WO2018200807A1

WO2018200807A1 - Three dimensional glass article and methods of making

Info

Publication number: WO2018200807A1
Application number: PCT/US2018/029562
Authority: WO
Inventors: James Gregory Couillard; Michael Patrick Donovan; Sean Matthew Garner; Atul Kumar; Michael Lesley Sorensen; Yawei Sun
Original assignee: Corning Incorporated
Priority date: 2017-04-26
Filing date: 2018-04-26
Publication date: 2018-11-01
Also published as: TW201843115A

Abstract

Embodiments of this disclosure pertain to a method of making a shaped glass article comprising securing a cold bent glass article in a retaining fixture to produce a retained, cold bent glass article; and ion-exchanging the retained, cold bent glass article to produce the shaped glass article. Embodiments of this disclosure also pertain to a curved glass article comprising a first and second opposing major surfaces; at least one curve having at least one convex surface and at least one concave surface in the vicinity of the curve on the second surface; wherein the first major surface exhibits a first surface compressive stress and the second major surface exhibits a second surface compressive stress that differs from the first surface compressive stress, and wherein the curved glass article retains the at least one curve while unsupported.

Description

THREE DIMENSIONAL GLASS ARTICLE AND METHODS OF MAKING

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

Provisional Application Serial No . 62/490, 178 filed on April 26, 2017, the content of which is relied upon and incorporated herein by reference in its entirety.

Field of Invention

[0002] The present disclosure relates generally to the field of three-dimensional (3D) shaped glass for various applications including for automotive interiors.

Background

[0003] There is a continuing need for technological innovation in the global automotive interiors industry. Vehicle manufactures are creating interiors that better connect, protect, and safely inform today's drivers and passengers. As the industry moves towards autonomous vehicles and driving, there is a need for creating appealing large format displays. There is an established trend towards larger displays, including touch functionality in the new models, from several OEMs and new market entrants. However, most of these displays consist of two dimensional plastic cover lenses (i.e., flat sheets). More recently, plastic has been replaced by glass due to the superior functionality and user experience that glass provides. Today's cover glass is still limited to a two dimensional surface (i.e., flat and planar). With growing interests from customers, and to maintain market positions, the automotive industry is expected to move to three dimensional surfaces made from glass. In view of these trends, a low cost technology to make three dimensional glass surfaces is desirable.

[0004] Three dimensional glass surfaces are conventionally formed via a hot forming, i.e., a molding process. The hot forming process is energy intensive due to the high temperatures involved and the energy required adds significant cost to the product.

[0005] An alternative to hot forming glass is cold bending glass. While the cold bending approach can be used to bend glass to make three dimensional parts, the approach has some design limitations due to residual stress that is generated in the bending. In some instances, bending a strengthened glass article generates a surface tensile stress that begins to outweigh the compressive stresses of the glass article. This bending stress results in a reaction force (i.e., rebound or restoration force) on the cold bent constraints such as frames with grooves, adhesives, and like constraints. While thicker glass articles can mechanically survive smaller radius bends, the stiffness of the glass requires a large force to maintain the shape.

Accordingly, there is a desire to reduce such reaction force to enable three dimensional glass surfaces for automotive, consumer electronics and similar industries n

Summary

[0006] A first aspect of this disclosure pertains to a method of making a shaped glass article comprising securing a cold bent glass article in a retaining fixture to produce a retained, cold bent glass article; and ion-exchanging the retained, cold bent glass article to produce the shaped glass article. In one or more embodiments, the method includes cold bending a strengthened glass article to produce at least one bend having at least one convex surface, and at least one concave surface to provide the cold bent glass article.

[0007] A second aspect of this disclosure pertains to a method of making a shaped glass article comprising: cold bending and securing a strengthened glass article in a retaining fixture to produce a retained, cold bent glass article having at least one bend with at least one convex surface and at least one concave surface; and ion-exchanging the retained, cold bent glass article to produce the shaped glass article.

[0008] A third aspect of this disclosure pertains to a curved glass article comprising: a first major surface and an opposing second major surface; at least one curve having at least one convex surface on the first major surface and at least one concave surface in the vicinity of the curve on the second surface; wherein the first major surface exhibits a first surface compressive stress at a first location and the second major surface exhibits a second surface compressive stress at a second location that is directly opposite the first location, wherein the first surface compressive stress is less than the second surface compressive stress, wherein the first surface compressive stress and the second surface compressive stress are in a range from about 200 MPa to about 1500 MPa, and wherein the curved glass article retains the at least one curve while unsupported.

Brief Description of the Drawings

[0009] Fig. 1 shows a flow chart of a known cold-bend process (100).

[0010] Fig. 2 is a flow chart of an exemplary process (200) of the disclosure.

[0011] Fig. 3 is a schematic of an embodiment of the disclosed process (300), where a starting flat glass (310) is transformed to a 3D shape (340).

[0012] Fig. 4 is an image of the glass-fixture assembly of Fig. 3. [0013] Fig. 5 is a graph showing a comparison of results for a first glass piece (500) (top curve pair) in a fixture only, and a second glass piece (510) (bottom curve pair) in a fixture and additionally employing a pin or bar force as shown in Fig. 4 (top half).

[0014] Fig. 6 is an image showing a cold-bent glass piece that is bent at its short edges around a barrel shaped fixture or jig.

Detailed Description

[0015] Various embodiments of the disclosure will be described in detail with reference to drawings, if any. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not limiting and merely set forth some of the many possible embodiments of the claimed invention.

Definitions

[0016] "Cold bending," "cold bend," and like terms refer to bending a glass article at a temperature below the glass transition temperature (T_g) of the glass. Cold-bending can occur, for example, at below 800 °C, such as at 700, 600, 500, 400, 300, 280, 200, 100, 50, and 25 °C, including intermediate values and ranges.

[0017] "IOX," "IOXing," 'TOX'ed," "ion-exchange," "ion-exchanging," or like terms refer to the ion exchange of ions, partially or completely, on at least a portion of the glass surface, on one or both sides as specified, with different ions such as an ion having a larger atomic radius compared to the exchanged ions such as K⁺ ions exchanged (i.e., replacing) for Na⁺ ions.

[0018] "Bend radius," "radius," or like terms refer to is the minimum radius measured to the inside curvature, alternatively or additionally, the maximum bend one can bend a glass sheet without damaging it or shortening its life. The smaller the bend radius, the greater is the material flexibility. A related term is "radius of curvature". As the radius of curvature of the bent part or piece decreases, the curvature increases; a large radius of curvature represents a low curvature and a small radius of curvature represents high curvature.

[0019] "Chord length" or like terms refer to a length of straight line segment joining two points on any curve. [0020] "Chord height," "sagittal," or like terms refer to the length of the vertical line from the midpoint of a chord to the curve itself.

[0021] "Arc length" or like terms refer to the length of the curve.

[0022] "About" modifying, for example, the quantity of an ingredient in a composition, concentrations, volumes, process temperature, process time, yields, flow rates, pressures, viscosities, and like values, and ranges thereof, or a dimension of a component, and like values, and ranges thereof, employed in describing the embodiments of the disclosure, refers to variation in the numerical quantity that can occur, for example: through typical measuring and handling procedures used for preparing materials, compositions, composites, concentrates, component parts, articles of manufacture, or use formulations; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of starting materials or ingredients used to carry out the methods; and like considerations. The term "about" also encompasses amounts that differ due to aging of a composition or formulation with a particular initial concentration or mixture, and amounts that differ due to mixing or processing a composition or formulation with a particular initial concentration or mixture.

[0023] "Optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0024] The indefinite article "a" or "an" and its corresponding definite article "the" as used herein means at least one, or one or more, unless specified otherwise.

[0025] Abbreviations, which are well known to one of ordinary skill in the art, may be used (e.g., "h" or "hrs" for hour or hours, "g" or "gm" for gram(s), "mL" for milliliters, and "rt" for room temperature, "nm" for nanometers, and like abbreviations).

[0026] Specific and preferred values disclosed for components, ingredients, additives, dimensions, conditions, times, and like aspects, and ranges thereof, are for illustration only; they do not exclude other defined values or other values within defined ranges. The composition and methods of the disclosure can include any value or any combination of the values, specific values, more specific values, and preferred values described herein, including explicit or implicit intermediate values and ranges.

[0027] A first aspect of this disclosure pertains to the use of a strengthening process to create a non-uniform or patterned compressive stresses on each side of a glass article, which will lead to bending of glass. This can be achieved by strengthening each side of the glass article to a different extent (e.g., by utilizing masking or other approaches).

[0028] In one or more embodiments, strengthening could be utilized to relieve some of the stresses in cold bend glass articles. In one or more such embodiments, a strengthened glass article will be cold bent and then further strengthened (e.g., chemically strengthened by an ion exchange process) to reduce bend stress experienced by the cold bent glass article.

