Complex curved glass articles and methods of forming same

Abstract

Reformed glass articles having a non-developable shape and associated molds and reforming techniques are described. The glass article may be shaped using a vacuum mold that includes a mold having a mold surface defining a mold cavity. The mold may also include a frame including a body disposed on the mold, the body including a top surface including one or more vacuum openings formed in the top surface. The top surface includes an outer edge, an inner edge, and a width W measured between the inner edge and the outer edge. The width W varies by no more than 10% with respect to the average value around the entire circumference of the vacuum mold. The vacuum mold includes a length L, a depth D, the depth D being 10% to 30% of the L. And W is from 0.06 L to 0.10 L. The reshaped glass article may be reshaped from the glass sheet to conform to the mold.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application Serial No. 63 / 536,763, filed September 6, 2023, pursuant to 35 USC § 119, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to vacuum forming of articles for use in various industries, such as consumer electronics, automotive, appliance, transportation, construction, defense, and medical. Specifically, this disclosure relates to the vacuum forming of glass articles having non-developable shapes, and the resulting vacuum-formed glass articles having non-developable shapes. Background Technology

[0003] Many products incorporate three-dimensional (3D) glass components. Examples of such components include curved LCD or LED TV screens, smartphones, and windows. The innovation in product shapes presents new challenges to the manufacturing processes of 3D parts, particularly those made of glass, which should possess excellent optical properties as well as desired scratch and impact resistance.

[0004] Therefore, methods for manufacturing 3D products, especially 3D glass products, with complex shapes and desired optical and mechanical properties have always been in demand. Summary of the Invention

[0005] This disclosure relates to vacuum forming apparatus and methods for reshaping glass sheets into curved glass articles having shapes that are relatively difficult to obtain using certain existing reshaping techniques (e.g., exhibiting unwrapable shapes and a bending depth of at least 200 mm). Using the apparatus and methods described herein, glass articles with such shapes can be obtained while exhibiting thickness uniformity and relatively low optical distortion compared to such existing methods. Specifically, glass articles formed by the methods and apparatus described herein exhibit relatively low warpage due to the careful construction of the frame supporting the periphery of the glass sheet during the forming process.

[0006] Aspect (1) of this disclosure relates to a curved glass article in an as-formed condition, the curved glass article comprising: a first main surface; a second main surface disposed opposite to the first main surface; a secondary surface extending between the first main surface and the second main surface; a peripheral region extending inwardly from the secondary surface to a boundary region, wherein a majority of the peripheral region is substantially flat; a central curved region disposed inside the boundary region; and a length L representing a maximum linear distance between separation points on the secondary surface measured in a first direction parallel to the first main surface in the peripheral region, wherein: in the central curved region, the first main surface comprises a concave shape and the second main surface comprises a convex shape, and the first main surface and the second main surface exhibit non-zero Gaussian curvature. The curved glass article exhibits a curvature depth of bending (DOB), which is represented by the maximum distance between a portion of the first main surface in the peripheral region and a portion of the first main surface in the central curved region, measured in a second direction perpendicular to the first direction. The curvature depth of bending (DOB) is between 10% and 30% of the length. The peripheral region includes a width measured parallel to the first main surface, the width variation being no more than 10% of the average value around the peripheral region, and the peripheral region exhibits one or less warp around its entire circumference.

[0007] Aspect (2) of this disclosure relates to curved glass articles according to aspect (1), wherein: 400 mm ≤ L ≤ 4000 mm, and 50 mm ≤ DOB ≤ 700 mm.

[0008] Aspect (3) of this disclosure relates to a curved glass article according to any one of aspects (1) to (2), wherein the glass article includes a width W, the width W representing the maximum linear distance between separation points on the secondary surface measured upward on a third party parallel to the first primary surface in the peripheral region and perpendicular to the first direction, wherein 200 mm ≤ W ≤ 2500 mm.

[0009] Aspect (4) of this disclosure relates to a curved glass article according to any one of aspects (1) to (3), wherein: the surface area of ​​the first main surface in a portion of the central curved region is 60,000 mm. 2 Or larger, and within the aforementioned portion, the uniformity of the thickness is 1000 mm per first main surface. 2 Surface area + / - 75 micrometers.

[0010] Aspect (5) of this disclosure relates to a curved glass article according to aspect (4), wherein the portion comprises a non-developable curved shape, the non-developable curved shape comprising a maximum compressive strain shape parameter greater than or equal to 3.0% and less than or equal to 10%, the maximum compressive strain shape parameter being measured between an imaginary central surface and an imaginary surface disposed between a first main surface and a second main surface.

[0011] Aspect (6) of this disclosure relates to a curved glass article according to any one of aspects (4) to (5), wherein, within the portion, the average thickness measured over the entire first main surface is greater than or equal to 0.5 mm and less than or equal to 2.5 mm.

[0012] Aspect (7) of this disclosure relates to a vacuum mold comprising: a mold having a complex, non-developable shape and defining a mold cavity; and a frame having a body disposed on the mold, the body having a top surface circumferentially surrounding the mold surface and having one or more vacuum openings formed therein, wherein the top surface comprises: an outer edge; an inner edge at which the body and the mold form an interface; and a width W measured between the inner edge and the outer edge in a first direction parallel to the top surface, wherein: the width W varies by no more than 10% relative to an average value around the entire circumference of the vacuum mold; the vacuum mold comprises a length L representing a maximum linear distance between separation points on the outer edge parallel to the top surface; the vacuum mold comprises a depth D measured as a maximum vertical distance between the top surface and the mold surface in a direction perpendicular to the top surface, the depth D being 10% to 30% of L; and W being 0.06. L to 0.10 L.

[0013] Aspect (8) of this disclosure relates to a curved glass article according to aspect (7), wherein the inner edge comprises a circumferential shape without linear segments having a length greater than L / 4.

[0014] Aspect (9) of this disclosure relates to a curved glass article according to aspect (8), wherein the second derivative of the circumferential shape is continuous over its entire range.

[0015] Aspect (10) of this disclosure relates to a curved glass article according to aspect (8), wherein the width W varies by no more than 5% relative to the average value of the entire circumference of the vacuum mold.

[0016] Aspect (11) of this disclosure relates to curved glass articles according to any one of aspects (7) to (10), wherein: 300 mm ≤ L ≤ 4000 mm, and 50 mm ≤ D ≤ 700 mm.

[0017] Aspect (12) of this disclosure relates to a curved glass article according to any one of aspects (7) to (11), wherein the body is formed of graphite, and wherein the vacuum mold is further contained on the top surface and disposed around the outer edge of a metal frame.

[0018] Aspect (13) of this disclosure relates to a curved glass article according to aspect (12), wherein the inner edge of the metal frame is disposed outside the one or more vacuum openings.

[0019] Aspect (14) of this disclosure relates to a curved glass article according to aspect (13), wherein it further comprises a stainless steel cloth welded around the inner edge and disposed around the outer edge.

[0020] Aspect (15) of this disclosure relates to a method of forming a curved glass article, the method comprising: placing a glass plate on a vacuum mold, the vacuum mold including a mold surface that at least partially defines a vacuum cavity, wherein the glass plate is placed on the vacuum mold such that the glass plate is in circumferential contact with a body of a frame around a top surface of the mold surface, wherein the top surface includes: one or more vacuum openings formed therein; an outer edge; an inner edge at which the body and the mold form an interface; and a width W, the width W being measured parallel to the top surface between the inner edge and the outer edge, wherein the width W varies by no more than 10% relative to an average value around the entire circumference of the vacuum mold, wherein the vacuum mold includes a length L, the length L representing the maximum linear distance between separation points on the outer edge measured parallel to the top surface, wherein the vacuum mold includes a depth D, the depth D being measured as the maximum vertical distance between the top surface and the mold surface in a second direction perpendicular to the top surface, the depth D being 10% to 30% of L, wherein W is 0.06 L to 0.10 L; heating the glass plate to the reforming temperature; applying vacuum pressure to the one or more vacuum openings such that one or more first portions of the glass plate are drawn into the one or more vacuum openings; and applying vacuum pressure to the vacuum cavity such that a second portion of the first glass plate is drawn into the vacuum cavity, thereby bringing the glass plate into contact with a portion of the mold surface, the portion being positioned at the depth D relative to the top surface.

[0021] Aspect (16) of this disclosure relates to the method according to aspect (15), wherein prior to the heating, the coefficient of static friction between the top surface and the glass plate is greater than 0.1 and less than or equal to 1.6.

[0022] Aspect (17) of this disclosure relates to a method according to any one of aspects (15) to (16), wherein when the glass plate is placed on the top surface, the entire peripheral edge of the glass plate is aligned with the outer edge.

[0023] Aspect (18) of this disclosure relates to the method according to aspect (14), wherein during the heating, the first portion is heated to a first temperature and the second portion is heated to a second temperature below the first temperature.

[0024] Aspect (19) of this disclosure relates to the method according to aspect (18), wherein the second temperature is 20°C to 120°C lower than the first temperature.

[0025] Aspect (20) of this disclosure relates to a method according to any one of aspects (15) to (19), wherein the second portion of the glass plate comprises an initial thickness (t1) before the glass plate is reshaped and a final thickness (t2) after the glass plate is reshaped, and wherein The range is 1.1 to 2.

[0026] Aspect (21) of this disclosure relates to a method according to any one of aspects (15) to (20), wherein the inner edge comprises a circumferential shape having a linear segment with a length greater than L / 4.

[0027] Aspect (22) of this disclosure relates to the method according to aspect (21), wherein the second derivative of the circumferential shape is continuous over its entire range.

[0028] Aspect (23) of this disclosure relates to a method according to any one of aspects (15) to (22), wherein: 300 mm ≤ L ≤ 4000 mm, and 50 mm ≤ D ≤ 700 mm.

[0029] Aspect (24) of this disclosure relates to a method according to any one of aspects (15) to (23), wherein the body is formed of graphite, wherein the vacuum mold further comprises a metal frame disposed on the top surface and around the outer edge, wherein the thickness of the metal frame is 0.7 mm to 1.5 mm.

[0030] Aspect (25) of this disclosure relates to the method according to aspect (24), wherein the inner edge of the metal frame is disposed outside the one or more vacuum openings.

[0031] Aspect (26) of this disclosure relates to the method according to aspect (25), wherein the vacuum mold further comprises a stainless steel cloth welded around the inner edge and disposed around the outer edge. Attached Figure Description

[0032] The accompanying drawings, incorporated herein by reference and forming part of this specification, illustrate embodiments of the present disclosure. Together with the description, the drawings further serve to explain the principles of the disclosed embodiments and to enable those skilled in the art to make and use the disclosed embodiments. These drawings are intended to be illustrative and not restrictive. While the present disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the drawings, the same reference numerals denote the same or functionally similar elements.

