WO2019245773A1 - Glass sheets with reduced particle adhesion - Google Patents

Abstract

A method for processing a glass sheet includes transporting the glass sheet into a chamber having an inner atmosphere with a water content that is lower than a water content of an atmosphere surrounding the chamber. An adhered glass particle density on a major surface of the glass sheet transported out of the chamber and washed in a washing step is lower than the adhered glass particle density on a major surface of the glass sheet maintained for the period of time in a comparative atmosphere.

Description

GLASS SHEETS WITH REDUCED PARTICLE ADHESION

Field

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S.

Provisional Application Serial No. 62/686721 filed on June 19, 2018 the content of which is relied upon and incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to glass sheets with reduced particle adhesion and more particularly to methods and apparatuses for processing glass sheets with reduced particle adhesion.

Background

[0003] In display applications, including televisions and hand held devices, such as telephones and tablets, there is an ever increasing trend toward higher resolution displays. Accordingly, in the production of glass articles used in the manufacture of such displays, there is demand for glass articles, such as glass sheets, having increasingly pristine surface quality. Such surface quality relates not only characteristics inherent to the glass sheet, such as smoothness and flatness, but also the presence of particles or other materials on the surfaces of the sheet that may adversely affect display resolution. Accordingly, there is a continuing need to manufacture and process glass articles, such as glass sheets, with increasingly pristine surface quality, including surfaces having a minimal presence of particles and other materials that may adversely affect display resolution.

SUMMARY

[0004] Embodiments disclosed herein include a method for processing a glass sheet. The method includes transporting the glass sheet into a chamber comprising an inner atmosphere. The inner atmosphere comprises a water content of no more than 50% of a water content of an atmosphere surrounding the chamber and a pressure that is higher than a pressure of the atmosphere surrounding the chamber. The method also includes maintaining the glass sheet in the chamber for a period of time. In addition, the method includes transporting the glass sheet out of the chamber. The method also includes washing the glass sheet in a washing step. An adhered glass particle density on a major surface of the glass sheet transported out of the chamber and washed in the washing step is lower than the adhered glass particle density on a major surface of the glass sheet maintained for the period of time in a comparative atmosphere and washed in the washing step. The comparative atmosphere has the same water content and pressure as the atmosphere surrounding the chamber.

[0005] Embodiments disclosed herein also include an apparatus for processing a glass sheet. The apparatus includes a chamber comprising an inner atmosphere. The inner atmosphere comprises a water content of no more than 50% of a water content of an atmosphere surrounding the chamber and a pressure that is higher than a pressure of the atmosphere surrounding the chamber. The chamber is configured to maintain the glass sheet in the atmosphere for a period of time.

[0006] Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the disclosed embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0007] It is to be understood that both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the claimed embodiments. The accompanying drawings are included to provide further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description serve to explain the principles and operations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. l is a schematic view of an example fusion down draw glass making apparatus and process;

[0009] FIG. 2 is a perspective view of a glass sheet;

[0010] FIG. 3 is a schematic side view of a portion of a glass sheet processing apparatus including a chamber and a glass sheet conveyor;

[0011] FIG. 4 is a schematic top view of the portion of the glass sheet processing apparatus shown in FIG. 3;

[0012] FIG. 5 is a schematic side view of a portion of a glass sheet processing apparatus including a chamber and a transition area; [0013] FIG. 6 is a schematic side view of a portion of a glass sheet processing apparatus including a chamber, a transition area, and a wash station; and

[0014] FIG. 7 is a chart showing adhered glass particle density on glass sheets under a variety of conditions.

DETAILED DESCRIPTION

[0015] Reference will now be made in detail to the present preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0016] Ranges can be expressed herein as from“about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, for example by use of the antecedent“about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0017] Directional terms as used herein - for example up, down, right, left, front, back, top, bottom - are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0018] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to 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. [0019] 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” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0020] As used herein, the term“chamber” refers to glass processing component having an at least partially enclosed area comprising an inner atmosphere that is capable of holding or storing at least one glass sheet for a period of time.

