Method and apparatus for manufacturing glass sheet from glass ribbon

Abstract

An apparatus for manufacturing a glass sheet from a glass ribbon comprises: a roller for providing the glass ribbon to the apparatus; an actuator configured to bend the glass ribbon along a predetermined cutting path by applying a first average stress and further bend a bent portion of the glass ribbon by applying a second average stress after scoring the glass ribbon; and a scribing device for scribing at least one point of the curved portion of the glass ribbon, where the second average stress is greater than the first average stress. According to the configuration described above, a glass sheet without multiple cracks can be manufactured by a simpler process, so that the glass sheet can be manufactured with high yield and at low cost.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority benefit of Korean Patent Application Serial No. 10 - 2024 - 0005590, filed on January 12, 2024, the content of which is relied upon and incorporated herein by reference in its entirety. Background Art

[0003] 1. Field

[0004] The present disclosure relates to an apparatus and method for manufacturing glass sheets from a glass ribbon.

[0005] More specifically, the present disclosure relates to an apparatus and method for manufacturing glass sheets by bending and scribing a glass ribbon.

[0006] 2. Description of the Related Art

[0007] Generally, a roll - to - sheet (R2S) assembly has been used as a system for manufacturing glass sheets (or glass substrates) by cutting an ultra - thin glass ribbon (or glass web). In such roll - to - sheet assemblies according to the related art, the glass ribbon is cut by pressing the glass ribbon along a predetermined breaking path of the glass ribbon with a constant force by using a center bar and / or scribing the glass ribbon.

[0008] However, glass ribbons are typically manufactured such that bead portions are formed at edge portions on opposite sides perpendicular to the transfer direction of the glass ribbon, and the bead portions are about 2 to 3 times thicker than a mass region that is an intermediate portion between the beads of the glass ribbon. When stress is applied by applying a constant pressure to the glass ribbon in a conventional manner, less internal stress appears in the relatively thin mass region, while greater internal stress appears in the relatively thick bead portions. Therefore, an accurate cut cross - section may not be formed along the predetermined cutting path in the mass region, or multiple cracks may be generated in the bead portions. Summary of the Invention

[0009] Provided is an apparatus and method for manufacturing glass sheets from a glass ribbon, by which the glass ribbon can be broken straight along a predetermined cutting path through a simpler process without generating multiple cracks in the bead portions of the glass ribbon.

[0010] According to one aspect of the present disclosure, an apparatus for manufacturing glass sheets from a glass ribbon includes: a roller; an actuator positioned after the roller in a receiving direction of the glass ribbon from the roller, the actuator being configured to receive the glass ribbon from the roller, bend the glass ribbon along a predetermined cutting path transverse to the receiving direction of the glass ribbon by applying a first average stress to the glass ribbon, and further bend a bent portion of the glass ribbon by applying a second average stress to the glass ribbon after scribing the glass ribbon; and a scribing device positioned near a first surface of the glass ribbon at the actuator and configured to scribe at least one point of the first surface of the bent portion of the glass ribbon; wherein the second average stress is greater than the first average stress.

[0011] In some embodiments, the actuator includes a central rod positioned near a second surface of the glass ribbon and at least two clamping rods positioned near the first surface of the glass ribbon, the second surface of the glass ribbon being opposite the first surface of the glass ribbon, wherein when bending the glass ribbon, the actuator applies the first average stress to the glass ribbon by moving the central rod a first average displacement such that the glass ribbon bends the first average displacement from a position of the glass ribbon in a direction from the second surface to the first surface, wherein when further bending the bent portion of the glass ribbon, the actuator applies the second average stress to the bent portion of the glass ribbon by moving the central rod a second average displacement such that the glass ribbon bends the second average displacement from the position of the glass ribbon in the direction from the second surface to the first surface, and wherein the second average displacement is greater than the first average displacement.

[0012] In some embodiments, a first clamping bar of the at least two clamping bars is in front of the central bar at the actuator in the receiving direction of the glass ribbon, and a second clamping bar of the at least two clamping bars is behind the central bar at the actuator in the receiving direction of the glass ribbon, wherein when bending the glass ribbon, the central bar moves perpendicular to the receiving direction of the glass ribbon towards the first surface of the glass ribbon to contact and press a predetermined cutting path on the second surface of the glass ribbon, such that the glass ribbon bends from its position towards the first surface by a first average displacement, the at least two clamping bars move perpendicular to the receiving direction of the glass ribbon towards the second surface of the glass ribbon to hold the glass ribbon, and wherein when further bending the bent portion of the glass ribbon, the central bar moves perpendicular to the receiving direction of the glass ribbon towards the first surface of the glass ribbon to press a predetermined cutting path on the second surface of the glass ribbon, such that the glass ribbon bends from its position towards the first surface by a second average displacement.