[0033] Figure 1A and 1B An apparatus for reshaping a material sheet according to one or more embodiments of the present disclosure is shown; Figure 2 One or more embodiments according to this disclosure are depicted. Figure 1A and 1B A perspective view of the mold and frame of the device shown; Figure 3A A crossing according to one or more embodiments of this disclosure is depicted. Figure 2 A cross-sectional view of the upper wall of the frame in line III-III; Figure 3B One or more embodiments according to this disclosure are depicted. Figure 3A A perspective view of the retaining frame of the upper wall shown; Figure 4 This is a flowchart of a method for forming a curved glass article having an indeformable shape according to one or more embodiments of the present disclosure; Figure 5 It is performed according to one or more embodiments of this disclosure. Figure 4 A cross-sectional view of a reshaped glass article formed as part of the method shown; Figure 6 The illustration schematically depicts one or more embodiments of the present disclosure. Figure 4 A side view of a curved glass article formed by the method shown; Figure 7A and 7B A mold construction is schematically depicted for use in a reshaping process simulating a first example glass article and a second example glass article, according to one or more embodiments of the present disclosure. Figure 8Aand 8B The description of one or more embodiments according to this disclosure is as follows: Figure 7A and 7B The simulated shape produced by the re-forming process on the mold structure depicted in the image; and Figure 9A and 9B The illustration depicts a scenario, according to one or more embodiments of the present disclosure, after the upper frame surface has been modified to have an increased width. Figure 7A and 7B The simulated shape produced by the reshaping process performed on the mold structure depicted in the image. Detailed Implementation

[0034] The following examples are illustrative and not limiting of this disclosure. Other suitable modifications and adaptations to various conditions and parameters commonly encountered in the art and obvious to those skilled in the art are within the spirit and scope of this disclosure.

[0035] Glass articles with non-developable curvature can be used in a variety of applications requiring transparent surfaces with non-developable curvature. Glass articles with non-developable curvature can provide the desired optical and mechanical properties while also providing the required curvature. As used herein, the term "non-developable curvature" or "non-zero Gaussian curvature" refers to a curvature with intersecting radii that cannot be formed by bending of a paperboard without stretching, tearing, or wrinkling. Exemplary non-developable curvatures include, but are not limited to, spherical curvature, spherical curvature, partially spherical curvature, and three-dimensional saddle curvature. "Developable curvature" or "zero Gaussian curvature" refers to a curvature that can be formed of a paperboard simply by bending. Exemplary developable curvatures include, but are not limited to, cylindrical and conical curvatures.

[0036] The reshaping process described herein facilitates the formation of glass articles with non-developable curvature, suitable optical properties, and suitable mechanical properties. The reshaping process utilizes vacuum forming technology to manufacture reshaped glass articles with non-developable surface shapes. Non-developable surface shapes can be produced while maintaining the thickness uniformity of the surface shape and avoiding glass wrinkling. By promoting thickness uniformity and avoiding wrinkling, non-developable surface shapes with desired optical and mechanical properties can be formed. Furthermore, by promoting thickness uniformity and avoiding wrinkling, large convex surface areas (e.g., greater than or equal to 10,000 mm²) can be produced without introducing optical or mechanical defects. 2 ≥20,000 mm 2 ≥30,000 mm 2 or greater than or equal to 60,000 mm 2 Greater than 1,000,000 mm 2 And less than 2,000,000 mm 2The non-developable surface shape (surface area).

[0037] The vacuum forming technology described herein can manufacture glass articles with complex curvatures, quantified by the maximum compressive strain shape parameters described herein, without wrinkling or breakage. The vacuum forming technology described herein may include vacuum reshaping of a glass sheet using a vacuum mold with one or more side-holding mechanisms that prevent wrinkling during deep Gaussian deformation of the glass, resulting in an undevelopable surface shape. As used herein, the term "deep" Gaussian deformation refers to the process of reshaping a glass sheet with an initial length L to a bending depth of at least 10% of its length (as measured by the maximum distance between portions on the main surface of the reshaped glass article in a direction perpendicular to the direction of the measured length). The one or more side-holding mechanisms may include vacuum openings designed to hold the glass sheet in place during vacuum forming while also facilitating free movement of the glass sheet to prevent wrinkling during deformation. The one or more side-holding mechanisms may be self-releasing holding mechanisms that help prevent the reshaped glass sheet from breaking during cooling and demolding.

[0038] The vacuum forming technology described herein offers one or more of the following advantageous features. In one or more embodiments, vacuum pressure forming allows a glass sheet to expand gradually and locally until it ultimately forms a highly unwrapable three-dimensional (3D) shape without wrinkling. In one or more embodiments, vacuum pressure forming allows a glass sheet to expand gradually and locally until it ultimately forms a highly unwrapable 3D shape without significantly reducing local thickness. In one or more embodiments, one side of the glass article can remain untouched during vacuum forming, thereby reducing the likelihood of defects. In one or more embodiments, a side holding mechanism can prevent glass warping, which could lead to vacuum leakage and incomplete reshaping of the glass sheet. In one or more embodiments, a side holding mechanism can prevent glass sliding during reshaping, which could lead to scratches, thus affecting the aesthetics and optical properties of the reshaped glass. In one or more embodiments, multiple glass sheets can be reshaped simultaneously.

[0039] In some embodiments, the vacuum forming technology described herein can be used to reshape multilayer glass sheets. The multilayer glass sheet may include a first layer (e.g., a top layer) formed of a first glass composition and a second layer (e.g., a bottom layer) formed of a second glass composition. In some embodiments, one of the glass layers may be a sacrificial layer that is removed after the glass sheet has been reshaped. For example, the bottom layer of a multilayer glass sheet that is in contact with the mold surface during reshaping may be removed after the reshaping process is complete. In such embodiments, removing the bottom glass layer can improve the surface quality of the reshaped glass article because any defects transferred to the bottom glass layer from the mold surface are removed. In some cases, removing a layer of a multilayer glass sheet can reduce or eliminate costly surface finishing processes, such as polishing. In some embodiments, an etching process may be used to remove a layer of a multilayer glass sheet.

[0040] Figure 1A and 1B An apparatus 100 for reshaping a glass plate 200 according to some embodiments is shown. Figure 1A The glass plate 200 before reshaping is shown. Figure 1B A glass plate 200 after reshaping is shown according to some embodiments. The glass plate 200 has a top surface 202, a bottom surface 204 opposite to the top surface 202, and an initial thickness 206 measured between the top surface 202 and the bottom surface 204 (i.e., the thickness of the glass plate 200 before reshaping). The glass plate 200 also includes a peripheral edge 208 defining the peripheral shape of the glass plate 200.

[0041] The dimensions of device 100 can be referenced. Figure 1A , 1B The coordinate axes depicted in Figure 2 are used for description. Unless otherwise stated, device 100 is configured in a direction parallel to the direction of gravity (i.e., the direction is...). Figure 1A , 1B The glass plate is reshaped in the Z direction (as described in section 2). That is, the glass article undergoes maximum deformation in the Z direction, thus exhibiting a certain depth of curvature at specific locations. The XY plane is depicted as perpendicular to the Z direction. The device 100 includes a frame 130 with an upper wall 132 having a flat top surface 134 disposed in the XY plane (the top surface 134 can also be approximated as a plane with an average height relative to any reference plane in the XY direction). Therefore, unless otherwise stated, when the device 100 is configured to perform a reshaping operation, the various dimensions of the glass plate 200 and the device 100 are expressed as measured in the direction of gravity or in a plane perpendicular to the direction of gravity.

[0042] In some embodiments, the initial thickness 206 of the glass plate 200 may range from 0.5 mm to 10 mm, including sub-ranges. In embodiments, the initial thickness 206 may range from 0.1 mm to 10 mm, 0.2 mm to 10 mm, 0.3 mm to 10 mm, 0.4 mm to 10 mm, 0.5 mm to 10 mm, 0.5 mm to 7 mm, 0.5 mm to 4 mm, or within a range with any two of these values ​​as endpoints.

[0043] Device 100 includes a vacuum mold 110 having a vacuum chamber 112 in which a glass plate 200 can be reshaped. In an embodiment, the glass plate 200 may at least partially define the vacuum chamber 112 after being placed on device 100. In some embodiments, device 100 may include one or more vacuum sources 170. The vacuum source 170 may be, for example, a vacuum pump. Vacuum mold 110 may include a frame 130 disposed around vacuum chamber 112. Frame 130 includes a top wall 132 having a top surface 134 and one or more vacuum openings 140. Each vacuum opening 140 includes a through hole 142 formed in top wall 132. Through hole 142 may be formed in top surface 134 of frame 130 and extend through the thickness of top wall 132. Top surface 134 of frame 130 has an outer peripheral edge 136 defining the peripheral shape of top surface 134. In some embodiments, one or more vacuum openings 140 disposed around the vacuum cavity 112 may include at least a single vacuum opening, which may include a through-hole 142 having a fully or partially annular shape disposed around all or part of the vacuum cavity 112. For example, Figure 2 An embodiment is depicted where the top surface 134 includes a plurality of vacuum openings 140 circumferentially surrounding the vacuum cavity 112. In some embodiments, adjacent vacuum openings of the plurality of vacuum openings 140 are spaced apart from each other by a spacing distance 148, which represents the minimum linear edge-to-edge spacing distance between adjacent vacuum openings of the plurality of vacuum openings 140 (e.g., measured in a direction parallel to the top surface 134). The spacing distance 148 may be greater than or equal to the effective diameter 146 of the through-hole 142 and less than or equal to three times the effective diameter 146 of the through-hole 142. Spacing distances 148 within this range can facilitate the reshaping of the glass plate 200 into a non-wrapable shape without wrinkling.

[0044] Although Figure 1A-2In the example depicted, the top surface 134 is flat; however, it should be understood that embodiments of the top surface 134 being curved and / or having a non-linear transition in surface height are conceivable. In such embodiments, distances expressed as measured in directions parallel or perpendicular to the top surface 134 can be calculated by treating such non-flat surfaces as flat surfaces at the average height of the top surface 134.

[0045] Return to reference Figure 1A-1B One or more vacuum sources 170 are in fluid communication with a vacuum chamber 112 and one or more vacuum openings 140, such that the one or more vacuum sources 170 can apply vacuum pressure to the vacuum chamber 112, the one or more vacuum openings 140, or both. In some embodiments, the device 100 may include a vacuum source 170a. In such embodiments, the vacuum source 170a can apply vacuum pressure to both the vacuum chamber 112 and the one or more vacuum openings 140. The vacuum source 170a can apply vacuum pressure to the vacuum chamber 112 and the one or more vacuum openings 140 simultaneously. In some embodiments, the vacuum source 170a can apply vacuum pressure to the vacuum chamber 112 and the one or more vacuum openings 140 sequentially. For example, the vacuum source 170a can first apply vacuum pressure to the one or more vacuum openings 140, and then apply vacuum pressure to the vacuum chamber 112 while still applying vacuum pressure to the one or more vacuum openings 140. A vacuum tube 172a can connect the vacuum source 170a to the vacuum chamber 112 and the one or more vacuum openings 140.

