Methods of making glass articles having complex 3D shapes

Abstract

A method of forming a glass article includes forming a local 3D complex shape in a flat glass sheet to produce an intermediate glass article having a first region having the at least one local 3D complex shape and a second region that is flat. The method further includes, after forming the local 3D complex shape, subjecting at least a portion of the intermediate glass article to a cold forming process to produce a glass article having the local 3D complex shape and at least one bend region having a curved surface.

Description

Attorney Docket No. SP25-136PCTMETHODS OF MAKING GLASS ARTICLES HAVING COMPLEX 3D SHAPESCROSS-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 / 848,670 filed July 22, 2025, and also claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63 / 733,539 filed December 13, 2024, the content of each of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] Principles and embodiments of the present disclosure relate generally to glass articles having complex 3D shapes and methods of making the glass articles having the complex 3D shapes.BACKGROUND

[0003] Many products include a three-dimensional (3D) glass article. Some examples of articles that include a 3D glass article include but are not limited to curved LCD or LED TV screens, smart phones, windows and other architectural structures, and consumer appliances. Innovations in the shape of products brings new challenges to the manufacturing processes for 3D parts, an in particular 3D parts that are made of glass, which should have excellent optical properties, along with desirable scratch-resistant and impact-resistant properties.

[0004] Additionally, vehicle manufacturers are creating interiors that better connect, protect, and safely inform today's drivers and passengers. As the industry moves towards autonomous driving, there is a need for creating large format, appealing displays. There is already a trend towards larger displays including touch functionality in the new models from several OEMs. However, most of these displays consist of two dimensional plastic cover lenses. Due to these emerging trends in the automotive interior industry and related industries, there is a need to develop a low cost technology to make three-dimensional transparent surfaces. Of further interest is the development of automotive interior parts that include bends in different directions, while maintaining complete independence between the bends.

[0005] Therefore, a continuing need exists for methods of manufacturing 3D articles, and in particular, 3D glass articles having complex shapes and desirable optical and mechanical properties.Attorney Docket No. SP25-136PCTSUMMARY

[0006] The present disclosure is directed to methods for manufacturing glass articles having complex 3 -dimensional (3D) shapes from flat glass sheets and the glass articles made by the methods. The methods disclosed herein include forming one or more local 3D complex shapes in one region of the flat glass sheet in a first forming process to produce an intermediate glass sheet having the local 3D complex shapes in a first region, and then, after forming the local 3D complex shapes in the first region, subjecting a second region of the intermediate glass article to a second forming process to produce a bend region having a curved surface. The second forming process may be a cold forming process conducted well below the glass transition temperature of the glass. The resulting glass articles have the local 3D complex shapes and the bend region, which is separate from the local 3D complex shapes.

[0007] According to a first aspect disclosed herein, a method of forming a glass article may comprise: forming at least one local 3D complex shape in a flat glass sheet to produce an intermediate glass article having a first region having the at least one local 3D complex shape and a second region that is flat; and after forming the at least one local 3D complex shape, subjecting at least a portion of the intermediate glass article to a cold forming process to produce a glass article having the at least one local 3D complex shape and at least one bend region having a curved surface.

[0008] A second aspect disclosed herein may include the first aspect, wherein at least one local 3D complex shape may be characterized by one or more of the following: a maximum compressive strain (MCS) of from about 0.5% to about 20%, wherein the MCS is the maximum compressive strain needed to flatten the at least one local 3D complex shape back to a flat sheet; a total curvature of greater than zero, where the total curvature is equal to a product of a first curvature with respect to a first axis and a second curvature with respect to a second axis; a glass thickness of at least about 0.5 mm and a radius of curvature of less than about 70 mm in at least one region of the local 3D complex shape; a glass thickness of at least about 0.1 mm and a radius of curvature of less than about 20 mm; or any combinations thereof.

[0009] A third aspect disclosed herein may include either one of the first or second aspects, wherein forming the at least one local 3D complex shape may comprise providing a monolithic mold having a flat region, at least one recess having a shape complimentary to the at least one local 3D complex shape, a retention feature configured to hold the glass sheet against a first surface of the mold during the forming, and a vacuum box disposed below the at least oneAttorney Docket No. SP25-136PCT recess and the retention feature, wherein the vacuum box may be in fluid communication with a vacuum source, the at least one recess, and the retention feature.

[0010] A fourth aspect disclosed herein may include the third aspect, wherein the monolithic mold may be made of graphite.

[0011] A fifth aspect disclosed herein may include either one of the third or fourth aspects, wherein the mold may have the first surface that contacts the flat glass sheet and a second surface opposite the first surface, wherein the vacuum box may be disposed on the second surface at a position opposite from the at least one recess.

[0012] A sixth aspect disclosed herein may include any one of the third through fifth aspects, wherein the retention feature may circumscribe the at least one recess and, upon application of a vacuum to the vacuum box, the retention feature may create a seal between the first surface of the mold and the flat glass sheet that may hold the flat glass sheet against the first surface of the mold and may maintain the vacuum in the vacuum box and between the mold and the flat glass sheet at the at least one recess.

[0013] A seventh aspect disclosed herein may include the sixth aspect, wherein the retention feature may comprise a groove on the first surface of the mold, the groove circumscribing the at least one recess, and a plurality of vacuum holes disposed in the groove and passing through the mold from the first surface to a second surface, wherein the vacuum box may be in fluid communication with the groove through the plurality of vacuum holes.

[0014] An eighth aspect disclosed herein may include the seventh aspect, wherein the groove may have a width of from about 3 to about 10 times a thickness of the flat glass sheet, such as from about 0.3 mm to about 20 mm.

[0015] A nineth aspect disclosed herein may include either one of the seventh or eighth aspects, wherein the groove may have a depth of from about 0.1 to about 10 times a thickness of the flat glass sheet, such as from about 0.1 mm to about 10 mm.

[0016] A tenth aspect disclosed herein may include the sixth aspect, wherein the retention feature may comprise an offset region of the monolithic mold disposed around the at least one recess, wherein in the offset region, the first surface of the mold may be offset away from the flat glass sheet relative to the first surface in the flat region.Attorney Docket No. SP25-136PCT

[0017] An eleventh aspect disclosed herein may include the tenth aspect, wherein the offset region may comprise a plurality of vacuum holes extending through the mold and in fluid communication with the vacuum box.

[0018] A twelfth aspect disclosed herein may include any one of the third through eleventh aspects, comprising a plurality of vacuum holes in the at least one recess.

[0019] A thirteenth aspect disclosed herein may include any one of the third through twelfth aspects, wherein the forming the at least one local 3D complex shape further may comprise loading the flat glass sheet into the mold, heating the flat glass sheet, and applying a vacuum to the vacuum box of the monolithic mold, wherein the heating and applying the vacuum may cause the flat glass sheet to deform into the at least one recess to produce the at least one local 3D complex shape.

[0020] A fourteenth aspect disclosed herein may include the thirteenth aspect, comprising heating the flat glass sheet to a reforming temperature that may be less than a glass transition temperature of the flat glass sheet.

[0021] A fifteenth aspect disclosed herein may include the fourteenth aspeect, wherein the reforming temperature may be from about 20 °C to about 60 °C less than the glass transition temperature of the flat glass sheet.

[0022] A sixteenth aspect disclosed herein may include either one of the fourteenth or fifteenth aspects, wherein the reforming temperature may be a temperature at which a viscosity of the flat glass sheet is from about IxlO72poise to about IxlO8poise, such as from about IxlO76poise to about IxlO8poise.

[0023] A seventeenth aspect disclosed herein may include any one of the fourteenth through sixteenth aspects, wherein heating the flat glass sheet may comprise at least partially masking portions of the flat glass sheet contacting the flat regions of the monolithic mold.

[0024] An eighteenth aspect disclosed herein may include any one of the fourteenth through seventeenth aspects, comprising applying the vacuum for a duration sufficient for the flat glass sheet to conform to the at least one recess of the monolithic mold.

[0025] A nineteenth aspect disclosed herein may include the eighteenth aspecct, wherein the duration of applying the vacuum may be up to about 2 minutes, such as from about 15 seconds to about 2 minutes, from about 30 seconds to about 1.5 minutes.Attorney Docket No. SP25-136PCT

[0026] A twentieth aspect disclosed herein may include any one of the fourteenth through nineteenth aspects, further comprising removing the vacuum from the vacuum box after the flat glass sheet has conformed to the at least one recess.

[0027] A twenty-first aspect disclosed herein may include any one of the fourteenth through twentieth aspects, further comprising removing the intermediate glass article from the monolithic mold after the flat glass sheet has conformed to the at least one recess.

[0028] A twenty-second aspect disclosed herein may include any one of the fourteenth through twenty-first aspects, further comprising controlled cooling of the intermediate glass article after the flat glass sheet has conformed to the at least one recess.

[0029] A twenty-third aspect disclosed herein may include the twenty-second aspecct, further comprising removing the intermediate glass article from the monolithic mold after the controlled cooling.

[0030] A twenty-fourth aspect disclosed herein may include any one of the first through twenty -third aspects, comprising subjecting the second region of the intermediate glass article to the cold forming process.

[0031] A twenty-fifth aspect disclosed herein may include any one of the first through twenty-fourth aspects, wherein the method does not include subjecting the first region of the intermediate glass article having the at least one local 3D complex shape to the cold forming.

[0032] A twenty-sixth aspect disclosed herein may include any one of the first through twenty-fifth aspects, comprising subjecting the intermediate glass article to the cold forming process at a cold forming temperature that may be at least about 200 °C less than a glass transition temperature of the flat glass sheet.

[0033] A twenty-seventh aspect disclosed herein may include any one of the first through twenty-sixth aspects, comprising subjecting the intermediate glass article to the cold forming process at a cold forming temperature of less than about 430 °C.

[0034] A twenty-eighth aspect disclosed herein may include any one of the first through twenty-seventh aspects, wherein the cold forming may comprise placing the second region of the intermediate glass sheet between a first form and a second form that is complimentary to the first form and gradually moving the first form and the second form towards each other at the cold forming temperature.Attorney Docket No. SP25-136PCT

[0035] A twenty-ninth aspect disclosed herein may include any one of the first through twenty-eighth aspects, further comprising edge finishing the intermediate glass article, decorating one or more surfaces of the intermediate glass article, or both.