[0013] In some embodiments, when bending the glass ribbon along the predetermined cutting path, the actuator applies less stress to a first end of the predetermined cutting path than to a second end of the predetermined cutting path.

[0014] In some embodiments, when further bending the bent portion of the glass ribbon, the actuator applies more stress to a first end of the predetermined cutting path of the glass ribbon than to a second end of the predetermined cutting path of the glass ribbon.

[0015] In some embodiments, when bending the glass ribbon, a first end of the central bar in a direction transverse to the receiving direction of the glass ribbon has a smaller displacement in a direction from the second surface to the first surface than a second end of the central bar.

[0016] In some embodiments, when further bending the bent portion of the glass ribbon, the first end of the central bar in the direction transverse to the receiving direction of the glass ribbon has a larger displacement in a direction from the second surface to the first surface than the second end of the central bar.

[0017] In some embodiments, at least one point on the first surface of the bent portion to be scribed by the scribing device is located at one end of a predetermined cutting path on the first surface of the glass ribbon.

[0018] In some embodiments, the distance between the center of the first clamping bar and the center of the second clamping bar is greater than 0 mm but less than or equal to 40 mm.

[0019] In some embodiments, the scribing device includes at least one of a cutting wheel or a laser device.

[0020] According to another aspect of the present disclosure, a method of manufacturing glass sheets from a glass ribbon includes: applying a first average stress to the glass ribbon by using a scoring device to bend the glass ribbon along a predetermined cutting path; using a scribing device to scribe at least one point of the bent portion of the glass ribbon; applying a second average stress to the glass ribbon by using the scoring device to further bend the bent portion of the glass ribbon.

[0021] In some embodiments, the scoring device includes an actuator that includes a central rod positioned near a second surface of the glass ribbon and at least two clamping rods positioned near a first surface of the glass ribbon, the second surface of the glass ribbon being opposite the first surface of the glass ribbon, wherein bending the glass ribbon along the predetermined cutting path includes applying the first average stress to the glass ribbon by moving the central rod a first average displacement such that the glass ribbon bends the first average displacement in a direction from the second surface to the first surface from a position of the glass ribbon, wherein further bending the bent portion of the glass ribbon includes applying the second average stress to the bent portion of the glass ribbon by moving the central rod a second average displacement such that the glass ribbon bends the second average displacement in the direction from the second surface to the first surface from the position of the glass ribbon, and wherein the second average displacement is greater than the first average displacement.

[0022] In some embodiments, a first clamping rod of the at least two clamping rods is located in front of the central rod in a receiving direction of the glass ribbon at the actuator, and a second clamping rod of the at least two clamping rods is located behind the central rod in the receiving direction of the glass ribbon at the actuator, wherein bending the glass ribbon includes applying the first average stress to the glass ribbon by moving the central rod perpendicular to the receiving direction of the glass ribbon toward the first surface of the glass ribbon to contact and press a predetermined cutting path of the second surface of the glass ribbon such that the glass ribbon bends the first average displacement from the position of the glass ribbon toward the first surface, wherein further bending the bent portion of the glass ribbon includes applying the second average stress to the bent portion of the glass ribbon by moving the central rod perpendicular to the receiving direction of the glass ribbon toward the first surface of the glass ribbon to press the predetermined cutting path of the second surface of the glass ribbon such that the glass ribbon bends the second average displacement from the position of the glass ribbon toward the first surface.

[0023] In some embodiments, bending the glass ribbon along the predetermined cutting path includes applying a smaller stress to a first end of the predetermined cutting path than to a second end of the predetermined cutting path of the glass ribbon.

[0024] In some embodiments, further bending the bent portion of the glass ribbon includes applying a greater stress to the first end of the predetermined cutting path than to the second end of the predetermined cutting path of the glass ribbon.

[0025] In some embodiments, when bending the glass ribbon, a first end of the center rod in a direction transverse to the receiving direction of the glass ribbon has a smaller displacement in a direction from the second surface to the first surface than a second end of the center rod.

[0026] In some embodiments, when further bending the bent portion of the glass ribbon, the first end of the center rod in a direction transverse to the receiving direction of the glass ribbon has a greater displacement in a direction from the second surface to the first surface than the second end of the center rod.

[0027] In some embodiments, at least one point of the bent portion to be scribed by the scribing device is located at an end of the predetermined cutting path on the first surface of the glass ribbon.

[0028] In some embodiments, at least one of bending the glass ribbon and further bending the bent portion of the glass ribbon includes generating an internal stress of at least 60 Mpa but less than 100 Mpa in the bead region of the glass ribbon.