[0046] In some embodiments, the device 100 may include a first vacuum source 170a in fluid communication with a vacuum chamber 112 and a second vacuum source 170b in fluid communication with one or more vacuum openings 140. In such embodiments, the first vacuum source 170a may apply vacuum pressure to the vacuum chamber 112 and apply vacuum pressure to the one or more vacuum openings 140 independently of the second vacuum source 170b. The first vacuum source 170a and the second vacuum source 170b may simultaneously apply vacuum pressure to the vacuum chamber 112 and one or more vacuum openings 140, respectively. In some embodiments, the first vacuum source 170a may apply vacuum pressure to the vacuum chamber 112, and the second vacuum source 170b may sequentially apply vacuum pressure to the one or more vacuum openings 140. For example, the second vacuum source 170b may first apply vacuum pressure to the one or more vacuum openings 140, and while the second vacuum source 170b is still applying vacuum pressure to the one or more vacuum openings 140, the first vacuum source 170a may apply vacuum pressure to the vacuum chamber 112.

[0047] In embodiments including a first vacuum source 170a and a second vacuum source 170b, a first vacuum tube 172a can connect the first vacuum source 170a to a vacuum chamber 112, and a second vacuum tube 172b can connect the second vacuum source 170b to one or more vacuum openings 140. In some embodiments, the second vacuum tube 172b can be connected to a vacuum distributor 174 configured to supply vacuum pressure to one or more vacuum openings 140.

[0048] In some embodiments, device 100 may include a vacuum chamber 160 defining a vacuum chamber 162. In such embodiments, a frame 130 may be coupled to the vacuum chamber 160. The frame 130 coupled to the vacuum chamber 160 may be integrally formed with the vacuum chamber 160 or mechanically coupled to the vacuum chamber 160 by one or more mechanical fasteners (e.g., bolts or screws). In some embodiments, the frame 130 may be integrally formed with the vacuum chamber 160. In some embodiments, the frame 130 may be a component of a mold 114 mechanically coupled to the vacuum chamber 160. In some embodiments, the frame 130 may be vertically adjustable relative to the vacuum cavity 112 to facilitate accurate adjustment of the top surface 134 and the top surface 113 of the vacuum cavity 112. It should be understood that, although Figure 1A-1B Top surface 113 is depicted as vertically aligned with top surface 134; however, it should be understood that embodiments are also contemplated where top wall 132 extends above top surface 113 and includes an end edge (inner edge) transitioning to mold surface 116. In such embodiments, top wall 132 contacts mold surface 116 at its inner edge.

[0049] In some embodiments, the vacuum chamber 112 may be defined by a mold 114 disposed within a vacuum chamber 162. The mold 114 includes a mold surface 116 and may include one or more vacuum holes 118 formed in the mold surface 116. The vacuum holes 118 may be through-holes extending from the mold surface 116 through the mold 114 to a bottom surface 120 of the mold 114. The vacuum holes 118 may be in fluid communication with one or more vacuum sources 170, such that the vacuum sources 170 can apply vacuum pressure to the vacuum chamber 112 through the vacuum holes 118.

[0050] The diameter of the vacuum hole 118 can be very small to minimize the impact on the bottom surface 204 of the glass plate 200 during reshaping. In some embodiments, the diameter of the vacuum hole 118 can range from 0.5 mm to 2 mm. In some embodiments, one or more vacuum openings 140 can be in fluid communication with the vacuum chamber 162 of the vacuum box 160. In embodiments including the mold 114, during reshaping, a second portion 230 of the glass plate 200 can be pulled toward the mold surface 116. For example, as Figure 1BAs shown, the second portion 230 of the glass plate 200 can be pulled toward the mold surface 116, thereby allowing the second portion 230 to acquire the curvature of the mold surface 116.

[0051] The mold surface 116 may contain a material that resists adhesion to the glass plate 200 during remolding. Exemplary materials for the mold surface 116 include, but are not limited to, graphite, boron nitride, silica soot, calcium carbonate, carbon soot, refractory metal alloys, molybdenum disulfide, or tungsten disulfide. In some embodiments, the mold 114 may be formed from any of these materials. In some embodiments, any of these materials may be coated onto the mold 114 to define the mold surface 116. For example, in some embodiments, the mold 114 may be made of a refractory metal alloy coated with molybdenum disulfide or tungsten disulfide to define the mold surface 116.

[0052] In some embodiments, the bottom surface 204 of the glass plate 200 may be coated with one or more protective layers to help prevent the glass plate 200 from adhering to the mold surface 116 and to help prevent mold-related defects from appearing on the bottom surface 204. Exemplary protective layers are described in U.S. Patent No. 10,364,175, which is hereby incorporated by reference in its entirety.

[0053] In some embodiments, the coefficient of thermal expansion (CTE) of the materials of the mold surface 116, the glass plate 200, and the top surface 134 of the frame 130 can be customized to help prevent glass adhesion, prevent glass slippage during remolding, and prevent glass breakage at different shrinkage rates during cooling. Additionally, the CTE of the materials of the mold surface 116, the glass plate 200, and the top surface 134 of the frame 130 can be customized to facilitate self-release of the glass plate 200 from the mold surface 116 and the top surface 134.

[0054] As used herein, the term coefficient of thermal expansion or "CTE" refers to the average coefficient of thermal expansion of a glass composition over a temperature range of 20°C to 300°C. Unless otherwise specified, the CTE of a layer is expressed in terms of 10. -7 / ℃ is expressed and determined using a push rod expander according to ASTM E228-11.

[0055] In some embodiments, the mold surface 116 may comprise a first material including a first CTE, the glass plate 200 may comprise a second material including a second CTE, and at least a portion of the top surface 134 of the frame 130 may comprise a third material including a third CTE. The third CTE may be greater than the second CTE, and the second CTE may be greater than the first CTE. In such embodiments, the different shrinkage rates of the materials can facilitate the self-release of the glass plate 200 from the vacuum mold 110 without breakage. In some embodiments, the CTE of the material of the mold surface 116 may range from 35 × 10⁻⁶. -7 / ℃ to 45 × 10 -7 / ℃. In some embodiments, the CTE of the material of the glass plate 200 may be in the range of 70 × 10⁻⁶. -7 / ℃ to 85 × 10 -7 / ℃. In some embodiments, the CTE of the material of the top surface 134 of the frame 130 may be in the range of 110 × 10 °C. -7 / ℃ to 130 × 10 -7 / ℃. In some embodiments, the material of the top surface 134 of the frame 130 may be in the range of CTE 110 × 10 -7 / ℃ to 130 × 10 -7 / ℃ metallic material. In some embodiments, the CTE of the material of the top surface 134 of the frame 130 can range from 170 × 10 -7 / ℃ to 180 × 10 -7 / ℃. In some embodiments, the material of the top surface 134 of the frame 130 may be in the range of CTE 170 × 10 -7 / ℃ to 180 × 10 -7 Austenitic stainless steel at / ℃.

[0056] In some embodiments, the through-hole 142 may have an effective diameter, and the top surface of the stop wall (not shown) is vertically spaced from the top surface 134 of the top wall 132 by a certain depth. In such embodiments, the depth may be less than or equal to half (½) of the effective diameter. By positioning the stop wall at a depth less than or equal to half (½) of the effective diameter, one or more vacuum openings 140 can prevent a first portion 220 of the glass plate 200 from being pulled too far into the through-hole 142. If the first portion 220 is pulled too far into the through-hole 142, this could cause the glass to break during cooling and / or demolding. Specifically, a depth less than or equal to half (½) of the effective diameter can prevent the first portion 220 from being pulled into a shape with an effective diameter greater than the effective diameter of the through-hole 142. If the first portion 220 is pulled into a shape with an effective diameter greater than the effective diameter of the through-hole 142, the reshaped glass plate will become stuck in the through-hole 142 and therefore cannot move freely during cooling and / or demolding, which could cause the glass to break.

[0057] As used herein, the term "effective diameter" is used to describe the size of a hole or opening; however, this term should not be construed as requiring the hole or opening to have a circular diameter or shape. Instead, the hole or opening may have a non-circular shape, and in such embodiments, the term "effective diameter" is intended to refer to the maximum cross-sectional dimension of the shape. For example, the "effective diameter" of a hole or opening with an elliptical cross-sectional shape would be the length of the principal axis of the elliptical shape. For holes or openings where the effective diameter varies along the depth of the hole or opening, the effective diameter is the maximum effective diameter. In some embodiments, the size of the through-hole 142 may be selected based on the initial thickness 206 of the glass plate 200. In some embodiments, the glass plate 200 may have an initial thickness 206, and the effective diameter of the through-hole 142 may be ten to fifteen times the initial thickness 206. An effective diameter that is ten to fifteen times the initial thickness allows the first portion 220 of the glass plate 200 to be pulled into the through-hole without applying excessively high vacuum pressure. Therefore, in embodiments, the effective diameter of the through-hole 142 may range from 5 mm to 120 mm, including sub-ranges. For example, in some embodiments, the effective diameter of the through hole 142 may be in the range of 5 mm to 10 mm, 10 mm to 30 mm, 10 mm to 50 mm, 10 mm to 100 mm, 10 mm to 120 mm, or in the range of any two of these values ​​as endpoints.

[0058] like Figure 1A-1BAs shown, the device 100 can be configured such that during the reshaping of the glass plate 200, the total contact area between the bottom surface 204 and the combined structure of the mold 114 and the frame 130 has a length L. The length L can represent the maximum linear dimension of the total contact area between the glass plate 200 and the combination of the mold 114 and the top surface 134, measured in a direction extending parallel to the top surface 134. Therefore, when the glass plate 200 (in its original as-cut condition before reshaping) is placed on the top surface 134, the overlap area between the glass plate 200 and the top surface 134 and the mold 114 can determine the length L. In an embodiment, when the glass plate 200 is placed on the top surface 134, the central axis of the glass plate 200 is aligned with the combined structure of the frame 130 and the mold 114. Therefore, the overlap area between the glass plate 200 and the top surface 134 can depend on the peripheral shape of the top surface 134 and the glass plate 200 before the start of reshaping. For example, when the peripheries of the top surface 134 and the bottom surface 204 are aligned and completely overlapped, the total contact area can be represented before remolding (as shown in...). Figure 1A The surface area of ​​the bottom surface 204 (as shown in the diagram). The preferred arrangement between the glass plate 200 and the top surface 134, which helps to minimize wrinkling during remolding, is described in more detail herein.