[0036] A thirtieth aspect disclosed herein may include the twenty-ninth aspect, where the edge finishing, decorating, or both may be conducted after forming the at least one local 3D complex shape and before subjecting the intermediate glass article to the cold forming process.

[0037] A thirty-first aspect disclosed herein may include any one of the first through thirtieth aspects, comprising providing the flat glass sheet.

[0038] A thirty-second aspect disclosed herein may include the thirty-first aspect, wherein the flat glass sheet may have a thickness of from about 0.1 mm to about 2 mm, such as from about 0.5 mm to about 1.5 mm, or about 0.5 mm to about 1.2 mm.

[0039] A thirty-third aspect disclosed herein may include either one of the thirty-first or thirty-second aspects, wherein the flat glass sheet may comprise an aluminosilicate glass, an alkali aluminosilicate glass, a soda lime glass, or a borosilicate glass.

[0040] A thirty-fourth aspect disclosed herein may include any one of the thirty-first through thirty -third aspects, wherein the flat glass sheet may be a strengthened flat glass sheet.

[0041] A thirty-fifth aspect disclosed herein may include any one of the first through thirtyfourth aspects, and may be directed to the glass article made by the method of any one of the first through thirty-fourth aspects, wherein the glass article may have the at least one local 3D complex shape and the at least one bend region that does not include the at least one local 3D complex shape.

[0042] A thirty-sixth aspect disclosed herein may the thirty-fifth aspect, wherein the at least one local 3D complex shape may have a maximum compressive strain (MCS) of from about 0.5% to about 20%, wherein the MCS is the maximum compressive strain needed to flatten the at least one local 3D complex shape back to a flat sheet.

[0043] A thirty-seventh aspect disclosed herein may include either one of the thirty-fifth or thirty-sixth aspects, wherein the at least one local 3D complex shape may have a non-zero Gaussian curvature or non-developable curvature.Attorney Docket No. SP25-136PCT

[0044] A thirty-eighth aspect disclosed herein may include any one of the thirty-fifth through thirty-seventh aspects, wherein the at least one local 3D complex shape may have a complex curvature characterized by a curvature in two or more directions.

[0045] A thirty-ninth aspect disclosed herein may include the thirty-eighth aspect, wherein at least one region of the at least one local 3D complex shape may have a total curvature of greater than zero, where the total curvature is equal to a product of a curvature along a first axis and a curvature along a second axis.

[0046] A fortieth aspect disclosed herein may include any one of the thirty-fifth through thirty-ninth aspects, wherein the glass article may have a glass thickness of at least 0.5 mm and the at least one local 3D complex shape may have a radius of curvature of less than about 70 mm in at least one portion of the at least one local 3D complex shape.

[0047] A forty-first aspect disclosed herein may include any one of the thirty-fifth through fortieth aspects, wherein the glass article may have a glass thickness of at least about 0.1 mm and the at least one local 3D complex shape may have a radius of curvature of less than about 20 mm in at least one portion of the at least one local 3D complex shape.

[0048] A forty-second aspect disclosed herein may include any one of the thirty-fifth through forty-first aspects, wherein: the glass article has an A surface and a B surface; the B surface is the surface of the glass article that contacted the monolithic mold during the DVF process; and in at least a portion of the at least one bend region that does not include the at least one local 3D complex shape, the B surface does not exhibit surface defects caused by contact with the monolithic mold under vacuum.

[0049] A forty -third aspect disclosed herein may include any one of the thirty -fifth through forty-second aspects, wherein the glass article is not curved in the region around the local 3D complex shape.

[0050] These and other aspects, advantages, and salient features will become apparent from the following detailed description, the accompanying drawings, and the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 schematically depicts a perspective view of a glass article having a local 3D complex shape and a bend region having a curved surface, according to embodiments shown and described herein;Attorney Docket No. SP25-136PCT

[0052] FIG. 2 is a flow diagram of a method of making the glass article of FIG. 1, according to embodiments shown and described herein;

[0053] FIG. 3 schematically depicts a perspective view of a monolithic mold for forming the local 3D complex shapes, according to embodiments shown and described herein;

[0054] FIG. 4 schematically depicts a cross-sectional view of the mold of FIG. 3 showing a vacuum box disposed below the mold, according to embodiments shown and described herein;

[0055] FIG. 5 A schematically depicts a retention feature of the mold of FIG. 4, according to embodiments shown and described herein;

[0056] FIG. 5B schematically depicts another embodiment of a retention feature for a monolithic mold, according to embodiments shown and described herein;

[0057] FIG. 6 schematically depicts another embodiment of a monolithic mold for forming the local 3D complex shape, according to embodiments shown and described herein;

[0058] FIG. 7 schematically depicts a cross-sectional view of the mold of FIG. 6 showing a vacuum box disposed below the mold, according to embodiments shown and described herein;

[0059] FIG. 8 schematically depicts a close-up cross-sectional view of the mold of FIG. 7 showing the grooved retention feature, according to embodiments shown and described herein;

[0060] FIG. 9 schematically depicts another embodiment of a monolithic mold having a T- shape, according to embodiments shown and described herein;

[0061] FIG. 10 schematically depicts a perspective view of the mold of FIG. 6 having a screen for controlling heating of the flat glass sheet during forming of the local 3D complex shape, according to embodiments shown and described herein;

[0062] FIG. 11 schematically depicts a perspective view of an intermediate glass article prepared using the mold of FIG. 3 and having a local 3D complex shape formed in a first region, according to embodiments shown and described herein;

[0063] FIG. 12 schematically depicts a side view of a cold forming process for creating a curve in a second region of the intermediate glass article of FIG. 11, according to embodiments shown and described herein;Attorney Docket No. SP25-136PCT

[0064] FIG. 13 is a photograph of a monolithic mold for Example 1, according to embodiments shown and described herein;

[0065] FIG. 14 is a photograph of an intermediate glass article made with the mold of FIG. 13, according to embodiments shown and described herein;

[0066] FIG. 15 is a photograph of a glass article produced from the intermediate glass article of FIG. 14 through cutting, edge finishing, and decorating, according to embodiments shown and described herein;

[0067] FIG. 16 is a photograph of a mold for Example 2, according to embodiments shown and described herein;

[0068] FIG. 17 schematically depicts an intermediate glass article made with the mold of FIG. 16, according to embodiments shown and described herein; and

[0069] FIG. 18 is a photograph of the glass article of Example 2 made from the intermediate glass article represented in FIG. 17, which was made with the mold shown in FIG. 16, according to embodiments shown and described herein.DETAILED DESCRIPTION

[0070] Reference will now be made in detail to embodiments of strengthened glass articles and methods of making the glass articles, examples of which are illustrated in the accompanying drawings. In particular, the present disclosure is directed to methods for manufacturing glass articles having complex 3D shapes from flat glass sheets and the glass articles made by the methods. Referring to FIG. 1, the glass articles 100 produced by the methods disclosed herein include at least one local 3D complex shape 110 and a bend region 120 that is separate from the local 3D complex shape 110, such that the bend region 120 does not include the local 3D complex shape 110. The methods disclosed herein for making the glass articles 100 include forming at least one local 3D complex shape 110 in a flat glass sheet and then cold forming to produce the glass articles 100 having the local 3D complex shape 110 and a bend region 120 separate from the local 3D complex shape 110. Referring to FIG. 2, the methods 200 may include providing 210 a flat glass sheet, forming 220 at least one local 3D complex shape in a flat glass sheet to produce an intermediate glass article having a first region comprising the at least one local 3D complex shape and a second region that is flat, and after forming 220 the at least one local 3D complex shape, subjecting 230 at least a portion of theAttorney Docket No. SP25-136PCT intermediate glass article to a cold forming process to produce the glass article having the at least one local 3D complex shape and at least one bend region having a curved surface.

[0071] In the following description, like reference characters designate like or corresponding parts throughout the several views shown in the figures. It is also understood that, unless otherwise specified, terms such as "top," "bottom," "outward," "inward," and the like are words of convenience and are not to be construed as limiting terms. In addition, whenever a group is described as comprising at least one of a group of elements and combinations thereof, it is understood that the group may comprise, consist essentially of, or consist of any number of those elements recited, either individually or in combination with each other. Similarly, whenever a group is described as consisting of at least one of a group of elements or combinations thereof, it is understood that the group may consist of any number of those elements recited, either individually or in combination with each other. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range as well as any ranges therebetween. As used herein, the indefinite articles "a," "an," and the corresponding definite article "the" mean "at least one" or "one or more," unless otherwise specified.

[0072] As used herein, "cold forming" refers to a process in which glass is shaped to have a curved or three-dimensional shape at a temperature that is at least about 200 °C less than the glass transition temperature of the glass, such as from room temperature to about 200 °C less than the glass transition temperature of the glass.

[0073] As used herein, "single curvature" bending is bending in at least a partial cylindrical-type shape that has a single radius of curvature and is characterized by a Gaussian curvature of zero, where the Gaussian curvature (K) is the product of principal curvatures ki and k2, where ki is the curvature with respect to a first bend axis and k2 is the curvature with respect to a second bend axis. The axis running through the center of the cylindrical-type bend and perpendicular to the radius of curvature is designated herein as the "bend axis." Line segments that are located on the surface of the bend region of the article and that run parallel to the bend axis are designated herein as "bend line segments." As bend line segments are parallel to the associated bend axis, bend regions that have parallel or non-parallel bend axes will have parallel or non-parallel bend line segments, respectively.

[0074] As used herein, "double curvature" or "cross curvature" bending results from two interacting single curvatures that have overlapping bend axes, with each single curvatureAttorney Docket No. SP25-136PCT having its own bend axis and radius of curvature. Such configurations include synclastic and anticlastic configurations. In a synclastic configuration, all normal sections of the bend region are concave shaped or convex shaped, such as for a shell-shaped or dome-shaped configuration. In an anticlastic configuration, some normal sections of the bend region will have a convex shape whereas others will have a concave shape, such as for a saddle-shaped configuration. The bend line segments for an article having double curvature will be curved due to the interaction of the two curvatures. Accordingly, the bend line segments for the two interacting curvatures in a double curvature are dependent and not independent. "Double curvature" or "cross curvature" can be characterized by a Gaussian curvature that is non-zero, where the Gaussian curvature (K) is the product of principal curvatures ki and k2.

