System and method for making glass sheets

Abstract

A system and method to make glass sheets that include a vertical electric melter, which causes a cold crown of batch materials over the molten glass to form, and a pair of forming rollers to form a ribbon of glass in a vertical orientation from the molten glass. The system and method further include at least one texturing roller to impart texture to the ribbon of glass. The ribbon of glass can be separated into glass sheets, which can be used as single wide solar cover glass sheet with texture on one or both primary surfaces and as-formed edges. The as-formed edges are stronger than the edges of conventionally manufactured sheets which are normally cut and ground and polished. The system and method can form relatively thin glass sheets from a wide variety of glass and glass ceramic compositions with viscosity curves steeper than conventional solar glass compositions.

Description

SYSTEM AND METHOD FOR MAKING GLASS SHEETSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63 / 638,667 filed April 25, 2024, the content of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The disclosure relates to a system and a method for making glass sheets, and in particular, glass cover sheets to cover photovoltaic cells in solar panels.BACKGROUND

[0003] Solar panels include photovoltaic cells that utilize photons from the Sun to generate electricity. In addition to the photovoltaic cells, the solar panels typically include a cover sheet over the photovoltaic cells. The cover sheet is substantially transparent to photons associated with wavelengths useful for the photovoltaic cells. The cover sheet is sometimes made of glass. A Sun-facing surface of the glass cover sheet is sometimes textured to reduce reflectance off, and increase transmittance through, the glass cover sheet.

[0004] Such glass cover sheets are typically made from a float glass process. The float glass process typically includes melting raw materials (e.g., sand, soda ash, and lime dolomite) in a furnace where heat is generated by combustion of natural gas to convert the raw materials into molten glass and delivering the molten glass onto a bed of molten tin. The molten glass spreads out on the molten tin, cools, and solidifies into a large glass sheet. The large glass sheet is then scored and separated into the glass cover sheets. A primary surface of the glass cover sheet is then textured, as mentioned, through processes such as chemical etching.

[0005] However, the float glass process used to make the glass cover sheets presents numerous problems. First, the combustion of natural gas to heat the batch materials in the furnace generates a suboptimal amount of carbon byproducts. Second, the raw materials are typically heated via conduction from combusted natural gas (e.g., flames) located above the batch of raw materials, which entails suboptimal heat transfer and thus suboptimal energy efficiency. Third, some glass compositions, which may otherwise be beneficial for glass cover sheet applications, are not suitable for the float glass process. Rather, typically only soda lime glass compositions are suitable for the float glass process, which is also problematic because soda lime glass has a suboptimally high melting point and includes sodium ions, which cause potential induced degradation of the very photovoltaic cells that thecover glass is supposed to protect. Fourth, absent other processing steps, glass sheets made via the float glass process have a thickness of 6.9 mm (e.g., equilibrium thickness), which is suboptimally thick. Fifth, lateral edges of the glass cover sheets are formed via scoring, which reduces the strength of the glass cover sheets at the lateral edges. Sixth, equipment necessary to perform the float glass process occupies a suboptimal amount of space (e.g., a long linear space). Seventh, the float glass industry requires use of an inert atmosphere to prevent tin oxidation which can be an added cost for the structural build (positive pressure environment) and maintenance of the process. Eighth, the secondary process to chemically etch the primary surface of the glass cover sheet takes a suboptimal amount of time and additional cost to perform.SUMMARY

[0006] The present disclosure addresses those problems with a system and method to make glass sheets that include a vertical electric melter, which causes a cold crown of batch materials over the molten glass to form, and a pair of forming rollers to form a ribbon of glass in a vertical orientation from the molten glass. The system and method further include at least one texturing roller to impart texture to the ribbon of glass.

[0007] According to a first aspect of the present disclosure, a system for making a glass sheet comprises: (1) a vertical electric melter configured to melt batch materials and form molten glass from the batch materials; (2) a pair of forming rollers establishing a nip between the pair of forming rollers, the pair of forming rollers configured (a) to rotate toward each other about parallel axes of rotation and (b) to manipulate the molten glass at the nip into a ribbon of glass extending in a vertical orientation downward from the molten glass at the nip; (3) a delivery system configured to deliver the molten glass from the vertical electric melter to the nip of the pair of forming rollers, from above the nip; (4) a conveyor disposed elevationally below the pair of forming rollers, the conveyer configured to convey the ribbon of glass away from a vertical plane extending between the pair of forming rollers; (5) an air turn assembly disposed elevationally below the pair of forming rollers, the air turn assembly configured to guide the ribbon of glass from the vertical orientation to a horizontal orientation on the conveyor; (6) at least one texturing roller configured to cause embossing of a texture onto one or more of a first primary surface and a second primary surface of the ribbon of glass; (7) at least one of (a) a pinch roller configured to form a pinch line across a width of the ribbon of glass and into a thickness of the ribbon of glass (b) (i) a scribe wheel positioned and configured to move diagonally relative to lateral edges of the ribbon of glass while the ribbonof glass is on the conveyor and thereby impart a score into the ribbon of glass and (ii) an element configured to cause separation of a glass cover sheet from the ribbon of glass at the score; and (8) at least one of (a) a grinder and polisher positioned to grind and to polish edges of the glass cover sheet formed via separation or (b) flame emitters positioned to direct a flame to edges of the glass cover sheet formed via separation.

[0008] According to a second aspect of the present disclosure, the system of the first aspect is presented, wherein the delivery system further comprises a forehearth configured to achieve and maintain a desired temperature of the molten glass from the vertical electric melter before the molten glass is delivered to the center nip between the pair of forming rollers.

[0009] According to a third aspect of the present disclosure, the system of any one of the first through second aspects is presented, wherein the delivery system comprises (i) a fish tail slot disposed elevationally above the nip of the pair of forming rollers and (ii) a screw feeder positioned to regulate flow rate of the molten glass into the fish tail slot.

[0010] According to a fourth aspect of the present disclosure, the system of any one of the first through third aspects is presented, wherein the delivery system comprises more than one fish tail slot disposed elevationally above the nip of the pair of forming rollers.

[0011] According to a fifth aspect of the present disclosure, the system of any one of the first through fourth aspects is presented, wherein the delivery system comprises a fish tail slot comprising (i) an outlet that is elongated having a length of greater than 0.7 meters disposed elevationally above the nip of the pair of forming rollers and (ii) more than one inlet into the fish tail slot.

[0012] According to a sixth aspect of the present disclosure, the system of any one of the first through second aspects is presented, wherein the delivery system comprises a fusion forming apparatus with a trough to receive the molten glass, opposing walls at least partially defining the trough and comprising outer side surfaces, and a root where the outer side surfaces converge, the root disposed elevationally above the nip of the pair of forming rollers.

[0013] According to a seventh aspect of the present disclosure, the system of the sixth aspect is presented, wherein the root of the fusion forming apparatus is disposed elevationally below a second horizonal plane tangential to outer surfaces of both of the pair of forming rollers and elevationally above a horizontal plane extending through the axes of rotation of the pair of forming rollers.

[0014] According to an eighth aspect of the present disclosure, the system of any one of the first through the seventh aspects further comprises a pair of sizing rollers, which include theat least one texturing roller, disposed elevationally below the pair of forming rollers and elevationally above the conveyer, the pair of sizing rollers separated by a gap through which the vertical plane extends.

[0015] According to a ninth aspect of the present disclosure, the system of the eighth aspect is presented, wherein the pair of sizing rollers are further configured to reduce a thickness of the ribbon of glass between the first primary surface and the second primary surface thereof.

[0016] According to a tenth aspect of the present disclosure, the system of any one of the first through ninth aspects is presented, wherein the at least one texturing roller is positioned above the conveyer and configured to apply force to the ribbon of glass while the conveyor is conveying the ribbon of glass to emboss the texture onto the ribbon of glass.

[0017] According to an eleventh aspect of the present disclosure, the system of the tenth aspect is presented, wherein the conveyor includes ceramic molds that are conveyed with the ribbon of glass, with the ceramic molds disposed under the ribbon of glass, and the texture embossed onto the ribbon of glass comes from at least one of the ceramic molds.

[0018] According to a twelfth aspect of the present disclosure, the system of any one of the first through eleventh aspects further comprises a pair of rollers, one of which is the pinch roller, disposed elevationally below the pair of forming rollers and separated by a gap through which the vertical plane extends.

[0019] According to a thirteenth aspect of the present disclosure, the system of any one of the first through twelfth aspects is presented, wherein the pinch roller is disposed above the conveyer and positioned to impart the pinch line into the ribbon of glass while the ribbon of glass is in the horizontal orientation on the conveyor.

[0020] According to a fourteenth aspect of the present disclosure, the system of any one of the first through thirteenth aspects is presented, wherein the pinch roller is configured to form the pinch line into the ribbon of glass while rolling across the width of the ribbon of glass.

[0021] According to a fifteenth aspect of the present disclosure, the system of any one of the first through fourteenth aspects further comprises a width measurer disposed elevationally below the pair of forming rollers but elevationally above the conveyor, the width measurer configured to generate output from which the width of the ribbon of glass can be determined.

[0022] According to a sixteenth aspect of the present disclosure, the system of any one of the first through fifteenth aspects further comprises an edge forming roller positioned above the conveyer, the edge forming roller comprising two blades separated by a distance and positioned to impart a thin pinch into the ribbon of glass to redefine the lateral edges of theribbon of glass and to narrow the width of the ribbon of glass while the conveyer is conveying the ribbon of glass.

[0023] According to a seventeenth aspect of the present disclosure, the system of any one of the first through sixteenth aspects further comprises a temperature controlled lehr configured to heat treat the glass cover sheet.

[0024] According to an eighteenth aspect of the present disclosure, the system of any one of the first through seventeenth aspects further comprises a roller hearth furnace configured to heat treat the glass cover sheet while the conveyor is conveying the glass cover sheet.

[0025] According to a nineteenth aspect of the present disclosure, a method of forming a glass cover sheet comprises: (a) a melting step comprising melting, in a vertical electric melter, batch materials to form molten glass; (b) a delivering step comprising delivering the molten glass vertically to a nip of a pair of forming rollers from above the pair of forming rollers; (c) a ribbon forming step comprising rotating the pair of forming rollers to form a ribbon of glass from the molten glass, the ribbon of glass (i) extending substantially vertically below the nip, (ii) comprising a first primary surface and a second primary surface, and (iii) further comprising lateral edges and a width between the lateral edges; (d) a texturing step comprising embossing a first texture onto one or both of the first primary surface and the second primary surface; (e) a reorienting step comprising guiding the ribbon of glass from a vertical orientation to a horizontal orientation upon a conveyor that pulls the ribbon of glass away from a vertical plane extending between the pair of forming rollers; (f) a separating step comprising separating a glass cover sheet from the ribbon of glass, the glass cover sheet comprising lateral edges, a forward edge orthogonal to the lateral edges, and a rear edge orthogonal to the lateral edges; and (g) a polishing step comprising either (i) grinding and then polishing the forward edge and the rear edge of the glass cover sheet or (ii) contacting the forward edge and the rear edge of the glass cover sheet with a flame, wherein, the melting step, the delivering step, the ribbon forming step, the texturing step, the reorienting step, the separating step, and the polishing step occur simultaneously in an extended batch or continuous process resulting in numerous of the glass cover sheet being separated from the ribbon of glass.

[0026] According to a twentieth aspect of the present disclosure, the method of the nineteenth aspect is presented, wherein during the melting step, at least a portion of the batch materials forms a cold crown over the molten glass.

[0027] According to a twenty-first aspect of the present disclosure, the method of the twentieth aspect is presented, wherein during the melting step, additional batch materials are delivered onto the cold crown within the vertical electric melter.

[0028] According to a twenty-second aspect of the present disclosure, the method of any one of the nineteenth through twenty-first aspects is presented, wherein the molten glass comprises a composition (on an oxide basis) that is substantially free of Na2O.

[0029] According to a twenty-third aspect of the present disclosure, the method of any one of the nineteenth through twenty-second aspects is presented, wherein during the delivering step, the molten glass is delivered into a fish tail slot via more than one input tube.

[0030] According to a twenty-fourth aspect of the present disclosure, the method of any one of the nineteenth through twenty -third aspects is presented, wherein during the delivering step, a screw feeder regulates a flow rate of the molten glass into a fish tail slot and the molten glass is delivered to the nip through the fish tail slot.

[0031] According to a twenty-fifth aspect of the present disclosure, the method of any one of the nineteenth through twenty -fourth aspects is presented, wherein during the delivering step, the molten glass is delivered to the nip through more than one fish tail slot.

[0032] According to a twenty-sixth aspect of the present disclosure, the method of any one of the nineteenth through twenty-fifth aspects is presented, wherein during the delivering step, the molten glass forms a contact angle of less than 45 degrees with both of the pair of forming rollers relative to a horizontal plane that extends through both axes of rotation of the pair of forming rollers.

[0033] According to a twenty-seventh aspect of the present disclosure, the method of any one of the nineteenth through twenty-sixth aspects is presented, wherein during the delivery step, the molten glass is delivered first into a trough of a fusion forming apparatus, the molten glass overflows opposing walls of the trough, down outer side surfaces of the opposing walls, and converges at a root, and then flows down into the nip between the pair of forming rollers.