[0029] In some embodiments, the distance between the center of the first clamping rod and the center of the second clamping rod is greater than 0 mm but less than or equal to 40 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] These and / or other aspects will become apparent and easier to understand from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0031] Figure 1 is a view schematically showing an example of a possible cut of a glass sheet;

[0032] Figure 2 shows a schematic side view (a) and a schematic front view (b) of a system for manufacturing a glass sheet from a glass ribbon according to the present disclosure;

[0033] Figure 3 is according to the present disclosureFigure 2 Top view of the single-cutting device;

[0034] Figure 4A is according to the present disclosure Figure 2 Schematic side view of the single-cutting device according to the present disclosure before bending the glass ribbon, and Figure 4B is according to the present disclosure Figure 2 Schematic side view of the single-cutting device according to the present disclosure after bending the glass ribbon;

[0035] Figure 5 is a schematic diagram showing the bending mode according to the change in the displacement of the opposite end portions of the center rod during the first bending and the second bending in the method of manufacturing a glass sheet from a glass ribbon according to the present disclosure;

[0036] Figure 6 is a view showing the stress distribution of the glass ribbon when performing the first bending on the glass ribbon according to the present disclosure;

[0037] Figure 7 is a view showing that the radius of curvature R of the bent portion of the glass ribbon changes according to the change in the overhang amount between the first clamping rod and the second clamping rod in the single-cutting device according to the present disclosure;

[0038] Figure 8 is a schematic flow chart of the method of manufacturing a glass sheet from a glass ribbon according to the present disclosure;

[0039] Figure 9 is a graph showing the crack propagation mode according to the change in the average displacement set during the first bending of the center rod on the Y-axis and the second bending of the center rod on the X-axis in the method of manufacturing a glass sheet from a glass ribbon according to the present disclosure; and

[0040] Figure 10 is a graph showing the correlation of the tensile stress σ on the glass ribbon according to the displacement of the center rod when applying a bending stress to each of two ultra-thin glass ribbons having thicknesses of 75 μm and 100 μm according to the present disclosure. Detailed Description of the Invention

[0041] Reference will be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the embodiments are described below only by referring to the drawings to explain aspects of the present description. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of..." modify the entire list of elements when preceding the list of elements, rather than modifying individual elements in the list.

[0042] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present disclosure to those of ordinary skill in the art. Throughout the drawings, like reference numerals represent like elements. In addition, various components and regions in the drawings are schematically illustrated. Therefore, the present disclosure is not limited to the relative sizes or distances drawn in the drawings.

[0043] Figure 1 is a view schematically showing an example of possible cuts that can be formed in a glass sheet.

[0044] In Figure 1 , (a) shows a case where multiple cracks are generated in a weld bead where the cutting stress propagation in the lateral direction of the receiving direction of the glass ribbon ends and thus crack branches are formed; (b) shows a case where cutting is performed well along a certain cutting path; (c) shows a case where the crack prematurely stops at the start portion of the opposite weld bead of the lateral cutting path of the glass ribbon; (d) shows a case where the crack does not propagate straight along the lateral cutting path of the glass ribbon but deviates (bump travels) from the crack propagation direction; (e) shows a case where the propagation of the crack stops midway; (f) shows a case where the crack does not properly initiate and propagate. The stress (ST) applied to the glass ribbon increases from (f) to (a). When cuts such as Figure 1 cases (a) and (c) to (e) occur, the yield rate of glass sheet manufacturing can be reduced, and additional subsequent processes may be required, thereby increasing the manufacturing process cost.

[0045] Figure 2 shows a schematic side view (a) and a schematic front view (b) of a system 200 for manufacturing a glass sheet from a glass ribbon 200 according to some embodiments of the present disclosure. Referring to Figure 2 , the system 200 may include: a reel unwinder 220 for unwinding the glass ribbon 210 from a reel; a guide roller 230 for guiding the direction of the unwound glass ribbon and / or holding the unwound glass ribbon; a singulation device 250 for cutting the glass ribbon 210 to manufacture a glass sheet; and an unloader for unloading the cut glass sheet.

[0046] In some embodiments, the system 200 may further include at least one edge position control (EPC) sensor 240 for detecting and controlling the position of the side surface edge of the glass ribbon 210 between the guide roller 230 and the singulation device 250. In addition, the system 200 may further include an unloader (e.g., a vacuum hand) 260 for unloading the cut glass sheet and an insert rewinder 270 for rewinding the glass ribbon 210.

[0047] Referring toFigure 2 According to the present disclosure, the singulation device 250 may include a roller 251, at least one actuator 252, and a scribing device 253. The roller 251 may be configured to control the position of the glass ribbon 210 to be provided to the singulation device 250 and maintain the position and tension of the glass ribbon 210 during the cutting process. The roller 251 may be, for example, an edge-driven roller (EDR).