[0075] As used herein, a "bend region" refers to a portion of an article that is curved in one or more directions. The bend region has non-zero curvature throughout the entire region. Bend regions can have single curvature or double curvature. In embodiments, the bend region has single curvature and does not have any cross curvature. A bend region may be adjacent to another bend region or may be adjacent to a flat region.

[0076] As used herein, a "flat region" of a glass article or monolithic mold refers to a portion of the glass article or monolithic mold that has substantially zero or zero curvature. As used herein, "substantially zero curvature" means a radius of curvature of at least about 1 meter. A flat region can be located between two or more bend regions. In embodiments, a minimum distance between two non-adjacent bend regions is at least 10 millimeters, and thus the flat region spans a distance of at least 10 millimeters. Exemplary flat regions can span distances including the following values or ranges defined therefrom: 10, 15, 20, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900 or 950 millimeters, or 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, 3, 3.5, 4, 4.5 or 5 meters.

[0077] As used herein, the terms "non-developable curvature" or "non-zero Gaussian curvature" means a curvature with crossed radii that cannot be formed with a sheet of paper by bending without also stretching, tearing, or wrinkling the paper. Exemplary non-developable curvatures include, but are not limited to, spherical curvatures, spheroid curvatures, partially spheroid curvatures, and three-dimensional saddle curvatures. A "developable curvature" or a "zero Gaussian curvature" means a curvature that can be formed with a sheet of paper byAttorney Docket No. SP25-136PCT bending alone. Exemplary developable curvatures include, but are not limited to, cylindrical and conical curvatures.

[0078] Thin glass sheets can be formed using a mold in combination with heat and vacuum pressure to produce complex 3D shapes in the glass sheet. The complex 3D shapes produced by this forming method can have curvatures with multiple radii of curvature, curvatures with small radius of curvature, non-developable curvature, or other complex types of shapes to meet challenging geometrical and optical requirements. These complex 3D shapes can be useful in applications related to automotive interiors, architectural applications, consumer electronics, consumer appliances, or other applications.

[0079] Thin glass sheets can also be formed through a cold-forming process to curve the thin glass sheet. During cold-forming, the curvature is applied to the thin glass sheet at temperatures well below the glass transition temperature of the thin glass sheet, such as at cold forming temperatures at least 200 °C less than the glass transition temperature of the glass, or from room temperature to at least 200 °C less than the glass transition temperature. However, cold forming is limited by the complexity of the shapes that can be achieved. For instance, cold forming is limited to developable curvatures such as cylindrical or conical curvatures and curvatures having a large radius of curvature (e.g., curvatures having a radius of curvature of at least 80 mm for glass thickness of 0.5 mm). Attempting to make more complex shapes from cold forming leads to cracking and / or breaking of the glass sheet.

[0080] There is a need for high precision, large glass articles that have a global 2D deformation (i.e., curved surface) and local 3D complex shapes entering or extending into the glass sheet. For instance, for a dashboard or middle console for an automotive interior application, there is a need for glass articles having a simple curvature as well as one or more local 3D complex shapes that extend into the glass sheet. When such glass articles have the combination of a curved region having a radius of curvature and one or more local 3D complex shapes formed in the glass, conventional sagging processes or press forming processes often result in glass wrinkling issues and / or surface damage.

[0081] A hot forming process, such as but not limited to deep vacuum forming (DVF) technology, press forming, and / or a sagging process could be used alone to form both the local 3D complex shape and the curved region having the radius of curvature, but would have many disadvantages. For instance, DVF can be challenging due to the following factors: (1) Glass deformation without surface wrinkling due to highly non-developable shapes; (2) Complex andAttorney Docket No. SP25-136PCT expensive multi-piece molds required to form both the local 3D complex shape and curved region; and (3) Glass surface damage linked to the combination of moderately low viscosity required for obtaining such deformation levels and forced contact against a mold or a pressing shape in order to precisely control the geometry. Cold forming of glass sheets can be challenging due to deformation according to aggressive radius of curvature in one direction at room temperature. Additionally, local 3D complex shapes having small radius of curvature and / or non-developable curvature cannot be efficiently made through cold forming without significant breakage of the glass articles.

[0082] The subject matter of the present application is directed to methods of glass forming that include forming the local 3D complex shape in a first region of the flat glass sheet through a first forming process to produce an intermediate glass article having the local 3D complex shape, and then, second, subjecting a second region of the intermediate glass article to a second forming process, which is a cold forming process, to produce a bend region having a curvature, such as a developable curvature. The resulting glass articles made by the disclosed methods have the local 3D complex shapes and a bend region that has a curved surface. The local 3D complex shape has a non-developable curvature and / or a curvature having a small radius of curvature (i.e., radius of curvature less than 80 mm for a glass thickness of at least 0.5 mm), and the bend region has a developable curvature and / or a curvature having large radius of curvature (i.e., a radius of curvature of at least 80 mm for glass thickness of at least 0.5 mm). The methods disclosed herein include a combination of the two forming processes to form the glass articles having a large 2D concave or convex deformation radius and / or developable curvature in the bend region and the local 3D complex shape separate from the bend region. The first forming process includes using a monolithic mold design having local retention features and flat surfaces for maintaining optical quality.

[0083] The monolithic mold for the first forming process for producing the local 3D complex shape is mostly flat and simple except for recesses for forming the local 3D complex shape. The simple design of the monolithic mold simplifies manufacturing and reduces manufacturing costs. For instance, the first surface of the mold (i.e., the top surface) for the first forming process is naturally flat, which makes it easier to install the flat glass sheet preform into the mold compared to the molds used in other more complex molding processes. The size of the flat glass sheet can be reduced, resulting in reduced waste, and more parts can be formed using the molds disclosed herein before needing to replace the mold. The mold thickness isAttorney Docket No. SP25-136PCT smaller and machined in a monolith, compared to a process of forming the entire glass article in a hot forming process, for which the mold is a stack due to the mold raw material dimensions. The glass article can be cut, edge finished, and decorated in 2D before cold-forming to produce the curve in the bend region. The glass article is only subjected to the first forming process in the area of the local 3D complex shape, and is only subject to gravity in the flat portion. This results in less copying of mold defects in the flat areas of the mold. The bend region is instead formed by the cold forming process, which does not impart the surface defects in the glass article to the extent of the first forming process. Thus, the surface degradation in the bend region can be reduced compared to conventional hot forming processes, among other features.

[0084] Referring to FIG. 2, the methods 200 disclosed herein for producing a glass article a glass sheet include forming at least one local 3D complex shape in a flat glass sheet in step 220 to produce an intermediate glass article having a first region comprising the at least one local 3D complex shape and a second region that is substantially flat. After the forming the at least one local 3D complex shape in the first forming process of step 220, the methods 200 may include subjecting at least a portion of the intermediate glass article to a cold forming process in step 230 to produce the glass article having the at least one local 3D complex shape and the bend region with the curved surface. The methods 200 may include providing the flat glass sheet in step 210. Providing the flat glass sheet in step 210 may come before forming the at least one local 3D complex shape in step 220. The methods 200 may also include cutting or trimming the edges of the intermediate glass article in step 222 (e.g., laser cutting or other cutting method), edge finishing the intermediate glass article in step 240, decorating the intermediate glass article in step 250, or a combination of these, which may be performed after forming the local 3D complex shape in step 220 and before the cold forming in step 230. Other intermediate steps may be conducted between the first forming process in step 220 and the second forming process in step 230. The methods 200 produce the glass article having at least one local 3D complex shape and the bend region.

[0085] The flat glass sheet may be of any type of glass suitable for the intended application. Types of suitable glass may include but are not limited to an aluminosilicate glass, an alkali aluminosilicate glass, a soda lime glass, a borosilicate glass, or a silica glass, for example. The flat glass sheet may be made by any conventional process, such as but not limited to a downdraw process, slot draw process, or float process, or other existing or future-developed glass process. In embodiments, the flat glass sheet may be a strengthened glass sheet, such asAttorney Docket No. SP25-136PCT a flat glass sheet strengthened through ion-exchange, thermal tempering, lamination, other strengthening process, or combinations thereof. In embodiments, the flat glass sheet is GORILLA® glass manufactured by Coming Incorporated.

[0086] The flat glass sheet may have a thickness that enables the flat glass sheet to be hot formed in the first forming process to produce the local 3D complex shape and then cold formed in the second forming process to produce the bend region. In embodiments, the flat glass sheet may have a thickness of at least about 0.1 mm, such as at least about 0.5 mm, at least about 0.7 mm, or at least about 1 mm. In embodiments, the thickness of the flat glass sheet may be not more than about 2 mm. When the thickness of the flat glass sheet is greater than about 2 mm, the thickness may be too great to allow for cold forming the intermediate glass sheet to produce the curved surface in the bend region. In embodiments, the flat glass sheet may have a thickness of from about 0.1 mm to 2 mm, such as from about 0.1 mm to about 1.5 mm, from about 0.1 mm to 1.2 mm, from about 0.1 mm to about 1 mm, from about 0.5 mm to about 2 mm, from about 0.5 mm to about 1.5 mm, from about 0.5 mm to about 1.2 mm, from about 0.5 mm to about 1 mm, from about 0.7 mm to about 2 mm, from about 0.7 mm to about 1.5 mm, from about 0.7 mm to about 1.2 mm, from about 0.7 mm to about 1 mm, from about 0.9 mm to about 2 mm, from about 0.9 mm to about 1.5 mm, from about 0.9 mm to about 1.2 mm, from about 0.9 mm to about 1 mm, from about 1 mm to about 2 mm, from about 1 mm to about 1.5 mm, from about 1 mm to about 1.2 mm, or any range or sub-range therebetween.