[0034] According to a twenty-eighth aspect of the present disclosure, the method of the twenty-seventh aspect is presented, wherein the root is disposed elevationally below a horizonal plane tangential to both of the pair of forming rollers and elevationally above a horizontal plane extending through the axes of rotation of the pair of forming rollers.

[0035] According to a twenty-ninth aspect of the present disclosure, the method of any one of the nineteenth through the twenty-eighth aspects further comprises a pre-delivery thermal conditioning step comprising, after the melting step and before the delivering step, raising orlowering a temperature of the molten glass from the vertical electric melter in a forehearth before the molten glass is delivered to the nip between the pair of forming rollers.

[0036] According to a thirtieth aspect of the present disclosure, the method of any one of the nineteenth through the twenty-ninth aspects further comprises a sizing step, which occurs after the ribbon forming step and before the texturing step, comprising rotating a pair of sizing rollers and contacting the ribbon of glass while the ribbon of glass is vertically oriented between the pair of sizing rollers and thereby decreasing a thickness of the ribbon of glass.

[0037] According to a thirty-first aspect of the present disclosure, the method of any one of the nineteenth through the thirtieth aspects is presented, wherein the texturing step further comprises rotating a pair of sizing rollers, at least one of which is a texturing roller, disposed below the pair of forming rollers while the ribbon of glass proceeds vertically downward between the pair of forming rollers, and the pair of sizing rollers contact the first primary surface and the second primary surface of the ribbon of glass and thereby emboss the first texture onto one or both of the first primary surface and the second primary surface.

[0038] According to a thirty-second aspect of the present disclosure, the method of the thirty- first aspect is presented, wherein the pair of sizing rollers additionally reduce a thickness of the ribbon of glass while embossing the first texture onto the ribbon of glass.

[0039] According to a thirty-third aspect of the present disclosure, the method of any one of the nineteenth through thirty-second aspects is presented, wherein the texturing step further comprises conveying the ribbon of glass upon the conveyor between a texturing roller and a conveyor surface, and the texture roller rotates and contacts the ribbon of glass with force sufficient to emboss the first texture, from one or both of the conveyor surface and the texturing roller, onto one or both of the first primary surface and the second primary surface of the ribbon of glass.

[0040] According to a thirty-fourth aspect of the present disclosure, the method of the thirty- third aspect is presented, wherein a ceramic mold of the conveyor embosses the first texture onto the second primary surface of the ribbon of glass.

[0041] According to a thirty-fifth aspect of the present disclosure, the method of any one of the nineteenth through thirty-fourth aspects is presented, wherein the first texture of the ribbon of glass is a repeating pattern of features having a largest dimension of less than 600 pm and a depth of less than 600 pm.

[0042] According to a thirty-sixth aspect of the present disclosure, the method of any one of the nineteenth through thirty-fifth aspects is presented, wherein the first texture of the glasscover sheet is a repeating pattern of features having a largest dimension of less than 600 pm and a depth of less than 20 pm.

[0043] According to a thirty-seventh aspect of the present disclosure, the method of any one of the nineteenth through thirty-sixth aspects is presented, wherein during the reorienting step, an air turn assembly provides an air bearing surface to precisely control reorientation of the ribbon of glass from the vertical orientation to the horizontal orientation without marking the glass.

[0044] According to a thirty-eighth aspect of the present disclosure, the method of any one of the nineteenth through thirty-seventh aspects further comprises a second texturing step occurring after the reorienting step comprising conveying the ribbon of glass upon the conveyor between a texturing roller and the conveyor, and the texturing roller rotates and contacts the ribbon of glass with force sufficient to emboss a second texture, from one or both of a ceramic mold and the texturing roller, onto one or both of the first primary surface and the second primary surface of the ribbon of glass.

[0045] According to a thirty-ninth aspect of the present disclosure, the method of the thirtyeighth aspect is presented, wherein the second texture is embossed over the first texture.

[0046] According to a fortieth aspect of the present disclosure, the method of any one of the nineteenth through thirty-ninth aspects further comprises a measuring step comprising determining the width of the ribbon of glass.

[0047] According to a forty-first aspect of the present disclosure, the method of the fortieth aspect is presented, wherein rotational speed of the pair of forming rollers during the ribbon forming step is controlled as a function of the measured width of the ribbon of glass during the measuring step.

[0048] According to a forty-second aspect of the present disclosure, the method of any one of the fortieth through forty-first aspects is presented, wherein a width measurer generates output from which the width of the ribbon of glass is determined during the measuring step.

[0049] According to a forty-third aspect of the present disclosure, the method of any one of the nineteenth through forty-second aspects further comprises an edge separating step, which occurs after the reorienting step but before the separating step, comprising conveying the ribbon of glass under an edge forming roller with two blades separated by a distance, which manipulats the ribbon of glass to redefine the lateral edges of the ribbon of glass and to narrow the width of the ribbon of glass.

[0050] According to a forty-fourth aspect of the present disclosure, the method of any one of the nineteenth through forty-third aspects is presented, wherein the width of the ribbon of glass is greater than or equal to 1 meter.

[0051] According to a forty-fifth aspect of the present disclosure, the method of any one of the nineteenth through forty-fourth aspects is presented, wherein (i) the separating step further comprises reducing a thickness of the ribbon of glass across the width of the ribbon of glass at a pinch line, and (ii) separation of the glass cover sheet from the ribbon of glass occurs at the pinch line spontaneously as the ribbon of glass cools.

[0052] According to a forty-sixth aspect of the present disclosure, the method of the fortyfifth aspect is presented, wherein a pair of rollers, at least one of which is a pinch roller, between which the ribbon of glass moves while the ribbon of glass is vertically oriented, form the pinch line into the ribbon of glass.

[0053] According to a forty-seventh aspect of the present disclosure, the method of the fortyfifth aspect is presented, wherein a pinch roller forms the pinch line into the ribbon of glass by rolling across the width of the ribbon of glass while the ribbon of glass is horizontally oriented and being conveyed.

[0054] According to a forty-eighth aspect of the present disclosure, the method of any one of the nineteenth through forty -fifth aspects is presented, wherein the separating step further comprises forming a score into the ribbon of glass across the width of the ribbon of glass and applying a force that causes separation of the glass cover sheet from the ribbon of glass.

[0055] According to a forty-ninth aspect of the present disclosure, the method of the fortyeighth aspect is presented, wherein the forming of the score into the ribbon of glass occurs while the ribbon of glass is disposed on the conveyor and in the horizontal orientation, and the score is generated with a scribe wheel that moves diagonally relative to the lateral edges of the ribbon of glass while the ribbon of glass is being conveyed.

[0056] According to a fiftieth aspect of the present disclosure, the method of any one of the nineteenth through the forty-ninth aspects further comprises a post-separation thermal conditioning step comprising, after the separating step, thermally treating the glass cover sheet.

[0057] According to a fifty-first aspect of the present disclosure, the method of fiftieth aspect is presented, wherein the post-separation thermal conditioning step occurs in a lehr offline from the conveyor.

[0058] According to a fifty-second aspect of the present disclosure, the method of the fiftieth aspect is presented, wherein the post-separation thermal conditioning step occurs in a roller hearth furnace and the conveyor conveys the glass cover sheet to the roller hearth furnace.

[0059] According to a fifty-third aspect of the present disclosure, the method of any one of the nineteenth through fifty-second aspects is presented, wherein the lateral edges of the glass cover sheet are the lateral edges of the ribbon of glass from which the glass cover sheet was separated during the separating step.

[0060] According to a fifty-fourth aspect of the present disclosure, the method of any one of the nineteenth through fifty-third aspects is presented, wherein the glass cover sheet further comprises a width between the parallel lateral edges of the glass cover sheet, and the width is greater than or equal to 1 m.

[0061] According to a fifty-fifth aspect of the present disclosure, the method of any one of the nineteenth through fifty-fourth aspects is presented, wherein (i) the glass cover sheet further comprises a first primary surface, a second primary surface, and a thickness between the first primary surface and the second primary surface, and (ii) the thickness of the glass cover sheet is less than 2.0 mm.

[0062] According to a fifty-sixth aspect of the present disclosure, the method of the fifty-fifth aspect is presented, wherein the thickness of the glass cover sheet is less than 0.5 mm.

[0063] According to a fifty-seventh aspect of the present disclosure, the method of any one of the nineteenth through fifty-sixth aspects further comprises an assembling step comprising assembling the glass cover sheet over one or more photovoltaic cells to form a solar panel.

[0064] Additional features and advantages 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 embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0065] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary and are intended to provide an overview or framework to understanding the nature and character of the claims.

[0066] The accompanying drawings are included to provide a further understanding of principles of the disclosure, and are incorporated in, and constitute a part of, this specification. The drawings illustrate one or more embodiments and, together with the description, serve to explain, by way of example, principles and operation of the disclosure. It is to be understood that various features of the disclosure disclosed in this specification andin the drawings can be used in any and all combinations. By way of non-limiting examples, the various features of the disclosure may be combined with one another according to the following embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The following is a description of the figures in the accompanying drawings. The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

[0068] FIG. l is a schematic diagram of a system of the present disclosure for making a glass sheet, illustrating components such as a vertical electric melter, a pair of forming rollers, a pair of sizing rollers including a texturing roller, a pinch roller, and a conveyor, among other components;

[0069] FIG. 2 is an elevational view of a cross-section of the vertical electric melter, illustrating that molten glass therein forms a cold crown of batch materials over the molten glass;

[0070] FIG. 3 is an elevational view of molten glass from the vertical electric melter being fed to a nip between the pair of forming rollers and the pair of forming rollers forming a ribbon of glass (in a molten or viscoelastic state) from the molten glass;

[0071] FIG. 4 is an elevational view similar to FIG. 3 but further illustrating the pair of sizing rollers further reducing thickness of the ribbon of glass received from the pair of forming rollers and a pair of rollers including the pinch roller with a pinch edge to form a pinch line into the ribbon of glass;

[0072] FIG. 5 is a perspective view of the pair of forming rollers, the pair of sizing rollers, and the pair of rollers with the pinch roller all manipulating the ribbon of glass while the ribbon of glass is in a vertical orientation;

[0073] FIG. 6 is a perspective view of embodiments of the system, illustrating a forehearth disposed in molten glass communication between the vertical electric melter and the pair of forming rollers, a screw feeder regulating the flow rate of molten glass fed to the pair of forming rollers, and a glass sheet on the conveyor having separated from the ribbon of glass at the pinch line, while the ribbon of glass is in a horizontal orientation on the conveyor;

[0074] FIG. 7 is an elevational view of an embodiment of components of the system illustrating multiple fish tail slots in molten glass communication with the forehearth to distribute molten glass to the pair of forming rollers with improved temperature consistency;

[0075] FIG. 8 is an elevational view of an embodiment of components of the system, illustrating a fish tail slot with multiple inlets and an outlet that is elongated to distribute molten glass to the pair of forming rollers with improved temperature consistency along the length of the pair of forming rollers;

[0076] FIG. 9 is a perspective view of an embodiment of components of the system, illustrating a fusion forming apparatus to deliver molten glass to the pair of forming rollers instead of the fish tail slot;

[0077] FIG. 10 is an elevational view of embodiments of components of the system, illustrating the fusion forming apparatus delivering molten glass in the form of an initial glass ribbon to the nip of the pair of forming rollers, which widens and thins the initial glass ribbon into the ribbon of glass that is further thinned and textured by the pair of sizing rollers (which include a texturing roller), all while the ribbon of glass is in the vertical orientation;

[0078] FIG. 10A is an elevational view of an embodiment of the fusion forming apparatus, illustrating a direct fired extension tip providing a root of the fusion forming apparatus closer to the nip between the pair of forming rollers and heat shields between an isopipe of the fusion forming apparatus and the pair of forming rollers;

[0079] FIG. 11 is an elevational view of embodiments of components of the system with the pair of forming rollers, the pair of sizing rollers, and the pair of rollers with the pinch roller all disposed above the conveyor, with a vertical plane extending therethrough, and the conveyor positioned to move the ribbon of glass and the glass sheet separated therefrom away from the vertical plane;

[0080] FIG. 12 is a perspective view of embodiments of components of the system, illustrating the texturing roller of the pair of sizing rollers including texturing features that emboss the features onto the ribbon of glass as the pair of sizing rollers manipulate the ribbon of glass;

[0081] FIG. 13 is an elevational view of embodiments of components of the system, illustrating the fusion forming apparatus feeding the molten glass to the pair of forming rollers and the pair of sizing rollers with the texturing roller embossing the texture onto the ribbon of glass;

[0082] FIG. 14 is a perspective view of an embodiment of the pair of sizing rollers, one of which is a texturing roller with texturing features on the outer surface thereof to emboss the texture onto the ribbon of glass while in the vertical orientation;

[0083] FIG. 15 is a schematic diagram of the texturing roller, instead of being of the pair of sizing rollers, disposed above the conveyor and imparts the texture onto the ribbon of glass, while the ribbon of glass is in the horizontal orientation moving down the conveyor, either directly from the ribbon of glass or from ceramic molds disposed under the ribbon of glass on the conveyor (or both);