[0059] After the glass plate 200 is placed on the top surface 134 (as shown in the image) Figure 1A As shown, when heated to the reforming temperature, the glass plate 200 tends to sag towards its center under gravity as the glass viscosity decreases. Figure 1A As shown, for example, at the start of heating, the glass plate 200 includes a support portion 240 in contact with at least one of the mold 114 and the top surface 134, and a loading portion 245 unsupported by the frame 130 or the mold 114. In an embodiment, the length of the loading portion 245 is at least 50% of the length L (e.g., at least 60%, at least 70%, at least 80%, or even at least 85% and less than or equal to 95%). During reshaping, the loading portion 245 tends to sag downwards under gravity, thereby lifting the support portion 240 off the top surface 134. The edge of the flat upper surface (the outer transition or corner of the curved mold surface 116) acts as a pivot point for the glass when it initially sags. Lifting the support portion 240 in this way may prevent the formation of a high-quality vacuum seal between the top surface 134 and the support portion 240, thereby reducing the effectiveness of one or more vacuum openings 140. This may cause the glass plate 200 to warp during reshaping and produce various optical defects (e.g., thickness non-uniformity) in the resulting part. Specifically, the critical warping load, which defines the minimum load that causes the glass plate to warp, can be defined as follows: in It is the critical warping stress. denoted as , where b is the bending stiffness of glass plate 200, , where b is the length of the loaded portion 245, , where h is the thickness of glass plate 200, and , where E is the elastic modulus of glass plate 200. It is the Poisson's ratio of the glass plate, and This is the warpage factor, which is related to the aspect ratio of the unloaded length and the loaded length. Equations 1 and 2 reveal that the critical warpage load is directly proportional to the glass thickness and inversely proportional to the square of the length 245 of the loaded portion. As the length of the loaded portion increases, the critical bending load decreases significantly, making the glass plate 200 more sensitive to warpage. Therefore, warpage can become a problem for particularly large parts.

[0060] like Figure 1B As shown, the device 100 can typically be configured such that after reshaping by the methods described herein to provide a reshaped glass article 250, the bottom surface 204 substantially conforms to the mold surface 116. Therefore, the reshaped glass article exhibits a bending depth 246, which represents the maximum vertical distance between different points on the top surface 202 in the direction of gravity. In embodiments, the bending depth 246 can range from 200 mm to 600 mm (e.g., 300 mm to 500 mm). In embodiments, the bending depth 246 is at least 10% of the length L of the contact area between the glass plate 200 and the combined structure of the upper surface 134 and the mold 114. For example, the bending depth 246 can range from 0.10 mm. L to 0.30 L, while the mold surface 116 exhibits a non-zero Gaussian curvature. In such embodiments, L can range from 1000 mm to 5000 mm (e.g., 1000 mm to 3000 mm).

[0061] It has been found that certain structural features of frame 130 facilitate the reshaping of glass plate 200 to a bending depth 246 without introducing warping that would severely degrade the optical properties of the reshaped glass article 250. These features of frame 130 have been found particularly advantageous when glass plate 200 is cut to have the same peripheral shape as the top surface 134 of frame 130. This contrasts with certain other reshaping methods. For example, some existing methods (such as some described in International Patent Application No. PCT / US2022 / 025696, published as WIPO Publication No. WO 2022 / 231933 A1, which is hereby incorporated in its entirety by reference) involve excessively large glass plates, such that the peripheral portion of the glass plate extends outward from frame 130. After heating the glass plate, this peripheral portion can be bent around the outer side of frame 130 to increase stiffness and prevent severe warping. However, it has been found that a relatively large extension (over 150 mm) is required to achieve the desired sealing conditions. Such a large extension reduces material utilization. The frame 130 according to this disclosure is designed to eliminate severe warping without requiring this costly extension.

[0062] It has been found that the shape of the upper surface 134 of the frame 130 is a factor affecting the warp performance of the device 100. Figure 2 In the embodiments depicted, for example, the upper surface 134 is shown as including an outer (or “outer”) edge 262 and an inner (or “inner”) edge 264. In the depicted embodiment, the inner edge 264 represents the transition point between the upper surface 134, which has a non-zero Gaussian curvature, and the mold surface 116. Therefore, the inner edge 264 may be the glass plate 200 (see [link to documentation]). Figure 1A-1B The contact area between the upper surface 134 and the mold 114 transitions from a flat area (e.g., on the upper surface 134) to a curved area (e.g., on the mold surface 116). The outer edge 262 circumferentially surrounds the inner edge 264, such that the upper surface 134 has a width 268, which is measured at a specific point around the circumference of the frame 130 in a direction perpendicular to the inner edge 264 and perpendicular to the direction of gravity.

[0063] In some embodiments, the frame 130 may include a channel 156 formed in the top surface 134 and fluidly connected to a plurality of vacuum openings 140. In such embodiments, the channel 156 may include a plurality of channel portions 158 connecting two adjacent vacuum openings of one or more vacuum openings 140. In embodiments including the channel 156, the channel 156 may extend through each of the plurality of vacuum openings 140 to facilitate the application of vacuum pressure to each vacuum opening 140.

[0064] In an embodiment, when the peripheral edge 208 of the glass plate 200 (see...) Figure 1A When the glass plate 200 coincides with the outer edge 262 of the upper surface 134 (i.e., the glass plate 200 can be cut to have the same outer shape as the upper surface 134), the frame 130 can be used. Therefore, the length L of the contact area between the glass plate 200 and the combined structure of the upper surface 134 and the mold 114 (see...) Figure 1B The maximum length 266 of the outer edge 262 can be equal to the maximum linear distance between two points on the outer edge 262 measured in a direction parallel to the upper surface 134. The maximum width 270 can also be defined as the maximum linear distance between two points on the outer edge 262 measured in a direction perpendicular to the maximum length 266. In an embodiment, the maximum width 270 is greater than or equal to 500 mm and less than or equal to 2000 mm. In the depicted embodiment, the sizes of the maximum length 266 and the maximum width 270 are set for window forming in automotive applications. It should be understood that different sizes can be used for alternative applications of various curved glass articles formed by the techniques described herein.

[0065] Referring to the upper surface 134, it has been found that structuring the outer edge 262 and the inner edge 264 such that the width 268 is relatively consistent around the circumference of the frame 130 helps reduce warping by providing uniform support around the perimeter of the glass plate 200. In an embodiment, for example, the variation in width 268 does not exceed 10% of its average value (the average value can be calculated by measuring the width 268 at 100 equally spaced locations around the inner edge 264). The difference between the maximum and minimum width values ​​and the average width can be less than 10% of the average value. In an embodiment, the variation in width 268 does not exceed 5% of the average value or even 2% of the average value.

[0066] It was also found that the average width 268 should be greater than or equal to 6% of the maximum length 266 in order to effectively reduce the loading length of the glass plate and decrease warping sensitivity. Keeping the average width 268 less than or equal to 10% of the maximum length 266 also helps to provide a relatively high material utilization rate. It was also found that less than or equal to 8% of the maximum length 266 provides sufficient support to prevent warping while providing even higher material utilization rates. Therefore, the average width 268 can range from 6% to 10% of the maximum length 266, or more preferably from 6% to 8% of the maximum length.

[0067] The 6% lower limit of the average width 268 is to provide sufficient contact area between the glass plate 200 and the upper surface 134. When the glass plate 200 is heated to the reforming temperature, frictional forces are generated between the glass plate 200 and the upper surface 134 in the contact area, thereby limiting the tangential displacement of the glass. Limiting the movement of the glass in a direction tangential to the top surface 134 (e.g., toward the geometric center of the mold 114) advantageously prevents the glass plate 200 from sagging as the glass is heated. Preventing the center of the glass from sagging helps maintain a vacuum seal at one or more vacuum openings 140, which is beneficial for strain management and improved warpage performance within the glass throughout the reforming process. This limitation, achieved by the size of the upper surface 134 as described herein, can be achieved without contact with (e.g., without clamping or placing any weights) the top surface 202 of the glass plate 200. Limiting contact with the top surface 202 advantageously eliminates potential optical defects.

[0068] Regardless of the final shape of the glass article to be used (e.g., a portion of the reshaped glass article 250 can be cut out and used for the desired end purpose), the shape of the inner edge 264 has been found to be an important factor in reducing warping. Specifically, it has been found that abrupt changes in curvature of the inner edge 264 (or continuous second derivatives around the entire circumference defined by the inner edge 264) should be limited. Furthermore, the length of any linear segment of the inner edge 264 should be limited. A “linear segment” can be characterized as a segment whose deviation from the segment in a direction perpendicular to the straight line connecting the two endpoints of the segment does not exceed 1 mm. Specifically, it has been found that the linear segments of the inner edge 264 should not exceed 25% of the maximum length 266 to help improve the warping performance of the reshaped glass article 250. Providing a smooth inner edge 264 without long linear segments can advantageously avoid strain in the glass during reshaping and provide better control during sagging.

[0069] Another parameter that can be used to reduce warping during the reshaping process is the temperature distribution of the glass plate 200 after it is placed on the frame 130 and heated. It has been found that during heating, the central portion of the glass plate 200 (e.g., Figure 1A The portion of the loading section 245 depicted in the image is heated to a temperature higher than the peripheral portion of the glass plate 200 (e.g., including...). Figure 1A A lower temperature in the support portion 240 can prevent center sagging before a vacuum seal is formed and helps prevent warping. This temperature difference can be achieved through any suitable mechanism. For example, in some embodiments, the vacuum mold 110 may include a cooling block 192 in contact with the bottom surface 120 of the vacuum mold 110 opposite the mold surface 116 (see [link to relevant documentation]). Figure 1AIn some embodiments, cooling block 192 may include a loop for circulating coolant. In such embodiments, cooling block 192 may include a coolant inlet 194 and a coolant outlet 196. Exemplary coolants for cooling block 192 include, but are not limited to, air and water. In some embodiments, cooling block 192 may additionally or alternatively include a radiator or cooling fins. In some embodiments, cooling block 192 may contact the bottom surface 120 of vacuum mold 110 opposite the central surface region 122 of mold surface 116. Cooling block 192 may locally reduce the temperature of mold surface 116 during remolding. In embodiments, the central surface region 122 may be heated to a temperature 20°C to 120°C lower than the support portion 240 to facilitate the formation of a vacuum seal.

[0070] exist Figure 2 In the illustrated embodiment, mold surface 116 includes a central surface region 122 and a peripheral surface region 124. In such embodiments, the surface temperature of the central surface region 122 can be controlled to have a first maximum temperature during remolding, and the surface temperature of the peripheral surface region 124 can be controlled to have a second maximum temperature during remolding. In some embodiments, one or more cooling blocks 192 (see...) can be utilized. Figure 1A-1B This is used to control the maximum surface temperature of the central surface region 122 and / or the peripheral surface region 124. In some embodiments, the first maximum temperature may be 20°C to 50°C lower than the second maximum temperature. In some embodiments, the first maximum temperature may be 20°C to 120°C lower than the second maximum temperature. In some embodiments, the first maximum temperature may be 50°C to 120°C lower than the second maximum temperature.

[0071] In an embodiment, the central surface region 122 may have a first maximum radius of curvature, and the peripheral surface region 124 adjacent to the central surface region 122 may have a second maximum radius of curvature smaller than the first maximum radius of curvature. In some embodiments, the second maximum radius of curvature may be at least 5% smaller than the first maximum radius of curvature. In an embodiment, the central surface region 122 may be a region of the mold surface 116 containing the desired shape of the final glass article (e.g., cut from the reshaped glass article). That is, the central surface region 122 may have a concave curvature that matches the convex bottom surface 204 of the reshaped glass article 250. In such embodiments, a central portion of the glass plate 200 may be pulled toward the central surface region 122 of the mold surface 116, thereby allowing the second portion 230 to acquire the curvature of the central surface region 122.