[0087] The flat glass sheet may be substantially flat, meaning that at any point on the glass sheet, a curvature of the glass sheet in any and every direction is at least 1 meter (i.e., greater than or equal to 1 meter). Aside from being substantially flat, the flat glass sheet may have any shape that is appropriate for a given application and is not particularly limited with respect to two-dimensional shape. The flat glass sheet may have a 2D shape that is rectangular, square, polygonal, oval, circular, T-shaped, L-shaped, irregular shaped, or other shape. In embodiments, the flat glass sheet may be rectangular in shape. In embodiments, the flat glass sheet may have a T-shape or an L-shape. The size of the flat glass sheet is not particularly limited. Factors that affect the maximum size of the flat glass sheet may include the size of the equipment available for the various forming steps (e.g., size of the dynamic lehr oven for conducting the first forming process, for example).

[0088] As previously discussed, the methods include forming the at least one local 3D complex shape in the flat glass sheet to produce an intermediate glass sheet. The at least oneAttorney Docket No. SP25-136PCT local 3D complex shape is characterized by a shape that cannot be easily or realistically formed in the glass sheet through a cold forming process, such as shapes having complex curvatures (e.g., small radius of curvature, non-developable curvatures, etc.) or shapes extending deep into the glass surface. In embodiments, the at least one local 3D complex shape may be characterized by a maximum compressive strain (MCS), which represents the maximum amount of strain required to flatten the local 3D complex shape back to a flat sheet. In embodiments, the local 3D complex shape may be a shape having an MCS of at least about 0.5%, such as at least about 0.7%, or at least about 1.0%. In embodiments, the local 3D complex shape may be a shape having an MCS of from about 0.5% to about 20%, such as from about 0.5% to about 15%, from about 0.5% to about 10%, from about 0.5% to about 5%, from about 0.7% to about 20%, from about 0.7% to about 15%, from about 0.7% to about 10 %, from about 0.7% to about 5%, from about 0.7% to about 20%, from about 0.7% to about 15%, from about 0.7% to about 10 %, or from about 0.7% to about 5%.

[0089] The local 3D complex shape may be characterized by at least one region of the local3D complex shape having a complex curvature. The complex curvature in at least one region of the local 3D complex shape may be a curvature that cannot be attained from a cold forming process, such as a non-developable curvature, a curvature having a small radius of curvature, and / or a curvature that is curved in two or more directions (i.e., two or more axis of curvature). In embodiments, at least one region of the local 3D complex shape may include a non- developable curvature. In embodiments, at least one region of the local 3D complex shape may have a total curvature that is not equal to zero, where the total curvature is equal to a product of a first principle curvature with respect to a first axis and a second principle curvature with respect to a second axis. In embodiments, at least one region of the local 3D complex shape has a total curvature of greater than zero.

[0090] The local 3D complex shape may be characterized by at least one region of the local3D complex shape having a small radius of curvature such that the curvature cannot be produced in the glass article by cold forming alone. In embodiments, the flat glass sheet may have a thickness of greater than or equal to about 0.5 mm, and at least one region of the local 3D complex shape may have a radius of curvature of less than 80 mm, such as not more than about 70 mm, not more than about 60 mm, not more than about 50 mm, or not more than about 40 mm, from greater than 0 mm to less than 80 mm, from greater than 0 mm to about 70 mm, from greater than 0 mm to about 60 mm, from greater than 0 mm to about 50 mm, from greaterAttorney Docket No. SP25-136PCT than 0 mm to about 40 mm, from about 1 mm to about 70 mm, from about 1 mm to about 60 mm, from about 1 mm to about 50 mm, from about 1 mm to about 40 mm, from about 1 mm to about 30 mm, from about 1 mm to about 20 mm, from about 5 mm to about 70 mm, from about 5 mm to about 60 mm, from about 5 mm to about 50 mm, from about 5 mm to about 40 mm, from about 5 mm to 30 mm, or from about 5 mm to about 20 mm. In embodiments, the flat glass sheet may have a thickness of greater than or equal to about 0.1 mm, and at least one region of the local 3D complex shape may have a radius of curvature of not more than about 20 mm, such as not more than about 18 mm, not more than about 15 mm, not more than about 13 mm, not more than about 12 mm, or not more than about 10 mm, such as from about 0.1 mm to about 20 mm, from about 0.1 mm to about 18 mm, from about 0.1 mm to about 15 mm, from about 0.1 mm to about 13 mm, from about 0.1 mm to about 12 mm, from about 0.1 mm to about 10 mm, from about 1 mm to about 20 mm, from about 1 mm to about 18 mm, from about 1 mm to about 15 mm, from about 1 mm to about 13 mm, from about 1 mm to about 12 mm, from about 1 mm to about 10 mm, from about 5 mm to about 20 mm, from about 5 mm to about 18 mm, from about 5 mm to about 15 mm, from about 5 mm to about 13 mm, from about 5 mm to about 12 mm, or from about 5 mm to about 10 mm.

[0091] The step 220 of forming the local 3D complex shape in the flat glass sheet to produce the intermediate glass article may include providing a monolithic mold having at least one recess corresponding to the local 3D complex shape, loading the flat glass sheet onto the mold, heating the flat glass sheet, and applying a vacuum to a vacuum box of the monolithic mold, wherein the heating and applying the vacuum causes the flat glass sheet to deform into the recesses in the mold to produce the local 3D complex shapes in the flat glass sheet.

[0092] Referring now to FIGS. 3 and 4, one embodiment of the mold 300 for forming the local 3D complex shape is graphically depicted. The mold 300 may be a monolithic mold, meaning that the mold 300 may be a single piece of material, instead of a more complex mold, which can have a plurality of pieces or may be formed as a stack. The mold 300 may have a flat region 302, at least one recess 310 having a shape complimentary to the local 3D shape, a retention feature 320 configured to hold the flat glass sheet against a first surface 304 of the mold 300 during the forming, and a vacuum box 330 disposed below the at least one recess 310 and the retention feature 320. Referring to FIG. 4, the vacuum box 330 is in fluid communication with a vacuum source (not shown), the recess 310, and the retention feature 320. The mold 300 has the first surface 304 and a second surface 306 opposite the first surfaceAttorney Docket No. SP25-136PCT304. The first surface 304 is the surface of the mold 300 that contacts the flat glass sheet during the first forming process. The mold 300 may further have a plurality of vacuum holes 326 disposed in the recess and positioned in the retention feature 320.

[0093] The mold 300 may be manufactured from a non-stick material, such as but not limited to graphite or other non-stick material. The first surface 304 of the mold 300 can comprise a material that resists adhesion to the flat glass sheet during reformation. Exemplary materials for the first surface 304 of the mold 300 include, but are not limited to, graphite, boron nitride, silica soot, calcium carbonate, carbon soot, a refractory metallic alloy, molybdenum disulfide, or tungsten disulfide. In embodiments, mold 300 may be formed of any of these materials. In embodiments, any of these materials can be coated onto the first surface 104 of the mold 300 to define the mold surface. For example, in embodiments, mold 300 can be a made of a refractory metallic alloy coated with molybdenum disulfide or tungsten disulfide to define the first surface 304. In embodiments, the mold 300 may be a graphite mold. The mold 300 may be machined from a graphite block to have the one or more recesses 310 complimentary to the local 3D complex shapes. The mold 300 may have a generally constant thickness, even in the area of the recesses 310 and retention features 320. The constant thickness of the mold 300 may reduce variations in thermal environment between different points in the flat glass sheet during the forming of the local 3D complex shapes.

[0094] In embodiments, the mold 300 may include a frame 340, which may hold the mold 300 and protect the mold 300 from exposure to oxygen or other contaminants in the heating environment. In embodiments, the frame 340 may be a metal frame that circumscribes the peripheral edge of the mold 300. In embodiments, the mold 300 does not have a frame 340. When the heating environment used to heat the glass sheet is controlled, such as by controlling the concentration of different gases (e.g., oxygen) in the heating environment, the frame 340 may not be required, particularly when the concentration of oxygen can be controlled to a low level. An example of a controlled heating environment may include a lehr oven.

[0095] Referring again to FIG. 3, the mold 300 has the flat region 302 and the at least one recess 310. The flat region 302 of the mold 300 is a region in which the first surface 304 is flat or substantially flat, meaning that the first surface 304 has a radius of curvature of at least 1 meter. The portions of the flat glass sheet contacting the flat region 302 of the first surface 304 of the mold 300 remains flat or substantially after the first forming step. The mold 300 can have one or a plurality of recesses 310. The at least one recess 310 may have a shape that isAttorney Docket No. SP25-136PCT complimentary to the desired local 3D complex shape to be formed in the flat glass sheet. Thus, when the glass sheet is heated and a vacuum applied, the glass sheet deforms into the at least one recess 310, resulting in formation of the local 3D complex shape in the glass sheet. When the mold 300 includes a plurality of recesses, the recesses may have the same shape or different shapes. In embodiments, the mold 300 may be used to form a single glass article having multiple different local 3D complex shapes, in which case, the recesses may have different shapes. In embodiments, the mold 300 may be used to form a plurality of glass articles from a single glass sheet, in which case the recesses 310 may have the same shape.

[0096] Referring to FIG. 4, the mold 300 includes the vacuum box 330 positioned on the second surface 306 of the mold 300 below the area in which the recesses 310 are formed in the mold 300 (i.e., in the -Z direction of the coordinate axis in FIG. 4 relative to the recesses 310). The vacuum box 330 may cover the recesses 310 and retention features 320 circumscribing the recesses 310. The vacuum box 330 may be in fluid communication with the recesses 310 and the retention features 320 through one or a plurality of vacuum holes 326, which may allow the vacuum box 330 to create a vacuum between the flat glass sheet and the mold 300 in the regions of the recesses 310 and retention features 320. The vacuum box 330 may also be in fluid communication with a vacuum source (not shown), such as but not limited to a vacuum pump, aspirator / venture device, or other vacuum system. The vacuum box 330 may be made of the same material as the mold 300, and may be attached to the second surface 306 of the mold 300 in a gas tight manner. In embodiments, the vacuum box 330 is machined to be integral with the mold 300.