[0084] FIG. 16 is a perspective view of one of the ceramic molds, which can have texturing features to emboss onto the ribbon of glass or not, that travels along the conveyor under the ribbon of glass;

[0085] FIG. 17 is a schematic diagram of embodiments of components of the system, illustrating the pinch roller disposed above the conveyor to form the pinch line into the ribbon of glass while the ribbon of glass is in the horizontal orientation on the conveyor;

[0086] FIG. 17A is a schematic diagram of embodiments of components of the system, illustrating again the pinch roller disposed above the conveyor to form the pinch line into the ribbon of glass while the ribbon of glass is in the horizontal orientation on the conveyor and the conveyor further including a series of ceramic coated rollers;

[0087] FIG. 18 is a schematic diagram of embodiments of components of the system, illustrating the pinch roller having an axis of rotation that permits the pinch roller to form the pinch line into the ribbon of glass by rolling on a diagonal path from one lateral edge of the ribbon of glass to the other lateral edge of the ribbon of glass;

[0088] FIG. 19 is a perspective view of embodiments of components of the system, illustrating, instead of a pinch roller, a scribe wheel positioned to score the ribbon of glass from above the conveyor while the ribbon of glass is in the horizontal orientation;

[0089] FIG. 20 is an elevational view of embodiments of the conveyor of the system, illustrating the conveyor including the ceramic molds that travel with the ribbon of glass and a positive pressure actuator to push down on a texturing or thin pinch roller that operates on the ribbon of glass in embodiments where the ribbon of glass is either thin pinched for part separation or textured;

[0090] FIG. 21 is a perspective view of an edge finishing module of the system, illustrating the edge finishing module including flame emitters positioned along the conveyor to contact forward and rearward edges of the glass sheet formed via separation from the ribbon of glass with flames;

[0091] FIG. 22 is a perspective view an edge forming roller of the system, illustrating the edge forming roller including blades separated by a distance and configured to rotate whilethe ribbon of glass is on the conveyor in the horizontal orientation and impart a pinch line orthogonal to the width of the ribbon of glass, which separates thereat upon cooling to narrow the lateral edges of the ribbon of glass;

[0092] FIG. 23 is a perspective view of a heat treatment module of the system, illustrating the heat treatment module including a roller hearth furnace positioned to accept the glass sheets from the conveyor to heat treat (e.g., anneal) the glass sheets;

[0093] FIG. 24 is a flow chart of a method of the present disclosure to form the glass sheets, illustrating a melting step, a ribbon forming step, a texturing step, a reorienting step, and a separating step, among others;

[0094] FIG. 25 is an elevational view of a solar panel, illustrating the solar panel including the glass sheet made via the system and the method of the present disclosure, with the glass sheet covering photovoltaic cells and a frame holding the glass sheet and the photovoltaic cells together;

[0095] FIG. 26, pertaining to Example 1, reproduces atomic force microscopy images of the texture imparted onto the glass sheet made via the system and the method of the present disclosure;

[0096] FIG. 27, pertaining to Example 2, reproduces images of texturing features of a texturing roller and the features of the texture embossed onto the glass sheet;

[0097] FIG. 28, pertaining to Example 3, reproduces images of texturing features of a texturing roller and the features of the texture embossed onto the glass sheet;

[0098] FIG. 29, pertaining to Example 4, reproduces images of texturing features of a texturing roller, including a magnified image showing the texturing feature more closely, and the ribbon of glass on the conveyor having been textured at a first primary surface thereof;

[0099] FIG. 30, pertaining to Example 5, is a schematic diagram illustrating the pair of forming rollers, the pair of sizing rollers (neither of which is a texturing roller) below the pair of forming rollers, a pair of texturing rollers disposed below the pair of sizing rollers, and the pinch roller disposed above the conveyor;

[0100] FIG. 31, pertaining to Example 6, is a schematic diagram illustrating the pair of forming rollers, the pair of sizing rollers (one of which is a texturing roller) below the pair of forming rollers, and the pinch roller disposed above the conveyor;

[0101] FIG. 32, pertaining to Example 7, is a schematic diagram illustrating the pair of forming rollers, the pair of sizing rollers (one of which is a texturing roller) below the pair of forming rollers, and the pair of texturing rollers (one or both having texture to impart)positioned to impart texture onto the ribbon of glass while the ribbon of glass is in the horizontal orientation;

[0102] FIG. 33, pertaining to Example 8, is a schematic diagram illustrating the pair of forming rollers, the pair of sizing rollers (neither of which is a texturing roller) below the pair of forming rollers, a pair of rollers (one of which is the pinch roller) below the pair of sizing rollers, and a texturing roller disposed above the ceramic molds of the conveyor positioned to impart texture onto the ribbon of glass while the ribbon of glass is in the horizontal orientation;

[0103] FIG. 34, pertaining to Example 9, is an image of a glass sheet made from the system and method of the present disclosure including the edge forming roller to narrow the lateral edges of the ribbon of glass from which the glass sheet was separated;

[0104] FIG. 35, pertaining to Example 10, is an image of a ribbon of glass made from the system and method of the present disclosure including the pinch line and a texture thereon; and

[0105] FIG. 36, pertaining to Example 11, reproduces images of one of the lateral edges of the glass sheet (inherited from the ribbon of glass) made from the system and the method of the present disclosure (left images), the forward or rearward edge of the glass sheet after separation from the ribbon of glass at the pinch line (top right), and the forward or rearward edge of the glass sheet after being contacted with a flame (bottom right).DETAILED DESCRIPTION

[0106] Additional features and advantages will be set forth in the detailed description which follows and will be apparent to those skilled in the art from the description, or recognized by practicing the embodiments as described in the following description, together with the claims and appended drawings.

[0107] Referring to FIG. 1, a system 10 for making a glass sheet 12 is herein described. The system 10 includes a vertical electric melter 14, a pair of forming rollers 16, 18 a delivery system 20, at least one texturing roller 22, a conveyor 24, and an air turn assembly 26.

[0108] Referring additionally to FIG. 2, the vertical electric melter 14 is configured to melt batch materials 28 and form molten glass 30 from the batch materials 28. For example, the vertical electric melter 14 includes a sidewall 32 and a bottom wall 34, which contain the batch materials 28 and the molten glass 30 therein. In addition, the vertical electric melter 14 includes one or more batch electrodes 36 and a distributor 38. The distributor 38 distributesthe batch materials 28 necessary to form the molten glass 30 of the desired composition. The batch materials 28 are converted into the molten glass 30. The batch materials 28 can include cullet. The one or more batch electrodes 36 carry electrical current that is resisted and thereby generates heat that raises the batch materials 28 to the temperature sufficient to form the molten glass 30. At least a portion of the batch materials 28 forms a cold crown 40 over the molten glass 30, through which the one or more batch electrodes 36 extend into the molten glass 30. As the molten glass 30 is withdrawn from the vertical electric melter 14 at an outlet 42, the distributor 38 adds additional of the batch materials 28 onto the cold crown 40. A fusion line 44 represents the boundary between the molten glass 30 and the cold crown 40 (sometimes referred to as a batch blanket). That is, the fusion line 44 is in fact both the top surface of the molten glass 30, and the bottom of the cold crown 40. The fill rate of the batch materials 28 supplied from the distributor 38 is controlled to maintain a target level of the molten glass 30, as the molten glass 30 is withdrawn from the outlet 42, and the molten glass 30 is replenished from the batch materials 28 near the fusion line 44 of the cold crown 40.

[0109] Referring additionally to FIGS. 3-5, the pair of forming rollers 16, 18 establish a nip 46 therebetween. Both of the pair of forming rollers 16, 18 have an outer surface 48. The pair of forming rollers 16, 18 may be formed out of a wide variety of materials such as steel, Inconel, and so on. Both of the pair of forming rollers 16, 18 can rotate about an axis of rotation 50 and are configured to rotate toward each other about their respective axes of rotation 50, as noted by the arrows. For example, the pair of forming rollers 16, 18 can be driven by one or more motors. The axes of rotation 50 are upon the same horizontal plane 52 and are parallel to each other. The outer surfaces 48 of the pair of forming rollers 16, 18 at the horizontal plane 52 are separated by a gap 54. A vertical plane 56 extends through the gap 54. As further discussed, the molten glass 30 from the vertical electric melter 14 is delivered to the nip 46, and the pair of forming rollers 16, 18 manipulate (e.g., flatten, thin, and smoothen) the molten glass 30 into a ribbon of glass 58. The outer surfaces 48 can be temperature controlled. The rotational speed of the pair of forming rollers 16, 18 and temperature at the outer surfaces 48 thereof, as well and the size of the gap 54 between the pair of forming rollers 16, 18, are carefully selected and controlled to produce the ribbon of glass 58 with a width 60 and a thickness 62 of desired values. The width 60 is the distance between lateral edges 64 of the ribbon of glass 58. The thickness 62 is between a first primary surface 66 and a second primary surface 68 of the ribbon of glass 58. The heatextraction from both the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58 can be made to be symmetrical. The molten glass 30 is replenished to the nip 46 as the pair of forming rollers 16, 18 manipulate the molten glass 30 into the ribbon of glass 58. The ribbon of glass 58 extends downward 70 from the molten glass 30 in the nip 46 in a vertical orientation 72 substantially parallel with and encompassing the vertical plane 56.

[0110] Referring additionally to FIGS. 6-10A, as mentioned, the system 10 includes the delivery system 20. The delivery system 20 is configured to deliver the molten glass 30 from the vertical electric melter 14 to the nip 46 of the pair of forming rollers 16, 18, from above the nip 46. For example, the delivery system 20 can include piping 74 in communication with the outlet 42 of the vertical electric melter 14. In embodiments, the delivery system 20 further includes a forehearth 76 in communication with the piping 74. The molten glass 30 flows from the outlet 42 of the vertical electric melter 14, through the piping 74, and into the forehearth 76. The forehearth 76 is configured to achieve and maintain a desired temperature of the molten glass 30 from the vertical electric melter 14 before the molten glass 30 is delivered to the nip 46 between the first pair of forming rollers 16, 18, as well as uniformity of temperature within the forehearth 76, such as with heating elements, sensors, and a controller controlling the heating elements as a result of output from the sensors. The more uniform the temperature of the molten glass 30 within the forehearth 76, the more uniform the flow rate of the molten glass 30 out of the forehearth 76 and thus from the delivery system 20 overall to the pair of forming rollers 16, 18.

[0111] In embodiments, the delivery system 20 further includes a fish tail slot 78. The fish tail slot 78 resembles a fish tail in that the fish tail slot 78 includes an inlet 80 that can be generally circular and an outlet 82 that is fanned out along the vertical plane 56. The molten glass 30 is directed from the forehearth 76 to the inlet 80 of the fish tail slot 78, through the fish tail slot 78, and out the outlet 82 of the fish tail slot 78. The outlet 82 of the fish tail slot 78 is disposed elevationally above the nip 46 of the pair of forming rollers 16, 18. Thus, the molten glass 30 flows from the outlet 82 of the fish tail slot 78 and to the nip 46.

[0112] In embodiments, the delivery system 20 further includes a screw feeder 84. The screw feeder 84 is positioned, such as within the forehearth 76 and near the inlet 80 of the fish tail slot 78, to control the flow rate of the molten glass 30 from the forehearth 76 and into the fish tail slot 78 through the inlet 80. One or more motors 86 can drive the screw feeder 84. More than one screw feeder 84 can be utilized. A purpose of the screw feeder 84 is to precisely control the flow rate of the molten glass 30 being delivered independent from thetemperature (and therefore viscosity) of the molten glass 30. Without the screw feeder 84 for flow control, the flow rate of the molten glass 30 increases with lowering viscosity (higher delivery temperature) and decreases with increasing viscosity (lower delivery temperature) if no other modifications are made.

[0113] In embodiments (see FIG. 7), the delivery system 20 includes more than one fish tail slot 78 and inlet 80 assembly disposed elevationally above the nip 46 of the pair of forming rollers 16, 18. The molten glass 30 from the forehearth 76 (or multiple forehearths 76) is directed into the more than one fish tail slots 78. The delivery system 20 including more than one fish tail slot assemblies (fish tail 78 and inlet 80) may distribute the molten glass 30 across a wider section of the nip 46 (along the vertical plane 56 parallel to the axes of rotation 50) than just one inlet 80 feeding one fish tail slot 78.

[0114] In embodiments (see FIG. 8), the outlet 82 of the fish tail slot 78 is elongated having a length of greater than 0.7 m. In such embodiments, the fish tail slot 78 includes more than one inlet 80. The molten glass 30 then flows from the forehearth 76, through the more than one inlet 80, into the fish tail slot 78, and out of the outlet 82 into the nip 46. The more than one inlet 80 decreases temperature variation of the molten glass 30 exiting the outlet 82 and into the nip 46. Each of the more than one inlets 80 can include a dedicated screw feeder 84 to ensure uniform glass flow rates at each of the inlets 80.