[0029] In one or more embodiments, the glass article includes a first major surface and an opposing second major surface. In one or more embodiments, the glass article has a sheet configuration and has a thickness (t) that is substantially constant. In one or more

embodiments, the glass article has a sheet configuration and has a thickness (t) that is nonuniform. Thickness (t) is defined as a distance between the first major surface and the second major surface. The thickness (t) as used herein refers to the maximum thickness of the glass article. In the embodiment shown, the glass article includes a width (W) defined as a first maximum dimension of one of the first or second major surfaces orthogonal to the thickness (t), and a length (L) defined as a second maximum dimension of one of the first or second surfaces orthogonal to both the thickness and the width. In other embodiments, the dimensions discussed herein may be average dimensions.

[0030] In one or more embodiments, the glass article has a thickness (t) that is about 1.5 mm or less. For example, the thickness may be in a range from about 0.01 mm to about 1.5 mm, 0.02 mm to about 1.5 mm, 0.03 mm to about 1.5 mm, 0.04 mm to about 1.5 mm, 0.05mm to about 1.5 mm, 0.06 mm to about 1.5 mm, 0.07 mm to about 1.5 mm, 0.08 mm to about 1.5 mm, 0.09 mm to about 1.5 mm, 0.1 mm to about 1.5 mm, from about 0.15 mm to about 1.5 mm, from about 0.2 mm to about 1.5 mm, from about 0.25 mm to about 1.5 mm, from about 0.3 mm to about 1.5 mm, from about 0.35 mm to about 1.5 mm, from about O.4 mm to about 1.5 mm, from about 0.45 mm to about 1.5 mm, from about 0.5 mm to about 1.5 mm, from about 0.55 mm to about 1.5 mm, from about 0.6 mm to about 1.5 mm, from about 0.65 mm to about 1.5 mm, from about 0.7 mm to about 1.5 mm, from about 0.01 mm to about 1.4 mm, from about 0.01 mm to about 1.3 mm, from about 0.01 mm to about 1.2 mm, from about 0.01 mm to about 1.1 mm, from about 0.01 mm to about 1.05 mm, from about 0.01 mm to about 1 mm, from about 0.01 mm to about 0.95 mm, from about 0.01 mm to about 0.9 mm, from about 0.01 mm to about 0.85 mm, from about 0.01 mm to about 0.8 mm, from about 0.01 mm to about 0.75 mm, from about 0.01 mm to about 0.7 mm, from about 0.01 mm to about 0.65 mm, from about 0.01 mm to about 0.6 mm, from about 0.01 mm to about 0.55 mm, from about 0.01 mm to about 0.5 mm, from about 0.01 mm to about 0.4 mm, from about 0.01 mm to about 0.3 mm, from about 0.01 mm to about 0.2 mm, from about 0.01 mm to about 0.1 mm, from about 0.04 mm to about 0.07 mm, from about 0.1 mm to about 1.4 mm, from about 0.1 mm to about 1.3 mm, from about 0. 1 mm to about 1.2 mm, from about 0. 1 mm to about 1.1 mm, from about 0.1 mm to about 1.05 mm, from about 0.1 mm to about 1 mm, from about 0.1 mm to about 0.95 mm, from about 0.1 mm to about 0.9 mm, from about 0.1 mm to about 0.85 mm, from about 0.1 mm to about 0.8 mm, from about 0.1 mm to about 0.75 mm, from about 0.1 mm to about 0.7 mm, from about 0.1 mm to about 0.65 mm, from about 0.1 mm to about 0.6 mm, from about 0.1 mm to about 0.55 mm, from about 0. 1 mm to about 0.5 mm, from about 0. 1 mm to about 0.4 mm, or from about 0.3 mm to about 0.7 mm.

[0031] In one or more embodiments, the glass article has a width (W) in a range from about 5 cm to about 250 cm, from about 10 cm to about 250 cm, from about 15 cm to about 250 cm, from about 20 cm to about 250 cm, from about 25 cm to about 250 cm, from about 30 cm to about 250 cm, from about 35 cm to about 250 cm, from about 40 cm to about 250 cm, from about 45 cm to about 250 cm, from about 50 cm to about 250 cm, from about 55 cm to about 250 cm, from about 60 cm to about 250 cm, from about 65 cm to about 250 cm, from about 70 cm to about 250 cm, from about 75 cm to about 250 cm, from about 80 cm to about 250 cm, from about 85 cm to about 250 cm, from about 90 cm to about 250 cm, from about 95 cm to about 250 cm, from about 100 cm to about 250 cm, from about 1 10 cm to about 250 cm, from about 120 cm to about 250 cm, from about 130 cm to about 250 cm, from about 140 cm to about 250 cm, from about 150 cm to about 250 cm, from about 5 cm to about 240 cm, from about 5 cm to about 230 cm, from about 5 cm to about 220 cm, from about 5 cm to about 210 cm, from about 5 cm to about 200 cm, from about 5 cm to about 190 cm, from about 5 cm to about 180 cm, from about 5 cm to about 170 cm, from about 5 cm to about 160 cm, from about 5 cm to about 150 cm, from about 5 cm to about 140 cm, from about 5 cm to about 130 cm, from about 5 cm to about 120 cm, from about 5 cm to about 1 10 cm, from about 5 cm to about 1 10 cm, from about 5 cm to about 100 cm, from about 5 cm to about 90 cm, from about 5 cm to about 80 cm, or from about 5 cm to about 75 cm.

[0032] In one or more embodiments, the glass article has a length (L) in a range from about 5 cm to about 250 cm, from about 10 cm to about 250 cm, from about 15 cm to about 250 cm, from about 20 cm to about 250 cm, from about 25 cm to about 250 cm, from about 30 cm to about 250 cm, from about 35 cm to about 250 cm, from about 40 cm to about 250 cm, from about 45 cm to about 250 cm, from about 50 cm to about 250 cm, from about 55 cm to about 250 cm, from about 60 cm to about 250 cm, from about 65 cm to about 250 cm, from about 70 cm to about 250 cm, from about 75 cm to about 250 cm, from about 80 cm to about 250 cm, from about 85 cm to about 250 cm, from about 90 cm to about 250 cm, from about 95 cm to about 250 cm, from about 100 cm to about 250 cm, from about 1 10 cm to about 250 cm, from about 120 cm to about 250 cm, from about 130 cm to about 250 cm, from about 140 cm to about 250 cm, from about 150 cm to about 250 cm, from about 5 cm to about 240 cm, from about 5 cm to about 230 cm, from about 5 cm to about 220 cm, from about 5 cm to about 210 cm, from about 5 cm to about 200 cm, from about 5 cm to about 190 cm, from about 5 cm to about 180 cm, from about 5 cm to about 170 cm, from about 5 cm to about 160 cm, from about 5 cm to about 150 cm, from about 5 cm to about 140 cm, from about 5 cm to about 130 cm, from about 5 cm to about 120 cm, from about 5 cm to about 110 cm, from about 5 cm to about 1 10 cm, from about 5 cm to about 100 cm, from about 5 cm to about 90 cm, from about 5 cm to about 80 cm, or from about 5 cm to about 75 cm.

[0033] In one or more embodiments, the glass article has a surface area in a range from about 10 cm² to about 50,000 cm²

[0034] Suitable glass compositions for use in the glass article include soda lime glass, alumino silicate glass, borosilicate glass, boroaluminosilicate glass, alkali-containing alumino silicate glass, alkali-containing borosilicate glass, and alkali-containing

boroaluminosilicate glass. In one or more embodiments, may be a single composition layer or may include multiple layers of different compositions and thicknesses.

[0035] In one or more embodiments, the glass article may be strengthened. In one or more embodiments, the glass article may be strengthened to include a compressive stress that extends from a surface to a depth of compression or depth of compressive stress layer (DOL). The compressive stress at the surface is referred to as the surface CS. The CS regions are balanced by a central portion exhibiting a tensile stress. At the DOL, the stress crosses from a compressive stress to a tensile stress. The compressive stress and the tensile stress are provided herein as absolute values.

[0036] In one or more embodiments, the glass article is strengthened in two or more steps to achieve a first partially strength level (i.e., strengthened to a degree that is a portion of the final strength level in terms of surface CS and DOL) and a final strength level. In one or more embodiments, the strengthening process used to strengthen the glass article may include any one or combinations of a thermal strengthening process, a chemical strengthening process and a mechanical strengthening process.

[0037] In one or more embodiments, the glass article may be mechanically strengthened by utilizing a mismatch of the coefficient of thermal expansion between portions of the article to create a compressive stress region and a central region exhibiting a tensile stress. In some embodiments, the glass article may be thermally strengthened by heating the glass to a temperature above the glass transition point and then rapidly quenching.

[0038] In one or more embodiments, the glass article may be chemically strengthened by ion exchange. In the ion exchange process, ions at or near the surface of the glass article are replaced by - or exchanged with - larger ions having the same valence or oxidation state. In embodiments in which the glass article comprises an alkali alumino silicate glass, ions in the surface layer of the article and the larger ions are monovalent alkali metal cations, such as Li+, Na+, K+, Rb+, and Cs+. Alternatively, monovalent cations in the surface layer may be replaced with monovalent cations other than alkali metal cations, such as Ag+ or the like. In such embodiments, the monovalent ions (or cations) exchanged into the glass article generate a stress. It should be understood that any alkali metal oxide containing glass article can be chemically strengthened by an ion exchange process.