[0072] In one embodiment, one or more vacuum holes 118 of the vacuum mold 110 may be formed in the peripheral surface region 124 of the mold surface 116. In another embodiment, the mold vacuum 110 may not have vacuum holes 118 formed in the central surface region 122. By not providing vacuum holes 118 in the central surface region 122, any potential defects introduced by the vacuum holes 118 during the reshaping of the glass plate on the central surface region 122 can be avoided. In another embodiment, the surface area of ​​the central surface region 122 may be 10,000 mm². 2 Or even 60,000 mm 2 Or larger. In some embodiments, the surface area of ​​the central surface region 122 may range from 00,000 mm. 2 up to 8 m 2 In some embodiments, the surface area of ​​the central surface region 122 may range from 60,000 mm. 2 Up to 6 m 2 In some embodiments, the surface area of ​​the central surface region 122 may range from 60,000 mm. 2 up to 3 m 2 .

[0073] In some embodiments, the vacuum mold 110 may include a slot 126 formed in the mold surface 116 and demarcating a central surface region 122 from a peripheral surface region 124. The size of the slot 126 is configured such that a portion of the reshaped glass article 250 is not pulled into the slot 126 during reshaping. In some embodiments, one or more vacuum holes 118 may be formed in the slot 126. In embodiments, the width of the slot 126 may be in the range of 1 mm to 4 mm. In embodiments, the width of the slot 126 may be customized based on the initial thickness 206 of the glass plate 200 reshaped using the vacuum mold 110. In some embodiments, the width of the slot 126 may be in the range of 100% to 300% of the initial thickness 206. In embodiments, the depth of the slot 126 may be 1 mm or less. In embodiments, the depth of the slot 126 may be in the range of 30% to 50% of the slot width. In such embodiments, the depth of the slot 126 may range from 20 micrometers to 1 mm. In one embodiment, the slot 126 extends through the mold 110 to provide a path for laser cutting the central surface region 122 from the reshaped glass article 250.

[0074] In one embodiment, the mold surface 116 may include a contact indicator 128. The contact indicator 128 may be, for example, a raised indentation or a contact sensor. In embodiments including the contact indicator 128, the contact indicator 128 can provide a signal that the reshaped glass plate 201 is in contact with the mold surface 116. In some embodiments, the contact indicator 128 may be located on a peripheral surface region 124 of the mold surface 116.

[0075] Now for reference Figure 3A Additional features of the top wall 132 of the frame 130 are described according to an example embodiment. Figure 3A It shows crossing Figure 2 The figure shows a cross-sectional view of the top wall 132 of line III-III. As shown, the top wall 132 includes a body 300 and a retaining frame 310 disposed on the body 300. The body 300 includes an inner surface 302 and an outer surface 304. In an embodiment, the body 300 is attached to a mold 114 (e.g., via regularly spaced screws in the upper surface 306 of the body 300) such that the inner surface 302 transitions into the mold surface 116 (e.g., the inner edge 264 of the upper surface 134 may be formed in the body 300 at or outside the inner surface 302). In an embodiment, the inner surface 302 is shaped as an extension of the mold surface 116 (see Figure 114). Figure 1A-1B This allows for a smooth interface with the mold 114. In one embodiment, the retaining frame 310 extends around the outer surface 304 of the body 300 (e.g., wraps around the outer surface 304 to the lower surface of the body 300), such that the outer edge 262 of the upper surface 134 is formed by the retaining frame 310. In another embodiment, the body 300 is formed of the same material as the mold 114 (e.g., both may be made of graphite) and also has the same thickness as the mold 114 to provide a consistent thermal mass throughout the combined structure of the frame 130 and the mold 114. It has been found that a uniform distribution of thermal mass can control stress in the glass and help reduce wrinkling.

[0076] In the depicted embodiment, the inner portion of the upper surface 134 (near the inner edge 264) is formed by the body 300, while the outer portion of the upper surface 134 is formed by the retaining frame 310. The retaining frame 310 may be formed of a metallic material or alloy (e.g., stainless steel) and serves to prevent the body 300 from oxidizing during heating and cooling. The thickness of the retaining frame 310 may be much smaller than the thickness of the body 300, so as not to effectively alter the thermal mass of the body 300. In the embodiment, the thickness of the retaining frame 310 ranges from 0.7 mm to 1.5 mm. Therefore, the combination of the retaining frame 310 and the body 300 helps to provide a uniform thermal mass distribution to control wrinkling, while also protecting the body 300 from oxidation. The retaining frame 310 may include an inner edge 312 disposed on the upper surface 306 of the body 300. The inner edge 312 may be disposed outside the channel portion 158 (and thus outside one or more vacuum openings 140), such that the retaining frame 310 does not disrupt the formation of the vacuum seal.

[0077] In one embodiment, the retaining frame 310 can be used to attach the friction-enhancing structure to the body 300. In another embodiment, when the glass plate 200 initially contacts the frame 130 (before heating), the static coefficient of friction between the glass plate 200 and the friction-enhancing structure can be greater than 0.1. Figure 3B For example, a view depicting the retaining frame 310 removed from the body 300 is shown. As shown, the retaining frame 310 includes a first portion 314 and a second portion 316. When placed on the body 300 (see...), Figure 3A The first portion 314 can be positioned adjacent to (or in contact with) the upper surface 306, and the second portion 316 can be positioned adjacent to (or in contact with) the lower surface of the body 300. As shown, when the first portion 314 is mounted on the body 300, it forms an inner edge 312 disposed on the upper surface 306.

[0078] like Figure 3AAs shown, stainless steel cloth 320 can be spot-welded to retaining frame 310 and positioned such that when glass plate 200 is initially placed on frame 130, glass plate 200 is in contact with stainless steel cloth 320. Stainless steel cloth is advantageous because the high coefficient of friction between the stainless steel cloth and glass (greater than 0.1 and less than or equal to 1.6) prevents tangential movement of the glass from causing center sagging. Furthermore, the low modulus of the steel cloth allows the cloth to follow local dimensional changes of the glass during heating and cooling. Stainless steel cloth 320 provides temporary attachment points with the glass, which follow the glass during the remolding process to prevent the glass from detaching from frame 130 and to facilitate the formation of a vacuum seal. In an embodiment, stainless steel cloth 320 is wound around the inner edge 312 of retaining frame 310 and molded to the underside of first portion 314. This configuration maximizes the contact area between stainless steel cloth 320 and glass plate 200, thereby maximizing friction. Additionally, stainless steel cloth can be wound around the outer surface 304 of body 300 (see...). Figure 3A Furthermore, it can be dotted onto the lower surface of the second part 316. In this way, the entire retaining frame 310 in contact with the glass plate 200 is covered with stainless steel cloth 320, thereby maximizing the contact area.

[0079] Figure 4 A method 400 for reshaping a glass plate 200 according to some embodiments is illustrated. Unless otherwise stated, the steps of method 400 need not be performed in the order set forth herein. In embodiments, method 400 may use methods described herein with respect to... Figure 1A-3B The device 100 described is used for execution. Therefore, reference will be made to... Figure 1A-3B The various components depicted in the text help to describe the method and understand method 400.

[0080] In step 402, a glass plate 200 is placed on a vacuum mold 110. When the glass plate 200 is placed on the vacuum mold 110, it can be positioned such that it covers the vacuum cavity 112, and the bottom surface 204 of the glass plate 200 is in direct contact with the top surface 134 of the frame 130. In some embodiments, the glass plate 200 may have a peripheral shape defined by a peripheral edge 208 and having a first periphery, and the outer peripheral edge 136 of the frame 130 may have a shape matching the shape of the first periphery. In some embodiments, step 402 may include placing multiple glass plates 200 on the vacuum mold 110. Multiple glass plates 200 may be placed on the vacuum mold 110 in a stacked configuration. In such embodiments, method 400 may simultaneously reshape multiple glass plates 200.

[0081] In step 404, the glass plate 200 is heated to the reforming temperature. One or more heat sources 190 of the device 100 can heat the glass plate 200 to the reforming temperature. In some embodiments, the reforming temperature may range from 600°C to 900°C. Exemplary heat sources 190 include conventional heating devices and infrared (IR) heating devices. In some embodiments, a heat shield 180 may be placed on the top surface 202 of the glass plate 200 during reforming to help control the temperature of the glass plate 200.

[0082] In step 406, a vacuum pressure may be applied to one or more vacuum openings 140. The vacuum pressure applied to the one or more vacuum openings 140 in step 406 may be sufficient to pull one or more first portions 220 of the glass plate 200 into the one or more vacuum openings 140. In embodiments including multiple vacuum openings 140, applying a vacuum pressure to the multiple vacuum openings 140 may pull multiple first portions 220 of the glass plate 200 into the multiple vacuum openings 140. In some embodiments, the vacuum pressure applied to the vacuum openings 140 in step 406 may pull a third portion of the glass plate 200 into a channel 156 of the vacuum mold 110. In some embodiments, the vacuum pressure applied to the one or more vacuum openings 140 may range from 0.1 bar to 0.3 bar. In some embodiments, the vacuum pressure may be applied to the one or more vacuum openings 140 in step 406 for a duration of 30 seconds to 120 seconds. In some embodiments, the vacuum pressure may be applied to the one or more vacuum openings 140 at a rate of 5 liters / minute to 20 liters / minute.

[0083] The vacuum pressure applied in step 406 seals the glass plate 200 to the top surface 134 of the frame 130, thereby creating a vacuum seal around the periphery of the second portion 230 of the glass plate 200. Additionally, the vacuum pressure applied in step 406 helps to hold the glass plate 200 and prevent any lateral movement of the glass during the application of vacuum pressure in the reshaping process. This facilitates controlled localized deformation and elongation of the second portion 230 of the glass plate 200, resulting in a wrinkle-free reshaped glass article.

[0084] By holding the glass plate 200 in place using vacuum pressure during remolding, the remolding process can be performed without mechanically clamping the glass plate 200 to the top surface 134 of the frame 130. Eliminating mechanical clamping minimizes the stress applied to the glass plate 200 during heating and cooling. Excessive stress during heating and cooling, such as mechanical and / or thermal stresses generated at the interface between the glass and the clamping mechanism, can lead to undesirable glass deformation and / or glass failure. Furthermore, using vacuum pressure to hold the glass plate 200 during remolding eliminates the need for any mechanical release mechanisms that could damage the glass when removing it from the vacuum mold 110. One or more vacuum openings 140 described herein allow the glass plate 200 to self-release during cooling and demolding, thereby minimizing stress applied to the glass.