[0115] In embodiments, (see FIGS. 9 and 10), instead of a fish tail slot 78, the delivery system 20, includes a fusion forming apparatus 88 to deliver the molten glass 30 to the nip 46 of the pair of forming rollers 16, 18. The fusion forming apparatus 88 includes an isopipe 90. The isopipe 90 comprises an upper trough-shaped part 92 and a lower wedge-shaped part 94, which, in combination, form a unitary forming body. The upper trough-shaped part 92 comprises a first trough side wall 96 having a first internal trough side surface 98, a second trough side wall 100 having a second internal trough side surface 102, and a trough bottom surface 104, which together define an open channel (also called a “trough”) 106 into which the molten glass 30 from the forehearth 76 is introduced, typically through an inlet tube 108 or open end of the trough 106. The trough 106 is filled with the molten glass 30 and the molten glass 30 is allowed to flow over a first trough top surface 110 of the first trough side wall 96 and a second trough top surface 112 of the second trough side wall 100 as two separate glass ribbons, down along a first outer side surface 114 and a second outer side surface 116, to a root 118 where the first and second outer side surfaces 114, 116 converge, the two glass ribbons fuse to form a unitary initial glass ribbon 120 (but still the molten glass30), which is fed into the nip 46 of the pair of forming rollers 16, 18. The pair of forming rollers 16, 18 manipulate the molten glass 30 (in the form of the unitary initial glass ribbon 120 from the fusion forming apparatus 88) into the ribbon of glass 58. In some instances, incorporation of the fusion forming apparatus 88 may allow bypass of the pair of forming rollers 16, 18 to the pair of sizing rollers 132, 134.

[0116] The root 118 is disposed elevationally above the nip 46 of the pair of forming rollers 16, 18 and is disposed at or near the vertical plane 56. In addition, in embodiments, the root 118 is disposed elevationally below a second horizontal plane 122 that is tangential to the outer surfaces 48 of both of the pair of forming rollers 16, 18.

[0117] Referring to FIG. 10A, in embodiments, the root 118 may be elongated or tapered to extend below the second horizontal plane 122 and closer to the nip 46. However, the root 118 is disposed above the horizontal plane 52 that extends through the axes of rotation 50 of the pair of forming rollers 16, 18. In such embodiments, the two separate glass ribbons flowing down the first outer side surface 114 and the second outer side surface 116 may not converge to form the unitary glass ribbon 120 but rather a puddle of the molten glass 30 between the pair of forming rollers 16, 18. The width 60 of the ribbon of glass 58 (and thus of the glass sheet 12) may be relatively increased by placing the root 118 of the isopipe 90 as close to the nip 46 of the pair of forming rollers 16, 18 as possible, in order to minimize the time that the molten glass 30 has to attenuate before being formed by the pair of forming rollers 16, 18. Less attenuation means greater the width 60 of the ribbon of glass 58 that the pair of forming rollers 16, 18 form. A direct fired extension tip 119 that is thermally controlled can provide the elongation or taper of the root 118. Thermally controlling the direct fired extension tip 119 allows the temperature of the molten glass 30 to be adjusted.

[0118] Further, heat shields 121, which can be water cooled, provide a barrier between the very hot environment around the isopipe 90 (glass temperatures above 1000°C / 1200°C) and the pair of forming rollers 16, 18, which, in some embodiments, need to be kept below 600 °C at the outer surfaces 48 thereof to avoid overheating and wrapping the molten glass 30 around the pair of forming rollers 16. 18.

[0119] The incorporation of the fusion forming apparatus 88 into the system 10 gives rise to the possibility of the ribbon of glass 58 being a laminate of a core glass composition and surrounded by a cladding glass composition. The fusion forming apparatus 88 herein described could be modified to include a second trough (not illustrated) disposed above the trough 106. The cladding glass composition flows from the second trough as two ribbonsover the two ribbons from the trough 106 and converges at the root 118 over the two ribbons from the through 106.

[0120] Referring additionally to FIG. 11, as mentioned, the system 10 further includes the conveyor 24. The conveyor 24 is disposed elevationally below the pair of forming rollers 16, 18. The vertical plane 56 can extend through the conveyor 24 near a first end 124 of the conveyor 24. The conveyor 24 is configured to convey the ribbon of glass 58 away from the vertical plane 56. For example, the conveyor 24 includes a conveyor belt 126 and a belt driver (e.g., a motor) that causes the conveyor belt 126 to rotate as indicated by the arrow. When the ribbon of glass 58 reaches the conveyor belt 126, the ribbon of glass 58 is still hot and flexible. Thus, the ribbon of glass 58 proceeds in a horizontal orientation 128 on the conveyor belt 126 away from the vertical plane 56.

[0121] As mentioned, the system 10 further includes the air turn assembly 26. The air turn assembly 26 is disposed elevationally below the pair of forming rollers 16, 18. The air turn assembly 26 is configured to direct the ribbon of glass 58 from the vertical orientation 72 to the horizontal orientation 128 on the conveyor 24, without damaging the ribbon of glass 58. For example, the air turn assembly 26 is disposed adjacent to the first end 124 of the conveyor belt 126, faces the first primary surface 66 of the ribbon of glass 58The air turn assembly 26 provides a non-contact (air bearing) turning surface to guide the ribbon of glass 58 from the vertical orientation 72 to the horizontal orientation 128 without causing damage (e.g., marking) to the ribbon of glass 58. When the ribbon of glass 58 in the vertical orientation 72 meets the horizontal traveling conveyor belt 126 (which can include ceramic molds 164), the ribbon of glass 58 is pulled along by the conveyor belt 126 and the ceramic molds 164 and the air turn assembly 26 holds the portion of the ribbon of glass 58 temporally preceding the conveyor belt 126 in the vertical orientation 72 and provides an air bearing (zero friction surface layer of air) that guides the change in direction of the ribbon of glass 58 from the vertical orientation 72 to the horizontal orientation 128 in a very precise manner.

[0122] Referring additionally to FIGS. 12-16, as mentioned, the system 10 further includes the at least one texturing roller 22. The at least one texturing roller 22 is configured to cause embossing of a texture 130 onto one or more of the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58. The texture 130 remains upon the glass sheet 12 and can cause an anti -reflectance effect, among other options.

[0123] In embodiments (see FIGS. 12-14), the system 10 further includes a pair of sizing rollers 132, 134, which include the at least one texturing roller 22. The pair of sizing rollers132, 134 are disposed elevationally below the pair of forming rollers 16, 18. The pair of sizing rollers 132, 134 are disposed elevationally above the conveyor 24. Each of the pair of sizing rollers 132, 134 includes an axis of rotation 136. Another horizontal plane 138 extends through the axes of rotation 136 of the pair of sizing rollers 132, 134. Each of the pair of sizing rollers 132, 134 includes an outer surface 140. The outer surfaces 140 oppose each other and are separated by a gap 142 through which the vertical plane 56 extends. The ribbon of glass 58 exiting the pair of forming rollers 16, 18 thus proceeds between the pair of sizing rollers 132, 134 and next to the at least one texturing roller 22. The pair of sizing rollers 132, 134 are configured to rotate against each other as indicated by the arrows. For example, each of the pair of sizing rollers 132, 134 can be rotated by a motor.

[0124] In embodiments, the pair of sizing rollers 132, 134, in addition to embossing the ribbon of glass 58 with the texture 130, are configured to reduce the thickness 62 of the ribbon of glass 58. For example, the pair of sizing rollers 132, 134 can both impart the texture 130 onto and reduce the thickness 62 of the ribbon of glass 58 by forcing the pair of sizing rollers 132, 134 toward each other with the ribbon of glass 58 therebetween. The pair of sizing rollers 132, 134 can include spacer rings 144 that limit how close the pair of sizing rollers 132, 134 can be forced toward each other and thereby define the thickness 62 of the ribbon of glass 58 leaving the pair of sizing rollers 132, 134. To comply with conservation of material volume, the ribbon of glass 58 exiting forming rollers 16, 18 traveling at a given process speed must exit the pair of sizing rollers 132, 134 at an increased process speed because the thickness 62 of the ribbon of glass 58 exiting the pair of sizing rollers 132, 134 is less thick (thinner) than the thickness 62 of the ribbon of glass 58 entering the pair of sizing rollers 132, 134.

[0125] In embodiments, to move the pair of sizing rollers 132, 134, the system 10 includes pneumatic cylinders 146, a frame 148, a translational drive motor 150, an upper shaft 152, a lower shaft 154, and a middle shaft 156. The pneumatic cylinders 146, or other suitable translational drive devices such as hydraulic cylinders, electric stepper or servo motors, or any other translational drive devices capable of creating a satisfactory translational drive force, move the pair of sizing rollers 132, 134 toward one another. As the pair of sizing rollers 132, 134 move toward one another, as mentioned, the spacer rings 144 on the pair of sizing rollers 132, 134 come into contact against each other and precisely form / defme the gap 142 between the outer surfaces 140 of the pair of sizing rollers 132, 134. The translational drive motor 150 can be an electric motor, such as a servo or stepper motor, or other suitablerotational drive mechanism, such as a pneumatic or hydraulic motor, that rotationally drives the pair of sizing rollers 132, 134 via right angle gear box 153, rotation gear box 155 for counter-rotating the pair of sizing rollers 132, 134, and Schmidt couplings 156, such that the pair of sizing rollers 132, 134 are rotationally driven in opposite directions at a precision controlled speed. The Schmidt couplings 156 allow for relative translational movement of the pair of sizing rollers 132, 134 (which move relative to the frame 148) relative to the output shafts of the rotation gear box 155 (which are fixed relative to the frame 148), while retaining the rotational drive connection there between and driving of the pair of sizing rollers 132, 134 at a precision controlled rotational speed. Bearing blocks 158 of the sizing roller 134 are mounted on outer ends of the upper and lower shafts 152, 154. The inner ends of the upper and lower shafts 152, 154 are attached to the housing or mounting plate of the pneumatic cylinders 146, such that the piston moves the middle shaft 156 relative to the upper and lower shafts 152, 154 to bring the pair of sizing rollers 132, 134 closer to or further from each other.

[0126] In embodiments where the pair of sizing rollers 132, 134 include the at least one texturing roller 22, one of both the pair of sizing rollers 132, 134 has texturing features 160 formed in or on the outer surface 48 thereof. In the illustrated embodiments, the sizing roller 134 (as the texturing roller 22) includes the texturing features 160 while the sizing roller 132 is smooth. The texturing features 160 may be formed utilizing a laser, by way of example only, to engrave an outer surface 162 of the at least one texturing roller 22 (e.g., the outer surface 140 of the sizing roller 134) or using manufacturing techniques widely used in the printing industry to form Anilox rollers. The laser may be employed to engrave a regular, repeatable pattern of texturing features 160 on the outer surface 162 of the at least one texturing roller 22, or it may form the texturing features 160 in a random fashion on the outer surface 162 of the at least one texturing roller 22. The texturing features 160 may be all the same size and geometric shape, or two or more, or even random sizes and geometric shapes. The texturing features 160 are primarily illustrated in the drawings as recesses, such as pits or crevices, in the outer surface 162 of the at least one texturing roller 22 that form correspondingly shaped raised features, such as bumps or ridges, on the first primary surface 66 of the ribbon of glass 58. The texturing features 160 may alternatively be raised features, such as bumps or ridges, which form correspondingly shaped recesses, such as pits or crevices, on the first primary surface 66 of the ribbon of glass 58. The texturing features 160 may be formed by direct laser engraving, applying arc plasma sprayed ceramic surfacecoatings, or any other suitable engraving or material removal process such as etching, sand blasting, as well as other surface replication methods. Raised features may be formed on the outer surface 162 of the at least one texturing roller 22 with any suitable material deposition process. The texturing features 160 formed in the at least one texturing roller 22 and that are imparted to the first primary surface 66 and / or the second primary surface 68 of the ribbon of glass 58 may have dimensions as small as 10 pm to 12 pm.

[0127] As an alternative to, or in addition to, the pair of sizing rollers 132, 134, the at least one texturing roller 22 can be one of a pair of texturing rollers 22 disposed below the pair of forming rollers 16, 18. One or both of the pair of texturing rollers 22 can have texturing features 160.

[0128] As a further alternative, the at least one texturing roller 22 (see FIGS. 11 and 15) can be positioned above the conveyor 24 and configured to apply force to the ribbon of glass 58 while the conveyor 24 is conveying the ribbon of glass 58 to emboss the texture 130 onto the ribbon of glass 58. In embodiments, the at least one texturing roller 22 includes the texturing features 160. As the conveyor 24 conveys the ribbon of glass 58 in the horizontal orientation 128 away from the vertical plane 56, the at least one texturing roller 22 is pressed downward 70 upon the ribbon of glass 58, the at least one texturing roller 22 is rotated, and the texturing features 160 are embossed into the first primary surface 66 of the ribbon of glass 58.

[0129] In embodiments where the at least one texturing roller 22 is positioned to emboss the texture 130 while the ribbon of glass 58 is in the horizontal orientation 128, the system 10 can include the pair of sizing rollers 132, 134 without any texturing features 160 that would emboss the texture 130. The pair of sizing rollers 132, 134 thus solely reduce the thickness 62 of the ribbon of glass 58. The pair of forming rollers 16, 18 and the pair of sizing rollers 132, 134 can be separated by sufficient space to permit inclusion of a spray coating applicator to add a coating to either or both of the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58.