[0039] Ion exchange processes are typically carried out by immersing a glass article in a molten salt bath (or two or more molten salt baths) containing the larger ions to be exchanged with the smaller ions in the glass article. It should be noted that aqueous salt baths may also be utilized. In addition, the composition of the bath(s) may include more than one type of larger ion (e.g., Na+ and K+) or a single larger ion. It will be appreciated by those skilled in the art that parameters for the ion exchange process, including, but not limited to, bath composition and temperature, immersion time, the number of immersions of the glass article in a salt bath (or baths), use of multiple salt baths, additional steps such as annealing, washing, and the like, are generally determined by the composition of the glass article (including the structure of the article and any crystalline phases present) and the desired DOL and CS of the glass article that results from strengthening. Exemplary molten bath composition may include nitrates, sulfates, and chlorides of the larger alkali metal ion. Typical nitrates include KN03, NaN03, LiN03, NaS04 and combinations thereof. The temperature of the molten salt bath typically is in a range from about 380°C up to about 450°C, while immersion times range from about 15 minutes up to about 100 hours depending on glass article thickness, bath temperature and glass (or monovalent ion) diflusivity. However, temperatures and immersion times different from those described above may also be used.

[0040] In one or more embodiments, the glass articles may be immersed in a molten salt bath of 100% NaN03, 100% KN03, or a combination of NaN03 and KN03 having a temperature from about 370 °C to about 480 °C. In some embodiments, the glass article may be immersed in a molten mixed salt bath including from about 1% to about 99% KN03 and from about 1% to about 99% NaN03. In one or more embodiments, the glass article may be immersed in a second bath, after immersion in a first bath. The first and second baths may have different compositions and/or temperatures from one another. The immersion times in the first and second baths may vary. For example, immersion in the first bath may be longer than the immersion in the second bath.

[0041] In one or more embodiments, the glass article may be immersed in a molten, mixed salt bath including NaN03 and KN03 (e.g., 49%/5 1%, 50%/50%, 51 % 49%) having a temperature less than about 420 °C (e.g., about 400 °C or about 380 °C). for less than about 5 hours, or even about 4 hours or less.

[0042] Ion exchange conditions can be tailored to provide a "spike" or to increase the slope of the stress profile at or near the surface of the resulting glass article. The spike may result in a greater surface CS value. This spike can be achieved by single bath or multiple baths, with the bath(s) having a single composition or mixed composition, due to the unique properties of the glass compositions used in the glass articles described herein.

[0043] In one or more embodiments, where more than one monovalent ion is exchanged into the glass article, the different monovalent ions may exchange to different depths within the glass article (and generate different magnitudes stresses within the glass article at different depths). The resulting relative depths of the stress-generating ions can be determined and cause different characteristics of the stress profile.

[0044] CS is measured using those means known in the art, such as by surface stress meter (FSM) using commercially available instruments such as the FSM-6000, manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurements rely upon the accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC in turn is measured by those methods that are known in the art, such as fiber and four point bend methods, both of which are described in ASTM standard C770-98 (2013), entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient," the contents of which are incorporated herein by reference in their entirety, and a bulk cylinder method. As used herein CS may be the "maximum compressive stress" which is the highest compressive stress value measured within the compressive stress layer. In some embodiments, the maximum compressive stress is located at the surface of the glass article. In other embodiments, the maximum compressive stress may occur at a depth below the surface, giving the compressive profile the appearance of a "buried peak."

[0045] DOL may be measured by FSM or by a scattered light polariscope (SCALP) (such as the SCALP-04 scattered light polariscope available from Glasstress Ltd., located in Tallinn Estonia), depending on the strengthening method and conditions. When the glass article is chemically strengthened by an ion exchange treatment, FSM or SCALP may be used depending on which ion is exchanged into the glass article. Where the stress in the glass article is generated by exchanging potassium ions into the glass article, FSM is used to measure DOL. Where the stress is generated by exchanging sodium ions into the glass article, SCALP is used to measure DOL. Where the stress in the glass article is generated by exchanging both potassium and sodium ions into the glass, the DOL is measured by SCALP, since it is believed the exchange depth of sodium indicates the DOL and the exchange depth of potassium ions indicates a change in the magnitude of the compressive stress (but not the change in stress from compressive to tensile); the exchange depth of potassium ions in such glass articles is measured by FSM. Central tension or CT is the maximum tensile stress and is measured by SCALP.

[0046] In one or more embodiments, the glass article maybe strengthened to exhibit a DOL that is described a fraction of the thickness t of the glass article (as described herein). For example, in one or more embodiments, the DOL may be equal to or greater than about 0.05t, equal to or greater than about 0. It, equal to or greater than about 0.1 It, equal to or greater than about 0.12t, equal to or greater than about 0.13t, equal to or greater than about 0.14t, equal to or greater than about 0.15t, equal to or greater than about 0.16t, equal to or greater than about 0.17t, equal to or greater than about 0.18t, equal to or greater than about 0.19t, equal to or greater than about 0.2t, equal to or greater than about 0.2 It. In some

embodiments, The DOL may be in a range from about 0.08t to about 0.25t, from about 0.09t to about 0.25t, from about 0.18t to about 0.25t, from about 0.1 It to about 0.25t, from about 0.12t to about 0.25t, from about 0.13t to about 0.25t, from about 0.14t to about 0.25t, from about 0.15t to about 0.25t, from about 0.08t to about 0.24t, from about 0.08t to about 0.23t, from about 0.08t to about 0.22t, from about 0.08t to about 0.21t, from about 0.08t to about 0.2t, from about 0.08t to about 0.19t, from about 0.08t to about 0.18t, from about 0.08t to about 0.17t, from about 0.08t to about 0.16t, or from about 0.08t to about 0.15t. In some instances, the DOL may be about 20 μιη or less. In one or more embodiments, the DOL may be about 40 μιη or greater (e.g., from about 40 μιη to about 300 μιη, from about 50 μιη to about 300 μιη, from about 60 μιη to about 300 μιη, from about 70 μιη to about 300 μιη, from about 80 μιη to about 300 μιη, from about 90 μιη to about 300 μιη, from about 100 μιη to about 300 μιη, from about 110 μιη ΐο about 300 μιη, from about 120 μιη ΐο about 300 μιη, from about 140 μιη ΐο about 300 μm, from about 150 μιη ΐο about 300 μιη, from about 40 μιη to about 290 μm, from about 40 μιη to about 280 μιη, from about 40 μιη to about 260 μιη, from about 40 μm to about 250 μιη, from about 40 μιη to about 240 μιη, from about 40 μιη to about 230 μm, from about 40 μιη to about 220 μιη, from about 40 μιη to about 210 μιη, from about 40 μm to about 200 μιη, from about 40 μιη to about 180 μιη, from about 40 μιη to about 160 μm, from about 40 μιη to about 150 μιη, from about 40 μιη to about 140 μιη, from about 40 μm to about 130 μιη, from about 40 μιη to about 120 μιη, from about 40 μιη to about 1 10 μιη, or from about 40 μιη to about 100 μm.

[0047] In one or more embodiments, the strengthened glass article may have a CS (which may be found at the surface or a depth within the glass article) of about 200 MPa or greater, 300 MPa or greater, 400 MPa or greater, about 500 MPa or greater, about 600 MPa or greater, about 700 MPa or greater, about 800 MPa or greater, about 900 MPa or greater, about 930 MPa or greater, about 1000 MPa or greater, or about 1050 MPa or greater. In one or more embodiments, the strengthened glass article may have a CS (which may be found at the surface or a depth within the glass article) from about 200 MPa to about 1500 MPa, from about 250 MPa to about 1500 MPa, from about 300 MPa to about 1500 MPa, from about 350 MPa to about 1500 MPa, from about 400 MPa to about 1500 MPa, from about 450 MPa to about 1500 MPa, from about 500 MPa to about 1500 MPa, from about 550 MPa to about 1500 MPa, from about 600 MPa to about 1500 MPa, from about 200 MPa to about 1400 MPa, from about 200 MPa to about 1300 MPa, from about 200 MPa to about 1200 MPa, from about 200 MPa to about 1100 MPa, from about 200 MPa to about 1050 MPa, from about 200 MPa to about 1000 MPa, from about 200 MPa to about 950 MPa, from about 200 MPa to about 900 MPa, from about 200 MPa to about 850 MPa, from about 200 MPa to about 800 MPa, from about 200 MPa to about 750 MPa, from about 200 MPa to about 700 MPa, from about 200 MPa to about 650 MPa, from about 200 MPa to about 600 MPa, from about 200 MPa to about 550 MPa, or from about 200 MPa to about 500 MPa.