[0097] The mold 300 may have one or more retention features 320 that hold the flat glass sheet to the first surface 304 of the mold 300 when vacuum is applied to the vacuum box 330. The retention features 320 may circumscribe the recesses 310 in the mold 300 so that, when vacuum is applied to the vacuum box 330, the retention features 320 create a seal between the flat glass sheet and the first surface 304 of the mold 300. This enables vacuum to be drawn between the glass sheet and the mold 300 in area of the recesses 310. Without the retention features 320, the vacuum may not be sufficient to cause the flat glass sheet to deform into the recesses 310 of the mold 300. In embodiments, the retention features 320 circumscribe the at least one recess 310 and, upon application of a vacuum to the vacuum box 330, the retention features 320 create a seal between the first surface 304 of the mold 300 and the flat glass sheet, wherein the seal holds the flat glass sheet against the first surface 304 of the mold 300 andAttorney Docket No. SP25-136PCT maintains the vacuum in the vacuum box 330 and between the mold 300 and the flat glass sheet at the recesses 310. The retention features 320 further reduce or prevent the vacuum in the recesses 310 from pulling the glass of the glass sheet towards the recesses, which can cause deforming (e.g., warping) of the flat regions of the glass sheet. The retention features 320 may be positioned as close as possible to the outer edges of the recesses 310 for forming the local 3D complex shapes. However, if the retention features 320 are too close, the retention features 320 may not be able to maintain the seal around the recesses 310, which can lead to loss of vacuum. The spacing of the retention features 320 from the recesses 310 can depend on the shape of the recesses 310.

[0098] Referring to FIG. 4, in embodiments, the retention feature 320 may be an offset region 321 in which the first surface 304 of the mold 300 is offset from the first surface 304 in the flat region 302 of the mold 300. In the offset region 321, the first surface 304 is offset away from the flat glass sheet relative to the first surface 304 in the flat region 302 (i.e., offset in the — Z direction of the coordinate axis of FIG. 4). The offset region 321 surrounds the recess(es) 310 for creating the local 3D complex shape. In the offset region 321, the mold 300 may have a thickness that is the same as the thickness in the flat region 302 in order to minimize variations in thermal environment of the flat glass sheet during forming. As such, the second surface 306 may also have an offset region in which the second surface 306 is offset from the second surface 306 in the flat region 302, such as being offset towards the vacuum box (-Z direction of the coordinate axis of FIG. 4). The offset of the first surface 304 may have the same magnitude as the offset of the second surface 306. The offset region 321 may include a plurality of vacuum holes 326 spaced apart from each other and arranged at the edges of the offset region 321. The plurality of vacuum holes 326 may be in fluid communication with the vacuum box 330 to apply a vacuum to the offset region 321 during forming.

[0099] At the interface between the flat region 302 and the offset region 321, the first surface 304 may have a step 322 where the first surface 304 undergoes a step change from the flat region 302 to the offset region 321. Referring now to FIG. 5A, the offset region 321 may include the step 322 transitioning from the flat region 302 to the offset region 321 surrounding the recess(es) 310. The vacuum holes 326 of the offset region 321 may be positioned proximate to the step 322 and in the offset region 321. As previously discussed, the vacuum holes 326 enable a vacuum to be applied at the boundary of the offset region 321 to create a seal that holds the flat glass sheet against the mold and prevents the glass from being pulled towards theAttorney Docket No. SP25-136PCT recess 310 during the forming. The step 322 in the offset region 321 may have a depth Ds that is up to 1 mm, such as from 0.1 mm to 1 mm. If the step 322 is too shallow, the vacuum may not be sufficient to lock the glass sheet against mold 300, which may allow the glass sheet to slip against the mold 300 resulting in warp. If the step 322 is too deep, the vacuum may cause the formation of a defect, such as a bump, on the B surface of the glass sheet. The step 322 may circumscribe the recess(es) 310 and may be a close as possible to the recess(es) 310 while still being able to maintain the vacuum against the flat glass sheet and lock the flat glass sheet against the mold 300 during forming. If the step 322 is too close to the recess 310, the offset region 321 may not be able to maintain the vacuum during the forming process. If the step 322 is too far away from the recess 310, then a greater portion of the B surface of the glass article will take on surface defects through contact with the first surface 304 of the mold 300 in combination with the applied heat and vacuum.

[0100] Referring now to FIG. 5B, in embodiments, the retention features 320 may be a groove 324 on the first surface 304 of the mold 300. Referring to FIGS. 6-8, the groove 324 completely circumscribes the recess 310. The groove 324 may have at least one vacuum hole disposed in the groove 324. Referring again to FIG. 5B, the vacuum holes 326 pass through the mold 300 from the first surface 304 to the second surface 306, so that the vacuum box 330 (FIG. 7) is in fluid communication with the groove 324 through the vacuum holes 326.

[0101] The groove 324 may have a width WG and depth DG that are sufficient to create sufficient vacuum to lock the flat glass sheet to the mold 300 around the perimeter of the recess 310, but not so great that the groove 324 causes defects in the B-surface of the flat glass sheet (i.e., the surface of the glass sheet contacting the mold 300). The width WG and depth DG of the groove 324 may depend on the thickness of the glass and complexity of the local 3D complex shape to be formed in the flat glass sheet. In embodiments, the groove 324 may have a width WG of from about 3 to about 10 times the thickness of the flat glass sheet, such as from about 3 to about 8, from about 3 to about 5, from about 4 to about 10, from about 4 to about 8, from about 5 to about 10, or from about 5 to about 8 times the thickness of the flat glass sheet. In embodiments, the groove 324 may have a width WG of from about 0.3 mm to about 20 mm, such as from about 0.3 mm to about 10 mm, from about 0.3 mm to about 5 mm, from about 0.3 mm to about 1.5 mm, from about 0.3 mm to about 1 mm, from about 0.5 mm to about 20 mm, from about 0.5 mm to about 10 mm, from about 0.5 mm to about 5 mm, from about 0.5 mm to about 1.5 mm, from about 0.5 mm to about 1 mm, from about 1 mm to about 20 mm, fromAttorney Docket No. SP25-136PCT about 1 mm to about 10 mm, from about 1 mm to about 5 mm, from about 1 mm to about 3 mm, from about 1 mm to about 2 mm, from about 1.5 mm to about 20 mm, from about 1.5 mm to about 10 mm, from about 1.5 mm to about 5 mm, from about 1.5 mm to about 3 mm, or any range or subrange therebetween.

[0102] The groove may have a depth DG of from about 0.1 to about 10 times the thickness of the flat glass sheet, such as from about 0.1 to about 8, from about 0.1 to about 5, from about 0.1 to about 3, from 0.1 to about 1, from about 0.5 to about 10, from about 0.5 to about 8, from about 0.5 to about 5, from about 0.5 to about 3, from about 0.5 to about 1, from about 1 to about 10, from about 1 to about 8, from about 1 to about 5, from about 1 to about 3, or from about 3 to about 10 times the thickness of the flat glass sheet. The depth DG of the groove 124 may depend on the thickness of the glass and the complexity of the local 3D complex shape to be formed in the flat glass sheet. For less complicated local 3D complex shapes, the groove 324 can be shallower, while for more complex local 3D complex shapes, the groove 324 can be deeper. If the groove 324 is too shallow, the vacuum may not be sufficient and the flat glass sheet may slip against the mold 300 during the forming, leading to warping of the intermediate glass article. Conversely, if the groove 324 is too deep, the vacuum may be too strong and may cause defects in the B-surface of the intermediate glass article. In embodiments, the groove 324 may have a depth DG of from about 0.1 mm to about 10 mm, such as from about 0.1 mm to about 8 mm, from about 0.1 mm to about 5 mm, from about 0.1 mm to about 4 mm, from about 0.1 mm to about 3 mm, from about 0.1 mm to about 1 mm, from about 0.1 mm to about 10 mm, from about 0.5 mm to about 10 mm, from about 0.5 mm to about 8 mm, from about 0.5 mm to about 5 mm, from about 0.5 mm to about 4 mm, from about 0.5 mm to about 3 mm, from about 0.5 mm to about 1 mm, from about 1 mm to about 10 mm, from about 1 mm to about 8 mm, from about 1 mm to about 5 mm, from about 1 mm to about 4 mm, from about 1 mm to about 3 mm, from about 3 mm to about 10 mm, from about 3 mm to about 8 mm, from about 3 mm to about 5 mm, or any range or subrange therebetween.

[0103] Referring now to FIGS. 6-8, another embodiment of a mold 300 for forming the local 3D complex shape is schematically depicted. The mold 300 in FIGS. 6-8 has the groove 324 as the retention feature 320. As shown in FIGS. 6-8, the groove 324 may circumscribe the recess 310 and may be positioned as close as possible to the recess 310 to reduce the area of the B-surface of the flat glass sheet that contacts the mold 300 under vacuum, which can reduce the area of the B surface of the intermediate glass article having surface defects. The grooveAttorney Docket No. SP25-136PCT324 type of retention feature 320 can be positioned closer to the recess 310 compared to the offset region 321 type of retention feature 320. If the groove 324 is too close to the recess 310, then the groove 324 may lose the seal against the glass sheet during the forming process, which can cause the flat glass sheet to slip relative to the mold 300, leading to warp.

[0104] Referring FIG. 6-8, the mold 300 may have an overall two-dimensional shape that is rectangular in order to form the local 3D complex shape in a flat glass sheet having a rectangular shape. However, the mold 300 is not limited to rectangular two-dimensional shapes. Referring to FIG. 9, in embodiments, the mold 300 may have an overall two- dimensional shape that is T-shaped in order to form the local 3D complex shape in a flat glass sheet cut into a T-shape. The mold 300 may have any suitable overall two-dimensional shape, such as an L-shape, polygonal shape, a circular shape, an oval shape, irregular shape, or any other shape selected for a particular application.