[0130] In a variation (see FIG. 16), the conveyor 24 includes the ceramic molds 164 that are conveyed with the ribbon of glass 58. The ceramic molds 164 are disposed under the ribbon of glass 58. The ceramic molds 164 are in a spaced, sequential order, on the conveyor belt 126 such that any given ceramic mold 164 is adjacent to at least two other of the ceramic molds 164. The ceramic molds 164 are oriented substantially horizontally, such that gravity assists in the ribbon of glass 58 laying atop the ceramic molds 164. The texture 130embossed onto the ribbon of glass 58 comes from at least one of the ceramic molds 164. As the ribbon of glass 58 is conveyed away from the vertical plane 56, the at least one texturing roller 22 rotates and compresses the ribbon of glass 58 between the at least one texturing roller 22 and the ceramic molds 164. The ceramic molds 164 each have the texturing features 160, which are then embossed onto the second primary surface 68 of the ribbon of glass 58. In embodiments, both the ceramic molds 164 and the at least one texturing roller 22 include the texturing features 160. In those embodiments, both the ceramic molds 164 and the at least one texturing roller 22 emboss the texturing features 160 (which can be the same or different) onto the second primary surface 68 and the first primary surface 66, respectively, of the ribbon of glass 58. In embodiments, the ceramic molds 164 are metal molds with a ceramic coating. Metal molds without ceramic may also work.

[0131] Referring additionally to FIGS. 17, 17A, and 18, in embodiments, the system 10 includes a pinch roller 166, which has a pinch edge 168. The pinch roller 166 is configured to form a pinch line 170, via the pinch edge 168, into the ribbon of glass 58 laterally between the lateral edges 64 and into but not entirely through the thickness 62 of the ribbon of glass 58. The pinch roller 166 can be one of a pair of rollers 172, 174 (see FIG. 4) with axes of rotation 176 disposed on a horizontal plane 178 elevationally below the pair of forming rollers 16, 18 and the pair of sizing rollers 132, 134 (if included). The pair of rollers 172, 174 are separated by a gap 180 through which the vertical plane 56 extends. As the ribbon of glass 58 is in the vertical orientation 72, the pair of rollers 172, 174 rotate against each other as indicated by the arrows and the pinch roller 166 forms the pinch line 170 into the ribbon of glass 58.

[0132] Alternative to the pair of rollers 172, 174 with the pinch roller 166, the pinch roller 166 (see FIGS. 17, 20) can be disposed above the conveyor 24 and positioned to impart the pinch line 170, via the pinch edge 168, into the ribbon of glass 58 while the ribbon of glass 58 is in the horizontal orientation 128 on the conveyor 24. As the ribbon of glass 58 is conveyed away from the vertical plane 56, the pinch roller 166 rotates and the pinch edge 168 forms the pinch line 170 into the ribbon of glass 58. A positive pressure actutor 173 can push down on the pinch roller 166 or a texturing roller 22 that operates on the ribbon of glass in embodiments where the ribbon of glass is either thin pinched for part separation or textured.

[0133] In a variation (see FIG. 17 A), the system 10 includes the pair of forming rollers 16, 18, the pair of sizing rollers 132, 134, and then the pair of rollers 172, 174, at least one of which is the texturing roller 22 to impart texture to the ribbon of glass 58 while in the verticalorientation 72. After the air turn assembly 26 assists the ribbon of glass 58 to take the horizontal orientation 128, the pinch roller 166 with the pinch edge 168 imparts the pinch line 170 into the ribbon of glass 58. The pinch roller 166 may need to be raised / lowered and the rotationally position synchronized (e.g., through the use of rotational pauses) with the ribbon of glass 58 to obtain the glass sheet 12 of a length 201 (see FIG. 1) desired, such as 2 meters. The ribbon of glass 58 then proceeds to a series of ceramic coated rollers 171 of the conveyor 24, which help transport the ribbon of glass 58 or the glass sheets 12 separated therefrom at the pinch line 170 further downstream. This setup would form the pinch line 170 right after the air turn to the horizontal orientation 128. In embodiments, both the pinch roller 166 and a pressure roller 167 thereunder are textured to impart the texture 130 onto the ribbon of glass 58. It can be noted here that the speed of the conveyor 24 components (e.g., the conveyor belt 126, rotational speed of the series of ceramic coated rollers 171, and so on) can affect the thickness 62 of the ribbon of glass 58. Slower speeds can increase the thickness 62, while faster speeds can decrease the thickness 62.

[0134] As yet another alternative, the pinch roller 166 (see FIG. 18) is configured to form the pinch line 170 into the ribbon of glass 58 while rolling across the width 60 of the ribbon of glass 58. For example, the pinch roller 166 can have a circumferential raised trim edge 169 that protrudes into the first primary surface 66 of the ribbon of glass 58 as the pinch roller 166 traverses from lateral edge 64 to the other lateral edge 64. A traveling anvil wheel 182, with a smooth outer surface 183, is disposed below the ribbon of glass 58. The traveling anvil wheel 182 traverses with the pinch roller 166 and resists the force of the pinch roller 166 pushing down onto the ribbon of glass 58. The motion of the pinch roller 166 and traveling anvil wheel 182 is such that the pinch line 170 would end up perpendicular to both lateral edges 64.

[0135] In all the instances of the pinch roller 166, as the ribbon of glass 58 continues to travel along the conveyor 24 away from the vertical plane 56, the ribbon of glass 58 continues to cool. The reduced temperature is sufficient to initiate a break of the ribbon of glass 58 along the pinch line 170, such that the glass sheet 12 separates from the ribbon of glass 58. Self-separation occurs spontaneously due to the through-thickness thermal gradient developing a concentrated area of stress at the pinch line 170. Multiple of the glass sheets 12 so separate from the ribbon of glass 58 as system 10 generates the ribbon of glass 58 anew.

[0136] Referring additionally to FIG. 19, instead of the pinch roller 166, the system 10 can include a scribe wheel 184. The scribe wheel 184 is positioned and configured to movediagonally relative to lateral edges 64 of the ribbon of glass 58 while the ribbon of glass 58 is on the conveyor 24 and thereby add a score 185 to the ribbon of glass 58. The motion of the scribe wheel 184 would be at an angle to the lateral edges 64 chosen as a function of the speed of the ribbon of glass 58 such that the score 185 would end up perpendicular to both lateral edges 64. For example, the system 10 can include a frame 186 with two legs 188 - one leg 188 on both sides of the conveyor 24. One leg 188 is disposed further away from the vertical plane 56 than the other leg 188. In addition, the system 10 can include a cross-panel 190 that extends above the conveyor 24 from one leg 188 to the other leg 188. The crosspanel 190 thus extends diagonally across the conveyor 24. The cross-panel 190 supports a rod 192 that can be actuated parallel to the cross-panel 190. The rod 192 supports the scribe wheel 184. The scribe wheel 184 can be actuated closer to or further away from the conveyor 24 with movement of the scribe wheel 184 guided by guide bars 194. As the ribbon of glass 58 moves along the conveyor belt 126, the scribe wheel 184 can be moved to the leg 188 closest to the vertical plane 56. The scribe wheel 184 is then forced down to contact the ribbon of glass 58 while simultaneously moving to the other leg 188. The scribe wheel 184 thus imparts the score 185 into the ribbon of glass 58.

[0137] In addition to the scribe wheel 184, the system 10 includes an element configured to cause separation of the glass sheet 12 from the ribbon of glass 58 at the score 185 that the scribe wheel 184 created. For example, the conveyor 24 can include a positive pressure actuator 196 that can blow air from the conveyor 24 to facilitate lifting the ribbon of glass 58 at the score 185 and thus assist the glass sheet 12 in separating from the ribbon of glass 58 at the score 185.

[0138] Referring additionally to FIG. 21, the system 10 further includes an edge finishing module 198. The edge finishing module 198 processes at least edges 200, 202 (e.g., forward edge 200 and rearward edge 202) of the glass sheet 12 that were formed via separation from the ribbon of glass 58. The edge finishing module 198 can be disposed downstream of the conveyor 24. However, the edge finishing module 198 can be performed on the conveyor 24 if properly oriented with a lift and turn feature.

[0139] In embodiments, the edge finishing module 198 includes flame emitters 204. The flame emitters 204 are positioned to direct a flame 206 to the edges 200, 202 of the glass sheet 12 formed via separation. Flame emitters 204 can be positioned adjacent to both sides of the conveyor 24 below, and emit the flames 206 onto the edges 200, 202 of the glass sheet 12 as the glass sheet 12 is conveyed away from the vertical plane 56. The glass sheet 12 canbe rotated 90 degrees horizontally before being contacted with the flames 206. The edge finishing module 198 can finish the lateral edges 64 of the glass sheet 12 as well, if desired. In other embodiments, the edge finishing module 198 includes a grinder and polisher. The grinder and polisher grinds and polishes at least the edges 200, 202 of the glass sheet 12 that were formed via separation.

[0140] In embodiments (see FIG. 6), the system 10 further includes a width measurer 208. An example of the width measurer 208 is a vision system width measurer, such as a laser line scanner. The width measurer 208 is disposed elevationally below the pair of forming rollers 16, 18 but elevationally above the conveyor 24. The width measurer 208 is configured to generate output from which the width 60 of the ribbon of glass 58 can be determined while the ribbon of glass 58 is in the vertical orientation 72 or in the horizontal orientation 128. For example, the width measurer 208 can be positioned above the conveyor belt 126 and facing the first primary surface 66 of the ribbon of glass 58 while the ribbon of glass 58 is on the conveyor belt 126 in the horizontal orientation 128 moving away from the vertical plane 56. Based on the output that the width measurer 208 generates, one or more of the rotational speeds of the pair of forming rollers 16, 18, the screw feeder 84 associated with feeding molten glass 30 to the fish tail slot 78, and so on can be controlled so as to maintain the width 60 at a predetermined value. In general, increasing the rotational speed of the pair of forming rollers 16, 18 decreases the width 60 of the ribbon of glass 58, while decreasing the rotational speed of the pair of forming rollers 16, 18 increases the width 60 of the ribbon of glass 58. As the width 60 of the ribbon of glass 58 is produced at the predetermined value, the lateral edges 64 of the glass sheet 12 (carried over from the lateral edges 64 of the ribbon of glass 58) would not need to be subjected to the edge finishing module 198.

[0141] Referring additionally to FIG. 22, in embodiments, the system 10 further includes an edge forming roller 210. The edge forming roller 210 is positioned above the conveyor 24 to interact with the ribbon of glass 58 while the ribbon of glass 58 is being conveyed away from the vertical plane 56 in the horizontal orientation 128. The edge forming roller 210 includes two blades 212, which a distance 214 separates. The two blades 212 are positioned to cut or thin pinch the ribbon of glass 58 to narrow the width 60 of the ribbon of glass 58 and redefine the lateral edges 64 of the ribbon of glass 58. The edge forming roller 210 rotates about an axis of rotation 216 that is generally orthogonal to the lateral edges 64 of the ribbon of glass 58. More preferably, the edge forming roller 210 is not needed, and the system 10 is able to generate the ribbon of glass 58 with the width 60 as desired with the pair of formingrollers 16, 18 and the pair of sizing rollers 132, 134, if included. The edge forming roller 210, if needed, is used to precisely define the width 60 of the ribbon of glass 58 and would create, via thin pinch and subsequent separation of edge glass, the lateral edges 64 that may need to be further finished via the edge finishing module 198 (or similar) mentioned above (e.g., fire polished). Thin-pinched glass separates upon cooling leaving the new width 60 and redefined lateral edges 64. A force can be applied to the ribbon of glass 58 to assist such separation.

[0142] Referring additionally to FIG. 23, in embodiments the system 10 further includes a heat treatment module 218. The heat treatment module 218 heat treats the glass sheet 12. For example, the heat treatment module 218 can anneal the glass sheet 12 to release residual stress in the glass sheet 12. In embodiments, the heat treatment module 218 includes a temperature controlled lehr that is configured (e.g., with heating elements) to heat treat the glass sheet 12.

[0143] In embodiments (see FIG. 23), the heat treatment module 218 is a roller hearth furnace 220. In embodiments, the conveyor 24 (such as including the series of ceramic coated rollers 171) or a subsequent conveyor extends into the roller hearth furnace 220 so that the glass sheet 12 can be heat treated soon after separation from the ribbon of glass 58. The roller hearth furnace 220 heat treats the glass sheet 12 (e.g., with heating elements, such as electrical resistance heating elements) while the conveyor 24 is conveying the glass sheet 12 in the horizontal orientation 128.

[0144] Referring now additionally to FIG. 24, a method 300 of forming the glass sheet 12 is herein disclosed. The method 300 includes a melting step 302, a delivering step 304, a ribbon forming step 306, a texturing step 308, a reorienting step 310, a separating step 312, and a polishing step 314. In embodiments, those steps 302-314 are completed in the order presented.