[0048] In one or more embodiments, the strengthened glass article may have a maximum tensile stress or central tension (CT) of about 20 MPa or greater, about 30 MPa or greater, about 40 MPa or greater, about 45 MPa or greater, about 50 MPa or greater, about 60 MPa or greater, about 70 MPa or greater, about 75 MPa or greater, about 80 MPa or greater, or about 85 MPa or greater. In some embodiments, the maximum tensile stress or central tension (CT) may be in a range from about 40 MPa to about 100 MPa, from about 50 MPa to about 100 MPa, from about 60 MPa to about 100 MPa, from about 70 MPa to about 100 MPa, from about 80 MPa to about 100 MPa, from about 40 MPa to about 90 MPa, from about 40 MPa to about 80 MPa, from about 40 MPa to about 70 MPa, or from about 40 MPa to about 60 MPa.

[0049] After a strengthening process, the resulting strengthened glass article can include a symmetric stress profile or an asymmetric stress profile. A symmetric stress profile exists when both major surfaces of the glass article are symmetrically chemical strengthened and exhibit substantially the same surface compressive stress and depth of compressive stress layer. In one or more embodiments, the resulting strengthened glass article can exhibit an asymmetric stress profile exists in which the glass article exhibits different surface compressive stress on one major surface compared to the opposing major surface, at locations on each major surface that are directly opposite from one another.

[0050] In one or more embodiments, the glass article has at least one curve having at least one convex surface on the first major surface and at least one concave surface in the vicinity of the curve on the second surface, as shown in Figure 6 (340). In one or more embodiments, the curved glass article has a single bend. In one or more embodiments, curved glass article comprises a first convex bend and a second convex bend. In one or more embodiments, the curved glass article comprises a first convex bend and a first concave bend.

[0051] In one or more embodiments, the at least one curve has a bend radius (measured at the concave surface) of about 20 mm or greater, 40 mm or greater, 50 mm or greater, 60 mm or greater, 100 mm or greater, 250 mm or greater or 500 mm or greater. In one or more embodiments, the bend radius is in a range from about 50 mm to about 10,000 mm. For example, the bend radius may be in a range from about 20 mm to about 1500 mm, from about 30 mm to about 1500 mm, from about 40 mm to about 1500 mm, from about 50 mm to about 1500 mm, 60 mm to about 1500 mm, from about 70 mm to about 1500 mm, from about 80 mm to about 1500 mm, from about 90 mm to about 1500 mm, from about 100 mm to about 1500 mm, from about 120 mm to about 1500 mm, from about 140 mm to about 1500 mm, from about 150 mm to about 1500 mm, from about 160 mm to about 1500 mm, from about 180 mm to about 1500 mm, from about 200 mm to about 1500 mm, from about 220 mm to about 1500 mm, from about 240 mm to about 1500 mm, from about 250 mm to about 1500 mm, from about 260 mm to about 1500 mm, from about 270 mm to about 1500 mm, from about 280 mm to about 1500 mm, from about 290 mm to about 1500 mm, from about 300 mm to about 1500 mm, from about 350 mm to about 1500 mm, from about 400 mm to about 1500 mm, from about 450 mm to about 1500 mm, from about 500 mm to about 1500 mm, from about 550 mm to about 1500 mm, from about 600 mm to about 1500 mm, from about 650 mm to about 1500 mm, from about 700 mm to about 1500 mm, from about 750 mm to about 1500 mm, from about 800 mm to about 1500 mm, from about 900 mm to about 1500 mm, from about 950 mm to about 1500 mm, from about 1000 mm to about 1500 mm, from about 1250 mm to about 1500 mm, from about 20 mm to about 1400 mm, from about 20 mm to about 1300 mm, from about 20 mm to about 1200 mm, from about 20 mm to about 1 100 mm, from about 20 mm to about 1000 mm, from about 20 mm to about 950 mm, from about 20 mm to about 900 mm, from about 20 mm to about 850 mm, from about 20 mm to about 800 mm, from about 20 mm to about 750 mm, from about 20 mm to about 700 mm, from about 20 mm to about 650 mm, from about 20 mm to about 200 mm, from about 20 mm to about 550 mm, from about 20 mm to about 500 mm, from about 20 mm to about 450 mm, from about 20 mm to about 400 mm, from about 20 mm to about 350 mm, from about 20 mm to about 300 mm, from about 20 mm to about 250 mm, from about 20 mm to about 200 mm, from about 20 mm to about 150 mm, from about 20 mm to about 100 mm, from about 20 mm to about 50 mm, from about 60 mm to about 1400 mm, from about 60 mm to about 1300 mm, from about 60 mm to about 1200 mm, from about 60 mm to about 1100 mm, from about 60 mm to about 1000 mm, from about 60 mm to about 950 mm, from about 60 mm to about 900 mm, from about 60 mm to about 850 mm, from about 60 mm to about 800 mm, from about 60 mm to about 750 mm, from about 60 mm to about 700 mm, from about 60 mm to about 650 mm, from about 60 mm to about 600 mm, from about 60 mm to about 550 mm, from about 60 mm to about 500 mm, from about 60 mm to about 450 mm, from about 60 mm to about 400 mm, from about 60 mm to about 350 mm, from about 60 mm to about 300 mm, or from about 60 mm to about 250 mm. In one or more embodiments, glass articles having a thickness of less than about 0.4 mm may exhibit a bend radius that is less than about 100 mm, or less than about 60 mm.

[0052] In one or more embodiments, wherein the first major surface exhibits a first surface compressive stress at a first location and the second major surface exhibits a second surface compressive stress at a second location that is directly opposite the first location, wherein the first surface compressive stress is less than the second surface compressive stress (due to the second major surface being concave and in compression). In some embodiments, the difference between the first compressive stress and the second compressive stress is in a range from about 10 MPa to about 500 MPa (e.g., from about 10 MPa to about 450 MPa, from about 10 MPa to about 400 MPa, from about 10 MPa to about 350 MPa, from about 10 MPa to about 300 MPa, from about 10 MPa to about 250 MPa, from about 10 MPa to about 200 MPa, from about 10 MPa to about 150 MPa, from about 10 MPa to about 100 MPa, from about 10 MPa to about 50 MPa, from about 20 MPa to about 500 MPa, from about 25 MPa to about 500 MPa, from about 50 MPa to about 500 MPa, from about 75 MPa to about 500 MPa, from about 100 MPa to about 500 MPa, from about 150 MPa to about 500 MPa, from about 200 MPa to about 500 MPa, from about 250 MPa to about 500 MPa, from about 300 MPa to about 500 MPa, from about 350 MPa to about 500 MPa, from about 400 MPa to about 500 MPa, or from about 450 MPa to about 500 MPa).

[0053] In one or more embodiments, the first surface compressive stress and the second surface compressive stress are in a range from about 200 MPa to about 1500 MPa (and subranges described herein) but still differ.

[0054] In one or more embodiments, the curved glass article retains the at least one curve while unsupported by any other structure or material. Known cold bent glass articles can be contrasted because such known cold bent articles may exhibit a first surface compressive stress that differs from the second compressive stress, but do not maintain a curved shape if unsupported by any other structure or material. Known hot formed articles that are curved using heat can be contrasted because such hot formed glass articles maintain a curved shape while unsupported by any other structure or material but the first surface compressive stress and the second surface compressive stress do not differ as a result of curving or shaping. [0055] In one or more embodiments, the first major surface and/or the second major surface include a surface treatment. The surface treatment may cover at least a portion of the first major surface and/or the second major surface. Exemplary surface treatments include an easy- to -clean surface, an anti-glare surface, an anti-reflective surface, a haptic surface, and a decorative surface. In one or more embodiments, the at least a portion of the first major surface and/or the second major surface may include any one, any two or all three of an antiglare surface, an anti-reflective surface, a haptic surface, and a decorative surface. For example, first major surface may include an anti-glare surface and the second major surface may include an anti-reflective surface. In another example, the first major surface includes an anti-reflective surface and the second major surface includes an anti-glare surface. In yet another example, the first major surface comprises either one of or both the anti-glare surface and the anti-reflective surface, and the second major surface includes the decorative surface.

[0056] In one or more embodiments, the curved glass sheet article may include display or touch panel disposed on or attached to one or both the first major surface and the second major surface.

[0057] In one or more embodiments, the curved glass sheet article has a first major surface and a second major surface, and includes at least one curve of the glass sheet, the curve having at least one convex surface and at least one concave surface in the vicinity of the curve; and at least one of the first major surface, the second major surface, or both major surfaces, is ion- exchanged, and has a strength of from 400 MPa to 1500 MPa, and the curved glass piece or curved glass sheet article has permanent or semi-permanent curve or shape retention. In one or more embodiments, the curved glass sheet article made by the method can further comprise, for example, a display screen, a cover glass, a window glass, a structural glass, a glass component of a vehicle, or a combination thereof. In one or more embodiments, the at least one curve of the glass sheet can have, for example, a bend radius of from 50 mm to 10,000 mm.

[0029] A second aspect of this disclosure pertains to a method of making a shaped glass article comprising: securing a cold bent glass article in a retaining fixture to produce a retained, cold bent glass article; and strengthening (e.g., by ion-exchanging) the retained, cold bent glass article to produce the shaped glass article. In one or more embodiments, the shaped glass article has a single bend. In one or more embodiments, the shaped glass article comprises a first convex bend and a second convex bend. In one or more embodiments, the shaped glass article comprises a first convex bend and a first concave bend. In one or more embodiments the cold-bent glass article glass article or shaped glass article has a surface area in a range from about 10 cm² to about 50,000 cm², a thickness in a range from about 0.4 mm to 2 about mm, and the at least one bend has a bend radius in a range from about 50 mm to about 10,000 mm.