[0021] As used herein, the term“atmosphere” refers to a primarily gaseous fluid of an area or region, such as a primarily gaseous fluid in an at least partially enclosed area of a chamber (“inner atmosphere”) or a primarily gaseous fluid surrounding the chamber.

[0022] As used herein, the term“washing step” refers to a step involving washing at least one major surface of a glass sheet. The washing can, for example, include contacting a fluid, such as a gas or liquid, with at least one major surface of the glass sheet such as by, for example, spraying, dipping, rolling, or ultrasonic washing.

[0023] As used herein, the term“adhered glass particle density” refers to the measured density in particles per square meter (pcs/m²) of particles identified as adhered glass according to the Adhered Glass Particle Density Measurement Technique as described herein.

[0024] As used herein, the term“high velocity gas flow” refers to a primarily gaseous fluid, such as air, flowed through at least one orifice, such as a nozzle or air knife, at a velocity of at least about 5 meters per second (m/s).

[0025] Shown in FIG. 1 is an exemplary glass manufacturing apparatus 10. In some examples, the glass manufacturing apparatus 10 can comprise a glass melting furnace 12 that can include a melting vessel 14. In addition to melting vessel 14, glass melting furnace 12 can optionally include one or more additional components such as heating elements (e.g., combustion burners or electrodes) that heat raw materials and convert the raw materials into molten glass. In further examples, glass melting furnace 12 may include thermal

management devices (e.g., insulation components) that reduce heat lost from a vicinity of the melting vessel. In still further examples, glass melting furnace 12 may include electronic devices and/or electromechanical devices that facilitate melting of the raw materials into a glass melt. Still further, glass melting furnace 12 may include support structures (e.g., support chassis, support member, etc.) or other components.

[0026] Glass melting vessel 14 is typically comprised of refractory material, such as a refractory ceramic material, for example a refractory ceramic material comprising alumina or zirconia. In some examples glass melting vessel 14 may be constructed from refractory ceramic bricks. Specific embodiments of glass melting vessel 14 will be described in more detail below.

[0027] In some examples, the glass melting furnace may be incorporated as a component of a glass manufacturing apparatus to fabricate a glass substrate, for example a glass ribbon of a continuous length. In some examples, the glass melting furnace of the disclosure may be incorporated as a component of a glass manufacturing apparatus comprising a slot draw apparatus, a float bath apparatus, a down-draw apparatus such as a fusion process, an up- draw 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 schematically illustrates glass melting furnace 12 as a component of a fusion down-draw glass manufacturing apparatus 10 for fusion drawing a glass ribbon for subsequent processing into individual glass sheets.

[0028] The glass manufacturing apparatus 10 (e.g., fusion down-draw apparatus 10) can optionally include an upstream glass manufacturing apparatus 16 that is positioned upstream relative to glass melting vessel 14. In some examples, a portion of, or the entire upstream glass manufacturing apparatus 16, may be incorporated as part of the glass melting furnace 12

[0029] As shown in the illustrated example, the upstream glass manufacturing apparatus 16 can include a storage bin 18, a raw material delivery device 20 and a motor 22 connected to the raw material delivery device. Storage bin 18 may be configured to store a quantity of raw materials 24 that can be fed into melting vessel 14 of glass melting furnace 12, as indicated by arrow 26. Raw materials 24 typically comprise one or more glass forming metal oxides and one or more modifying agents. In some examples, raw material delivery device 20 can be powered by motor 22 such that raw material delivery device 20 delivers a predetermined amount of raw materials 24 from the storage bin 18 to melting vessel 14. In further examples, motor 22 can power raw material delivery device 20 to introduce raw materials 24 at a controlled rate based on a level of molten glass sensed downstream from melting vessel 14. Raw materials 24 within melting vessel 14 can thereafter be heated to form molten glass 28.