[0105] Forming the local 3D complex shape in the flat glass sheet may include loading the flat glass sheet onto the mold 300 and heating the flat glass sheet. The flat glass sheet may be heated in a dynamic lehr oven. Forming the local 3D complex shape in the flat glass sheet may include heating at least a portion of the flat glass sheet to a reforming temperature. The reforming temperature may depend on the glass composition of the flat glass sheet. The reforming temperature may be a temperature at which a viscosity of the flat glass sheet is from about IxlO7 2poise (IxlO6 2kilopascal seconds (kPa*sec) where 1 poise = 0.1 kPa*sec) to about IxlO8poise (IxlO7kPa*sec), such as from about IxlO7 4poise to about IxlO8poise, from about IxlO76poise to about IxlO8poise, or any range or subrange therebetween. The reforming temperature is less than a glass transition temperature of the flat glass sheet. In embodiments, the reforming temperature may be from about 20 °C to about 60 °C less than the glass transition temperature of the flat glass sheet.

[0106] Heating the flat glass sheet to the reforming temperature may include concentrating the heating on the region of the glass sheet to be formed into the local 3D complex shape. In embodiments, heating the flat glass sheet may include at least partially masking portions of the flat glass sheet contacting the flat regions 302 of the monolithic mold 300. Heating the entire flat glass sheet to the reforming temperature may cause the B surface of the flat glass sheet to conform to any defects in the first surface 304 of the mold 300. However, not heating the rest of the flat glass sheet at all may create a high temperature gradients in the flat glass sheet during forming, which can cause the flat glass sheet to crack and / or break. Thus, the region of flatAttorney Docket No. SP25-136PCT glass sheet to be formed into the local 3D complex shape can be heated to the reforming temperature, while the remainder of the flat glass sheet may be heated to a temperature less than the reforming temperature, such as at a temperature at which the viscosity of the flat glass sheet is less than about IxlO7poise, such as less than about IxlO6 5poise, or even less than about IxlO6poise. In embodiments, the remainder of the flat glass sheet not having the local 3D complex shape may be heated to a temperature that is at least about 80 °C less than the glass transition temperature of the flat glass sheet, such as at least about 100 °C less than the glass transition temperature of the flat glass sheet, or even at least about 200 °C less than the glass transition temperature of the flat glass sheet.

[0107] Referring now to FIG. 10, in embodiments, the selective heating of the flat glass sheet 150 may include applying a screen 350 above the flat glass sheet 150 (i.e., in a direction in the +Z direction of the coordinate axis of FIG. 10). The screen 350 may be positioned above the flat glass sheet 150 after the flat glass sheet 150 is loaded onto the mold 300. The screen 350 may have a large opening 352 and a plurality of small openings 354. The large opening 352 may be positioned over the region of the flat glass sheet 150 to be formed into the local 3D complex shape, such as over the recesses 310 of the mold 300. The large opening 352 may allow for direct heating of the region of the flat glass sheet 150 to be formed into the local 3D complex shape to the reforming temperature. The small openings 354 may be spaced apart and may have a size that is substantially smaller than the size of the large opening 352. The small openings 354 may at least partially mask the flat glass sheet 150 from the heat source in regions of the flat glass sheet outside of the regions to be formed into the local 3D complex shape. The partial masking of the flat glass sheet 150 in these regions may cause these regions to be heated to a temperature less than the reforming temperature. Heating these regions to a temperature less than the reforming temperature may reduce temperature gradients in the glass sheet during forming while at the same time reducing or preventing the B surface of the flat glass sheet 150 from conforming to defects in the first surface of the mold 300.

[0108] During or after heating, the flat glass sheet 150 is pushed against the mold 300 and into the recesses 310 on the mold through difference in pressure. The application of heat and pressure difference causes the flat glass sheet 150 to exactly copy the shape of the recesses 310 in the mold 300 to form the local 3D complex shape. The forming may include applying a pressure difference to the flat glass sheet 150 in the region to be formed into the local 3D complex shape when the flat glass sheet 150 is at the reforming temperature. Applying theAttorney Docket No. SP25-136PCT pressure difference at the reforming temperature causes the flat glass sheet to deform into the recesses 310 in the mold 300 to exactly copy the shape of the recesses 310 in the mold 310.

[0109] In embodiments, applying the pressure difference to the flat glass sheet in the region of the recesses 310 of the mold 300 may include applying a vacuum for a duration sufficient for the flat glass sheet 150 to conform to the at least one recess 310 of the monolithic mold 300. The vacuum may be applied through the vacuum box 330 and the vacuum holes 326 of the mold 300. In embodiments, the vacuum pressure applied to the vacuum box 330 and vacuum holes 326 can range from about 0.1 bars to about 0.3 bars. In embodiments, vacuum pressure can be applied to the vacuum box 330 and vacuum holes 326 at a rate of from about 5 liters per minute to about 20 liters per minute. In embodiments, forming the local 3D complex shape may include applying the vacuum for a duration sufficient to cause the flat glass sheet to deform into the recesses 310 in the mold 300. In embodiments, the duration of applying the vacuum may be up to about 2 minutes, such as up to about 1.5 minutes, from about 15 seconds to about 2 minutes, from about 15 seconds to about 1.5 minutes, from about 15 second to about 1 minute, from about 30 seconds to about 2 minutes, from about 30 seconds about 1.5 minutes, from about 30 seconds to about 1 minute, from about 1 minutes to about 2 minutes, from about 1 minute to about 1.5 minutes, or any range or subrange therebetween.

[0110] Once the flat glass sheet has conformed to the recesses 310 in the mold 300 to produce the local 3D complex shape, the methods may include removing the vacuum from the vacuum box 330 and then removing the intermediate glass article from the monolithic mold 300. In embodiments, removing intermediate glass article from the mold 300 can include injecting one or more nitrogen pulses into the vacuum box 330. In embodiments including one or more nitrogen pulses, the nitrogen pulse can facilitate demolding of the intermediate glass article and inhibit oxidation of the vacuum mold, which can still be at a high temperature immediately after reforming. In embodiments, removing the intermediate glass article from the monolithic mold may include laser cutting the intermediate glass article around a perimeter of the intermediate glass article. In embodiments, the laser cutting may remove at least about 30 mm of glass from around the edges of the intermediate glass article, where the glass removed may be non-flat surfaces at the edges of the intermediate glass article. In embodiments, the intermediate glass article may be trimmed into a specific shape or to specific dimensions depending on the final application of the glass article.Attorney Docket No. SP25-136PCT

[0111] In embodiments, the method of forming the local 3D complex shape may include controlled cooling of the intermediate glass article after the glass sheet has conformed to the recess 310 in the mold 300 to produce the local 3D complex shape. Controlled cooling may include cooling the intermediate glass article at a cooling rate that is slower than allowing the intermediate glass article to cool to room temperature passively. In embodiments, the forming may be conducted in a dynamic lehr over having a plurality of temperature zones, where the controlled cooling comprising passing the intermediate glass article through a series of the temperature zones in the dynamic lehr over, where the temperature zones have progressively decreasing temperatures. When the methods includes controlled cooling, the intermediate glass article may be removed from the mold before or after controlled cooling.

[0112] In embodiments, the process of forming the local 3D complex shape in the flat glass sheet to produce the intermediate glass article may be a deep vacuum forming (DVF) process. Further information one DVF process can be found in co-pending U.S. Patent Application No. 18 / 288,618, filed on April 21, 2022, entitled "Complexly curved glass articles and methods of forming the same," the entire contents of which are incorporated herein by reference. Other methods of forming the local 3D complex shape in the intermediate glass article are contemplated, such as but not limited to press forming process, sagging processes, molding, or other types of methods suitable for forming the local 3D complex shapes in the flat glass sheet.

[0113] Referring again to FIG. 2, following the forming in step 220, the intermediate glass article may optionally be subjected to one or more intermediate steps, such as cutting or trimming (step 222), edge finishing (step 240), decorating (step 250), coating, polishing, etching, ion exchange strengthening, other finishing process, separating into a plurality of intermediate glass articles, trimming the intermediate glass article into a specific shape, or combinations of intermediate steps prior to the cold forming process. In embodiments, the methods disclosed herein may include edge finishing the intermediate glass article, decorating one or more surfaces of the intermediate glass article, or both. Edge finishing may include flame working, laser treating, or otherwise heating the edges of the intermediate glass article to produce a finished edge free of any sharp regions. Decorating the intermediate glass article may include applying one or more decorative coatings, such as but not limited to inks or paints, onto one more surfaces of the intermediate glass article. For instance, in embodiments, at least a portion of the finished glass article may serve as a display cover glass having one or more visual areas surrounded by black matrix areas, and decorating the intermediate glass articleAttorney Docket No. SP25-136PCT may include applying black matrix inks in black matrix areas around the visual areas. Other types of coatings, such as inks, paints, optical coatings, etc., may be applied to surfaces of the intermediate glass article during the decorating.

[0114] Referring now to FIG. 11, one embodiment of an intermediate glass article 140 subjected to the forming process is schematically depicted. The intermediate glass article 140 has the local 3D complex shape(s) 110 formed in a first region 142. The intermediate glass article 140 may have a second region 144 that does not have the local 3D complex shape(s) 110 and may be generally flat. The intermediate glass article 140 has an A surface 102 and a B surface 104, where the B surface 104 is the surface of the intermediate glass article 140 that contacted the first surface of the mold. As shown in FIG. 11, the local 3D complex shape 110 may be recessed from the A surface 104. Aside from the local 3D complex shape 110, the intermediate glass article 140 may be generally flat (i.e., having a radius of curvature of at least 1 meter).

[0115] The intermediate glass article 140 may have surface defects in the B surface 104 in portions of the first region 142. The surface defects in the B surface 104 in portions of the first region 142 may result from contact of the B surface with the mold at the reforming temperature and under the pressure difference. Conversely, the B surface 104 in the second region 144 may have significantly less surface defects compared to the first region 142. Since the second region 144 is heated to a temperature less than the reforming temperature, the B surface 104 in the second region 142 is less prone to conforming to defects in the first surface of the mold during the forming step. Thus, the B surface 104 in the second region 144 exhibits significantly less surface defects compared to the B surface 104 in the first region 142. This may provide for greater optical performance of the second region 144 compared to the first region 142 and may make the second region 144 suitable for use as cover glass for electronic displays. The intermediate glass article 140 may further have finished edges and / or other decorations / coatings resulting from the intermediate steps.