[0030] In one or more embodiments, the method includes cold bending a strengthened glass article to produce at least one bend or curve having at least one convex surface, and at least one concave surface to provide the cold bent glass article. In one or more embodiments, securing the cold bent glass article in a retaining fixture comprises attaching at least two edges of the glass article to a rigid frame. In one or more embodiments, cold bending the strengthened glass article and securing the cold bent glass article occur simultaneously.

[0031] In one or more embodiments, the method includes strengthening the glass article before cold bending by one or more of thermal strengthening, chemical strengthening or mechanical strengthening, as described herein. The resulting strengthened glass article may have a symmetric stress profile or asymmetric stress profile, as described herein. In one or more embodiments, the strengthened glass article may have a surface CS and/or a DOL as otherwise described herein the first aspect. In one or more embodiments, the strengthened glass article comprises at least one chemically strengthened major surface. The glass article may a thickness (t), width (W) and/or length (L) as described herein.

[0032] In one or more embodiments, prior to ion-exchanging the retained glass, the method may include applying a force on at least one point of the convex surface of the retained, cold bent glass article. In some embodiments, applying a force comprises applying a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent glass article, applying a line of force to at least one line on the convex surface of the retained, cold bent glass article, applying a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass, applying a force comprises applying a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass, and/or applying a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion- exchanged glass. In one or more embodiments, the steps of cold bending or securing the cold bent glass article comprises at least one of or both: wrapping a glass article about a form; and pressing the glass article with at least one form. In one or more embodiments, the steps of cold bending or securing the cold bent glass article comprises wrapping the strengthened glass article about the form and applying a force to at least one point on the convex surface. In one or more embodiments, applying the force to at least one point on the convex surface comprises any one or more of applying: a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent, first ion-exchanged glass; a line of force to at least one line on the convex surface of the retained, cold bent, first ion- exchanged glass; a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass; a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass; and a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

In one or more embodiments, at least two of cold bending the strengthened glass article, securing the cold bent glass article, and ion-exchanging the retained cold bent glass article, are performed simultaneously.

[0033] In one or more embodiments, the step of securing the resulting cold bent glass article in a retaining fixture comprises fixing the cold bent glass article to a predetermined bend radius to produce the shaped glass in the fixture.

[0034] In one or more embodiments, the method includes separating the shaped glass article from the retaining fixture to produce a free-standing shaped glass article, and the shaped glass article retains its bend or curve in the absence of external forces. In one or more

embodiments, the shaped glass article has a surface compressive stress in a range from about 400 MPa to about 1500 MPa, and a depth of compressive stress layer in a range from about 15 micrometers to 75 micrometers. The shape glass article may have a surface compressive stress and/or depth of compressive stress layer as described herein with respect to the first aspect.

[0035] A third aspect of this disclosure pertains to a method of making a shaped glass article. In one or more embodiments, the method includes cold bending a first ion-exchanged flat glass article to produce a cold bent, first ion-exchanged glass having at least one bend and at least one convex surface and at least one concave surface; securing the resulting cold bent, first ion-exchanged glass in a retaining fixture to produce a retained, cold bent, first ion- exchanged glass, i.e., "frxturing"; and ion-exchanging the resulting retained, cold bent, first ion-exchanged glass to produce the shaped glass article.

[0036] In one or more embodiments, the cold bending or securing the resulting cold bent, first ion-exchanged glass in a retaining fixture can comprise, for example, attaching at least two edges of the glass to a rigid frame.

[0037] In one or more embodiments, the cold bending or securing the resulting cold bent, first ion-exchanged glass in a retaining fixture can comprise, for example, attaching at least two edges of the glass to a rigid frame.

[0038] In one or more embodiments, a magazine or cassette fixture having a plurality of glass mounting locations can be selected, for example, to accommodate a plurality of flat glass pieces. Once the glass pieces have been mounted into the magazine or cassette, a

predetermined force can be applied to one or more portions of the exterior, interior, or both, of the cassette, with the result that the plurality of mounted glass pieces can be all be uniformly shaped at the same time providing greater dimensional uniformity within and between batches. In embodiments, the abovementioned mentioned magazine or cassette fixture can be manually or mechanically loaded with a plurality of flat glass pieces, the fixture can be compressed and held in place to bend or shape the plurality of the fixtured glass pieces in the magazine or cassette, and the combined fixture and fixed and bent glass pieces (i.e., assembly) can be immersed and contacted with a suitable ion-exchange bath. In embodiments, the magazine or cassette fixture can additionally include the application of one or more point or line sources of force on each of the glass pieces to produce additional controlled distortion and shaping of the glass pieces prior to or during the ion-exchange treatment.

[0039] In one or more embodiments, the cold bending or securing of the resulting cold bent, first ion-exchanged glass in a retaining fixture can further comprise applying at least one of: a point source of force, e.g., a pin or "pinning", to at least one point on the convex surface of the retained, cold bent, first ion-exchanged glass.

In one or more embodiments, the disclosed method can further comprises applying at least one of: a point source of force to at least one point on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent, first ion-exchanged glass; a line of force to at least one line on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass; a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass; or a combination thereof. In one or more embodiments, the sources of force can include alternative geometric shapes, for example, a square outline (such as a cookie cutter) or square pin (such as an embossing tool), a rectangular outline or rectangular pin, a circular outline or circular pin, an oval outline or an oval pin, and like shapes or geometries, or combinations thereof.

[0040] In embodiments, the cold bending or securing the resulting cold bent, first ion- exchanged glass in a retaining fixture can further comprise, for example, at least one of:

wrapping the first ion-exchanged flat glass article about a form, e.g., a portion of cylinder, a hemi-cylinder, a sphere, a hemisphere, a saddle point surface, and like geometries, or combinations thereof; pressing the first ion-exchanged flat glass article with at least one form (e.g., rigid or resilient form having a shape of, for example, a cylinder, a hemi-cylinder, a sphere, a hemisphere, a saddle point surface, and like geometries, or a portion thereof of such as a band or strap); or a combination of both wrapping and pressing.

[0041] In embodiments, the cold bending or securing the resulting cold bent, first ion- exchanged glass in a retaining fixture can further comprise: wrapping the first ion-exchanged flat glass article about a form, e.g., a cylinder, a hemi-cylinder, a sphere, a hemisphere, and like geometries (i.e., "wrapping"), and applying one or more of: a point source of force, e.g., a pin or "pinning", to at least one point, or in embodiments, a plurality of point sources of force, on the convex surface of the wrapped, retained, cold bent, first ion-exchanged glass.

[0042] In embodiments, the cold bending or securing the resulting cold bent, first ion- exchanged glass in a retaining fixture includes wrapping the first ion-exchanged flat glass article about a form and applying one or more of:

a point source of force to at least one point on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent, first ion-exchanged glass; a line of force to at least one line on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion- exchanged glass; a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass; or a combination thereof.

[0043] In embodiments, the securing comprises fixing the resulting cold bent, first ion- exchanged glass in a retaining fixture to a predetermined bend radius (e.g., as measured by, e.g., a chord length, chord height, or fixture radius) to produce the shaped glass in the fixture.

[0044] In embodiments, the first ion-exchanged flat glass article can have, for example: an area of from 10 to 50,000 cm², a thickness 0.4 to 2 mm, and preferably a thickness of from 0.55 to 0.7 mm, and the at least one bend has a bend radius of from 50 to 10000 mm.

[0045] In one or more embodiments, the shaped glass article can have a single bend, two bends, a plurality of bends, and like bend configurations.

[0046] In one or more embodiments, the shaped glass article can be a sheet having, for example, a first convex bend and a second convex bend.

[0047] In one or more embodiments, the shaped glass article can be a sheet having a first convex bend and a first concave bend.

[0048] In one or more embodiments, the disclosed method of making can have, for example, at least two of the method steps selected from: the cold bending; the securing; and the ion-exchanging, can be accomplished simultaneously.

[0049] In one or more embodiments, the cold bending and the securing can be accomplished simultaneously.

[0050] In one or more embodiments, the cold bending and the ion-exchanging can be accomplished sequentially or simultaneously.

[0051] In one or more embodiments, the cold bending can be accomplished, for example, below the glass transition temperature (T_g) of the glass sheet, for example, at ambient temperatures and without the application of additional or an external heat source.

[0052] In one or more embodiments, the first ion-exchanged flat glass article has, for example, at least one major surface that has been ion exchanged.

[0053] In one or more embodiments, the first ion-exchanged flat glass article has, for example, both major surfaces ion exchanged.

[0054] In one or more embodiments, the method of making can further comprise, for example, separating the shaped glass article from the retaining fixture to produce a free- standing shaped glass article, and the shaped glass article retains its shape in the absence of external forces.

[0055] In one or more embodiments, the shaped glass article has a compression, for example, of from 400 to 1500 MPa, and a depth of layer (DOL), for example, of from 15 to 75 microns.