[0030] Glass manufacturing apparatus 10 can also optionally include a downstream glass manufacturing apparatus 30 positioned downstream relative to glass melting furnace 12. In some examples, a portion of downstream glass manufacturing apparatus 30 may be incorporated as part of glass melting furnace 12. In some instances, first connecting conduit 32 discussed below, or other portions of the downstream glass manufacturing apparatus 30, may be incorporated as part of glass melting furnace 12. Elements of the downstream glass manufacturing apparatus, including 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, downstream components of the glass manufacturing apparatus may be formed from a platinum-rhodium alloy including from about 70 to about 90% by weight platinum and about 10% to about 30% by weight rhodium. However, other suitable metals can include molybdenum, palladium, rhenium, tantalum, titanium, tungsten and alloys thereof.

[0031] Downstream glass manufacturing apparatus 30 can include a first conditioning (i.e., processing) vessel, such as fining vessel 34, located downstream from melting vessel 14 and coupled to melting vessel 14 by way of the above-referenced first connecting conduit 32. In some examples, molten glass 28 may be gravity fed from melting vessel 14 to fining vessel 34 by way of first connecting conduit 32. For instance, gravity may cause molten glass 28 to pass through an interior pathway of first connecting conduit 32 from melting vessel 14 to fining vessel 34. It should be understood, however, that other conditioning vessels may be positioned downstream of melting vessel 14, for example between melting vessel 14 and fining vessel 34. In some embodiments, a conditioning vessel may be employed between the melting vessel and the fining vessel wherein molten glass from a primary melting vessel is further heated to continue the melting process, or cooled to a temperature lower than the temperature of the molten glass in the melting vessel before entering the fining vessel.

[0032] Bubbles may be removed from molten glass 28 within fining vessel 34 by various techniques. For example, raw materials 24 may include multivalent compounds (i.e. fining agents) such as tin oxide that, when heated, undergo a chemical reduction reaction and release oxygen. Other suitable fining agents include without limitation arsenic, antimony, iron and cerium. Fining vessel 34 is heated to a temperature greater than the melting vessel temperature, thereby heating the molten glass and the fining agent. Oxygen bubbles produced by the temperature-induced chemical reduction of the fining agent(s) rise through the molten glass within the fining vessel, wherein gases in the molten glass produced in the melting furnace can diffuse or coalesce into the oxygen bubbles produced by the fining agent. The enlarged gas bubbles can then rise to a free surface of the molten glass in the fining vessel and thereafter be vented out of the fining vessel. The oxygen bubbles can further induce mechanical mixing of the molten glass in the fining vessel. [0033] Downstream glass manufacturing apparatus 30 can further include another

conditioning vessel such as a mixing vessel 36 for mixing the molten glass. Mixing vessel 36 may be located downstream from the fining vessel 34. Mixing vessel 36 can be used to provide a homogenous glass melt composition, thereby reducing cords of chemical or thermal inhomogeneity that may otherwise exist within the fined molten glass exiting the fining vessel. As shown, fining vessel 34 may be coupled to mixing vessel 36 by way of a second connecting conduit 38. In some examples, molten glass 28 may be gravity fed from the fining vessel 34 to mixing vessel 36 by way of second connecting conduit 38. For instance, gravity may cause molten glass 28 to pass through an interior pathway of second connecting conduit 38 from fining vessel 34 to mixing vessel 36. It should be noted that while mixing vessel 36 is shown downstream of fining vessel 34, mixing vessel 36 may be positioned upstream from fining vessel 34. In some embodiments, downstream glass manufacturing apparatus 30 may include multiple mixing vessels, for example a mixing vessel upstream from fining vessel 34 and a mixing vessel downstream from fining vessel 34. These multiple mixing vessels may be of the same design, or they may be of different designs.

[0034] Downstream glass manufacturing apparatus 30 can further include another

conditioning vessel such as delivery vessel 40 that may be located downstream from mixing vessel 36. Delivery vessel 40 may condition molten glass 28 to be fed into a downstream forming device. For instance, delivery vessel 40 can act as an accumulator and/or flow controller to adjust and/or provide a consistent flow of molten glass 28 to forming body 42 by way of exit conduit 44. As shown, mixing vessel 36 may be coupled to delivery vessel 40 by way of third connecting conduit 46. In some examples, molten glass 28 may be gravity fed from mixing vessel 36 to delivery vessel 40 by way of third connecting conduit 46. For instance, gravity may drive molten glass 28 through an interior pathway of third connecting conduit 46 from mixing vessel 36 to delivery vessel 40.