[0145] The melting step 302 includes melting, in the vertical electric melter 14, the batch materials 28 for the molten glass 30. As explained above, the distributor 38 can deliver the batch materials 28 to the vertical electric melter 14. During the melting step 302, at least a portion of the batch materials 28 forms the molten glass 30 and at least a portion forms the cold crown 40 over the molten glass 30. As molten glass 30 is withdrawn from the vertical electric melter 14, some of the batch materials 28 from the cold crown 40 become the molten glass 30, and the distributor 38 adds the batch materials 28 anew onto the cold crown 40 within the vertical electric melter 14. There are no compositional limitations for the batchmaterials 28 and the molten glass 30 (and thus the ribbon of glass 58 and the glass sheet 12). However, in embodiments, the composition of the molten glass 30 (and thus the ribbon of glass 58 and the glass sheet 12) is substantially free of alkali oxides such as Na2O. Substantially free means that that composition does not purposefully include alkali oxides such as Na?O but some may be present in trace amounts because of contamination in the batch materials 28, the vertical electric melter 14 and other processing equipment.

[0146] As mentioned, the method 300 further includes the delivering step 304. The delivering step 304 includes delivering the molten glass 30 vertically to the nip 46 of the pair of forming rollers 16, 18, from above the pair of forming rollers 16, 18. In embodiments, during the delivering step 304, the molten glass 30 is delivered into the fish tail slot 78 via more than one inlet 80 into the fish tail slot 78. In embodiments, during the delivering step 304, the screw feeder 84 regulates the flow rate of the molten glass 30 into the inlet 80 or the inlets 80 of the fish tail slot 78. In all those embodiments including the fish tail slot 78, the molten glass 30 is delivered to the nip 46 through the fish tail slot 78. In embodiments, during the delivering step 304, the molten glass 30 is delivered to the nip 46 through more than one fish tail slot 78.

[0147] In embodiments, during the delivering step 304, the molten glass 30 forms a contact angle a (see FIG. 3) of less than 45 degrees with both of the pair of forming rollers 16, 18 relative to the horizontal plane 52 that extends through both axes of rotation 50 of the pair of forming rollers 16, 18. The angle a can be increased or decreased by increasing or decreasing, respectively, the rotational speed of the pair of forming rollers 16, 18. Although use of the fish tail slot 78 can achieve the contact angle a of less than 45 degrees, the fusion forming apparatus 88 may be able to achieve the contact angle a of less than 45 degrees more easily. In general, the lower the contact angle a, the lower the thickness 62 of the ribbon of glass 58 the pair of forming rollers 16, 18 can form (and thus the lower the thickness 62 of the glass sheet 12). Further, the closer the contact angles a of each of the pair of forming rollers 16, 18 are to each other, the greater the similarity in the thermal histories of the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58. In embodiments, during the delivering step 304, the molten glass 30 is delivered first into the trough 106 of the fusion forming apparatus 88, and the molten glass 30 overflows the opposing walls 96, 100 of the trough 106. The molten glass 30 then flows down the outer side surfaces 114, 116 of the walls 96, 100 as separate ribbons 316, 318, which then converge at the root 118. The molten glass 30 then flows down into the nip 46 between the pair offorming rollers 16, 18. In embodiments, the root 118 is disposed elevationally below the second horizonal plane 122 tangential to both of the pair of forming rollers 16, 18 and elevationally above the horizontal plane 52 extending through the axes of rotation 50 of the pair of forming rollers 16, 18.

[0148] In embodiments, the method 300 further includes a pre-delivery thermal conditioning step 320. The pre-delivery thermal conditioning step 320 occurs after the melting step 302 and before the delivering step 304. The pre-delivery thermal conditioning step 320 includes raising or lowering a temperature of the molten glass 30 from the vertical electric melter 14 before the molten glass 30 is delivered to the center nip 46 between the first pair of forming rollers 16, 18. The pre-delivery thermal conditioning step 320 can occur in the forehearth 76.

[0149] As mentioned, the method 300 further includes the ribbon forming step 306. The ribbon forming step 306 includes rotating the pair of forming rollers 16, 18 to form the ribbon of glass 58 from the molten glass 30. The ribbon of glass 58 extends substantially vertically below the nip 46, along or proximate the vertical plane 56.

[0150] In embodiments, the method 300 further includes a sizing step 322. The sizing step 322 occurs after the ribbon forming step 306 and before the texturing step 308. The sizing step 322 includes rotating the pair of sizing rollers 132, 134 and contacting the ribbon of glass 58 while the ribbon of glass 58 is vertically oriented and disposed between the pair of sizing rollers 132, 134. The sizing step 322 thereby decreases the thickness 62 of the ribbon of glass 58. The process surface speed of the pair of sizing rollers 132, 134 will be greater than the process surface speed of the pair of forming rollers 16, 18, and the difference in surface speeds will depend upon the difference between the thickness 62 of the ribbon of glass 58 exiting the pair of forming rollers 16, 18 and the thickness 62 of the ribbon of glass 58 exiting the pair of sizing rollers 132, 134.

[0151] As mentioned, the method 300 further includes the texturing step 308. The texturing step 308 includes embossing the texture 130 onto one or both of the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58. In embodiments, the texturing step 308 further is performed at least in part by rotating the pair of sizing rollers 132, 134, one of which is the texturing roller 22, while the ribbon of glass 58 proceeds vertically downward 70 between the pair of sizing rollers 132, 134. The pair of sizing rollers 132, 134 contact the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58 and thereby embosses the texture 130 onto one or both of the first primary surface66 and the second primary surface 68 of the ribbon of glass 58. In embodiments, the pair of sizing rollers 132, 134 additionally reduce the thickness 62 of the ribbon of glass 58 while embossing the texture 130 onto the ribbon of glass 58.

[0152] In embodiments, the texturing step 308 includes conveying the ribbon of glass 58 upon the conveyor 24 between the texturing roller 22 and the conveyor 24 surface, while the ribbon of glass 58 is in the horizontal orientation 128. The texturing roller 22 rotates and contacts the ribbon of glass 58 with force sufficient to emboss the texture 130. The texture 130 comes from either or both of the conveyor 24 and the texturing roller 22. The texture 130 can be embossed onto one or both of the first primary surface 66 and the second primary surface 68 of the ribbon of glass 58. The texturing roller 22 can emboss the texture 130 onto the first primary surface 66 of the ribbon of glass 58. The ceramic mold 164, as explained, can emboss the texture 130 onto the second primary surface 68 of the ribbon of glass 58.

[0153] In embodiments, the texture 130 imparted to the ribbon of glass 58 and thus the glass sheet 12 is a repeating pattern of features 324 (see, e.g., FIGS. 26-29) having a largest dimension of less than 600 pm and a depth into the thickness 62 of less than 600 pm, such as less than 100 pm and less than 20 pm. In embodiments, the features 324 are hexagonal pyramids (FIG. 27), wells (see FIG. 28), or truncated pyramids (see FIG. 29).

[0154] As mentioned, the method 300 further includes the reorienting step 310. The reorienting step 310 includes guiding the ribbon of glass 58 from the vertical orientation 72 to the horizontal orientation 128 upon the conveyor 24 that pulls the ribbon of glass 58 away from the vertical plane 56 extending between the pair of forming rollers 16, 18. The air turn assembly 26 can support the reorienting step 310 by providing a non-contact air bearing surface to guide the ribbon of glass 58 from the vertical orientation 72 to the horizontal orientation 128 upon the conveyor belt 126, without damaging the ribbon of glass 58. The ribbon of glass 58 is still sufficiently viscous during the reorienting step 310 such that the ribbon of glass 58 does not separate even at the pinch line 170.

[0155] In embodiments, the method 300 further includes a second texturing step 326. The second texturing step 326 occurs after the reorienting step 310 and thus while the ribbon of glass 58 is in the horizontal orientation 128. The second texturing step 326 includes conveying the ribbon of glass 58 upon the conveyor 24 between the texturing roller 22 and the conveyor 24. The texturing roller 22 rotates and contacts the ribbon of glass 58 with sufficient force to emboss a second texture 130 (not separately illustrated), from one or both of the ceramic molds 164 and the texturing roller 22, onto one or both of the first primarysurface 66 and the second primary surface 68 of the ribbon of glass 58. In embodiments, the second texture 130 is embossed over the texture 130 that was already embossed onto the ribbon of glass 58, such as by the texturing roller 22 of the pair of sizing rollers 132, 134.

[0156] In embodiments, the method 300 further includes a measuring step 328. The measuring step 328 can occur after or before the reorienting step 310. The measuring step 328 includes determining the width 60 of the ribbon of glass 58. In embodiments, the rotational speed of the pair of forming rollers 16, 18 during the ribbon forming step 306 is controlled as a function of the measured width 60 of the ribbon of glass 58 during the measuring step 328. The rotational speed of the pair of sizing rollers 132, 134 and the speed of the conveyor belt 126, among other things, can additionally be controlled as a function of the width 60 as measured during the measuring step 328. In embodiments, the width measurer 208 generates output from which the width 60 of the ribbon of glass 58 is determined during the measuring step 328.

[0157] In embodiments, the method 300 further includes an edge separating step 330. The edge separating step 330 occurs after the reorienting step 310 but before the separating step 312. The edge separating step 330 includes conveying the ribbon of glass 58 under the edge forming roller 210 with two blades 212 separated by the distance 214. The two blades 212 of the edge forming roller 210 form a thin pinch into or cut the ribbon of glass 58 to redefine the lateral edges 64 of the ribbon of glass 58 and to narrow the width 60 of the ribbon of glass 58. With or without inclusion of the edge separating step 330, in embodiments, the width 60 of the ribbon of glass 58 is greater than or equal to 1 m. The width 60 of the ribbon of glass 58 can be less than 1 m, however.

[0158] As mentioned, the method 300 further includes the separating step 312. The separating step 312 includes separating the glass sheet 12 from the ribbon of glass 58. As mentioned, the glass sheet 12 includes the lateral edges 64 inherited from the lateral edges 64 of the ribbon of glass 58, the forward edge 200 orthogonal to the lateral edges 64, and the rear edge 202 orthogonal to the lateral edges 64. The forward edge 200 and the rear edge 202 of the glass sheet 12 are formed from separation of glass sheets 12 from the ribbon of glass 58 in sequence.

[0159] In embodiments, the separating step 312 further includes reducing the thickness 62 of the ribbon of glass 58 across the width 60 of the ribbon of glass 58 at the pinch line 170. The separating step 312 can begin by forming the pinch line 170 in the ribbon of glass 58. In embodiments, the pair of rollers 172, 174, at least one of which is the pinch roller 166,between which the ribbon of glass 58 moves while the ribbon of glass 58 is vertically oriented, form the pinch line 170 into the ribbon of glass 58. In other embodiments, the pinch roller 166 is disposed above the conveyor 24 and positioned to impart the pinch line 170 into the ribbon of glass 58 while the ribbon of glass 58 is in the horizontal orientation 128 on the conveyor 24. In still other embodiments, the pinch roller 166 forms the pinch line 170 into the ribbon of glass 58 by rolling across the width 60 of the ribbon of glass 58 while the ribbon of glass 58 is in the horizontal orientation 128 and being conveyed. As explained above, separation of the glass sheet 12 from the ribbon of glass 58 occurs at the pinch line 170 spontaneously as the ribbon of glass 58 cools.

[0160] In other embodiments, instead of creating the pinch line 170, the separating step 312 includes forming the score 185 into the ribbon of glass 58 across the width 60 of the ribbon of glass 58 and applying the force that causes separation of the glass sheet 12 from the ribbon of glass 58. The forming of the score 185 into the ribbon of glass 58 can occur while the ribbon of glass 58 is disposed on the conveyor 24 and in the horizontal orientation 128. The score 185 can be generated with the scribe wheel 184. The scribe wheel 184 can move diagonally relative to the lateral edges 64 of the ribbon of glass 58 while the ribbon of glass 58 is being conveyed. The force can be generated with air pressure as described. In still other embodiments, the separating step 312 could be performed via laser cutting of the ribbon of glass 58.

[0161] As mentioned, the method 300 further includes the polishing step 314. In embodiments, the polishing step 314 includes grinding and then polishing the forward edge 200 and the rearward edge 202 of the glass sheet 12. The grinding and polishing can be performed downstream of the conveyor 24. In embodiments, the polishing step 314 includes contacting the forward edge 200 and the rearward edge 202 of the glass sheet 12 with the flame 206. The flame emitters 204 coupled to the conveyor 24, or some other conveyor downstream, can form the flames 206 that contact the glass sheet 12. The glass sheets 12 can be rotated 90 degrees from their orientation when first separated from the ribbon of glass 58 before the polishing step 314 occurs.

[0162] The melting step 302, the delivering step 304, the ribbon forming step 306, the texturing step 308, the reorienting step 310, the separating step 312, and the polishing step 314 occur simultaneously on different portions of the ribbon of glass 58 or glass sheet 12, as the case may be, in an extended batch or continuous process resulting in numerous of the glass sheet 12 being separated, in sequence, from the ribbon of glass 58.