[0056] In one or more embodiments, the disclosure provides a method of making a shaped glass article comprising cold bending and securing a first ion-exchanged flat glass article in a retaining fixture to produce a secured, cold bent, first ion-exchanged glass having at least one bend, the bend having at least one convex surface and at least one concave surface; and ion- exchanging the resulting secured, cold bent, first ion-exchanged glass to produce the shaped glass article. In embodiments, the cold bending and securing, and the ion-exchanging are accomplished by at least one of: sequentially, simultaneously, continuously, or a combination thereof.

[0057] The present disclosure is advantaged in several aspects. Without being bound by theory, it is believed that 3D displays with curved cover glass articles formed using the disclosed method will exhibit lower residual stress, and consequently offer more design options for designers, e.g., choosing cold bend restraints, bend radius, or combinations thereof. In addition, it is believed that embodiments of the disclosed method can eliminate a hot-bending step used in conventional forming methods, and can lead to lower production costs for curved glass articles.

[0058] In one or more embodiments, the embodiments of this disclosure provide curved or 3D glass articles that can be made, for example, by forming (i.e., bending or shaping) and strengthening the article, either sequentially in a two-step process or simultaneously in a single step process. The resulting three-dimensional (3D) glass article can be used in a variety of applications, including for example, in an automotive interior, in consumer electronics, and like applications.

[0059] In one or more embodiments, the differential or asymmetric strengthening process can create different stresses on opposite sides (i.e., first and second major surfaces) of the glass article, which can facilitate bending properties of the glass article and contribute to strength properties of the glass article. Additionally, subsequent strengthening (e.g., by ion exchange) can be used to relieve some of the stresses in a cold bend glass article. [0060] In one or more embodiments, the glass article can be "partially" strengthened (i.e., to an extent of less than 100% or incomplete strengthening and/or can be strengthened to to create differential stresses on opposite major surfaces (i.e., first and second major surfaces), which can facilitate bending properties of the glass and contribute to strength properties of the glass. In embodiments, the glass article can be manually or mechanically cold bent using a holding fixture and then strengthened (e.g., by ion exchange process). After the subsequent strengthening process, due to initial asymmetric stress, the bend stress experienced by the glass article can be lower than the bend stress before strengthening.

[0061]

[0062] Referring to the Figures, Fig. 1 shows a flow chart of a known cold-bend process (100). The glass article is chemically strengthened via an ion-exchange process (1 10). The chemically strengthened or ion-exchanged flat sheets of glass are then cold-bent ( 1 15) using a constraint such as grooved frame on a support, or adhesives. The constraint provides a reaction force or rebound force to keep the glass bent during the life of the product (120) such as in an automotive interior display panel. If the constraint is removed or released, the glass returns to its normal flat state releasing all the configurational stored potential energy.

[0063] Fig. 2 is a flow chart of an exemplary process (200) of the disclosure, where a flat glass article (205) is optionally IOX'd (210) on demand, for example, for 2 hour at 420°C. Alternatively, the flat glass article can be IOX'd (210) in advance and placed in inventory for use as needed. In any event, a first IOX'd flat sheet is placed or fitted in a fixture and bent (213). The bending can be concomitant with the placing, fitting, securing, etc., of the first IOX'd flat sheet in the fixture. The fixtured and bent first IOX'd flat sheet provides a fixtured and bent substrate having a first cord length (or bend radius). The fixtured and bent substrate is then subjected to a second IOXing (215), for example, for 2 to 3 hr at 420°C, to yield, when removed from the fixture, a bent substrate (220) having a second cord length or bend radius. The second IOXing produces a 3D formed substrate (221). A cord height of the unfixtured bent substrate can be less than a cord height of the fixtured and bent substrate due some relaxation (e.g., 1 to 1,000%). In embodiments, the un-fixtured bent substrate (221), i.e., the resulting formed 3D shape can be attached to backing support or holder, such as metal, plastic, or glass, to form a supported 3D glass product (225). The attachment of the 3D glass shape to a backing support can be accomplished by any suitable means or method, such as a fastener, an adhesive, and like instrumentalities. [0064] Fig. 3 is a schematic of a disclosed process (300), where a starting flat glass (310) is transformed to a 3D shape (340). The schematic of Fig. 3 shows the disclosed process (300), where a starting flat glass (310) is optionally ion-exchanged (315) (e.g., 2 hours at 420°C), or alternatively, ion-changed in advance. Next, the ion-exchanged glass or a previously ion- exchanged glass is cold-bent to cold-bend glass piece (320) in a fixture (330) to a certain specified radius, for example, defined by first chord length (325). The cold-bent glass, while still mounted in the fixture, is then ion-exchanged (335), for example, for an additional 2 to 4 hours at 420°C. The resulting ion-exchanged and bent glass part when removed from the fixture yields a three-dimensional glass shape (340) having a chord height (345). The free standing bent glass part (340) can then optionally be attached to a suitable backing support (not shown) to form a supported 3D product, for example, an automotive interior display. Optionally, the cold-bend glass piece (320) in a fixture (330) can be further shaped by additional external forces such a pin or bar (327) contacting the cold-bend glass piece (320), for example, at one or more points, along one or more lines, or similar contacting, to apply a compressive force (329) to the pin or bar (327) to cause further controlled distortion or perturbation of the initial bend shape, for example, rounding of the fixtured piece to a shape having a cross-section segment that more closely approximates a circular or oval (321) contour (i.e., a portion or segment of the dotted line oval). The subsequent ion-exchange (335) of the fixtured piece further fixes the bend shape of the fixtured piece. Depending upon the extent of the bending, some relaxation from the full bend of the piece may be observed when the piece is removed from the fixture.

[0065] Fig. 4 is an image of the frxturing of Fig. 3 showing a first glass piece (320) (bottom half) in a fixture, and a second glass piece (top half) in a fixture that is additionally being deformed or shaped with a pin or bar member (327) to achieve a more rounded profile having a cylindrical or oval shape or contour (321).

[0066] Fig. 5 is a graph showing a comparison of results for a first glass piece (top curve pair) in a fixture only, and a second glass piece (510) (bottom curve pair) in a fixture and additionally employing a pin or bar force as shown in Fig. 4 (top half). Curve (500) has an average sum of square error (SSE) from nominal of 0.07%, i.e., dotted curve (505). Curve (510) has an average SSE from nominal of 0.013%, i.e., dotted curve (515).

[0067] Fig. 6 is an image showing a cold-bent glass piece that is bent at its short edges around a barrel shaped fixture or jig (600) (top and bottom ends) and the cold-bent glass piece (610) is attached or held to the fixture with fastener, for example, one or more such as a pair of hoop-type or barrel-type clamps (620), straps, bands, or like brackets, near the long side edges.

[0068] In embodiments, the disclosed two-step ion-exchange process achieves three dimensional glass shapes. In embodiments, the glass is partially ion-exchanged in a first step (i.e., 2 hours at 420°C) in, for example, a flat state. Thereafter, the partially ion-exchanged glass can be cold-bent in fixture to a certain radius defined by a chord length. The resulting cold-bent glass is then mounted in a fixture and is ion-exchanged in second step for an additional 2 hours at 420°C. The resultant part or piece yields a three-dimensional shape which can optionally be attached to a plastic, metal, or like flexible or rigid backing support to form a supported shaped glass product.

[0069] In embodiments, features of the disclosed method can include, for example: A substrate, which includes a glass capable of IOX processing, and having a thickness of less than 5 mm, e.g., of from 0.01 to 4.99 mm. The substrate can have a non-uniform thickness. The substrate can be a single composition layer or can include multiple layers of different compositions and thicknesses. The thinner the glass, the lower the stiffness and the easier it is for IOX stress to create substrate bending.

[0070] In embodiments, the glass article when fixtured can be kept flat or can be bent to a shaped or curved surface before or during the IOX process.

Table 1 lists examples of 3D glass parts prepared in a two-step IOX and bending process including, for example: ion-exchanging a flat glass sample (e.g., size: 2" x 6") of indicated thickness for 2 hr at 420 °C; mounting the resulting ion-exchanged sample in the bend fixture (e.g., bending along the 6" length direction of the flat glass sample), having the indicated chord length, and ion-exchanging again for 2 hr at 420°C. Surface profile measurements on 3D glass parts were performed using ATOS scanner. "CS" is the compressive strength and "DOL" is the depth of layer of the exchanged ions on the glass article.

Table 1. Equivalent radius of glass parts after the disclosed two-step IOX process.