[0035] Downstream glass manufacturing apparatus 30 can further include forming apparatus 48 comprising the above-referenced forming body 42 and inlet conduit 50. Exit conduit 44 can be positioned to deliver molten glass 28 from delivery vessel 40 to inlet conduit 50 of forming apparatus 48. For example, exit conduit 44 may be nested within and spaced apart from an inner surface of inlet conduit 50, thereby providing a free surface of molten glass positioned between the outer surface of exit conduit 44 and the inner surface of inlet conduit 50. Forming body 42 in a fusion down draw glass making apparatus can comprise a trough 52 positioned in an upper surface of the forming body and converging forming surfaces 54 that converge in a draw direction along a bottom edge 56 of the forming body. Molten glass delivered to the forming body trough via delivery vessel 40, exit conduit 44 and inlet conduit 50 overflows side walls of the trough and descends along the converging forming surfaces 54 as separate flows of molten glass. The separate flows of molten glass join below and along bottom edge 56 to produce a single ribbon of glass 58 that is drawn in a draw or flow direction 60 from bottom edge 56 by applying tension to the glass ribbon, such as by gravity, edge rolls 72 and pulling rolls 82, to control the dimensions of the glass ribbon as the glass cools and a viscosity of the glass increases. Accordingly, glass ribbon 58 goes through a visco-elastic transition and acquires mechanical properties that give the glass ribbon 58 stable dimensional characteristics. Glass ribbon 58 may, in some embodiments, be separated into individual glass sheets 62 by a glass separation apparatus 100 in an elastic region of the glass ribbon. A robot 64 may then transfer the individual glass sheets 62 to a conveyor system using gripping tool 65, whereupon the individual glass sheets may be further processed.

[0036] FIG. 2 shows a perspective view of a glass sheet 62 having a first major surface 162, a second major surface 164 extending in a generally parallel direction to the first major surface (on the opposite side of the glass sheet 62 as the first major surface) and an edge surface 166 extending between the first major surface 162 and the second major surface 164 and extending in a generally perpendicular direction to the first and second major surfaces 162, 164.

[0037] Further processing of glass sheets 62 may, for example, include grinding, polishing, and/or beveling of edge surfaces 166 and/or treating or washing at least one of first and second major surfaces 162, 164. Such glass sheets 62 may also be divided into smaller glass sheets 62. During these and other potential processing steps it may be necessary to temporarily store glass sheets 62 before, after, or between various process steps. Such storage may cause certain adverse effects to the quality of the glass sheets, including increased adherence of small glass particles on at least one of first and second major surfaces 162, 164. Such glass particles can, for example, be generated during certain processing steps, including the separation of glass ribbon 58 into individual glass sheets 62 as well grinding, polishing, and/or beveling steps.

[0038] FIGS. 3 and 4 show, respectively, schematic side and top views of a portion of a glass sheet processing apparatus including a chamber 200 and a glass sheet conveyor 300. Chamber 200 includes an entrance 202 through which one or more glass sheets 62 can be transported into the chamber 200. Chamber 200 also includes channels 204 through which a fluid may be flowed. In addition, chamber 200 includes humidity sensors 206. [0039] Glass sheets 62 can be transported out of chamber 200 through action of conveyor 300. Conveyor 300 can include any conveyance mechanism known to persons having ordinary skill in the art including but not limited to rolling-based mechanisms, sliding-based mechanisms, and levitation-based mechanisms, such as air bearings. In addition, while glass sheet 62 in FIGS. 2 and 3 is shown being conveyed in a generally horizontal direction, embodiments disclosed herein include conveyance mechanisms in which glass sheets are conveyed in other directions, such as a vertical direction.