[0163] In embodiments, the method 300 further includes a post-separation thermal conditioning step 332. The post-separation thermal conditioning step 332 occurs after the separating step 312. The post-separation thermal conditioning step 332 includes thermally treating the glass sheet 12. The post-separation thermal conditioning step 332 can occur in the lehr offline from the conveyor 24. Alternatively, the post-separation thermal conditioning step 332 can occur in the roller hearth furnace 220, while the conveyor 24 or some other downstream conveyor conveys the glass sheet 12 through the roller hearth furnace 220.

[0164] In embodiments, the lateral edges 64 of the glass sheet 12 are the lateral edges 64 of the ribbon of glass 58 from which the glass sheet 12 was separated during the separating step 312. This can occur when there is no edge separating step 330, and the lateral edges 64 of the ribbon of glass 58 are not ground and polished. The glass sheet 12 further includes the width 60 between the parallel lateral edges 64 of the glass sheet 12 inherited from the ribbon of glass 58. In embodiments, the width 60 is greater than or equal to 1 m. In addition, the glass sheet 12 includes the first primary surface 66 inherited from the first primary surface 66 of the ribbon of glass 58, the second primary surface 68 inherited from the second primary surface 68 of the ribbon of glass 58, and the thickness 62 between the first primary surface 66 and the second primary surface 68. In embodiments, the thickness 62 is less than 2.0 mm, such as less than 0.5 mm. The thickness 62 can be within a range of from 0.5 mm to 2.6 mm, although the thickness 62 can be thicker or thinner than that range.

[0165] Referring additionally to FIG. 25, in embodiments, the method 300 further includes an assembling step 334. The assembling step 334 includes assembling the glass sheet 12 over one or more photovoltaic cells 336 to form a solar panel 338. The solar panel 338 can include a frame 340 that secures the glass sheet 12 and the one or more photovoltaic cells 336 together.

[0166] The glass sheet 12 and the method 300 address the problems set forth in the Background, in a variety of ways. First, the vertical electric melter 14 uses primarily electricity rather than natural gas to heat the batch ingredients and form the molten glass 30. Thus, the system 10 avoids the level of combustion of natural gas that the float glass process uses. Second, the vertical electric melter 14 causes formation of the cold crown 40 over the molten glass 30 and the electrode 36 heats the molten glass 30 under the cold crown 40. Thus, heat transfer to the molten glass 30 and energy efficiency is improved over the float glass process. Further, the cold crown 40 abates pollution by covering the molten glass 30. Third, the vertical electric melter 14 and the pair of forming rollers 16, 18 of the system 10can handle a wider range of glass compositions than the float glass process, including glass compositions lacking alkali oxides such as Na?O (beneficial for reducing potential induced degradation of photovoltaic cells 336) and having a relatively high viscosity curve. Fourth, the system 10, with the pair of forming rollers 16, 18 and optionally the pair of sizing rollers 132, 134, can form the glass sheet 12 with the thickness 62 that is much less than the 6.9 mm thickness of the glass sheets formed via the float glass process. The thickness 62 of the glass sheet 12 being reduced results in less weight for the solar panel 338 and less use of batch materials 28. Fifth, in embodiments of the method 300 and the glass sheet 12, the lateral edges 64 of the glass sheet 12 are inherited as-formed from the ribbon of glass 58 (while the glass is still in the molten state) and not further processed (e.g., not ground and polished, or fire polished). The combination of precise flow rate of the molten glass 30 provided by the screw feeder(s) 84, combined with the precise measurement of the width 60 of the ribbon of glass 58 by the width measurer 208 to provide feedback to the rotational speed of the pair of forming rollers 16, 18, provides ability to precisely control the width 60 of the ribbon of glass 58 and the glass sheets 12 separated therefrom to be precisely as desired for end product. Therefore, the glass sheets 12 do not require any secondary processing steps to finish the lateral edges 64 thereof. The as formed lateral edges 64 of the glass sheet 12 are extremely strong — at least equivalent to the forward edge 200 and rearward edge 202 subjected to fire polishing. Thus, the lateral edges 64 of the glass sheet 12 are as strong or stronger than the scored, ground, and polished lateral edges 64 of a glass sheet 12 formed via a float glass process. Sixth, the system 10 and the method 300 impart the texture 130 (including overlapping textures 130 on the same first primary surface 66 or second primary surface 68) onto the ribbon of glass 58 via the at least one texturing roller 22 before the glass sheet 12 is separated therefrom. Thus, the need to chemically etch the glass sheet 12 is avoided, which saves the time and expense of doing so. In short, the system 10 and the method 300 makes the glass sheet 12 at a desired width 60 but reduced thickness 62 and with texture 130, with less combustion of carbon containing fuels, and with more compositional options than float glass processes. Further, the ribbon of glass 58 is formed on or along the vertical plane 56, rather than horizontally as the float glass process does, and thus the system 10 and method 300 occupy less horizontal space.

[0167] EXAMPLES

[0168] Example 1 - A ribbon of glass was formed and then passed through a pair of sizing rollers, one of which was a textured roller, in a vertical orientation and subsequently changedto a horizontal orientation on a conveyor belt. The features on the ribbon of glass were of the nanometer size, as atomic force microscopy images and analysis reveal (as reproduced at FIG. 26).

[0169] Example 2 - A ribbon of glass was formed in a vertical orientation and changed to a horizontal orientation on a conveyor belt. A roller above the conveyor was a texturing roller with micron scale features. The roller was pushed down onto the ribbon of glass and embossed the features onto the first primary surface of the ribbon of glass. The features on the ribbon of glass were of micrometer size, as optical microscopy images and analysis reveal (as reproduced at FIG. 27).

[0170] Example 3 - A ribbon of glass was formed and then passed through a pair of sizing rollers, one of which was a textured roller, in a vertical orientation and subsequently changed to a horizontal orientation on a conveyor belt. The texture on the ribbon of glass was micrometer size, as optical microscopy images and analysis reveal (as reproduced at FIG. 28). More particular, the texture was repeating wells measuring 0.5 mm in diameter and 0.5 pm- 10 pm in depth.

[0171] Example 4 - A ribbon of glass was formed in a vertical orientation and changed to a horizontal orientation on a conveyor belt. A roller above the conveyor was a texturing roller with micron scale features. The roller was pushed down onto the ribbon of glass and embossed the features onto the first primary surface of the ribbon of glass. The texture on the ribbon of glass was micrometer size, as optical microscopy images and analysis reveal (as reproduced at FIG. 29). More particularly, the texture was repeating truncated pyramids measuring 400-500 pm by ~50 pm deep. The roller had long narrow rectangular pyramid shaped spokes with rectangular (square) tips that measured approximately 100 pm on each side and these posts penetrated the glass sheet to depths of 400 to 500 pm.

[0172] Example 5 - For Example 5, various process conditions to form a ribbon of glass were explored using embodiments of the system and the method described herein. The system was set up as illustrated at FIG. 30, with a pair of forming rollers, a pair of sizing rollers below the pair of forming rollers (without any texturing roller), and a pair of texturing rollers below the pair of sizing rollers. The process conditions and results in terms of the width and the thickness of the ribbon of glass are presented in Table 1 below. The system further included a pinch roller above the conveyor to impart a pinch line into the ribbon of glass. Upon cooling, glass sheet separated on the conveyor from the ribbon of glass at the pinch lines.In Table 1 above, “Top Gap” refers to the distance between the outer surfaces of the pair of forming rollers that determines the thickness of the glass ribbon exiting the forming rollers. “Mid Gap” refers to the distance between the outer surfaces of the pair of sizing rollers that determines the thickness of the glass ribbon exiting the sizing rollers, “Bot Gap” refers to the distance between the outer surfaces of the subsequent pair of sizing / texturing rollers that determines the thickness of the glass ribbon exiting the sizing / texturing rollers, “Top Speed” refers to the surface speed of the pair of forming rollers that determines the linear process speed of the glass ribbon exiting the forming rollers, “Mid Speed” refers to the surface speed of the pair of sizing rollers that determines the linear process speed of the glass ribbon exiting the sizing rollers, “Bottom Speed” refers to the surface speed of the sizing / texturing rollers that determines the linear process speed of the glass ribbon exiting the sizing / texturing rollers, “Conv Speed” refers to the speed of the conveyor belt away from the vertical plane extending through the pairs of rollers, “Measured Thickness” refers to the thickness of a glass sheet separated from the ribbon of glass, “Measured Width” refers to the width of the glass sheet separated from the ribbon of glass, and “Est Flow Rate” refers to the mass quantity of molten glass delivered to the pair of forming rollers as a function of time.

[0173] Example 6 - For Example 6, various process conditions to form a ribbon of glass were explored using embodiments of the system and the method described herein. The system was set up as illustrated at FIG. 31, with a pair of forming rollers and a pair of sizing rollers below the pair of forming rollers (including a texturing roller as one of the sizing rollers). The process conditions and results in terms of the width and the thickness of the ribbon of glass are presented in Table 2 below. The system further included a pinch roller above the conveyor to impart a pinch line into the ribbon of glass. Upon cooling, glass sheets separate on the conveyor from the ribbon of glass at the pinch lines. In Table 2 below, the column labels have the same meaning as those explained for Table 1.

[0174] Example 7 - Example 7, as illustrated at FIG. 32, is an embodiment of the system where the molten glass is introduced between the pair of forming rollers, which forms the ribbon of glass. The ribbon of glass then proceeds along the vertical plane to a pair of sizing rollers, at least one of which is a texturing roller. The ribbon of glass is then reoriented horizontally and fed between another pair of rollers that also impart texture. The ribbon of glass then proceeds along a conveyor to be separated into glass sheets via scoring.

[0175] Example 8 - Example 8, as illustrated at FIG. 33, is an embodiment of the system where the molten glass is introduced between the pair of forming rollers, which forms the ribbon of glass. The ribbon of glass then proceeds along the vertical plane to a pair of sizing rollers, at least one of which is a texturing roller. The ribbon of glass then proceeds along the vertical plane to a pair of rollers, one of which is a pinch roller to impart a pinch line into the ribbon of glass. The ribbon of glass is then reoriented horizontally and fed onto a conveyor. On the conveyor, the ribbon of glass is fed between a texturing roller and a ceramic mold. Upon cooling, glass sheets separate on the conveyor from the ribbon of glass at the pinch lines.

[0176] Example 9 - For Example 9, a ribbon of glass was prepared according to the system and the method described herein. The ribbon of glass had a width of 3.5 inches. While in the horizontal orientation, the ribbon of glass was contacted by an edge forming roller. The edge forming roller had two blades separated by a distance of 2.5 inches. The edge forming roller narrowed the width of the ribbon of glass from 3.5 inches to 2.5 inches and redefined the lateral edges of the ribbon of glass. Glass sheets were separated from the ribbon of glass along the pinch lines. An image of one of the glass sheets, along with the cullet formed by the edge forming roller from the ribbon of glass, is reproduced at FIG. 34.

[0177] Example 10 - For Example 10, a ribbon of glass was formed according to the system and method described herein. The separating step included using a pinch roller to impart a pinch line into the ribbon of glass. The ribbon of glass was also subjected to a texturing step. An image of the ribbon of glass on the conveyor belt showing the pinch lines therein is reproduced at FIG. 35. The image additionally shows the conveyor including ceramic molds.

[0178] Example 11 - For Example 11, a ribbon of glass was formed according to the system and method described herein. A pinch roller imparted pinch lines into the ribbon of glass. A glass sheet was separated from the ribbon of glass along pinch line. No edge forming roller was used, and the lateral edges of the glass sheet were inherited from the lateral edges of the ribbon of glass, which were formed from the glass composition still in the molten state. The forward edge and the rearward edge of the glass sheet, which were formed from separation of the ribbon of glass along pinch lines, were then subjected to flame polishing. Images of the lateral edges (left) of the glass sheet and the forward and rearward edges (right) - both before flame polishing (top right) and after flame polishing (bottom right) - are reproduced at FIG. 36.

[0179] Review of the image illustrates at the bottom left that the pair of forming rollers make the lateral edges of the ribbon of glass naturally rounded, which is thought to improve strength at the lateral edges. Further, at the top right, the forward and rearward edges of the glass sheet formed via separation of the ribbon of glass at the pinch line, is not rounded. However, after flame polishing, as shown in the bottom right, the forward and rearward edges of the glass sheet has a rounded profile, again thought to increase the strength thereof.

[0180] Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the disclosure, which is defined by the following claims, as interpreted according to the principles of patent law, including the doctrine of equivalents.