[0085] In step 408, a vacuum pressure may be applied to the vacuum chamber 112. The vacuum pressure applied to the vacuum chamber 112 may be sufficient to pull the second portion 230 of the glass plate 200 into the vacuum chamber 112. In some embodiments, the vacuum pressure applied to the vacuum chamber 112 in step 408 may range from 0.1 bar to 0.3 bar. In some embodiments, the vacuum pressure may be applied to the vacuum chamber 112 for a duration of 30 seconds to 120 seconds. In some embodiments, the vacuum pressure is applied to the vacuum chamber 112 at a rate of 10 liters / minute to 100 liters / minute. In some embodiments, a vacuum pressure is applied to one or more vacuum openings 140 in step 406 before the vacuum pressure is applied to the vacuum chamber 112 in step 408. In some embodiments, steps 406 and 408 may be performed simultaneously, such that a vacuum pressure is applied to one or more vacuum openings 140 while a vacuum pressure is being applied to the vacuum chamber 112. In some embodiments, applying vacuum pressure to the vacuum chamber 112 in step 408 can pull the second portion 230 of the glass plate 200 toward the mold surface 116 defining the vacuum chamber 112 of the mold 114. In some embodiments, applying vacuum pressure to the vacuum chamber 112 in step 408 can pull the second portion 230 of the glass plate 200 into the vacuum chamber 112, and the second portion 230 can be freely shaped within the vacuum chamber 112. In such embodiments, by controlling the vacuum pressure, time, and temperature within the vacuum chamber 112, the second portion 230 can be reshaped within the vacuum chamber 112 without being pulled toward the mold surface of the mold.

[0086] In some embodiments, vacuum pressure can be applied to vacuum chamber 112 and / or one or more vacuum openings 140 without using a vacuum source. In such embodiments, vacuum pressure can be applied by abruptly stopping the application of heat after the remolding temperature has been reached. This may cause the air in vacuum chamber 112 and / or vacuum chamber 162 to cool rapidly, resulting in a significant gas volume contraction within vacuum chamber 112 and / or vacuum chamber 162. This significant gas volume contraction may pull one or more first portions 220 of glass plate 200 into one or more vacuum openings 140, and / or pull a second portion 230 of glass plate into vacuum chamber 112.

[0087] In some embodiments, the second portion 230 of the glass plate 200 may have an initial thickness 206 (t1) before the glass plate 200 is reshaped and a final thickness 207 (t2) after the glass plate is reshaped. This difference in thickness may be due to deformation of the glass plate during reshaping. In some embodiments, the ratio of the initial thickness 206 to the final thickness 207 is ( The range of initial thickness to final thickness can be from 1.1 to 2. This indicates that the glass sheet 200 has been deformed and stretched into its final shape. This deformation and stretching of the glass is similar to how glass is formed during glassblowing. By allowing the glass to deform and stretch freely into its final shape, the stress applied to the glass can be minimized, which in turn helps to prevent the glass from cracking and wrinkling.

[0088] After the glass plate 200 is reshaped in step 408, the vacuum pressure applied to the vacuum chamber 112 and one or more vacuum openings 140 can be released, and the reshaped glass plate can be allowed to cool to the annealing temperature in step 412. In step 412, the reshaped glass plate can be held at the annealing temperature to alleviate internal residual stresses generated during reshaping. After annealing, the reshaped glass plate can be cooled to room temperature in step 414 and removed from the vacuum mold 110 in step 416. Steps 410-414 can use any suitable heating profile, such as the heating profile described in International Patent Application No. PCT / US2022 / 025696, published as WIPO Publication No. WO 2022 / 231933 A1.

[0089] Figure 5A reshaped glass article 250 formed according to steps 402-416 of method 400 according to an example embodiment is schematically depicted. As shown, the reshaped glass article includes a first primary surface 502 (corresponding to the top surface 202), a second primary surface 504 opposite the first primary surface 502 (corresponding to the bottom surface 204), and a secondary surface 506 extending between the first primary surface 502 and the second primary surface 504. The secondary surface 506 may correspond to the peripheral edge 208 of the glass plate 200 before reshaping, which, as described herein, may be cut to have the same peripheral shape as the upper surface 134. Method 400 may cause the second primary surface 504 to conform to the shape of the combined structure of the upper surface 134 and the mold surface 116 that are in contact with the glass plate 200 during reshaping. Therefore, the structure of the reshaped glass article 250 is substantially determined by the structure of the mold 114 and the frame 130.

[0090] like Figure 5 As shown, the reshaped glass article 250 includes a peripheral region 510 extending inward from the subsurface 506 to the boundary region 520. Most of the peripheral region 510 may be substantially flat. As used herein, the term "substantially flat" means that the article appears to have a planar shape when viewed from a distance of 1 m without magnification. Apart from the fact that the first portion 220 of the glass plate 200 has already been shaped by interaction with one or more vacuum openings 140, the peripheral region 510 may correspond herein to the description of... Figure 1A-1B The described support portion 240. In an embodiment, the surrounding area 510 includes the portion described herein. Figure 2 The width 268 of the described upper surface 134 corresponds to the width. The boundary region 520 represents a portion of the glass plate 200 that bends around the inner edge 264 of the upper surface 134 during reshaping, and / or at this portion, the shape of the reshaped glass article 250 changes from a flat shape to a non-developable shape. The reshaped glass article 250 further includes a central curved region 530 disposed within the boundary region 520. The central curved region 530 may correspond to a second portion 230 that is pulled toward the mold surface 116 during the execution of method 400. Within the central curved region 530, a first main surface 502 comprises a concave shape, and a second main surface 504 comprises a convex shape.

[0091] The dimensions of the reshaped glass article 250 can correspond to the dimensions of the combined structure of the frame 130 and the mold 114 that contact the glass plate 200 during reshaping. Therefore, the reshaped glass article 250 can include a maximum length representing the maximum linear distance between separation points on the secondary surface 506 measured in a first direction parallel to the first primary surface 502 in the peripheral region 510. The maximum length can correspond to the dimensions of the glass article oriented towards... Figure 2 The maximum length 266 depicted is provided by the value. The reshaped glass article 250 exhibits a bend depth DOB, which is represented by the maximum distance between a portion of the first main surface 502 in the peripheral region 510 and a portion of the first main surface in the central bend region 530, measured in a second direction perpendicular to the first direction. The bend depth DOB is 10% to 30% of the maximum length. Consistent with the upper surface 134, the peripheral region 510 includes a width 540 whose variation in the first direction does not exceed 10% of the average value around the peripheral region 510.

[0092] As this article is about Figure 2-3B The design of the frame 130 described herein results in a reshaped glass article 250 that exhibits minimal warping immediately after reshaping. For example, it has been found that, compared to glass articles with a smaller frame width, this provides the advantages discussed herein. Figure 2 The width 268 of the described upper surface 134 (e.g., 6% to 10% of the length) reduces the amount of warpage in the reshaped glass article. As used herein, the term "warpage" refers to an upward-facing localized bulge in the surface of the reshaped glass article during reshaping. It has been found that glass articles formed in this disclosure exhibit one or fewer warpages in the peripheral region 510 (in some cases, no warpage was observed when the inner edge 264 exhibited the shape characteristics described herein and / or when stainless steel cloth was used). In contrast, glass articles reshaped to a similar shape using other processes have been found to exhibit more than two warpages. These warpages may form in the peripheral portion before vacuum pressure is applied, thereby causing the central curved region to deviate significantly from the desired shape and exhibit poor optical distortion performance. In some embodiments, the reshaped glass article may exhibit a maximum warpage amplitude of less than 20 mm in the peripheral region 510 (warpage above the height of the peripheral portion of the first main surface 502).

[0093] Refer again Figure 4After removing the reshaped glass article 250 from the vacuum mold 110, in step 418, excess glass sheet material can be removed from the reshaped glass article to form a curved glass article. For example, removing excess glass sheet material may include removing all portions of the reshaped glass sheet 201 formed on the outer side of the central surface region 122. (See reference...) Figure 5 A portion 550 of the central curved region 530 can be cut from the reshaped glass article 250 to form a curved glass article. In some embodiments, a cutting process (e.g., laser cutting or water jet cutting) can be used to remove excess glass sheet material. In some embodiments, mechanical scribing and glass breaking along the scribing lines can be used to remove excess glass sheet material. In step 420, one or more post-reshaping processes can be performed on the reshaped glass sheet 201 or the reshaped glass article 250. Post-reshaping processes include, but are not limited to, polishing, ion exchange, etching, and lamination processes. Post-reshaping processes can be performed before or after step 418.

[0094] Figure 6 A curved glass article 1400 formed by method 400 is depicted. For example, it can be formed by cutting away... Figure 5 The portion 550 of the reshaped glass article 250 depicted herein forms the curved glass article 1400. An imaginary surface 1402 is shown, and this imaginary surface can be used to determine the maximum compressive strain shape parameter indicating the complexity of the curved shape of the curved glass article 1400. In an embodiment, the imaginary surface 1402 represents an imaginary plane into which points contained in the imaginary central surface 1412 defined by the glass article 1400 can be displaced during simulation, as indicated by arrow 1414, to determine the complexity of the curved shape of the glass article 1400. Compared to certain pre-existing thermoforming techniques, the reshaped technique described herein is capable of producing glass articles with greater complexity, while the glass article 1400 advantageously exhibits higher thickness uniformity and a relatively low level of optical distortion.

[0095] As shown in the figure, the glass article 1400 includes a first curved surface 1404, a second curved surface 1406, and a thickness 1408 extending between the first curved surface 1404 and the second curved surface 1406. In an embodiment, the first curved surface 1404 and the second curved surface 1406 define a non-developable surface shape of the glass article 1400. In an embodiment, the thickness 1408 represents the distance between the first curved surface 1404 and the second curved surface 1406 along a direction 1410 perpendicular to the first curved surface 1404. As will be understood, given a non-developable surface shape, the direction 1410 for measuring the thickness 1408 can vary as a function of a position on the first curved surface 1404. In an embodiment, the thickness 1408 may correspond to a minimum distance from the first curved surface 1404 to the second curved surface 1406 measured from a specific point on the first curved surface 1404. In embodiments, the thickness 1408 can range from 0.25 mm to 10 mm, 0.5 mm to 5 mm, 0.5 mm to 2.5 mm, 2.5 mm to 5 mm, 2.5 mm to 10 mm, or within a range with any two of these values ​​as endpoints. In embodiments, the thickness 1408 can range from 0.1 mm to 10 mm, 0.2 mm to 10 mm, 0.3 mm to 10 mm, 0.4 mm to 10 mm, 0.5 mm to 10 mm, 0.6 mm to 10 mm, 0.7 mm to 10 mm, 0.8 mm to 10 mm, 0.9 mm to 10 mm, 1 mm to 10 mm, 1.1 mm to 10 mm, 1.2 mm to 10 mm, 1.4 mm to 10 mm, 1.5 mm to 10 mm, 1.6 mm to 10 mm, 1.8 mm to 10 mm, 2 mm to 10 mm, 2.1 mm to 1 mm. 0 mm, 2.5 mm to 10 mm, 3 mm to 10 mm, 4 mm to 10 mm, 5 mm to 10 mm, 0.1 mm to 9 mm, 0.1 mm to 8 mm, 0.1 mm to 7 mm, 0.1 mm to 6.5 mm, 0.1 mm to 6 mm, 0.1 mm to 5.5 mm, 0.1 mm to 5 mm, 0.5 mm to 4 mm, 0.7 mm to 3.6 mm, 0.7 mm to 3.3 mm, 0.7 mm to 2.1 mm, 0.7 mm to 1.6 mm, or 0.7 mm to 1.1 mm, or within a range with any two of these values ​​as endpoints.