[0040] Chamber 200 encloses an inner atmosphere 208. The inner atmosphere 208 comprises a water content (i.e., water vapor content) of no more than 50%, such as no more than 40%, and further such as no more than 30%, including between 10% and 50%, and further including between 20% and 40% of a water content of an atmosphere surrounding the chamber 210. The inner atmosphere 208 also comprises a pressure that is higher than a pressure of the atmosphere surrounding the chamber 210, such as a pressure of at least about 1 KPa, such as at least about 2 KPa, and further such as at least about 5 KPa, and yet further such as at least about 10 KPa, including from about lKPa to about 20 KPa and further including from about 2 KPa to about 10 KPa higher than a pressure of the atmosphere surrounding the chamber 210.

[0041] The lower water content (i.e., lower relative humidity) and higher pressure of the inner atmosphere 208 relative to the atmosphere surrounding the chamber 210 can be established by flowing a fluid, such as at least partially dehumidified air, through channels 204 and into inner atmosphere 208 of chamber 200. For example, the fluid flowing through channels 204 can have a water content that is less than or equal to than the desired water content of the inner atmosphere 208, such as a water content of no more than 50%, such as no more than 40%, and further such as no more than 30%, including between 10% and 50%, and further including between 20% and 40% of a water content of an atmosphere surrounding the chamber 210.

[0042] In certain exemplary embodiments, the temperature of the inner atmosphere 208 ranges from about 20°C to about 35°C and the water content of the inner atmosphere is less than or equal to about 10 grams of water vapor per kilogram of air, such as from about 5 to about 10 grams of water vapor per kilogram of air.

[0043] As shown, for example in FIG. 3, a plurality of glass sheets 62 are held in chamber 200. The period of time for which glass sheets 62 may be held or maintained in chamber 200, while not limited, may, for example, be at least about 3 hours, such as at least about 6 hours, and further such as at least about 12 hours, and still yet further such as at least about 24 hours, including from about 3 hours to about 240 hours, such as from about 6 hours to about 120 hours, and further such as from about 12 hours to about 60 hours.

[0044] Entrance 202 through which one or more glass sheets 62 can be transported into the chamber 200 can have a gap height H that is no more than four times a thickness of the glass sheet 62. For example, if the glass sheet 62 has a thickness of less than or equal to about 0.5 millimeters, entrance 202 can have a gap height H that is less than or equal to about 2 millimeters. Minimization of gap height H of entrance 202 can help mitigate diffusion of atmosphere surrounding the chamber 210 into inner atmosphere 208.

[0045] Chamber 200 may comprise any sufficiently rigid material suitable holding or storing glass sheets 62 for a period of time while minimizing diffusion or permeation of atmosphere surrounding the chamber 210 into inner atmosphere 208. For example, chamber 200 may comprise a metal, such as aluminum, and may further comprise a coated metal, such as a metal, such as aluminum, coated with a scratch resistant material, such as Teflon. Area around entrance 202 may comprise a rigid or flexible material. For example, flexible material may comprise a plastic material, such as polyvinyl chloride (PVC), polypropylene (PP), acrylonitrile butadiene styrene (ABS), or an acrylic material.

[0046] As noted above, chamber 200 can include at least one humidity sensor 206. In certain exemplary embodiments, the water content of the inner atmosphere 208 can be controlled using the at least one humidity sensor 206. For example, at least one humidity sensor 206 can be used as a component of a feedback control mechanism that measures the water content or humidity of the inner atmosphere 208 and then controls or adjusts the flow of fluid through channels 204 in response to the measured water content or humidity of inner atmosphere 208.

[0047] FIG. 5 shows a schematic side view of a portion of a glass sheet processing apparatus including a chamber 200 and a transition area 400. As shown in FIG. 5, glass sheet 62 is transported out of the chamber 200 and into the transition area 400. Transition area comprises a high velocity gas flow, which can be flowed through a high velocity gas flow orifice 402, such as a nozzle or air knife. The velocity of high velocity gas flow can, for example, range from about 5 meters per second to about 30 meters per second, such as from about 10 meters per second to about 20 meters per second. Transition area 400, including high velocity gas flow, can further prevent diffusion of atmosphere surrounding the chamber 210 into inner atmosphere 208.

