阅读说明：本技术 具有减少的静电电荷的玻璃片及其生产方法 (Glass sheet having reduced electrostatic charge and method of producing the same ) 是由 冯江蔚 于 2019-02-22 设计创作，主要内容包括：一种制造和处理玻璃制品的方法,其中制品的处理包含将等离子体流(如包括大气压等离子体喷流的等离子体流)导向制品的主表面。上述处理可减少在主表面上的绝对测量电压。(A method of making and treating a glass article, wherein the treatment of the article comprises directing a plasma stream (e.g., a plasma stream comprising an atmospheric pressure plasma jet) toward a major surface of the article. The above process may reduce the absolute measurement voltage on the main surface.)

1. A method for making a glass article, the method comprising:

forming the glass article, the glass article comprising a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction perpendicular to the first and second major surfaces; and

Directing a plasma stream toward the first major surface, wherein directing the plasma stream toward the first major surface reduces an absolute measured voltage on the first major surface by at least about 35% and changes an average surface roughness, Ra, of the first major surface by less than about 20%.

2. The method of claim 1, wherein the plasma stream comprises an atmospheric pressure plasma jet.

3. The method of claim 1, wherein the plasma stream comprises an atmospheric pressure linear stream.

4. The method of claim 1, wherein the plasma comprises at least one component selected from the group consisting of: nitrogen, argon, oxygen, helium and CDA.

5. The method of claim 1, wherein the plasma is substantially free of fluorine.

6. The method of claim 1, wherein the plasma is generated at a power of at least about 300 watts.

7. A glass article made by the method of claim 1.

8. A method for treating a glass article comprising a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction normal to the first and second major surfaces, the method comprising:

Directing a plasma stream toward the first major surface, wherein directing the plasma stream toward the first major surface reduces an absolute measured voltage on the first major surface by at least about 35% and changes an average surface roughness, Ra, of the first major surface by less than about 20%.

9. The method of claim 8, wherein the plasma stream comprises an atmospheric pressure plasma jet.

10. The method of claim 8, wherein the plasma stream comprises an atmospheric pressure linear stream.

11. The method of claim 8, wherein the plasma comprises at least one component selected from the group consisting of: nitrogen, argon, oxygen, helium and CDA.

12. The method of claim 8, wherein the plasma is substantially free of fluorine.

13. The method of claim 8, wherein the plasma is generated at a power of at least about 300 watts.

14. A glass article made by the method of claim 8.

15. A glass article comprising a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction normal to the first and second major surfaces, wherein an absolute measurement voltage across the first major surface is less than about 0.25kV and an average surface roughness, Ra, of the first major surface is less than about 0.3 nm.

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

Technical Field

The present disclosure relates generally to glass sheets having reduced electrostatic charge and methods of producing the same.

Background

In the production of glass articles, such as glass sheets for display applications (including televisions and handheld devices such as telephones and tablets), there are often multiple processing steps in which contact between the surface of the glass and other surfaces can create electrostatic charges on the surface of the glass. The accumulation of such charge on the surface of the glass can adversely affect the performance of electronic devices incorporating such glass articles. Accordingly, there is a continuing need to control and reduce the generation of electrostatic charges on glass articles used in, for example, display applications and other electronic devices.

Disclosure of Invention

Embodiments disclosed herein include methods for making glass articles. The method includes forming the glass article. The glass article includes a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction perpendicular to the first and second major surfaces. The method also includes directing a plasma stream toward the first major surface. Directing a plasma stream toward a first major surface reduces an absolute measured voltage on the first major surface by at least about 35% and alters an average surface roughness, Ra, of the first major surface by less than about 20%.

Embodiments disclosed herein also include methods of treating glass articles. The glass article includes a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction perpendicular to the first and second major surfaces. The method includes directing a plasma stream toward the first major surface. Directing a plasma stream toward a first major surface reduces an absolute measured voltage on the first major surface by at least about 35% and alters an average surface roughness, Ra, of the first major surface by less than about 20%.