0.4 130.18 872.3 MPa / 35.4 μιη (L) 5.21 /542

868. I MPa / 37.6 μιη (C)

857.3 MPa / 35.0 μπ (R)

0.55 130.18 883.9 MPa / 35.7 μιη (L) 5.48 / 529

886.9 MPa / 36.6 μιη (C)

891.7 MPa / 35.3 μιη (R)

0.7 130.18 892.9 MPa / 35.5 μιη (L) 5.64 / 514

923.0 MPa / 37.6 μιη (C)

904.1 MPa/ 35.0 μτη (R)

1.1 139.70 Not available 3.94 / 736

[0071] The results listed in Table 2 indicate that cylindrical shaped glass piece segments prepared according to the present disclosure, such as using a barrel shaped fixture form and hoop clamps, can have a bend radius or curvature comparable to or better than pieces prepared by a hot formed method. A target radius of 695 mm was achieved with a 125 mm fixture radius and 7 hours total ion-exchanging (i.e., first 3 hr, and second 4 hr). Examples 1, 2 and 3 used the fixture shown in Fig. 4, and Examples 4 and 5 used the fixture shown in Fig. 6. The barrel radius (R_b) is the radius of a barrel form in a barrel fixture such as 125 mm. The radius (R_p) is the radius of the resultant glass piece after completing the disclosed asymmetric IOX process. SSE (i.e., the sum of squared errors of prediction) is the sum of the squares of residuals (deviations predicted from actual value of data). SSE-avg is the average of all SSE values measured at several locations on the part surface.

Table 2. Experimental results for shaped 3D glass pieces prepared using the barrel fixtures of Fig. 4 or Fig. 6.

Example & 1^st IOX 2^nd IOX Radius SSE-avg Fixture Fig. Set Point Time Time ("R") (mm)

(hours) (hours)

1 No Pin, Chord 2 2 1103.2 0.070

Fig. 4 Length c = 290

mm

2 Pin, Chord 2 2 1539.7 0.013

Fig. 4 Length c = 290

mm

3 Pin, Chord 3 2 598.9 0.231

[0072] In embodiments, the disclosed glass article can be a vehicle interior component. In embodiments, the vehicle interior component can include, for example, a support surface and the glass article on the support surface. In embodiments, the vehicle interior component can be selected, for example, from the group consisting of a display, a center console, a dashboard, a door panel, a pillar, a floor board, an arm rest, an instrument cluster cover, or a combination thereof. In embodiments, the disclosed glass article can further include one or more of an antiglare coating, an anti-reflective coating, an oleophobic coating, an anti-scratch coating, an ink coating, or a combination thereof. In embodiments, the disclosed support for the surface vehicle interior component can comprise, for example, fabric, leather, polymer, wood, metal, or combinations thereof. In embodiments, the disclosure provides a vehicle comprising a cabin and an interior, and the interior comprising at least one of the disclosed glass articles. In embodiments, the disclosure provides an automobile interior component comprising a cold- formed, curved glass sheet having at least a first portion having a first bend defining a first bend region with a set of first bend line segments.

EXAMPLES

[0078] The following Examples demonstrate making, use, and analysis of the disclosed articles and methods of making the articles in accordance with the above general procedures.

Example 1

[0079] A flat 0.7 mm thick alkali alumino -silicate glass sample (341.64 mm x 133 mm) was partially ion exchanged on each side for 2 hours (i.e., partially or incompletely rather than a typical ion exchange 4 hour time) in a molten potassium nitrate bath at 420°C followed by rinsing with water to remove salt residues. Thereafter, the partially ion-exchanged glass was cold bent in a fixture by pressing the two short sides. The fixture was made of stainless steel and contacted the glass only at the two short edges. The chord length of the cold-bent glass in the fixture was 290 mm. The cold-bent glass mounted in the fixture (i.e., the assembly) was immersed in the ion-exchange tank for an additional 2 hrs. After the 2 hours, the glass-fixture assembly was removed from the tank and rinsed with water to remove salt residues. The glass was removed from the fixture and surface profile measurements were performed using ATOS scanner. The radius of the resulting cylindrical contoured part was 1103.2 mm with average sum of square error (SSE) of 0.070.

Example 2

[0080] Example 1 was repeated with the exception that the cold-bent glass secured in the retaining fixture was pressed at the apex of the parabolic bend profile on the convex surface by a pin (e.g., a metal bar laid across the cold-bent glass). The pin made a line contact with the glass at the apex of parabolic bend (e.g., Figs. 3 and 4). The stainless-steel pin pressed the fixtured glass to achieve a bend profile having a more cylindrical contoured shape. The radius of the cylindrical contoured part, when removed from the fixture, was 1539.7 mm with average sum of square error (SSE) of 0.013. This example compared to Example 1 shows the benefit of using a pin to obtain a shaped glass product having a more cylindrical contoured shape in profile.

Example 3

[0081] Example 1 was repeated with the exception that the starting glass was first partially ion exchanged in a molten potassium nitrate bath for 3 hours at 420 °C followed by rinsing with water to remove salt residues. The resulting partially ion-exchanged glass was cold bent in a fixture by pressing the two short sides. The stainless steel fixture contacted the glass only at the two short edges. The chord length of the cold-bent glass in the fixture was 193 mm. The fixtured cold-bend glass was immersed in the ion-exchange tank for an additional 2 hours, then the glass-fixture assembly was removed from the tank and rinsed with water to remove salt residues. The resulting twice ion-exchanged glass was removed from the fixture and surface profile measurements were performed using ATOS scanner. The radius of the cylindrical contoured part was 598.9 mm with average sum of square error (SSE) of 0.231. Example 4

[0082] Example 1 was repeated with the exception that the starting glass sample was ion exchanged for 3 hours then rinsing. The partially ion-exchanged glass was cold-bent to 125 mm radius in a stainless steel cylindrical fixture. The fixture was designed to minimize contact with the major surfaces of the glass. The glass was constrained in the fixture along the length edge direction (cylindrical arc direction). The fixtured cold-bent glass assembly was immersed in the ion-exchange tank for 3 hours, and then removed from the tank and rinsed with water to remove salt residues. The twice ion-exchanged glass was removed from the fixture, and surface profile measurements were performed using ATOS scanner. The radius of the cylindrical contoured part was 810 mm having an average sum of square error (SSE) of 0.0172.

Example 5

[0083] Example 4 was repeated with the exception that the second ion exchange time of the fixtured bent glass assembly was 4 hrs. The radius of the cylindrical contoured part when removed from fixture was 695 mm having an average sum of square error (SSE) of 0.0127.

Comparative Example 6

[0084] Hot Forming. A flat 1.1 mm thick alkali alumino-silicate glass sample (331 mm x 331 mm) was hot formed using a 500 mm mold. The hot-formed glass piece after having been cooled to room temperature was ion exchanged for 4 hours in molten potassium nitrate salt batch at 420°C. The surface profile measurements were performed using ATOS scanner. The radius of the cylindrical part was 496.3 mm with average sum of square error (SSE) of 0.050.

[0085] Aspect ( 1) of this disclosure pertains to a method of making a shaped glass article comprising: securing a cold bent glass article in a retaining fixture to produce a retained, cold bent glass article; and ion-exchanging the retained, cold bent glass article to produce the shaped glass article.

[0086] Aspect (2) of this disclosure pertains to the method of Aspect ( 1), further comprising cold bending a strengthened glass article to produce at least one bend having at least one convex surface, and at least one concave surface to provide the cold bent glass article. [0087] Aspect (3) of this disclosure pertains to the method of Aspect (1) or Aspect (2) wherein securing the cold bent glass article in a retaining fixture comprises attaching at least two edges of the glass article to a rigid frame.

[0088] Aspect (4) of this disclosure pertains to the method of Aspect (3), wherein cold bending the strengthened glass article and securing the cold bent glass article occur simultaneously.

[0089] Aspect (5) of this disclosure pertains to the method of any one of Aspects (1) through (4), further comprising strengthening the glass article before cold bending by one or more of thermal strengthening, chemical strengthening or mechanical strengthening.

[0090] Aspect (6) of this disclosure pertains to the method of any one of Aspects (1) through (5), wherein, prior to ion-exchanging the retained glass, the method comprises applying a force on at least one point of the convex surface of the retained, cold bent glass article.

[0091] Aspect (7) of this disclosure pertains to the method of Aspect (6), wherein applying a force comprises applying a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent glass article.

[0092] Aspect (8) of this disclosure pertains to the method of Aspect (7), wherein applying a force comprises applying a line of force to at least one line on the convex surface of the retained, cold bent glass article.

[0093] Aspect (9) of this disclosure pertains to the method of any one of Aspects (6) through (8), wherein applying a force comprises applying a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

[0094] Aspect (10) of this disclosure pertains to the method of any one of Aspects (6) through (9), wherein applying a force comprises applying a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass.

[0095] Aspect (11) of this disclosure pertains to the method of any one of Aspects (6) through (10), wherein applying a force comprises applying a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

[0096] Aspect (12) of this disclosure pertains to the method of any one of Aspects (2) through (11), wherein cold bending or securing the cold bent glass article comprises at least one of or both: wrapping a glass article about a form; and pressing the glass article with at least one form.

[0097] Aspect (13) of this disclosure pertains to the method of Aspect (12), wherein cold bending or securing the cold bent glass article comprises wrapping the strengthened glass article about the form and applying a force to at least one point on the convex surface.