[0116] Referring again to FIG. 2, after forming the local 3D complex shapes in step 220, the methods disclosed herein may include the cold forming 230 of the second region 144 (FIG. 11) of the intermediate glass article 140 to produce the bend region 120 (FIG. 1) in the glass article 100. In embodiments, cold-forming the second region 144 of the intermediate glass article 140 may involve any of the techniques described in U.S. Pre-Grant Publication No. 2019 / 0329531 Al, entitled "Laminating thin strengthened glass to curved molded plasticAttorney Docket No. SP25-136PCT surface for decorative and display cover application," U.S. Pre-Grant Publication No. 2019 / 0315648 Al, entitled "Cold-formed glass article and assembly process thereof," U.S. PreGrant Publication No. 2019 / 0012033 Al, entitled "Vehicle interior systems having a curved cover glass and a display or touch panel and methods for forming the same," U.S. patent application Ser. No. 17 / 214,124, entitled "Curved glass constructions and methods for forming same," and U.S. Patent No. 12,122,236, granted on October 22, 2024, and entitled "Cold forming of complexly curved glass articles," which are hereby incorporated by reference in their entireties.

[0117] Cold-forming provides certain advantages for producing the glass articles according to the present disclosure. In particular, the low temperature at which the cold-forming is conducted may make the process less expensive compared to conventional hot-forming processes. Further, the temperatures associated with hot-forming processes have been known to thermally disrupt or degrade surface treatments or create optical distortions. For this reason, surface treatments were generally applied to curved glass articles, which increased the complexity of the surface treatment application process. Because cold-forming is done at much lower temperatures than conventional hot-forming, the surface treatments can be applied while the glass substrate is in a planar configuration without the concern that the bending operation will cause thermal disruption or degradation of the surface treatment.

[0118] Referring to FIG. 11, the methods disclosed herein may comprise subjecting the second region 144 of the intermediate glass article 140 to the cold forming process to form a concave or convex curvature in the second region 144 to produce the glass article (FIG. 1) having the local 3D complex shape 110 and the bend region 120. The first region 142 of the intermediate glass article 140 remains generally flat with the exception of the local 3D complex shape. Subjecting the local 3D complex shape 110 to the cold forming causes the glass to break at the local 3D complex shape 110. Thus, only the second region 144 is subjected to the cold forming, and the first region 142 of the intermediate glass article 140 is not subjected to the cold forming. In embodiments, the methods do not include subjecting a region (e.g., the first region) of the intermediate glass article having the at least one local 3D complex shape to the cold forming process.

[0119] Subj ecting the intermediate glass article to cold forming may be conducted at a cold forming temperature that is significantly less than the glass transition temperature of the glass and significantly less than the reforming temperature used for forming the local 3D complexAttorney Docket No. SP25-136PCT step. In embodiments, the cold forming temperature may be at least 200 °C less than the glass transition temperature of the glass, such as at least 300 °C, at least 400 °C, at least 500 °C or at least 800 °C less than the glass transition temperature of the flat glass sheet. In embodiments, the cold forming may be conducted at a cold forming temperature of from about 20 °C to about 800 °C, such as from about 20 °C to about 500 °C, from about 20 °C to about 200 °C, from about 20 °C to about 100 °C, from about 20 °C to about 50 °C, from about 25 °C to about 800 °C, from about 25 °C to about 500 °C, from about 25 °C to about 200 °C, from about 25 °C to about 100 °C, from about 25 °C to about 50 °C, or at about ambient temperature. In embodiments, the cold forming may be conducted at a cold forming temperature of from 20 °C to 50 °C or at about 25 °C.

[0120] Referring now to FIG. 12, in one example of a cold-forming process, the second region 144 of the intermediate glass article 140 may be positioned between two complementary forms, such as first form 410 and second form 420. The first form 410 and the second form 420 are then gradually moved towards each other by applying a force to the first form 410, the second form 420, or both at the cold forming temperature. As the first form 410 and second form 420 are moved toward each other, the second region 144 of the intermediate glass article 140 conforms to the shape of the two complimentary forms. In another example of cold forming, a metal frame may be attached around the periphery of the intermediate glass article 140 and force is applied to the metal frame to bend or twist the metal frame, which thereby bends or twists the intermediate glass article to produce the curved shape. Other cold-forming techniques are contemplated. The curvature has a relevant radius used for usual cold-forming operation, depending on the thickness of the glass.

[0121] Referring again to FIG. 1, the glass article 100 made by the methods disclosed herein may include the at least one local 3D complex shape 110 and at least one bend region 120 that does not include the at least one local 3D complex shape 110. The at least one local 3D complex shape 110 may be disposed in a flat region 130 of the glass article 100, where the flat region 130 is generally flat, meaning it has a radius of curvature of at least 1 mm. The glass article 100 has the A surface 102 and the B surface 104.

[0122] The local 3D complex shape 110 may have a maximum compressive strain (MCS) of from about 0.5% to about 20%, wherein the MCS is the maximum compressive strain needed to flatten the at least one local 3D complex shape back to a flat sheet. In embodiments, the local 3D complex shape 110 may have an MCS of from about 0.5% to about 15%, from about 0.5%Attorney Docket No. SP25-136PCT to 10%, from about 1% to about 20%, from about 1% to about 15%, from about 1% to about 10%, from about 2% to about 20%, from about 2% to about 15%, from about 2% to about 10%, from about 5% to about 20%, from about 5% to about 15%, from about 5% to about 10%, or any range or subrange therebetween.

[0123] The local 3D complex shape 110 may have a complex curvature in at least one portion of the local 3D complex shape 110. The complex curvature of the local 3D complex shape 110 may be a curvature that cannot be attained from a cold forming process, such as a curvature having a small radius of curvature, a curvature in two or more directions, or a non- developable curvature. In embodiments, the local 3D complex shape 110 may have a non- developable curvature, as defined herein. In embodiments, at least a portion of the local 3D complex shape 110 may have a total curvature that is non-zero, where the total curvature is equal to a product of a first principle curvature with respect to a first axis and a second principle curvature with respect to a second axis. In embodiments, a region of the local 3D complex shape 110 may have a total curvature of greater than zero.

[0124] In embodiments, at least a portion of the local 3D complex shape 110 may have a curvature having a small radius that cannot be produced through cold forming. In embodiments, the glass article 100 may have a glass thickness of at least about 0.5 mm, and at least a portion of the local 3D complex shape 110 may have a radius of curvature of less than 80 mm, such as less than about 70 mm, less than about 60 mm, less than about 50 mm, less than about 40 mm, from greater than 0 mm to 80 mm, from greater than 0 mm to about 70 mm, from greater than 0 mm to about 60 mm, from greater than 0 mm to about 50 mm, from greater than 0 mm to about 40 mm, from about 1 mm to 80 mm, from about 1 mm to about 70 mm, from about 1 mm to about 60 mm, from about 1 mm to about 50 mm, from about 1 mm to about 40 mm, from about 5 mm to about 70 mm, from about 5 mm to about 60 mm, from about 5 mm to about 50 mm, from about 5 mm to about 40 mm, from about 10 mm to about 70 mm, from about 10 mm to about 60 mm, from about 10 mm to about 50 mm, from about 10 mm to about 40 mm, or any range or subrange therebetween. In embodiments, the glass article 100 may have a glass thickness of at least about 0.1 mm, and at least a portion of the local 3D complex shape 110 may have a radius of curvature of less than or equal to about 20 mm, such as less than or equal to about 15 mm, less than or equal to about 13 mm, less than or equal to about 12 mm, less than or equal to about 10 mm, from about 0.1 mm to about 20 mm, from about 0.1 mm to about 18 mm, from about 0.1 mm to about 15 mm, from about 0.1 mm to about 13 mm,Attorney Docket No. SP25-136PCT from about 0.1 mm to about 12 mm, from about 0.1 mm to about 10 mm, from about 1 mm to about 20 mm, from about 1 mm to about 15 mm, from about 1 mm to about 13 mm, from about 1 mm to about 12 mm, from about 1 mm to about 10 mm, from about 5 mm to about 20 mm, from about 5 mm to about 15 mm, from about 5 mm to about 13 mm, from about 5 mm to about 12 mm, from about 5 mm to about 10 mm, or any range or subrange therebetween. The glass article 100 has a flat region 130 that includes the local 3D complex shape 110. The flat region 130 may be separate from the bend region 120 and may be generally flat (i.e., radius of curvature of greater than 1 meter) except for the local 3D complex shape 110. In embodiments, the glass article 100 is not curved in the region around the local 3D shape 110.

[0125] Referring again to FIG. 1, the glass article 100 has the bend region 120, which may correspond to the second area 144 of the intermediate glass article 140 once the curvature is applied to the second area 144 via cold forming. The bend region 120 is separate from the flat region 130 having the local 3D complex shape 110. As previously discussed, attempting to subject the flat region 130 having the local 3D complex shape 110 to cold forming results in breaking the glass article at the local 3D complex shape 110.

[0126] The bend region 120 has a curvature that is capable of being formed through a cold forming process. The bend region 120 of the glass article 100 can be characterized by a maximum compressive strain (MCS), which is the compressive strain needed to flatten the bend region 120 back to its original flat state (i.e., radius of curvature greater than 1 meter). The bend region 120 may have an MCS of less than 0.5%, such as less than or equal to 0.4%, less than or equal to 0.3%, less than or equal to 0.2%, or less than or equal to 0.1%, wherein the MCS is the maximum compressive strain needed to flatten the bend region 120 back to a flat sheet. In embodiments, the bend region 120 may have an MCS of from greater than 0% to less than 0.5%, such as from greater than 0% to about 0.4%, from greater than 0% to about 0.3%, from greater than 0% to about 0.2%, from greater than 0% to about 0.1%, from about 0.01% to less than 0.5%, from about 0.01% to about 0.4%, from about 0.01% to about 0.3%, from about 0.01% to about 0.2%, from about 0.01% to about 0.1%, from about 0.1% to less than 0.5%, from about 0.1% to about 0.4%, from about 0.1% to about 0.3%, from about 0.1% to about 0.2%, from about 0.2% to less than 0.5%, from about 0.2% to about 0.4%, from about 0.2% to about 0.3%, or any range or subrange therebetween.