Embodiments disclosed herein also include glass articles. The glass article includes a first major surface, a second major surface parallel to the first major surface, and an edge surface extending between the first and second major surfaces in a direction perpendicular to the first and second major surfaces. An absolute measurement voltage across the first major surface is less than about 0.25kV, and an average surface roughness Ra of the first major surface is less than about 0.3 nm.

Additional features and advantages of the embodiments disclosed herein will be set forth in the embodiments described below, and in part will be apparent to those skilled in the art from that description or recognized by practicing the disclosed embodiments described herein, including the embodiments described below, the claims, and the appended drawings.

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 embodiments of the application. 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 disclosure and together with the description serve to explain the principles and operations of the disclosure.

Drawings

FIG. 1 is a schematic view of an exemplary fusion downdraw glass manufacturing apparatus and process;

FIG. 2 is a perspective view of a glass sheet;

FIG. 3 is a perspective view of at least a portion of a primary surface treatment process using a plasma jet;

FIG. 4 is a schematic front view of a main surface treatment using a plasma jet;

FIG. 5 is a perspective view of at least a portion of a major surface treatment using a linear plasma stream; and

fig. 6 is a schematic front view of a main surface treatment using a linear plasma stream.

Detailed Description

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

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, 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.

Directional terms-e.g., upper, lower, right, left, front, rear, top, bottom-as used herein-are made with reference to the drawings as drawn only and are not intended to imply absolute orientation.

Unless explicitly stated otherwise, any method described herein is in no way intended to be construed as requiring that the steps of the method be performed in a particular order, nor in any device, particular orientation. Accordingly, when a method claim does not actually recite an order to be followed by the steps of the method, or when any apparatus claim does not actually recite an order or orientation to individual components, or when no further particular description in the claims or specification recites an order or orientation to specific components, or when a particular order or orientation to components of an apparatus is not recited, it is no way intended that an order or orientation be inferred, in any respect. This applies to any possible non-explicit basis for interpretation, including: logical considerations regarding the arrangement of steps, operational flow, order of components, or orientation of components; simple meanings derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

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" or "an" element includes aspects having two or more of the elements described above, unless the context clearly dictates otherwise.

As used herein, the term "plasma" refers to an ionized gas (ionizidgas) that includes positive ions and free electrons.

As used herein, the term "atmospheric pressure" when referring to an atmospheric pressure plasma jet or a linear atmospheric pressure plasma jet refers to a plasma flow discharged from an aperture, wherein the plasma pressure approximately matches the pressure of the surrounding atmosphere, including conditions wherein the plasma pressure is between 90% and 110% of 101.325 kilopascals (standard atmospheric pressure).

As used herein, the term "absolute measured voltage" refers to the absolute value of the voltage measured by the Voltage Measurement Technique (VMT) as described in the examples section herein. Thus, the term "reducing the absolute measured voltage" refers to reducing the absolute value of the measured voltage measured by the VMT as described in the examples section herein.

As used herein, the term "surface roughness Ra" refers to an arithmetic average surface roughness specified in JIS B0031 (1994).

As used herein, the term "clean dry air" (CDA) refers to air that includes less than 1 gram of water vapor per kilogram of air.

FIG. 1 illustrates an exemplary glass manufacturing apparatus 10. In some examples, glass manufacturing apparatus 10 can include a glass melting furnace 12, and glass melting furnace 12 can include a melting vessel 14. In addition to melting vessel 14, glass melting furnace 12 may optionally include one or more additional components, such as heating elements (e.g., burners or electrodes) that heat and convert the raw materials into molten glass. In a further example, glass melting furnace 12 may include a thermal management device (e.g., an insulating member) that reduces heat lost from the vicinity of the melting vessel. In still further examples, glass melting furnace 12 may include electronic devices and/or electromechanical devices that facilitate melting the raw materials into a glass melt. Still further, glass melting furnace 12 may include support structures (e.g., support pans, support members, etc.) or other components.