[0098] Aspect (14) ofthis disclosure pertains to the method of Aspect (13), wherein applying the force to at least one point on the convex surface comprises any one or more of applying: a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent, first ion-exchanged glass; a line of force to at least one line on the convex surface of the retained, cold bent, first ion-exchanged glass; a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass; a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass; and a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

[0099] Aspect (15) ofthis disclosure pertains to the method of any one of Aspects (1) through (14), wherein the securing the resulting cold bent glass article in a retaining fixture comprises fixing the cold bent glass article to a predetermined bend radius to produce the shaped glass in the fixture.

[00100] Aspect (16) ofthis disclosure pertains to the method of any one of Aspects (2) through (15), wherein the cold-bent glass article glass article has: a surface area in a range from about 10 cm²to about 50,000 cm², a thickness in a range from about 0.4 mm to 2 about mm, and the at least one bend has a bend radius in a range from about 50 mm to about 10,000 mm.

[00101] Aspect (17) ofthis disclosure pertains to the method of any one of Aspects (1) through (16), wherein the shaped glass article has a single bend.

[00102] Aspect (18) ofthis disclosure pertains to the method of any one of Aspects (1) through (16), wherein the shaped glass article comprises a first convex bend and a second convex bend.

[00103] Aspect (19) ofthis disclosure pertains to the method of any one of Aspects (1) through (16), wherein the shaped glass article comprises a first convex bend and a first concave bend. [00104] Aspect (20) of this disclosure pertains to the method of any one of Aspects (2) through (19), wherein at least two of cold bending the strengthened glass article, securing the cold bent glass article, and ion-exchanging the retained cold bent glass article, are performed simultaneously.

[00105] Aspect (21) of this disclosure pertains to the method of any one of Aspects (2) through (20), wherein cold bending is performed below the glass transition temperature of the glass article.

[00106] Aspect (22) of this disclosure pertains to the method of any one of Aspects (2) through (21), wherein the strengthened glass article comprises at least one chemically strengthened major surface.

[00107] Aspect (23) of this disclosure pertains to the method of any one of Aspects ( 1) through (21), further comprising separating the shaped glass article from the retaining fixture to produce a free-standing shaped glass article, and the shaped glass article retains its shape in the absence of external forces.

[00108] Aspect (24) of this disclosure pertains to the method of any one of Aspects (2) through (21), wherein the shaped glass article has a surface compressive stress in a range from about 400 MPa to about 1500 MPa, and a depth of compressive stress layer in a range from about 15 micrometers to 75 micrometers.

[00109] Aspect (25) of this disclosure pertains to a method of making a shaped glass article comprising: cold bending and securing a strengthened glass article in a retaining fixture to produce a retained, cold bent glass article having at least one bend with at least one convex surface and at least one concave surface; and ion-exchanging the retained, cold bent glass article to produce the shaped glass article.

[00110] Aspect (26) of this disclosure pertains to the method of Aspect (25), wherein the cold bending and securing, and the ion-exchanging are accomplished by at least one of: sequentially, simultaneously, continuously, or a combination thereof.

[00111] Aspect (27) of this disclosure pertains to a curved glass article comprising: a first major surface and an opposing second major surface; at least one curve having at least one convex surface on the first major surface and at least one concave surface in the vicinity of the curve on the second surface; and wherein the first major surface exhibits a first surface compressive stress at a first location and the second major surface exhibits a second surface compressive stress at a second location that is directly opposite the first location, wherein the first surface compressive stress is less than the second surface compressive stress, wherein the first surface compressive stress and the second surface compressive stress are in a range from about 200 MPa to about 1500 MPa, and wherein the curved glass article retains the at least one curve while unsupported.

[00112] Aspect (28) pertains to the curved glass article of Aspect (27), further comprising a display or touch panel disposed on or attached to the first major surface or the second major surface.

[00113] Aspect (29) pertains to the curved glass article of Aspect (27) or Aspect (28), wherein the at least one curve of has a radius of curvature in a range from about 50 mm to about 10,000 mm.

[00114] The disclosure has been described with reference to various specific embodiments and techniques. However, it should be understood that many variations and modifications are possible while remaining within the scope of the disclosure.

Claims

What is claimed is:

1. A method of making a shaped glass article comprising:

securing a cold bent glass article in a retaining fixture to produce a retained, cold bent glass article; and

ion-exchanging the retained, cold bent glass article to produce the shaped glass article.

2. The method of claim 1, further comprising cold bending a strengthened glass article to produce at least one bend having at least one convex surface, and at least one concave surface to provide the cold bent glass article.

3. The method of claim 1 or claim 2, wherein securing the cold bent glass article in a retaining fixture comprises attaching at least two edges of the glass article to a rigid frame.

4. The method of claim 3, wherein cold bending the strengthened glass article and securing the cold bent glass article occur simultaneously.

5. The method of any one of claims 1-4, further comprising strengthening the glass article before cold bending by one or more of thermal strengthening, chemical strengthening or mechanical strengthening.

6. The method of any one of claims 1-5, wherein, prior to ion-exchanging the retained glass, the method comprises applying a force on at least one point of the convex surface of the retained, cold bent glass article.

7. The method of claim 6, wherein applying a force comprises applying a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent glass article.

8. The method of claim 6 or claim 7, wherein applying a force comprises applying a line of force to at least one line on the convex surface of the retained, cold bent glass article.

9. The method of any one of claims 6-8, wherein applying a force comprises applying a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

10. The method of any one of claims 6-9, wherein applying a force comprises applying a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass.

1 1. The method of any one of claims 6-10, wherein applying a force comprises applying a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

12. The method of any one of claims 2-1 1, wherein cold bending or securing the cold bent glass article comprises at least one of or both:

wrapping a glass article about a form; and

pressing the glass article with at least one form.

13. The method of claim 12, wherein cold bending or securing the cold bent glass article comprises wrapping the strengthened glass article about the form and applying a force to at least one point on the convex surface.

14. The method of claim 13, wherein applying the force to at least one point on the convex surface comprises any one or more of applying:

a plurality of point source forces to a plurality of points on the convex surface of the retained, cold bent, first ion-exchanged glass;

a line of force to at least one line on the convex surface of the retained, cold bent, first ion-exchanged glass;

a plurality of line forces to a plurality of lines on the convex surface of the retained, cold bent, first ion-exchanged glass;

a curved line of force to at least one curved line on the convex surface of the retained, cold bent, first ion-exchanged glass; and a plurality of curved line forces to a plurality of curved lines on the convex surface of the retained, cold bent, first ion-exchanged glass.

15. The method of any one of claims 1-14 wherein the securing the resulting cold bent glass article in a retaining fixture comprises fixing the cold bent glass article to a

predetermined bend radius to produce the shaped glass in the fixture.

16. The method of any one of claims 2-15, wherein the cold-bent glass article glass article has:

A surface area in a range from about 10 cm² to about 50,000 cm²,

a thickness in a range from about 0.4 mm to 2 about mm, and

the at least one bend has a bend radius in a range from about 50 mm to about

10,000 mm.

17. The method of any one of claims 1-16, wherein the shaped glass article has a single bend.

18. The method of any one of claims 1-16, wherein the shaped glass article comprises a first convex bend and a second convex bend.

19. The method of any one of claims 1-16, wherein the shaped glass article comprises a first convex bend and a first concave bend.

20. The method of any one of claims 2-19, wherein at least two of cold bending the strengthened glass article, securing the cold bent glass article, and ion-exchanging the retained cold bent glass article, are performed simultaneously.

21. The method of any one of claims 2-20, wherein cold bending is performed below the glass transition temperature of the glass article.

22. The method of any one of claims 2-21, wherein the strengthened glass article comprises at least one chemically strengthened major surface.

23. The method of any one of claims 1-21 , further comprising separating the shaped glass article from the retaining fixture to produce a free-standing shaped glass article, and the shaped glass article retains its shape in the absence of external forces.

24. The method of any one of claims 2-21, wherein the shaped glass article has a surface compressive stress in a range from about 400 MPa to about 1500 MPa, and a depth of compressive stress layer in a range from about 15 micrometers to 75 micrometers.

25. A method of making a shaped glass article comprising:

cold bending and securing a strengthened glass article in a retaining fixture to produce a retained, cold bent glass article having at least one bend with at least one convex surface and at least one concave surface; and

26. The method of claim 25 wherein cold bending and securing, and the ion-exchanging are accomplished by at least one of: sequentially, simultaneously, continuously, or a combination thereof.

27. A curved glass article comprising:

a first major surface and an opposing second major surface;

at least one curve having at least one convex surface on the first major surface and at least one concave surface in the vicinity of the curve on the second surface; and

wherein the first major surface exhibits a first surface compressive stress at a first location and the second major surface exhibits a second surface compressive stress at a second location that is directly opposite the first location, wherein the first surface compressive stress is less than the second surface compressive stress,

wherein the first surface compressive stress and the second surface compressive stress are in a range from about 200 MPa to about 1500 MPa, and

wherein the curved glass article retains the at least one curve while unsupported.

28. The curved glass sheet article of claim 27 further comprising a display or touch panel disposed on or attached to the first major surface or the second major surface.

29. The curved glass sheet article of claim 27 or 28 wherein the at least one curve of has a radius of curvature in a range from about 50 mm to about 10,000 mm.