Claims

CLAIM(S)What is claimed is:

1. A system for making a glass sheet comprising: a vertical electric melter configured to melt batch materials and form molten glass from the batch materials; a pair of forming rollers establishing a nip between the pair of forming rollers, the pair of forming rollers configured (a) to rotate toward each other about parallel axes of rotation and (b) to manipulate the molten glass at the nip into a ribbon of glass extending in a vertical orientation downward from the molten glass at the nip; a delivery system configured to deliver the molten glass from the vertical electric melter to the nip of the pair of forming rollers, from above the nip; a conveyor disposed elevationally below the pair of forming rollers, the conveyer configured to convey the ribbon of glass away from a vertical plane extending between the pair of forming rollers; an air turn assembly disposed elevationally below the pair of forming rollers, the air turn assembly configured to guide the ribbon of glass from the vertical orientation to a horizontal orientation on the conveyor; at least one texturing roller configured to cause embossing of a texture onto one or more of a first primary surface and a second primary surface of the ribbon of glass; at least one of (a) a pinch roller configured to form a pinch line across a width of the ribbon of glass and into a thickness of the ribbon of glass (b) (i) a scribe wheel positioned and configured to move diagonally relative to lateral edges of the ribbon of glass while the ribbon of glass is on the conveyor and thereby impart a score into the ribbon of glass and (ii) an element configured to cause separation of a glass cover sheet from the ribbon of glass at the score; and at least one of (a) a grinder and polisher positioned to grind and to polish edges of the glass cover sheet formed via separation or (b) flame emitters positioned to direct a flame to edges of the glass cover sheet formed via separation.

2. The system of claim 1, wherein the delivery system further comprises a forehearth configured to achieve and maintain a desired temperature of the molten glass from the vertical electric melter before the molten glass is delivered to the center nip between the pair of forming rollers.

3. The system of any one of claims 1-2, wherein the delivery system comprises (i) a fish tail slot disposed elevationally above the nip of the pair of forming rollers and (ii) a screw feeder positioned to regulate flow rate of the molten glass into the fish tail slot.

4. The system of any one of claims 1-3, wherein the delivery system comprises more than one fish tail slot disposed elevationally above the nip of the pair of forming rollers.

5. The system of any one of claims 1-4, wherein the delivery system comprises a fish tail slot comprising (i) an outlet that is elongated having a length of greater than 0.7 meters disposed elevationally above the nip of the pair of forming rollers and (ii) more than one inlet into the fish tail slot.

6. The system of any one of claims 1-2, wherein the delivery system comprises a fusion forming apparatus with a trough to receive the molten glass, opposing walls at least partially defining the trough and comprising outer side surfaces, and a root where the outer side surfaces converge, the root disposed elevationally above the nip of the pair of forming rollers.

7. The system of claim 6, wherein the root of the fusion forming apparatus is disposed elevationally below a second horizonal plane tangential to outer surfaces of both of the pair of forming rollers and elevationally above a horizontal plane extending through the axes of rotation of the pair of forming rollers.

8. The system of any one of claims 1-7 further comprising: a pair of sizing rollers, which include the at least one texturing roller, disposed elevationally below the pair of forming rollers and elevationally above the conveyer, the pair of sizing rollers separated by a gap through which the vertical plane extends.

9. The system of claim 8, whereinthe pair of sizing rollers are further configured to reduce a thickness of the ribbon of glass between the first primary surface and the second primary surface thereof.

10. The system of any one of claims 1-9, wherein the at least one texturing roller is positioned above the conveyer and configured to apply force to the ribbon of glass while the conveyor is conveying the ribbon of glass to emboss the texture onto the ribbon of glass.

11. The system of claim 10, wherein the conveyor includes ceramic molds that are conveyed with the ribbon of glass, with the ceramic molds disposed under the ribbon of glass, and the texture embossed onto the ribbon of glass comes from at least one of the ceramic molds.

12. The system of any one of claims 1-11 further comprising: a pair of rollers, one of which is the pinch roller, disposed elevationally below the pair of forming rollers and separated by a gap through which the vertical plane extends.

13. The system of any one of claims 1-12, wherein the pinch roller is disposed above the conveyer and positioned to impart the pinch line into the ribbon of glass while the ribbon of glass is in the horizontal orientation on the conveyor.

14. The system of any one of claims 1-13, wherein the pinch roller is configured to form the pinch line into the ribbon of glass while rolling across the width of the ribbon of glass.

15. The system of any one of claims 1-14 further comprising: a width measurer disposed elevationally below the pair of forming rollers but elevationally above the conveyor, the width measurer configured to generate output from which the width of the ribbon of glass can be determined.

16. The system of any one of claims 1-15 further comprising:an edge forming roller positioned above the conveyer, the edge forming roller comprising two blades separated by a distance and positioned to impart a thin pinch into the ribbon of glass to redefine the lateral edges of the ribbon of glass and to narrow the width of the ribbon of glass while the conveyer is conveying the ribbon of glass.

17. The system of any one of claims 1-16 further comprising: a temperature controlled lehr configured to heat treat the glass cover sheet.

18. The system of any one of claims 1-17 further comprising: a roller hearth furnace configured to heat treat the glass cover sheet while the conveyor is conveying the glass cover sheet.

19. A method of forming a glass cover sheet comprising: a melting step comprising melting, in a vertical electric melter, batch materials to form molten glass; a delivering step comprising delivering the molten glass vertically to a nip of a pair of forming rollers from above the pair of forming rollers; a ribbon forming step comprising rotating the pair of forming rollers to form a ribbon of glass from the molten glass, the ribbon of glass (i) extending substantially vertically below the nip, (ii) comprising a first primary surface and a second primary surface, and (iii) further comprising lateral edges and a width between the lateral edges; a texturing step comprising embossing a first texture onto one or both of the first primary surface and the second primary surface; a reorienting step comprising guiding the ribbon of glass from a vertical orientation to a horizontal orientation upon a conveyor that pulls the ribbon of glass away from a vertical plane extending between the pair of forming rollers; a separating step comprising separating a glass cover sheet from the ribbon of glass, the glass cover sheet comprising lateral edges, a forward edge orthogonal to the lateral edges, and a rear edge orthogonal to the lateral edges; and a polishing step comprising either (i) grinding and then polishing the forward edge and the rear edge of the glass cover sheet or (ii) contacting the forward edge and the rear edge of the glass cover sheet with a flame,wherein, the melting step, the delivering step, the ribbon forming step, the texturing step, the reorienting step, the separating step, and the polishing step occur simultaneously in an extended batch or continuous process resulting in numerous of the glass cover sheet being separated from the ribbon of glass.

20. The method of claim 19, wherein during the melting step, at least a portion of the batch materials forms a cold crown over the molten glass.

21. The method of claim 20, wherein during the melting step, additional batch materials are delivered onto the cold crown within the vertical electric melter.

22. The method of any one of claims 19-21, wherein the molten glass comprises a composition (on an oxide basis) that is substantially free of Na2O.

23. The method of any one of claims 19-22, wherein during the delivering step, the molten glass is delivered into a fish tail slot via more than one input tube.

24. The method of any one of claims 19-23, wherein during the delivering step, a screw feeder regulates a flow rate of the molten glass into a fish tail slot and the molten glass is delivered to the nip through the fish tail slot.

25. The method of any one of claims 19-24, wherein during the delivering step, the molten glass is delivered to the nip through more than one fish tail slot.

26. The method of any one of claims 19-25, wherein during the delivering step, the molten glass forms a contact angle of less than 45 degrees with both of the pair of forming rollers relative to a horizontal plane that extends through both axes of rotation of the pair of forming rollers.

27. The method of any one of claims 19-26, wherein during the delivery step, the molten glass is delivered first into a trough of a fusion forming apparatus, the molten glass overflows opposing walls of the trough, down outer side surfaces of the opposing walls, and converges at a root, and then flows down into the nip between the pair of forming rollers.

28. The method of claim 27, wherein the root is disposed elevationally below a horizonal plane tangential to both of the pair of forming rollers and elevationally above a horizontal plane extending through the axes of rotation of the pair of forming rollers.

29. The method of any one of claims 19-28 further comprising: a pre-delivery thermal conditioning step comprising, after the melting step and before the delivering step, raising or lowering a temperature of the molten glass from the vertical electric melter in a forehearth before the molten glass is delivered to the nip between the pair of forming rollers.

30. The method of any one of claims 19-29 further comprising: a sizing step, which occurs after the ribbon forming step and before the texturing step, comprising rotating a pair of sizing rollers and contacting the ribbon of glass while the ribbon of glass is vertically oriented between the pair of sizing rollers and thereby decreasing a thickness of the ribbon of glass.

31. The method of any one of claims 19-30, wherein the texturing step further comprises rotating a pair of sizing rollers, at least one of which is a texturing roller, disposed below the pair of forming rollers while the ribbon of glass proceeds vertically downward between the pair of forming rollers, and the pair of sizing rollers contact the first primary surface and the second primary surface of the ribbon of glass and thereby emboss the first texture onto one or both of the first primary surface and the second primary surface.

32. The method of claim 31, whereinthe pair of sizing rollers additionally reduce a thickness of the ribbon of glass while embossing the first texture onto the ribbon of glass.

33. The method of any one of claims 19-32, wherein the texturing step further comprises conveying the ribbon of glass upon the conveyor between a texturing roller and a conveyor surface, and the texture roller rotates and contacts the ribbon of glass with force sufficient to emboss the first texture, from one or both of the conveyor surface and the texturing roller, onto one or both of the first primary surface and the second primary surface of the ribbon of glass.

34. The method of claim 33, wherein a ceramic mold of the conveyor embosses the first texture onto the second primary surface of the ribbon of glass.

35. The method of any one of claims 19-34, wherein the first texture of the ribbon of glass is a repeating pattern of features having a largest dimension of less than 600 pm and a depth of less than 600 pm.

36. The method of any one of claims 19-35, wherein the first texture of the glass cover sheet is a repeating pattern of features having a largest dimension of less than 600 pm and a depth of less than 20 pm.

37. The method of any one of claims 19-36, wherein during the reorienting step, an air turn assembly provides an air bearing surface to precisely control reorientation of the ribbon of glass from the vertical orientation to the horizontal orientation without marking the glass.

38. The method of any one of claims 19-37 further comprising: a second texturing step occurring after the reorienting step comprising conveying the ribbon of glass upon the conveyor between a texturing roller and the conveyor, and the texturing roller rotates and contacts the ribbon of glass with force sufficient to emboss a second texture, from one or both of a ceramic mold and the texturing roller, onto one or both of the first primary surface and the second primary surface of the ribbon of glass.

39. The method of claim 38, wherein the second texture is embossed over the first texture.

40. The method of any one of claims 19-39 further comprising: a measuring step comprising determining the width of the ribbon of glass.

41. The method of claim 40, wherein rotational speed of the pair of forming rollers during the ribbon forming step is controlled as a function of the measured width of the ribbon of glass during the measuring step.

42. The method of any one of claims 40-41, wherein a width measurer generates output from which the width of the ribbon of glass is determined during the measuring step.

43. The method of any one of claims 19-42 further comprising: an edge separating step, which occurs after the reorienting step but before the separating step, comprising conveying the ribbon of glass under an edge forming roller with two blades separated by a distance, which manipulates the ribbon of glass to redefine the lateral edges of the ribbon of glass and to narrow the width of the ribbon of glass.

44. The method of any one of claims 19-43, wherein the width of the ribbon of glass is greater than or equal to 1 meter.

45. The method of any one of claims 19-44, wherein the separating step further comprises reducing a thickness of the ribbon of glass across the width of the ribbon of glass at a pinch line, and separation of the glass cover sheet from the ribbon of glass occurs at the pinch line spontaneously as the ribbon of glass cools.

46. The method of claim 45, whereina pair of rollers, at least one of which is a pinch roller, between which the ribbon of glass moves while the ribbon of glass is vertically oriented, form the pinch line into the ribbon of glass.

47. The method of claim 45, wherein a pinch roller forms the pinch line into the ribbon of glass by rolling across the width of the ribbon of glass while the ribbon of glass is horizontally oriented and being conveyed.

48. The method of any one of claims 19-45, wherein the separating step further comprises forming a score into the ribbon of glass across the width of the ribbon of glass and applying a force that causes separation of the glass cover sheet from the ribbon of glass.

49. The method of claim 48, wherein the forming of the score into the ribbon of glass occurs while the ribbon of glass is disposed on the conveyor and in the horizontal orientation, and the score is generated with a scribe wheel that moves diagonally relative to the lateral edges of the ribbon of glass while the ribbon of glass is being conveyed.

50. The method of any one of claims 19-49 further comprising: a post-separation thermal conditioning step comprising, after the separating step, thermally treating the glass cover sheet.

51. The method of claim 50, wherein the post-separation thermal conditioning step occurs in a lehr offline from the conveyor.

52. The method of claim 50, wherein the post-separation thermal conditioning step occurs in a roller hearth furnace and the conveyor conveys the glass cover sheet to the roller hearth furnace.

53. The method of any one of claims 19-52, whereinthe lateral edges of the glass cover sheet are the lateral edges of the ribbon of glass from which the glass cover sheet was separated during the separating step.

54. The method of any one of claims 19-53, wherein the glass cover sheet further comprises a width between the parallel lateral edges of the glass cover sheet, and the width is greater than or equal to 1 m.

55. The method of any one of claims 19-54, wherein the glass cover sheet further comprises a first primary surface, a second primary surface, and a thickness between the first primary surface and the second primary surface, and the thickness of the glass cover sheet is less than 2.0 mm.

56. The method of claim 55, wherein the thickness of the glass cover sheet is less than 0.5 mm.

57. The method of any one of claims 19-56 further comprising: an assembling step comprising assembling the glass cover sheet over one or more photovoltaic cells to form a solar panel.

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