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

In some examples, a glass melting furnace can be incorporated as a component of a glass manufacturing apparatus to manufacture glass substrates, e.g., a continuous length of glass ribbon. In some examples, the glass melting furnace of the present disclosure may be incorporated as a component of a glass manufacturing apparatus including a flow-hole draw (slot draw) apparatus, a float bath (float bath) apparatus, a down-draw (down-draw) apparatus (e.g., a fusion process), an up-draw (up-draw) apparatus, a press-rolling apparatus, a tube-drawing (tube drawing) apparatus, or any other glass manufacturing apparatus that would benefit from aspects disclosed herein. By way of example, fig. 1 schematically depicts a glass melting furnace 12 as a component of a fusion downdraw glass manufacturing apparatus 10 for fusion drawing a glass ribbon for subsequent processing into individual glass sheets.

The glass manufacturing apparatus 10 (e.g., the fusion downdraw apparatus 10) can optionally include an upstream glass manufacturing apparatus 16, the upstream glass manufacturing apparatus 16 being located upstream relative to the glass melting vessel 14. In some examples, a portion or all of upstream glass manufacturing apparatus 16 can be incorporated as part of glass melting furnace 12.

As shown in the illustrated example, the upstream glass manufacturing apparatus 16 may include a storage bin (storage bin)18, a raw material delivery device 20, and a motor 22 connected to the raw material delivery device. Storage silo 18 may be configured to store a quantity of raw material 24, and the quantity of raw material 24 may be fed into melting vessel 14 of glass melting furnace 12, as indicated by arrow 26. The feedstock 24 typically includes one or more glass-forming metal oxides and one or more modifiers. In some examples, the feedstock delivery device 20 may be powered by a motor 22 such that the feedstock delivery device 20 delivers a predetermined amount of feedstock 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 the level of molten glass sensed downstream of the melting vessel 14. Thereafter, the raw materials 24 within the melting vessel 14 may be heated to form molten glass 28.

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

The downstream glass manufacturing apparatus 30 may include a first conditioning (i.e., processing) vessel, such as a fining vessel 34, located downstream from the melting vessel 14 and coupled to the melting vessel 14 by the first connecting conduit 32 described above. In some examples, molten glass 28 may be gravity fed from melting vessel 14 to fining vessel 34 through first connecting conduit 32. For example, gravity may cause molten glass 28 to flow from melting vessel 14 to fining vessel 34 via the internal path of first connecting conduit 32. However, it should be understood that 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 employed between the melting vessel and the fining vessel, wherein the molten glass from the primary melting vessel is further heated to continue the melting process, or cooled to a temperature below the temperature of the molten glass in the melting vessel prior to entering the fining vessel.

Bubbles can be removed from molten glass 28 within fining vessel 34 by various techniques. For example, the feedstock 24 may include multivalent compounds (i.e., fining agents), such as tin oxide, that undergo a chemical reduction reaction and release oxygen when heated. Other suitable fining agents include, but are not limited to, arsenic, antimony, iron, and cerium. Fining vessel 34 is heated to a temperature above the melting vessel temperature to heat the molten glass and fining agents. Oxygen bubbles generated by temperature-induced chemical reduction of one or more fining agents rise through the molten glass within the fining vessel, wherein gases in the molten glass generated in the melting furnace may diffuse or coalesce into the oxygen bubbles generated by the fining agents. The enlarged bubbles may then rise to the free surface of the molten glass in the fining vessel and then exit the fining vessel. The oxygen bubbles may further cause mechanical mixing of the molten glass in the fining vessel.