[0048] FIG. 6 is shows schematic side view of a portion of a glass sheet processing apparatus including a chamber 200, a transition area 400, and a wash station 500. As shown in FIG. 6, glass sheet 62 is transported out of transition area 400 and into wash station 500 wherein a washing step may be performed on the glass sheet 62. Wash station 500 comprises at least one wash orifice 502 for flowing at least one washing fluid on or in the vicinity of glass sheet 62. At least one washing fluid may comprise at least one liquid or gaseous fluid useable for washing glass sheets 62. Exemplary washing fluids include water, including deionized water and water comprising at least one detergent or surfactant.

[0049] Embodiments disclosed herein can include those in which at least one glass sheet 62 is maintained in chamber 200 for a period of time and an adhered glass particle density on a major surface of the glass sheet 62 transported out of the chamber 200 and washed in a washing step is lower than the adhered glass particle density on a major surface of the glass sheet 62 maintained for the period of time in a comparative atmosphere and washed in the washing step, the comparative atmosphere having the same water content and pressure as the atmosphere surrounding the chamber 210. For example, embodiments disclosed herein include those in which an adhered glass particle density on a major surface of the glass sheet 62 transported out of the chamber 200 and washed in the washing step is at least about 50% lower, such as at least about 75% lower, and further such as at least about 85% lower, and still further such as at least about 90% lower, including from about 50% lower to about 95% lower, and further including from about 75% lower to about 90% lower than the adhered glass particle density on a major surface of the glass sheet maintained for the period of time in the comparative atmosphere and washed in the washing step.

[0050] Adhered Glass Particle Density Measurement Technique

[0051] Adhered glass particle density, as referenced herein, was determined by counting the number of particles identified as adhered glass within a given area and then calculating the measured density in particles per square meter (pcs/m²) based on the counted particles in the given area. Particles were counted by scanning an entire sheet of glass using a camera and an autofocusing system as described in US patent no. 6,396,039, the entire disclosure of which is incorporated herein by reference, and then counting the number of particles determined by the observer to be adhered glass within images captured by the camera.

[0052] Examples

[0053] Adhered glass particle density was determined for six different experimental conditions. Specifically, sheets of Eagle XG^® glass having a thickness of about 0.5 millimeters and major surface area of about 1950 millimeters by 2250 millimeters were stored in a chamber under the following conditions: (1) storage time of about 3 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 80-90%; (2) storage time of about 3 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 30-45%; (3) storage time of about 6 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 80-90%; (4) storage time of about 6 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 30-45%; (5) storage time of about 12 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 80-90%; and (6) storage time of about 12 hours at a temperature of about 25°C and an inner atmosphere relative humidity of about 30-45%. Following storage in the chamber, the sheets were washed, dried, and then adhered glass particle density was determined for each sheet using the Adhered Glass Particle Density Measurement Technique described herein. The results are shown in FIG. 7.

[0054] As can be seen from FIG. 7, sheets stored at a relative humidity of about 30-45% showed significantly lower adhered glass particle density (ADG density) than sheets stored at a relative humidity of about 80-90% at each of the 3 hour, 6 hour, and 12 hour time periods. Specifically, sheets stored for the 3 hour time period at about 30-45% relative humidity showed about a 90% reduction in adhered glass particle density as compared to sheets stored for the 3 hour time period at about 80-90% relative humidity. Sheets stored for the 6 hour time period at about 30-45% relative humidity showed about an 85% reduction in adhered glass particle density as compared to sheets stored for the 6 hour time period at about 80-90% relative humidity. And sheets stored for the 12 hour time period at about 30-45% relative humidity showed about a 90% reduction in adhered glass particle density as compared to sheets stored for the 12 hour time period at about 80-90% relative humidity.

[0055] As the about 80-90% relative humidity condition is meant to approximate a condition of a comparative atmosphere having the same water content and pressure as the atmosphere surrounding the chamber, the examples show that when the relative humidity or water content of the inner atmosphere is reduced by at least about 50% relative to that condition, a substantial reduction of adhered glass particle density on a major surface of the glass sheets can be achieved. This, in turn, can enable the production of glass sheets used, for example, in electronic devices, having a minimal presence of adhered glass particles that may adversely affect display resolution.