[0127] The bend region 120 may have a simple curvature that can be attained from a cold forming process, such as a curvature having a large radius of curvature, a single curvature,Attorney Docket No. SP25-136PCT and / or a developable curvature. In embodiments, the bend region 120 may have a single curvature that has only one axis of curvature. In embodiments, the bend region 120 may have a developable curvature, as defined herein. In embodiments, the bend region 120 may have a curvature having a large radius of curvature. In embodiments, the glass article 100 may have a glass thickness of at least about 0.5 mm, and the bend region may have a radius of curvature of at least 80 mm, such as at least about 85 mm, at least about 90 mm, at least about 100 mm, from about 80 mm to about 1 meter, from about 80 mm to about 900 mm, from about 80 mm to about 800 mm, from about 80 mm to about 500 mm, from about 85 mm to about 1 meter, from about 85 mm to about 900 mm, from about 85 mm to about 800 mm, from about 85 mm to about 500 mm, from about 90 mm to about 1 meter, from about 90 mm to about 900 mm, from about 90 mm to about 800 mm, from about 90 mm to about 500 mm, from about 100 mm to about 1 meter, from about 100 mm to about 900 mm, from about 100 mm to about 800 mm, from about 100 mm to about 500 mm, or any range or subrange therebetween.

[0128] The glass articles 100 made by the processes disclosed herein may have less surface damage on the B surface 104 caused by contact with the mold compared to forming the glass articles with hot forming processes only. The B surface 104 is the surface of the glass article 100 that contacts the mold in the first forming process for making the local 3D complex shape 110. In the bend region 120 and in parts of the flat region 130 of the glass article 100, the B surface 104 does not exhibit surface defects caused by contact with the monolithic mold. This is due to these regions being maintained at temperatures below the reforming temperature and not being subjected to the pressure difference during the first reforming process. The absence of surface defects on the B surface 104 of the glass article 100 caused by contact with the mold may be important depending on the application for the glass article 100. In embodiments, the glass article 100 may be used in an application requiring high transmittance, such as when a portion of the bend region 120 serves as a cover glass for one or more display units. When high transmittance is required, the presence of surface defects on the B surface 104 of the glass article 100 can reduce the transmittance. Thus, reducing the surface defects on the B surface 104 of the glass article 100 can improve the light transmittance properties of the glass article 100.EXAMPLES

[0129] The various embodiments of the methods of forming the glass sheets and the glass articles produced from the methods will be further clarified by the following examples. TheAttorney Docket No. SP25-136PCT examples are illustrative in nature, and should not be understood to limit the subject matter of the present disclosure.

[0130] Example 1: Charsins Station for Automotive Interior

[0131] In Example 1, a charging station for an automotive interior was made from a glass sheet using the forming process disclosed herein. First, a glass preform was prepared from GORILLA® glass from Corning Incorporated. The glass preform was a flat glass sheet having a size of from 875 mm x 430 mm. A mold for conducting the first forming process was prepared according to the design in FIGS. 3 and 4. A photograph of the mold for example 1 is shown in FIG. 13. FIG. 13 shows the mold after top surface polishing, before placing the mold and associated flat glass sheet in a dynamic lehr oven. The flat glass sheet and mold were placed in the dynamic lehr over and the glass was heated and then pushed by difference in pressure against the mold to exactly copy the 3D shape of the recess in the mold. The glass article formed after the first forming process is shown in FIG. 14. For Example 1, the glass article was extracted from the mold, trimmed, edge finished, and decorated, but was not subjected to the cold forming. The finished glass article is shown in FIG. 15.

[0132] Example 2

[0133] In Example 2, an intermediate glass article was made from a glass sheet using the forming process disclosed herein. First, a glass preform was prepared from GORILLA® glass from Coming Incorporated. The glass preform was a flat glass sheet having a size of 875 mm x 430 mm. The thickness was 0.7 mm. A mold for conducting the first forming process was prepared according to the design shown in FIGS. 6-8. A photograph of the mold for Example 2 is shown in FIG. 16, which shows the mold and associated flat glass sheet after top surface polishing and before using in the dynamic lehr oven. The flat glass sheet and mold were placed in the dynamic lehr over and the glass was heated and was pushed by difference in pressure against the mold to exactly copy the 3D shape of the recess in the mold. A representation of the intermediate glass article formed from the first forming process is shown in FIG. 17. The intermediate glass article is shown in a line drawing because the optically clear nature of the intermediate glass article makes it difficult to see in a photograph.

[0134] The intermediate glass article of Example 2 was then subjected to cold forming to produce a glass article having a bend region having a curved surface with a radius of curvature of 1500 mm. Referring now to FIG. 18, the finished glass article 100 having the local 3DAttorney Docket No. SP25-136PCT complex shape 110 and the bend region 120 is shown. As shown in FIG. 18, an air vent part was attached to the local 3D complex shape 110 to produce a console assembly.

[0135] While various embodiments of the strengthened glass articles and methods for producing the strengthened glass articles have been described herein, it should be understood that it is contemplated that each of these embodiments and techniques may be used separately or in conjunction with one or more embodiments and techniques.

[0136] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

[0137] What is claimed is:

Claims

Attorney Docket No. SP25-136PCTCLAIMS1. A method of forming a glass article, the method comprising: forming at least one local 3D complex shape in a flat glass sheet to produce an intermediate glass article having a first region having the at least one local 3D complex shape and a second region that is flat; and after forming the at least one local 3D complex shape, subjecting at least a portion of the intermediate glass article to a cold forming process to produce the glass article having the at least one local 3D complex shape and at least one bend region having a curved surface.

2. The method of claim 1, wherein at least one local 3D complex shape is characterized by one or more of the following: a maximum compressive strain (MCS) of from about 0.5% to about 20%, wherein the MCS is the maximum compressive strain needed to flatten the at least one local 3D complex shape back to a flat sheet; a total curvature of greater than zero, where the total curvature is equal to a product of a first curvature with respect to a first axis and a second curvature with respect to a second axis; a glass thickness of at least about 0.5 mm and a radius of curvature of less than about 70 mm in at least one region of the local 3D complex shape; a glass thickness of at least about 0.1 mm and a radius of curvature of less than about 20 mm; or any combinations thereof.

3. The method of claim 1, wherein forming the at least one local 3D complex shape comprises providing a monolithic mold having a flat region, at least one recess having a shape complimentary to the at least one local 3D complex shape, a retention feature configured to hold the glass sheet against a first surface of the mold during the forming, and a vacuum box disposed below the at least one recess and the retention feature, wherein the vacuum box is in fluid communication with a vacuum source, the at least one recess, and the retention feature.Attorney Docket No. SP25-136PCT4. The method of claim 3, wherein the mold has the first surface that contacts the flat glass sheet and a second surface opposite the first surface, wherein the vacuum box is disposed on the second surface at a position opposite from the at least one recess.

5. The method of claim 3, wherein the retention feature circumscribes the at least one recess and, upon application of a vacuum to the vacuum box, the retention feature creates a seal between the first surface of the mold and the flat glass sheet that holds the flat glass sheet against the first surface of the mold and maintains the vacuum in the vacuum box and between the mold and the flat glass sheet at the at least one recess.

6. The method of claim 5, wherein the retention feature comprises a groove on the first surface of the mold, the groove circumscribing the at least one recess, and a plurality of vacuum holes disposed in the groove and passing through the mold from the first surface to a second surface, wherein the vacuum box is in fluid communication with the groove through the plurality of vacuum holes.

7. The method of claim 5, wherein the retention feature comprises an offset region of the monolithic mold disposed around the at least one recess, wherein in the offset region, the first surface of the mold is offset away from the flat glass sheet relative to the first surface in the flat region.

8. The method of claim 3, wherein the forming the at least one local 3D complex shape further comprises loading the flat glass sheet into the mold, heating the flat glass sheet, and applying a vacuum to the vacuum box of the monolithic mold, wherein the heating and applying the vacuum causes the flat glass sheet to deform into the at least one recess to produce the at least one local 3D complex shape.

9. The method of claim 8, comprising heating the flat glass sheet to a reforming temperature that is less than a glass transition temperature of the flat glass sheet.

10. The method of claim 9, wherein heating the flat glass sheet comprises at least partially masking portions of the flat glass sheet contacting the flat regions of the monolithic mold.

11. The method of claim 9, further comprising, after the flat glass sheet has conformed to the at least one recess, removing the vacuum from the vacuum box, and removing the intermediate glass article from the monolithic mold.Attorney Docket No. SP25-136PCT12. The method of claim 9, further comprising controlled cooling of the intermediate glass article after the flat glass sheet has conformed to the at least one recess.

13. The method of claim 1, comprising subjecting the second region of the intermediate glass article to the cold forming process.

14. The method of claim 1, comprising subjecting the intermediate glass article to the cold forming process at a cold forming temperature that is at least about 200 °C less than a glass transition temperature of the flat glass sheet or that is less than about 430 °C.

15. The method of claim 1, wherein the cold forming comprises placing the second region of the intermediate glass sheet between a first form and a second form that is complimentary to the first form and gradually moving the first form and the second form towards each other at the cold forming temperature.

16. The method of claim 1, further comprising edge finishing the intermediate glass article, decorating one or more surfaces of the intermediate glass article, or both, wherein the edge finishing, decorating, or both is conducted after forming the at least one local 3D complex shape and before subjecting the intermediate glass article to the cold forming process.

17. A glass article made by the method of claim 1, wherein the glass article has the at least one local 3D complex shape and the at least one bend region that does not include the at least one local 3D complex shape.

18. The glass article of claim 17, wherein the at least one local 3D complex shape has a maximum compressive strain (MCS) of from about 0.5% to about 20%, wherein the MCS is the maximum compressive strain needed to flatten the at least one local 3D complex shape back to a flat sheet.

19. The glass article of claim 17, wherein the at least one local 3D complex shape has a non-zero Gaussian curvature or non-developable curvature.

20. The glass article of claim 17, wherein the at least one local 3D complex shape has a complex curvature characterized by a curvature in two or more directions.

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