[0096] The value obtained when measuring the thickness 1408 can vary depending on the position on the first curved surface 1404. As described herein, the deep vacuum forming method promotes a substantially uniform thickness 1408 across the entire first curved surface 1404. For example, if the surface area of ​​the first curved surface 1404 is 1000 mm²... 2If a specific portion of the glass article 1400 is subjected to multiple thickness measurements (e.g., 10 measurements), the errors between these measurements are likely to be within 150 µm (e.g., such that the difference between the maximum and minimum values ​​obtained is less than or equal to 150 µm). In other words, the thickness uniformity of the glass article 1400 can be 1000 mm on each of the first curved surfaces 1404. 2 Surface area + / - 75 micrometers. In an embodiment, the thickness uniformity of the glass article 1400 can be 10,000 mm on each of the first curved surfaces 1404. 2 Surface area + / - 75 micrometers. In this embodiment, thickness uniformity is 1000 mm per first curved surface 1404. 2 Surface area + / - 50 micrometers. In this embodiment, thickness uniformity is 1000 mm per first curved surface 1404. 2 Surface area + / - 25 micrometers.

[0097] In an embodiment, the surface area of ​​at least one of the first curved surface 1404 and the second curved surface 1406 is 10,000 mm². 2 Up to 6 m 2 Within the range and the thickness uniformity is per 1000 mm 2 + / - 75 micrometers. In an embodiment, the surface area of ​​at least one of the first curved surface 1404 and the second curved surface 1406 is 10,000 mm². 2 Up to 6 m 2 Within the range and the thickness uniformity is per 10000 mm 2 + / - 75 micrometers. In an embodiment, the surface area of ​​at least one of the first curved surface 1404 and the second curved surface 1406 is 60,000 mm². 2 Up to 6 m 2 Within the range and the thickness uniformity is per 10000 mm 2 + / - 50 micrometers. In an embodiment, the surface area of ​​at least one of the first curved surface 1404 and the second curved surface 1406 is 60,000 mm². 2 Up to 6 m 2 Within the range and the thickness uniformity is per 10000 mm 2 + / - 25 micrometers.

[0098] In this embodiment, the non-developable surface shape defined by the first curved surface 1404 and the second curved surface 1406 comprises a maximum compressive strain shape parameter defined by the imaginary central surface 1412 and imaginary surface 1402 of the glass article 1400. The maximum compressive strain shape parameter represents the complexity of the shape, and the process described herein enables a flat glass sheet to be reformulated into this shape without introducing wrinkles or other significant thickness deviations. The maximum compressive strain shape parameter is primarily a function of the Gaussian curvature associated with the imaginary central surface 1412 and its dimensions (e.g., length and width in a specified coordinate system). The thickness of the glass has a slight effect on the maximum compressive strain shape parameter, but this effect is negligible.

[0099] The maximum compressive strain shape parameter can be calculated by simulating the imaginary central surface 1412 as an imaginary glass plate. The properties of the imaginary glass plate can be independent of the properties of the actual glass article 1400 (actually produced by the methods described herein). Unless otherwise stated, the imaginary glass plate has a thickness of 0.7 mm, a Young's modulus of 71.7 GPa, a Poisson's ratio of 0.21, and a density of 2440 kg / m³. 3 The hypothetical glass plate is discretized into three- or four-sided shell elements (or a combination thereof) associated with a commercially available finite element analyzer. In this embodiment, Ansys® Mechanical™ is used to calculate the shape parameters for maximum compressive strain, where the hypothetical central surface 1412 is discretized using SHELL181 elements (avoiding the degenerate triangle option unless used as filler in mesh generation). Specifically, the strain that may exist in the hypothetical glass plate when it (initially having the shape of the hypothetical central surface 1412) is flattened to have a planar shape with a hypothetical surface 1402 is simulated. Command scripts are used to specify boundary conditions associated with the simulated nodal displacements (e.g., to define the hypothetical surface 1402 used for flattening the hypothetical glass plate). Boundary conditions can also prevent rigid body motion of the hypothetical glass plate (e.g., by specifying that the hypothetical surface 1402 is tangent to a portion of the hypothetical central surface 1412). The nodes associated with each shell element are displaced along arrow 1414 until they are each located on the hypothetical surface 1402 (e.g., the z-coordinate of each node is set to zero in the coordinate system established by the boundary conditions, while the x or y coordinate of each node remains unchanged, such that the length and width of the simulated flattened glass plate are the same as the length and width of the initial glass artifact 1400 being simulated). Finite element analysis, including nonlinear analysis, is performed using an implicit method. The maximum value of the maximum principal strain is the maximum compressive strain shape parameter described herein. The mesh size associated with the shell elements is less than or equal to 0.5 mm to ensure convergent solutions.

[0100] The imaginary center surface 1412 is the surface representing the center plane of the glass article 1400. Each point on the imaginary center surface 1412 is equidistant from the first curved surface 1404 and the second curved surface 1406 along a direction extending perpendicular to the imaginary center surface 1412 at the point.

[0101] Some existing vacuum forming methods may not be able to produce glass articles with unformable shapes, where the maximum compressive strain parameter of the unformable shape is greater than 1% or 2%, without significant defects or thickness variations. In contrast, the deep vacuum forming method described herein can reshape flat glass sheets into curved glass articles having a curved surface defining an unformable shape, where the maximum compressive strain shape parameter of the unformable shape is greater than or equal to 3.0% (e.g., greater than or equal to 3.5%, greater than or equal to 4.0%, greater than or equal to 4.5%, greater than or equal to 5.0%). In one or more embodiments, the curved glass article has a curved surface defining an unformable shape with such a range of maximum compressive strain shape parameters, while still exhibiting at least 1000 mm thickness variation. 2 Thickness uniformity of part surface area + / - 75 µm (e.g., + / - 50 µm, + / - 25 µm).

[0102] In the embodiments, when the glass article has a periphery with a generally parallelepiped shape (or when the radius of curvature of most of the periphery of the glass article is greater than 10 m), the following equation can be used to approximate the maximum compressive strain shape parameter associated with the glass article 1400: Where κ is the average Gaussian curvature of the imaginary central surface 1412, l is the length of the imaginary glass plate simulated as a flattened glass plate, and w is the width of the flat glass plate (the units of each constant make the result in mm / m, which can be converted to a percentage by dividing the numerical mm / m result by 10). When the glass article contains a basically circular shape (or when the radius of curvature of most of the perimeter of the glass article is less than 10 m), the maximum compressive strain shape parameter can be mathematically approximated based on the following relationship: Where D is the diameter of the imaginary glass plate being flattened into a circular shape. The units associated with the constants in equations (1) and (2) are set such that the outputs of equations (1) and (2) are in mm / m (which can be converted to a percentage by dividing the output by 10).

[0103] In some embodiments, the curved shape of the reshaped glass article 1400 may have an optical power distortion of less than 300 millidiopters (mDI) in absolute form, measured by thickness 1408. In some embodiments, the range of optical power distortion of the curved shape of the reshaped glass article 1400, measured by thickness 1408, may be from 20 mDI to 300 mDI (in absolute form). In some embodiments, the range of optical power distortion of the curved shape of the reshaped glass article 1400, measured by thickness 1408, may be from 50 mDI to 300 mDI (in absolute form). In some embodiments, the range of optical power distortion of the curved shape of the reshaped glass article 1400, measured by thickness 1408, may be from 100 mDI to 300 mDI (in absolute form). The optical distortion of the curved surface can be measured according to DIN 52305:1995 ("Determining the optical distortion and refractive power of safety glazing material for roadvehicles").

[0104] In some embodiments, the measurable indentation density of the first curved surface 1404 of the reshaped glass article 1400 is less than 10 indentations / 100 mm. 2 Convex surface area. As used herein, a measurable indentation is a raised or recessed indentation formed on the first curved surface 1404 with an effective diameter greater than 1 mm. A measurable indentation can be determined by measuring the optical distortion of light transmitted through the first curved surface 1404 of the glass article 1400. If the optical distortion is 50 or more millidiopters (mdpt) after noise filtering of the measurement data, it indicates the presence of a measurable indentation; or if the optical distortion is 100 or more millidiopters (mdpt) before noise filtering of the measurement data, it indicates the presence of a measurable indentation. Optical distortion can be measured using an apparatus for measuring transmitted optical distortion on glass. For example, the LABSCAN screen system, available from ISRA Vision, can be used to measure optical distortion. For the purpose of evaluating the density of measurable indentations, at least 50,000 mm² of light transmitted through the first curved surface 1404 is analyzed. 2 Surface area, and calculated per 100 mm based on the total number of measurable indentations present. 2 The number of dents can be measured. To confirm 50,000 mm 2 per 100 mm of surface area 2 The accuracy of the number of dents can be re-analyzed on a 50,000 mm surface.2 5,000 mm inside the surface area 2 Surface area, and based on 5,000 mm 2 The total number of measurable indentations present in the surface area is calculated per 100 mm. 2 The number of dents can be measured.

[0105] As will be understood, the glass article 1400 can have various shapes, and there is no particular limitation on the specific form of the glass article 1400. For example, in an embodiment, the outer peripheral shape of the glass article 1400 may include a length (L) extending in a first direction parallel to the imaginary surface 1402 and a width (W) extending in a second direction parallel to the imaginary surface 1402 and perpendicular to the first direction. The length (L) and width (W) may represent the maximum dimensions of the glass article 1400 in the first and second directions, respectively. In an embodiment, the outer peripheral edge of the glass article 1400 may be approximately parallelepiped (e.g., rectangular). In an embodiment, the outer peripheral edge of the glass article 1400 may be approximately circular (e.g., such that the radius of curvature of most of the outer peripheral edge is less than 10 m) and includes a diameter (D) representing the maximum distance between two points on the outer peripheral edge.

[0106] Example The embodiments of this disclosure can be further understood from the following examples.

[0107] When a 2.3 mm thick soda-lime glass sheet is heated to a reshaping temperature above 570°C using isothermal heating, a model is created for reshaping the soda-lime glass sheet. Figures 7A-7B The model was created using the mold depicted in the image. The glass plate was cut to have a peripheral shape that matches the peripheral shape of the upper frame surface. For example... Figure 7A As shown, the mold 1500 according to the first example includes an upper frame surface 1502 with a width of 120 mm. As illustrated, the width is therefore less than 6% of the total length of the mold 1500. The upper frame surface 1502 also includes an inner edge 1504 that does not have the shape specified herein, said shape having a discontinuous second derivative and relatively long linear segments. Figure 7B As shown, the mold 1506 according to the second example includes an upper frame surface 1508 with a width of 120 mm. The width is therefore less than 6% of the total length of the mold 1506. In contrast to the mold 1500, the upper frame surface 1508 of the mold 1506 includes an inner edge 1510 having a continuous second derivative and no linear segment longer than 25% of the total length.

