thus, the time at which a sufficient (e.g., at least about 90%) reduction in the voltage difference for a given surface area of ​​the glass ribbon 58 is achieved can be less than about 5 seconds, such as less than about 2 seconds, or even such as less than about 1 second, such as from about 0.1 to about 5 seconds, or even such as from about 0.2 to about 2 seconds.

[0043] Achieving a sufficient (e.g., at least about 90%) voltage differential reduction of a given surface area of ​​the glass ribbon 58 in a sufficient time (e.g., less than about 5 seconds) may be facilitated, for example, by using an enhancer 400 (e.g., an air knife) in combination with the ionization source 300, 300', 300" (e.g., as shown in Figures 4 and 5) to increase the velocity of the ions 302 in the direction of the given surface area of ​​the glass ribbon 58. Such may also be accomplished by using the ionization source 300" with a soft x-ray ionizer (e.g., as shown in Figure 6), with or without the enhancer 400.

[0044] The step of achieving a reduction in the voltage difference between the surface region of the glass ribbon 58 and the ions 302 may also simultaneously achieve a reduction in the voltage difference between the surface region of the glass ribbon 58 and particles proximate the surface region of the glass ribbon 58, the reduction in the voltage difference resulting not only from interactions between the ions 302 and the surface region of the glass ribbon 58, but also from interactions between the ions 302 and the particles. Such a reduction in the voltage difference may reduce the electrostatic attraction between the surface region of the glass ribbon 58 and the particles, which may result in a reduction in the adhesion of particles on the surface region of the glass ribbon 58.

[0045] 8A and 8B show perspective views of an example glass manufacturing apparatus 10 and process including electrodes 350a, 350b, 350c, 350d according to embodiments disclosed herein. Specifically, each of electrodes 350a, 350b, 350c, and 350d includes a conductive bar. The conductive bar can include, for example, a generally cylindrical shape (i.e., a circular cross-section). The conductive bar can also include other shapes (such as having an elliptical or polygonal cross-section).

[0046] 8A, electrodes 350a and 350b are positioned above and below a separating device (not shown) along the width of glass ribbon 58 and glass sheet 62, respectively. Electrodes 350a and 350b may be reverse charged by one or more voltage sources, such as, for example, a dual output high voltage power supply, and one of electrodes 350a and 350b may be grounded.

[0047] 8B, electrodes 350c and 350d are positioned above and below a separation device (not shown) along the length of glass ribbon 58 and glass sheet 62, respectively. Electrodes 350c and 350d may be reverse charged by one or more voltage sources, such as, for example, a dual output high voltage power supply, and one of electrodes 350c and 350d may be grounded.

[0048] 9A and 9B show perspective views of an example glass manufacturing apparatus 10 and process including electrodes 350e, 350f according to embodiments disclosed herein. Electrode 350e in FIG. 9A includes a conductive sphere. Electrode 350f in FIG. 9B includes a conductive polygon (electrode 350f is shown as having a conical or triangular cross-section, although embodiments disclosed herein may include other polygonal shapes). Electrodes 350e, 350f can be charged by one or more voltage sources, such as, for example, a controllable power high voltage power supply.

[0049] 9A and 9B , electrodes 350e, 350f are shown positioned above pulling roll 82. Pulling roll 82 can impart a static charge to glass ribbon 58. To counter the static charge imparted to glass ribbon 58 by pulling roll 82, electrodes 350e, 350f can impart an opposite charge to glass ribbon 58.

[0050] For example, in certain exemplary embodiments, the pulling roll 82 can impart a negative charge to the glass ribbon 58, and the electrodes 350e, 350f can impart a positive charge to the glass ribbon 58. In other exemplary embodiments, the pulling roll 82 can impart a positive charge to the glass ribbon 58, and the electrodes 350e, 350f can impart a negative charge to the glass ribbon 58. Although Figures 9A and 9B show the electrodes 350e, 350f positioned above the pulling roll 82, embodiments disclosed herein can include embodiments in which the electrodes 350e, 350f are positioned relative to the pulling roll 82, such as below or to the side of the pulling roll 82.