The downstream glass manufacturing apparatus 30 may further comprise another conditioning vessel, such as a mixing vessel 36 for mixing molten glass. Mixing vessel 36 may be located downstream of fining vessel 34. Mixing vessel 36 may be used to provide a homogeneous glass melt composition, thereby reducing cord of chemical or thermal inhomogeneity that may otherwise exist within the refined 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, molten glass 28 may be gravity fed from fining vessel 34 to mixing vessel 36 through second connecting conduit 38. For example, gravity may cause molten glass 28 to flow from fining vessel 34 to mixing vessel 36 via the internal passage of second connecting conduit 38. It should be noted that although mixing vessel 36 is shown downstream of fining vessel 34, mixing vessel 36 may be located upstream of fining vessel 34. In some embodiments, downstream glass manufacturing apparatus 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 they may be of different designs.

The downstream glass manufacturing apparatus 30 may further comprise another conditioning vessel, such as a delivery vessel 40, which may be located downstream of the mixing vessel 36. The delivery vessel 40 can condition the molten glass 28 to be fed to a downstream forming device. For example, the delivery vessel 40 may act as an accumulator and/or flow controller to regulate and/or provide a consistent flow of molten glass 28 through the outlet conduit 44 to the forming body 42. As shown, the mixing vessel 36 may be coupled to the delivery vessel 40 by a third connecting conduit 46. In some examples, molten glass 28 may be gravity fed from mixing vessel 36 to delivery vessel 40 through third connecting conduit 46. For example, gravity may drive molten glass 28 from mixing vessel 36 to delivery vessel 40 via the internal path of third connecting conduit 46.

Downstream glass manufacturing apparatus 30 may further comprise a forming apparatus 48, forming apparatus 48 comprising forming body 42 described above and inlet conduit 50. Outlet conduit 44 may be positioned to deliver molten glass 28 from delivery vessel 40 to inlet conduit 50 of forming apparatus 48. For example, the outlet conduit 44 may be nested within and spaced apart from the inner surface of the inlet conduit 50, thereby providing a free surface of molten glass between the outer surface of the outlet conduit 44 and the inner surface of the inlet conduit 50. The forming body 42 in a fusion downdraw glass manufacturing apparatus may include a trough 52 in an upper surface of the forming body and converging forming surfaces 54 that converge in the draw direction along a bottom edge 56 of the forming body. The molten glass delivered to the forming trough via delivery vessel 40, outlet conduit 44 and inlet conduit 50 overflows the side walls of the trough and descends along converging forming surfaces 54 as individual streams of molten glass. Individual streams of molten glass are joined below and along bottom edge 56 to create a single glass ribbon 58, which single glass ribbon 58 is drawn from bottom edge 56 in a draw or flow direction 60 by applying tension to the glass ribbon (e.g., by gravity, edge rollers 72, and pull rollers 82) to control the dimensions of the glass ribbon as the glass cools and the viscosity of the glass increases. Thus, the glass ribbon 58 undergoes a viscous-elastic transition (visco-elastic transition) and acquires mechanical properties that impart stable dimensional characteristics to the glass ribbon 58. In some embodiments, glass ribbon 58 can be separated into individual glass sheets 62 by glass separation apparatus 100 in the elastic region of the glass ribbon. Robot 64 may then use gripping tool 65 to transfer individual glass sheet 62 to a conveyor system where the individual glass sheet may be further processed.

Glass sheet 62 may be further separated into individual glass blocks (tiles) by one or more methods known to those of ordinary skill in the art, for example, by mechanical cutting techniques. Exemplary dicing techniques include, for example, using a semiconductor dicing saw or mechanical scribing. The glass sheets 63 may also be separated into individual glass blocks by other techniques, such as laser-based cutting and separation techniques.

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

Fig. 3 illustrates a perspective view of at least a portion of a treatment process for first major surface 162 of glass sheet 62 using plasma jet 402. As shown in fig. 3, the treatment process includes directing a plasma jet toward the first major surface 162 via the plasma jet 402, wherein the plasma showerhead 400 moves relative to the first major surface 162 in a direction indicated by arrow 500. In certain exemplary embodiments, the plasma jet 402 comprises an atmospheric pressure plasma jet.