[0108] Figures 8A-8B It is described Figure 7A and 7BThe results of the mold remolding simulation depicted in the figure show that both molds resulted in three warps in the peripheral portion of the product. However, as... Figure 8A As shown, compared to Figure 8B The warping shown, caused by mold 1500, extends further inward toward the center of the glass article, potentially affecting the shape to a greater extent. As shown, the redesigned shape of the inner edge 1510 exhibits excellent edge quality (uniformity) and less noticeable warping, demonstrating the effectiveness of the mold described herein. For those with similar... Figure 7A and 7B The design depicted in the figure is another simulation of the mold, but the width of the upper surface is increased to 150 mm, which is more than 6% of the total length of the mold. Figure 9A It shows Figure 7A The result is a redesigned version of the mold depicted in the image. Figure 9B It shows Figure 7B The result is a redesigned version of the mold depicted in the image. For example... Figure 9A As shown, increasing the width of the upper frame surface 1502 eliminated two of the three folds. Figure 9B As shown, increasing the width of the upper frame surface 1508 eliminated all existing wrinkles. These results demonstrate the effectiveness of the mold described herein in eliminating wrinkles around the periphery of glass articles reshaped into complex Gaussian shapes.

[0109] Examples are provided for illustrative purposes and are not intended to limit this disclosure. Other suitable modifications and adaptations to various conditions and parameters commonly encountered in the art and readily apparent to those skilled in the art are permitted within the spirit and scope of this disclosure.

[0110] The indefinite article “a / an” used to describe an element or component indicates the presence of one or more of these elements or components. While these articles are generally used to indicate that the noun being modified is singular, the article “a / an” as used herein also includes plural nouns unless otherwise stated in specific contexts. Similarly, the definite article “the” as used herein also indicates that the noun being modified can be either singular or plural, unless otherwise stated in specific contexts.

[0111] The directional terms used herein (e.g., up, down, right, left, front, back, top, bottom, inward, outward) are used only with reference to the accompanying drawings and are not intended to imply absolute orientation.

[0112] As used in the claims, “comprising” is an open-ended transitional phrase. The list of elements following the transitional phrase “comprising” is a non-exclusive list, allowing for the possible presence of elements other than those specifically described in the list. As used in the claims, “consistently made of” or “constantly made of” limits the composition of the material to the specified materials and those that do not substantially affect the material’s fundamental and novel characteristics. As used in the claims, “consisting of” or “wholly made of” limits the composition of the material to the specified materials and excludes any unspecified materials.

[0113] Where a range of values ​​including upper and lower limits is described herein, unless otherwise stated in specific circumstances, the range is intended to include its endpoints, as well as all integers and fractions within the range. When a range is defined, the scope of the claims is not intended to be limited to the specific value stated. Furthermore, when a quantity, concentration, or other value or parameter is given in the form of a range, one or more preferred ranges, or a list of preferred upper and lower limits, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred range value and any lower or preferred range value, whether or not such pairs are disclosed individually. Finally, when the term “about” is used to describe the value or endpoint of a range, this disclosure should be understood to include the specific value or endpoint mentioned. Regardless of whether a numerical or range endpoint is described with “about,” the numerical or range endpoint is intended to include two embodiments: one modified by “about” and one not modified by “about.”

[0114] As used herein, the term “about” means a value within ± 5% of the stated value. For example, about 3 MPa can include any number between 2.85 MPa and 3.15 MPa.

[0115] The above description of this embodiment has used functional building blocks to illustrate implementations of specific functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined, provided that the specified functions and their relationships are appropriately performed.

[0116] It should be understood that the wording or terminology used herein is for descriptive purposes and not for limitation. The breadth and scope of this disclosure should not be limited to any of the exemplary embodiments described above, but should be defined in accordance with the appended claims and their equivalents.

Claims

1. A curved glass article in an as-formed condition, the curved glass article comprising: First primary surface; A second main surface, wherein the second main surface is positioned opposite the first main surface; The secondary surface extends between the first primary surface and the second primary surface; The peripheral region extends inward from the subsurface to the boundary region, wherein most of the peripheral region is substantially flat. A central curved surface region, wherein the central curved surface region is disposed inside the boundary region; as well as Length L, where length L represents the maximum linear distance between separation points on the secondary surface measured in a first direction parallel to the first primary surface in the peripheral region, wherein: Within the central curved surface region, the first primary surface has a concave shape and the second primary surface has a convex shape, and the first primary surface and the second primary surface exhibit non-zero Gaussian curvature. The curved glass article exhibits a bending depth DOB, which is represented by the maximum distance between a portion of the first main surface in the peripheral region and a portion of the first main surface in the central curved region, measured in a second direction perpendicular to the first direction. The bending depth DOB is between 10% and 30% of the length. The peripheral region includes a width measured parallel to the first main surface, and the width variation does not exceed 10% of the average value around the peripheral region. The surrounding area exhibits one or less warping around its entire circumference.

2. The curved glass article according to claim 1, wherein: 300 mm ≤ L ≤ 4000 mm, and 50 mm ≤ DOB ≤ 700 mm.

3. The curved glass article according to any one of claims 1 to 2, wherein the glass article includes a width W, the width W representing the maximum linear distance between separation points on the secondary surface measured upwards on a third surface parallel to the first primary surface in the peripheral region and perpendicular to the first direction, wherein 200 mm ≤ W ≤ 2500 mm.

4. The curved glass article according to any one of claims 1 to 3, wherein: The surface area of ​​the first primary surface in a portion of the central curved surface region is 60,000 mm. 2 Or larger, and Within the aforementioned portion, the uniformity of the thickness measured between the first main surface and the second main surface is 1000 mm per first main surface. 2 Surface area + / - 75 micrometers.

5. The curved glass article of claim 4, wherein the portion comprises a non-developable curved shape, the non-developable curved shape comprising a maximum compressive strain shape parameter greater than or equal to 3.0% and less than or equal to 10%, the maximum compressive strain shape parameter being measured between an imaginary central surface and an imaginary surface disposed between the first main surface and the second main surface.

6. The curved glass article according to any one of claims 4 to 5, wherein within the portion, the average thickness measured over the entire first main surface is greater than or equal to 0.5 mm and less than or equal to 2.5 mm.

7. A vacuum mold, the vacuum mold comprising: A mold, the mold comprising a mold surface having a complex, non-developable shape and defining a mold cavity; and A frame comprising a body mounted on the mold, the body including a top surface circumferentially surrounding the mold surface and including one or more vacuum openings formed therein, wherein the top surface includes: outer edge; Inner edge, at which the body and the mold form an interface; as well as Width W, which is measured between the inner edge and the outer edge in a first direction parallel to the top surface, wherein: The width W varies by no more than 10% relative to the average value of the entire circumference around the vacuum mold. The vacuum mold includes a length L, which represents the maximum linear distance between separation points on the outer edge parallel to the top surface. The vacuum mold includes a depth D, which is measured as the maximum vertical distance between the top surface and the mold surface in a direction perpendicular to the top surface. The depth D is 10% to 30% of L. W is 0.06 L to 0.10 L.

8. The vacuum mold of claim 7, wherein the inner edge comprises a circumferential shape without linear segments having a length greater than L / 4.

9. The vacuum mold according to claim 8, wherein the second derivative of the circumferential shape is continuous over its entire range.

10. The vacuum mold according to claim 8, wherein the width W varies by no more than 5% relative to the average value of the entire circumference of the vacuum mold.

11. The vacuum mold according to any one of claims 7 to 10, wherein: 300 mm ≤ L ≤ 4000 mm, and 50 mm ≤ D ≤ 700 mm.

12. The vacuum mold according to any one of claims 7 to 11, wherein the body is formed of graphite, and wherein the vacuum mold further comprises a metal frame disposed on the top surface and around the outer edge.

13. The vacuum mold of claim 12, wherein the inner edge of the metal frame is disposed outside the one or more vacuum openings.

14. The vacuum mold of claim 13, further comprising a stainless steel cloth welded around the inner edge and disposed around the outer edge.

15. A method for forming a curved glass article, the method comprising: A glass plate is placed on a vacuum mold, the vacuum mold including a mold surface that at least partially defines a vacuum cavity, wherein the glass plate is placed on the vacuum mold such that the glass plate is in circumferential contact with a top surface of the mold surface of the body of the frame, wherein the top surface includes: One or more vacuum openings are formed therein; outer edge; Inner edge, at which the body and the mold form an interface; and The width W is measured parallel to the top surface between the inner and outer edges, wherein the width W varies by no more than 10% relative to the average value of the entire circumference of the vacuum mold, wherein the vacuum mold includes a length L, which represents the maximum linear distance between separation points on the outer edge measured parallel to the top surface, and wherein the vacuum mold includes a depth D, which is measured as the maximum vertical distance between the top surface and the mold surface in a second direction perpendicular to the top surface, wherein the depth D is 10% to 30% of L, and W is 0.

06. L to 0.10 L; The glass plate is heated to the reshaping temperature; Apply vacuum pressure to the one or more vacuum openings, causing one or more first portions of the glass plate to be pulled into the one or more vacuum openings; as well as A vacuum pressure is applied to the vacuum chamber, causing a second portion of the first glass plate to be pulled into the vacuum chamber, thereby bringing the glass plate into contact with a portion of the mold surface, the portion being positioned at the depth D relative to the top surface.

16. The method of claim 15, wherein prior to the heating, the coefficient of static friction between the top surface and the glass plate is greater than 0.1 and less than or equal to 1.

6.

17. The method according to any one of claims 15 to 16, wherein when the glass plate is placed on the top surface, the entire peripheral edge of the glass plate is aligned with the outer edge.

18. The method of claim 15, wherein during the heating, the first portion is heated to a first temperature, and the second portion is heated to a second temperature lower than the first temperature.

19. The method of claim 18, wherein the second temperature is 20°C to 120°C lower than the first temperature.

20. The method according to any one of claims 15 to 19, wherein the second portion of the glass plate comprises an initial thickness (t1) before the glass plate is reshaped and a final thickness (t2) after the glass plate is reshaped, and wherein... The range is 1.1 to 2.

21. The method according to any one of claims 15 to 20, wherein the inner edge comprises a circumferential shape without linear segments having a length greater than L / 4.

22. The method of claim 21, wherein the second derivative of the circumferential shape is continuous over its entire range.

23. The method according to any one of claims 15 to 22, wherein: 300 mm ≤ L ≤ 4000 mm, and 50 mm ≤ D ≤ 700 mm.

24. The method according to any one of claims 15 to 23, wherein the body is formed of graphite, wherein the vacuum mold further comprises a metal frame disposed on the top surface and around the outer edge, wherein the thickness of the metal frame is 0.7 mm to 1.5 mm.

25. The method of claim 24, wherein the inner edge of the metal frame is disposed outside the one or more vacuum openings.

26. The method of claim 25, wherein the vacuum mold further comprises a stainless steel cloth welded around the inner edge and disposed around the outer edge.

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