[0051] The electrodes 350a-f may be configured to repel particles away from at least one of the first and second opposing major surfaces of the glass ribbon 58 and / or glass sheet 62. For example, in certain exemplary embodiments, one or more of the electrodes 350a-f may affect a charge of particles proximate the glass ribbon 58 and / or glass sheet 62 to reduce electrostatic attraction between the particles and the glass ribbon 58 and / or glass sheet 62. In certain exemplary embodiments, one or more of the electrodes 350a-f may affect an overall charge of the glass ribbon 58 and / or glass sheet 62 to reduce electrostatic attraction between the particles and the glass ribbon 58 and / or glass sheet 62.

[0052] In certain exemplary embodiments, one or more of the electrodes 350a-f can be monitored and / or controlled by a control mechanism, such as a feedback or feedforward control mechanism known to those skilled in the art. In certain exemplary embodiments, the control mechanism can be in communication with a condition measurement device, such as an electric field meter or voltmeter, that measures electrostatic charge or potential in or between one or more areas or regions, such as in regions proximate the glass ribbon 58 and / or glass sheet 62, including in regions including the glass ribbon 58 and / or glass sheet 62 and one or more electrodes 350a-f. The control mechanism can then, in response to one or more conditions measured by the condition measurement device, control or maintain the charge and / or voltage of the electrodes 350a-f relative to the glass ribbon 58 and / or glass sheet 62, for example, to thereby control or minimize electrostatic charge between the glass ribbon 58 and / or glass sheet 62 and particles in its vicinity.

[0053] Electrodes 350a-f can be operated, for example, with a power in the range of about 1 watt (W) to about 150 watts (W), an input AC voltage in the range of about 24 volts (V) to about 264 volts (V) (or an input DC voltage in the range of about 5 volts (V) to about 30 volts (V)), and an output voltage in the range of about 0 kilovolts (kV) to about 60 kilovolts (kV).

[0054] In certain exemplary embodiments, the closest distance between the electrodes 350a-f and the glass ribbon 58 can range, for example, from about 0 millimeters to about 2,000 millimeters, such as from about 10 millimeters to about 1,000 millimeters, or even from about 50 millimeters to about 500 millimeters.

[0055] In certain exemplary embodiments, one or more of the electrodes 350a-f may include at least one of tungsten, silicon, stainless steel, or Inconel.

[0056] The embodiments disclosed herein can enable the manufacture of glass articles with reduced particle density.For example, the embodiments disclosed herein include those in which the apparatus 10 is configured to manufacture glass articles, the density of particles having a diameter of less than about 212 μm, for example less than about 100 μm, further for example less than about 10 μm, further for example less than about 1 μm, further for example less than about 0.3 μm, for example from about 212 μm to about 0.3 μm per square centimeter is less than about 0.008, for example less than about 0.004, further for example less than about 0.002, for example from about 0.0001 to about 0.008, further for example from about 0.001 to about 0.004.

[0023] Embodiments disclosed herein also include a method of manufacturing a glass article comprising forming a glass article from at least a portion of the glass ribbon 58 article, wherein a density of particles having a diameter of less than about 212 μm, such as less than about 100 μm, further such as less than about 10 μm, further such as less than about 1 μm, further such as less than about 0.3 μm, such as from about 212 μm to about 0.3 μm on a major surface of the glass article is less than about 0.008, such as less than about 0.004, further such as less than about 0.002, such as from about 0.0001 to about 0.008, further such as from about 0.001 to about 0.004, per square centimeter.

[0057] Thus, embodiments disclosed herein can enable the production of glass articles with reduced particle density on one or more major surfaces. This can occur, for example, through the use of electrodes to affect a voltage difference between the glass ribbon 58 and / or glass sheet 62 and the particles in its vicinity. This can also occur, for example, through the use of an ionization source to induce ions 302 on at least one of the first and second opposing major surfaces of the glass ribbon 58 and / or glass sheet 62. For example, embodiments disclosed herein include those in which the voltage difference between the particles and the glass ribbon 58 and / or glass sheet 62 is reduced by at least about 90%, such as at least about 95%, or even, such as at least about 98%, e.g., from about 90% to about 99%, compared to a condition in which the electrodes do not direct the particles away from at least one of the first and second opposing major surfaces of the glass ribbon 58 and / or glass sheet 62 and / or the ions 302 are not directed from the ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon 58 and / or glass sheet 62.

[0058] Although the above embodiments are described with reference to a fusion downdraw process, it should be understood that such embodiments are also applicable to other glass forming processes, such as the float process, the slot draw process, the updraw process, the tube draw process, and the press rolling process.

[0059] Such processes can be used to manufacture glass articles that can be used, for example, in electronic devices as well as other applications.