Fig. 4 shows a schematic front view of a main surface treatment using a plasma jet 402. As shown in fig. 4, plasma showerhead 400 is moved across first major surface 162 of glass sheet 62 in the direction indicated by arrow 500. Specifically, the plasma shower head 400 alternately moves from left to right and then from right to left in moving the sheet downward as viewed from the perspective view shown in fig. 4. The plasma showerhead 400 may also rotate in the direction indicated by the dashed arrow 500' while moving substantially in the direction indicated by the arrow 500. Although the dashed arrow 500' illustrates a substantially circular clockwise movement, it should be understood that embodiments disclosed herein include other movements of the plasma showerhead 400, such as substantially circular counterclockwise movements, and clockwise or counterclockwise movements in other shapes (e.g., elliptical or polygonal).

Plasma jet 402 can be directed toward first major surface 162 under various processing parameters. In certain exemplary embodiments, the plasma jet 402 may be generated at a power of at least about 300 watts, such as at least about 500 watts, including from about 300 watts to about 800 watts, and further including from about 500 watts to about 700 watts.

In certain exemplary embodiments, the plasma jet 402 is generated via a direct current high voltage discharge that produces a pulsed arc, such as a voltage discharge of at least about 5kV, such as from about 5kV to about 15 kV. In certain exemplary embodiments, the plasma jet 402 is generated at a frequency of at least about 10kHz, such as from about 10kHz to about 100kHz, and further such as from about 30kHz to about 70 kHz. In certain exemplary embodiments, the plasma jet may have a beam length of from about 5 mm to about 40 mm and a widest beam width of from about 0.5 mm to about 15 mm.

In certain exemplary embodiments, the distance between the portions of the plasma showerhead 400 closest to the first major surface 162 (referred to herein as the "gap distance") is at least about 1 millimeter, such as at least about 5 millimeters, and further such as at least about 10 millimeters, such as from about 1 millimeter to about 25 millimeters, including from about 5 millimeters to about 20 millimeters.

In certain exemplary embodiments, the relative movement speed (referred to herein as the "scan speed") between the plasma showerhead 400 and the first major surface 162 may range from about 5 millimeters per second to about 250 millimeters per second, such as from about 10 millimeters per second to about 200 millimeters per second, and further such as from about 50 millimeters per second to about 150 millimeters per second.

Fig. 5 illustrates a perspective view of at least a portion of a treatment process for first major surface 162 of glass sheet 62 using linear plasma stream 452. As shown in fig. 5, the treatment process includes directing a plasma stream toward the first major surface 162 via a linear plasma device 450 via a linear plasma stream 452. In certain exemplary embodiments, the linear plasma flow 452 comprises a linear atmospheric pressure plasma flow.

Fig. 6 shows a schematic front view of a main surface treatment using a linear plasma stream 452. As shown in fig. 6, linear plasma device 450 is moved across first major surface 162 of glass sheet 62 in the direction indicated by arrow 550 (such movement of the linear plasma device across first major surface 162 of glass sheet 62 is referred to herein as "scanning").

In certain exemplary embodiments, linear plasma device 450 may scan first major surface 162 of glass sheet 62 at least once, such as from 1 to 10 times, and further such as from 2 to 6 times. When linear plasma device 450 scans first major surface 162 of glass sheet 62 more than once, linear plasma device 450 can, for example, move in the direction of arrow 550 on odd scans and move in the opposite direction indicated by arrow 550 on even scans.

Linear plasma stream 452 can be directed toward first major surface 162 under various processing parameters. In certain exemplary embodiments, linear plasma jet 452 may be generated at a power of at least about 300 watts, such as at least about 500 watts, including from about 300 watts to about 800 watts, and further including from about 500 watts to about 700 watts.