[0056] While the above embodiments have been described with reference to a fusion down draw process, it is to be understood that such embodiments are also applicable to other glass forming processes, such as float processes, slot draw processes, up-draw processes, tube drawing processes, and press-rolling processes. [0057] It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Thus it is intended that the present disclosure cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. A method for processing a glass sheet comprising:

transporting the glass sheet into a chamber comprising an inner atmosphere comprising a water content of no more than 50% of a water content of an atmosphere surrounding the chamber and a pressure that is higher than a pressure of the atmosphere surrounding the chamber;

maintaining the glass sheet in the chamber for a period of time; transporting the glass sheet out of the chamber; and

washing the glass sheet in a washing step;

wherein an adhered glass particle density on a major surface of the glass sheet transported out of the chamber and washed in the washing step is lower than the adhered glass particle density on a major surface of the glass sheet maintained for the period of time in a comparative atmosphere and washed in the washing step, the comparative atmosphere having the same water content and pressure as the atmosphere surrounding the chamber.

2. The method of claim 1, wherein the chamber comprises at least one channel and the method comprises flowing a fluid through the channel and into the inner atmosphere, the fluid comprising a water content of no more than 50% of the water content of the atmosphere surrounding the chamber.

3. The method of claim 1, wherein the temperature of the inner atmosphere

ranges from about 20°C to about 35°C and the water content of the inner atmosphere is less than or equal to about 10 grams of water vapor per kilogram of air.

4. The method of claim 1, wherein the period of time is at least about 3 hours.

5. The method of claim 1, wherein the adhered glass particle density on the

major surface of the glass sheet transported out of the chamber and washed in the washing step is at least about 50% lower than the adhered glass particle density of a major surface of the glass sheet maintained for the period of time in the comparative atmosphere and washed in the washing step.

6. The method of claim 1, wherein the chamber comprises at least one humidity sensor.

7. The method of claim 6, wherein the water content of the inner atmosphere is controlled using the at least one humidity sensor.

8. The method of claim 1, wherein the glass sheet is transported into the chamber through an entrance, the entrance comprising a gap height that is no more than four times a thickness of the glass sheet.

9. The method of claim 1, wherein the glass sheet transported out of the chamber is transported into a transition area comprising a high velocity gas flow.

10. The method of claim 9, wherein the glass sheet is transported out of the

transition area comprising a high velocity gas flow and transported into a wash station in order to perform the washing step.

11. A glass sheet made by the method of claim 1.

12. An electronic device comprising the glass sheet of claim 11.

13. An apparatus for processing a glass sheet comprising:

a chamber comprising an inner atmosphere comprising a water content of no more than 50% of a water content of an atmosphere surrounding the chamber and a pressure that is higher than a pressure of the atmosphere surrounding the chamber; wherein the chamber is configured to maintain the glass sheet in the atmosphere for a period of time.

14. The apparatus of claim 13, wherein the chamber comprises at least one

channel configured to flow a fluid comprising a water content of no more than 50% of the water content of the atmosphere surrounding the chamber into the inner atmosphere.

15. The apparatus of claim 13, wherein the temperature of the inner atmosphere ranges from about 20°C to about 35°C and the water content of the inner atmosphere is less than or equal to about 10 grams of water vapor per kilogram of air.

16. The apparatus of claim 13, wherein the period of time is at least about 3 hours.

17. The apparatus of claim 13, wherein the chamber comprises at least one

humidity sensor.

18. The apparatus of claim 17, wherein the water content of the inner atmosphere is controllable using the at least one humidity sensor.

19. The apparatus of claim 13, wherein the chamber comprises an entrance, the entrance comprising a gap height that is no more than four times a thickness of the glass sheet.

20. The apparatus of claim 13, wherein the apparatus further comprises a

transition area comprising a high velocity gas flow.

21. The apparatus of claim 20, wherein the apparatus further comprises a wash station.