[0060] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure, and therefore, the present disclosure is intended to cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

[0061] Preferred embodiments of the present invention will be described below in detail.

[0062] EMBODIMENT 1 1. An apparatus for producing a glass article, comprising: an enclosure having a first sidewall and a second sidewall, the enclosure forming an enclosure for an atmosphere and a glass ribbon having first and second opposing major surfaces extending in a lengthwise and widthwise direction, the first and second sidewalls configured to extend in the lengthwise and widthwise directions along at least a portion of the first and second opposing major surfaces; an ionization source configured to direct ions within the enclosure toward at least one of the first and second opposing major surfaces of the glass ribbon; and / or an electrode configured to repel particles away from at least one of the first and second opposing major surfaces of the glass ribbon. Equipped with the density of particles in the glass article having a diameter of less than about 212 μm on a major surface of the glass article is less than about 0.008 per square centimeter; Apparatus for manufacturing glass articles.

[0063] EMBODIMENT 2 2. The apparatus of embodiment 1, wherein the temperature of the atmosphere is at least about 200° C.

[0064] EMBODIMENT 3 2. The apparatus of embodiment 1, wherein the apparatus further comprises an enhancer configured to increase a flow rate of ions toward at least one of the first and second opposing major surfaces of the glass ribbon.

[0065] EMBODIMENT 4 4. The apparatus of embodiment 3, wherein the enhancer comprises an air knife.

[0066] EMBODIMENT 5 2. The apparatus of embodiment 1, wherein the ionization source comprises a corona discharge ionizer, a soft x-ray ionizer, or a nuclear ionizer.

[0067] EMBODIMENT 6 2. The apparatus of embodiment 1, wherein the ionization source comprises a conductive emitter housed within a thermal insulating material.

[0068] EMBODIMENT 7 7. The apparatus of embodiment 6, wherein the insulating material comprises a ceramic conduit.

[0069] EMBODIMENT 8 2. The device of embodiment 1, wherein the electrodes comprise a pair of oppositely charged electrodes.

[0070] EMBODIMENT 9 2. The device of embodiment 1, wherein the electrodes comprise at least one of a conductive bar, a conductive sphere, or a conductive polygon.

[0071] EMBODIMENT 10 2. The apparatus of claim 1, wherein the apparatus is configured to reduce a voltage difference between the particles and the glass ribbon by at least about 90% compared to a condition in which electrodes are not configured to direct particles away from at least one of the first and second opposing major surfaces of the glass ribbon and / or ions are not directed from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon.

[0072] EMBODIMENT 11 1. A method of making a glass article, comprising: flowing a glass ribbon having first and second opposing major surfaces extending in a length and width direction through an enclosure having a first sidewall and a second sidewall, the first and second sidewalls extending in the length and width directions along at least a portion of the first and second opposing major surfaces; directing ions from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon within the enclosure and / or using electrodes to repel particles away from at least one of the first and second opposing major surfaces of the glass ribbon; and forming the glass article from at least a portion of the glass ribbon. Including, the density of particles having a diameter of less than about 212 μm on a major surface of the glass article is less than about 0.008 per square centimeter; A method for producing a glass article.

[0073] EMBODIMENT 12 12. The method of embodiment 11, wherein the enclosure contains an atmosphere having a temperature of at least about 200°C.

[0074] EMBODIMENT 13 12. The method of claim 11, wherein the method further comprises using an enhancer to increase a flow rate of ions toward at least one of the first and second opposing major surfaces of the glass ribbon.

[0075] EMBODIMENT 14 14. The method of embodiment 13, wherein the enhancer comprises an air knife.

[0076] EMBODIMENT 15 12. The method of embodiment 11, wherein the ionization source comprises a corona discharge ionizer, a soft x-ray ionizer, or a nuclear ionizer.

[0077] EMBODIMENT 16 12. The method of embodiment 11, wherein the ionization source comprises a conductive emitter housed in a thermal insulating material.

[0078] EMBODIMENT 17 17. The method of embodiment 16, wherein the insulating material comprises a ceramic conduit.

[0079] EMBODIMENT 18 12. The method of embodiment 11, wherein the electrodes comprise a pair of oppositely charged electrodes.

[0080] EMBODIMENT 19 12. The method of embodiment 11, wherein the electrodes comprise at least one of a conductive bar, a conductive sphere, or a conductive polygon.