In certain exemplary embodiments, linear plasma stream 452 is generated via a direct barrier discharge (direct barrier discharge) having a frequency of at least about 1MHz, such as from about 1MHz to about 25MHz, and further such as from about 5MHz to about 15 MHz.

In certain exemplary embodiments, the gap distance between the portions of linear plasma device 450 closest to first major surface 162 is at least about 1 millimeter, such as at least about 5 millimeters, and further such as at least about 10 millimeters, such as from about 1 millimeter to about 25 millimeters, including from about 5 millimeters to about 20 millimeters.

In certain exemplary embodiments, the scan speed between linear plasma device 450 and first major surface 162 may range from about 1 millimeter per second to about 100 millimeters per second, such as from about 10 millimeters per second to about 70 millimeters per second, and further such as from about 20 millimeters per second to about 40 millimeters per second.

While fig. 3-6 show the plasma stream being directed toward first major surface 162 of glass sheet 62 via plasma jet 402 or linear flow 452, it is to be understood that embodiments disclosed herein encompass embodiments in which the plasma stream is directed toward second major surface 164 of glass sheet 62 via plasma jet 402 or linear flow 452, such as embodiments in which the plasma stream is directed toward both first major surface 162 and second major surface 164 of glass sheet 62. For example, embodiments disclosed herein include embodiments in which the plasma stream is directed toward first major surface 162 and second major surface 164 of glass sheet 62 simultaneously or separately via an atmospheric plasma jet or an atmospheric linear stream.

In certain exemplary embodiments, at least one of first major surface 162 and second major surface 164 can be heated, such as by a resistive heater or an inductive heater, to a temperature of at least about 100 ℃, such as at least about 200 ℃, and further such as at least about 300 ℃, and yet further such as at least about 400 ℃, and yet further such as at least about 500 ℃, including a temperature range from about 100 ℃ to about 600 ℃, prior to directing the plasma stream toward the major surfaces. Exemplary embodiments also include embodiments wherein the temperature of the primary surface is maintained within the above range for a period of time after directing the plasma stream toward the primary surface.

In certain exemplary embodiments, the plasma via plasma jet 402 or linear flow 452 comprises at least one component, such as at least two components, and further such as at least three components, selected from the group consisting of: nitrogen, argon, oxygen, helium and CDA, which are excited and at least partially converted into a plasma state. In certain exemplary embodiments, the plasma comprises nitrogen and at least one component selected from the group consisting of: argon, oxygen, helium and CDA. In certain exemplary embodiments, the plasma includes nitrogen and at least one component selected from argon and helium.

In certain exemplary embodiments, the plasma via plasma jet 402 or linear flow 452 comprises at least about 80 mol% nitrogen, such as at least from about 80 mol% to about 100 mol% nitrogen, and further such as from about 85 mol% to about 95 mol% nitrogen. In certain exemplary embodiments, the plasma comprises at least about 80 mol% nitrogen and at least 2 mol% (e.g., at least 5 mol%) of at least one component selected from the group consisting of: argon, oxygen, helium and CDA. In certain exemplary embodiments, the plasma comprises at least about 80 mol% nitrogen and at least 2 mol% (e.g., at least 5 mol%) of at least one component selected from the group consisting of: argon and helium.

In certain exemplary embodiments, the plasma via plasma jet 402 or linear flow 452 is substantially free of components known to those skilled in the art to substantially etch glass, such as substantially free of acid etchants. In certain exemplary embodiments, the plasma via the plasma jet 402 or the linear flow 452 is substantially free of fluorine, including any fluorine-containing compounds. For example, embodiments disclosed herein include embodiments wherein the plasma via plasma jet 402 or linear flow 452 is substantially free of HF, CF4, and SF 6.

Directing the plasma stream toward first major surface 162 via plasma jet 402 or linear stream 452 according to embodiments herein may reduce the absolute measured voltage on the first major surface by at least about 35%, such as at least about 40%, and further such as at least about 50%, and still further such as at least about 100% as compared to a glass surface that has not been subjected to plasma treatment.