[0081] EMBODIMENT 20 12. The method of claim 11, wherein a voltage difference between the particles and the glass ribbon is reduced by at least about 90% compared to a condition in which electrodes do not move particles away from at least one of the first and second opposing major surfaces of the glass ribbon and / or ions are not directed from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon.

[0082] EMBODIMENT 21 12. A glass article produced by the method of claim 11.

[0083] EMBODIMENT 22 22. An electronic device comprising the glass article of claim 21. [Explanation of symbols]

[0084] 10. Glass manufacturing equipment 42 Molded body 58 Glass Ribbon 62 Glass Sheet 64 Robot 65 Grip Tool 82 Pulling Roll 100 Glass Separator 106 Scoring Device 108 Nosing 200 units 206 Separation member 208 Enclosure 300, 300', 300” Ionization Source 302 Aeon 304 Conductive Emitter 306 Thermal Insulation Materials 308 Heat shielding and cooling enclosure 310 Soft X-ray Photoionizer 312 Soft X-ray Photo Eye 314 High temperature radioluminescent cover 350a, 350b, 350c, 350d, 350e, 350f electrode 400 Enhancer

Claims

1. In an apparatus for manufacturing a glass article, a housing having a first sidewall and a second sidewall, the housing forming an enclosure for an atmosphere and a glass ribbon having first and second opposing major surfaces extending in a length direction and a width direction, the first and second sidewalls being configured to extend in the length direction and the width direction along at least a part of the first and second opposing major surfaces; an ionization source configured to direct ions towards at least one of the first and second opposing major surfaces of the glass ribbon within the housing, and / or an electrode configured to deflect particles away from at least one of the first and second opposing major surfaces of the glass ribbon and comprising, wherein the density of particles in the glass article having a diameter of less than about 212 μm on the major surface of the glass article is less than about 0.008 per square centimeter. An apparatus for manufacturing a glass article.

2. The apparatus according to claim 1, wherein the temperature of the atmosphere is at least about 200°C.

3. The apparatus according to claim 1, further comprising an enhancer configured to increase the flow rate of ions towards at least one of the first and second opposing major surfaces of the glass ribbon.

4. The apparatus according to claim 1, wherein the ionization source includes a corona discharge ionizer, a soft X-ray ionizer, or a nuclear ionizer.

5. The apparatus according to claim 1, wherein the ionization source includes a conductive emitter housed within a heat insulating material.

6. The apparatus according to claim 1, wherein the electrode includes a pair of oppositely charged electrodes.

7. The apparatus according to claim 1, wherein the apparatus is configured to reduce the voltage difference between the particles and the glass ribbon by at least about 90% compared to a condition where the electrodes are not configured to repel particles from at least one of the first and second opposing major surfaces of the glass ribbon and / or a condition where ions are not directed from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon. **Claim 8** In a method of manufacturing a glass article, flowing a glass ribbon having first and second opposing major surfaces extending in a length direction and a width direction through a housing having a first sidewall and a second sidewall, the first and second sidewalls extending in the length direction and the width direction along at least a portion of the first and second opposing major surfaces, and in the housing, directing ions from an ionization source toward at least one of the first and second opposing major surfaces of the glass ribbon and / or using electrodes to repel particles from at least one of the first and second opposing major surfaces of the glass ribbon, and forming the glass article from at least a portion of the glass ribbon comprising wherein the density of particles having a diameter of less than about 212 μm on the major surface of the glass article is less than about 0.008 per square centimeter. A method of manufacturing a glass article. **Claim 9** The method according to claim 8, wherein the housing includes an atmosphere having a temperature of at least about 200°C. **Claim 10** The method according to claim 8, further comprising increasing a flow rate of ions directed toward at least one of the first and second opposing major surfaces of the glass ribbon using an enhancer. **Claim 11** The method according to claim 8, wherein the ionization source includes a corona discharge ionizer, a soft X-ray ionizer, or a nuclear ionizer.

12. The method according to claim 8, wherein the ionization source includes a conductive emitter housed within a heat insulating material.

13. The method according to claim 8, wherein the electrodes include a pair of oppositely charged electrodes.

14. The voltage difference between the particles and the glass ribbon is at least about 90% lower compared to the condition that the electrodes do not move the particles away from at least one of the first and second opposing major surfaces of the glass ribbon, and / or the condition that ions are not guided from the ionization source towards at least one of the first and second opposing major surfaces of the glass ribbon. The method according to claim 8.

Images