For example, directing a plasma stream toward first major surface 162 via plasma jet 402 or linear stream 452 in accordance with embodiments herein may result in an absolute measured voltage on first major surface 162 of less than about 0.25kV, such as less than about 0.20kV, and further such as less than about 0.15kV, and yet further such as less than about 0.10kV, and yet further such as less than about 0.05kV, including from about 0kV to about 0.25kV, and further including from about 0.05kV to about 0.20kV, and still further including from about 0.10kV to about 0.15 kV.

Moreover, directing the plasma stream toward the first major surface 162 via the plasma jet 402 or the linear stream 452 according to embodiments herein may change the average surface roughness Ra of the first major surface by less than about 20%, such as less than about 15%, and further such as less than about 10%, and still further such as less than about 5%, including from about 0% to about 20%, and further including from about 5% to about 15%.

For example, directing the plasma stream toward the first major surface 162 via the plasma jet 402 or the linear stream 452 according to embodiments herein may result in an average surface roughness Ra of the first major surface 162 of less than about 0.3nm, such as less than about 0.25nm, including from about 0.15nm to about 0.3nm, and further including from about 0.20nm to about 0.25 nm.

Examples of the invention

Embodiments herein are further illustrated with reference to the following non-limiting examples:

example 1

Eagle having a thickness of about 0.5 mm and first and second major surface dimensions of about 100 mm by atmospheric pressure plasma jet or by linear atmospheric pressure plasma jet as set forth in Table 1Samples of the glass sheet were subjected to major surface treatment. Prior to atmospheric plasma surface treatment, each sample was washed with an aqueous solution containing about 2.5 wt% of a Parker250 or Semiclean KG detergent available from Parker Hannifin, followed by six rapid rinses (QDR) in deionized water.

Each sample having a major surface treated by an atmospheric pressure plasma jet (referred to as a "jet" in table 1) was scanned in a manner similar to that depicted in fig. 4, wherein the plasma jet scan speed was about 100 millimeters per second, the frequency of the ac power source was about 50KHz, and the power ranged from about 500 watts to about 650 watts.

Each sample having a major surface treated by a linear atmospheric pressure plasma stream (referred to as "linear" in table 1) was scanned in a manner similar to that depicted in fig. 6, with a scan speed of about 30 millimeters per second, four scans per sample, using a 13.56MHz power supply, and a power range from about 550 watts to about 650 watts.

The gap distance (referred to as "gap" in table 1) was allowed to vary for various processes, as was also allowed for the plasma composition and flow rate in standard liters per minute (SLM) as reported in table 1.

Voltage Measurement Technique (VMT)

The measured voltage on the major surface of each treated sample was determined using a Voltage Measurement Technique (VMT), wherein each sample was separated from a stainless steel vacuum stage that applied a relative negative pressure of about 20Pa and had at least the same surface area as the treated surface of the sample at a separation rate of about 10 millimeters per second. Once the sample was separated from the vacuum stage by a distance of about 80 mm, voltage measurements were taken at a distance of about 1 inch from the sample using a Monroe Electronics electrostatic field apparatus. This measurement is referred to as V80 in table 1. After this measurement, the 80 mm distance between the sample and the vacuum table was maintained, and a second measurement, referred to in table 1 as vtable, was made after approximately 1 minute.

The results of the processing are set forth in table 1 (where the absolute measured voltage is the absolute value of each measured voltage listed in the table). Untreated Eagle

The glass control samples were also subjected to VMT as described above and had a major surface measurement voltage of about-0.35 kV (corresponding to a major surface absolute measurement voltage of about 0.35 kV).

TABLE 1

Although the above embodiments have been described with reference to a fusion down-draw process, it should be understood that the above embodiments may also be applied to other glass forming processes, such as float processes, orifice-draw processes, up-draw processes, tube-draw processes, and roller processes.

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