[0048] The actuator 252 may be positioned behind the roller 251 in the receiving direction of the glass ribbon 210 from the roller 251 and is configured to receive the glass ribbon 210 from the roller 251 and perform a first bending of the glass ribbon 210 by applying a first average stress to the glass ribbon 210 along a predetermined cutting path. The actuator 252 may be configured to further perform a second bending of the glass ribbon 210 by applying a second average stress to the bent portion of the glass ribbon 210 after scribing at least one point on the predetermined cutting path of the glass ribbon 210. In this state, the second average stress applied during the second bending may be greater than the first average stress applied during the first bending.

[0049] The scribing device 253 may be positioned near the first surface of the glass ribbon at the actuator (252). The scribing device 253 may be configured to scribe at least one point on the first surface of the bent portion of the glass ribbon 210. Here, scribing at least one point on the first surface of the bent portion of the glass ribbon 210 means creating a defect at at least one point on the first surface of the glass ribbon. During the second bending, the defect will precisely create a crack at a desired site on the predetermined cutting path of the glass ribbon 210 and allow the crack to propagate along the predetermined cutting path.

[0050] According to some embodiments, the singulation device 250 may further include at least one EPC sensor 257 for detecting and controlling the side surface edge position of the glass ribbon 210 between the roller 251 and the actuator 252.

[0051] The first bending for applying a weak stress to the predetermined cutting path of the glass ribbon 210 may generate a basic stress field in the cutting path of the glass ribbon 210 before scribing, thereby forming a straight guiding line for expanding the crack generated later during the second bending. Scribing at least one point on the cutting path of the glass ribbon 210 creates a defect in the glass ribbon 210, and the crack initiates from the defect during the second bending. During the second bending in which a stress greater than the stress during the first bending is applied, the crack initiates from the scribed portion weakened by the defect, and thus the crack can expand straight along the guiding line formed during the first bending, thereby minimizing the generation of multiple cracks in the bead portion. Therefore, after the second bending, it can be as Figure 1Perform a final cut as shown in the cutting pattern (b) so that when manufacturing glass sheets, the manufacturing yield can be improved with a simple process.

[0052] According to some embodiments, as Figure 2 shown, the actuator 252 may further include a center rod 254 positioned near the second surface of the glass ribbon at the actuator 252 and at least two clamping rods 255 and 256 positioned near the first surface of the glass ribbon at the actuator. The second surface of the glass ribbon is opposite the first surface of the glass ribbon. The center rod 254 may bend the glass ribbon 210 by applying stress to the glass ribbon 210 in a direction transverse to the receiving direction of the glass ribbon 210 from the roller 251 along a predetermined cutting path, and thus may generate a tensile stress such that cracks can be generated and / or propagated along the cutting path. The at least two clamping rods 255 and 256 may be positioned near the first surface of the glass ribbon 210 and include a first clamping rod 255 and a second clamping rod 256. The clamping rods 255 and 256 may hold the glass ribbon 210 and / or isolate the portion of the glass ribbon 210 bent by the center rod 254.

[0053] Figure 3 is according to the present disclosure Figure 2 top view of the singulation device 250. Figure 4A is according to the present disclosure Figure 2 schematic side view of the singulation device before bending the glass ribbon, and Figure 4B is according to the present disclosure Figure 2 schematic side view of the singulation device after bending the glass ribbon.

[0054] Referring to Figure 3 , the actuator 252 may include two or more sub-actuators and may include, for example, two servo motors. As Figure 3 illustrated, when using two sub-actuators (e.g., servo motors) 252, the two sub-actuators 252 may be respectively connected to the first end portion and the second end portion of the center rod 254 and may move the first end portion and the second end portion of the center rod 254 perpendicular to the receiving direction of the glass ribbon. The first sub-actuator and the second sub-actuator may move the first end portion and the second end portion of the center rod 254 perpendicular to the receiving direction of the glass ribbon toward the first surface of the glass ribbon 210 during the bending of the glass ribbon 210 and may make different displacements of the first end portion and the second end portion of the center rod 254, respectively. This separate movement of the first end portion and the second end portion of the center rod 254 allows different levels of stress to be applied to the first end portion and the second end portion of the glass ribbon 210 along a predetermined cutting path, respectively.

[0055] Referring to Figure 2 , Figure 4A andFigure 4B Among them, at least two clamping rods 255 and 256, the first clamping rod 255 can be located in front of the center rod 254 in the receiving direction D1 of the glass ribbon 210. The second clamping rod 256 among the at least two clamping rods 255 and 256 can be located behind the center rod 254 in the receiving direction D1 of the glass ribbon 210. Figure 4A It shows that the center rod 254 moves in the direction D2 from the second surface to the first surface of the glass ribbon 210 to contact the second surface of the glass ribbon 210, and the clamping rods 255 and 256 move in the direction from the first surface to the second surface of the glass ribbon 210 to contact the first surface of the glass ribbon 210. In Figure 4A the displacement (d) of the glass ribbon 210 towards the clamping rods 255 and 256 in the direction D2 will be 0 mm.

[0056] Referring to FIG. 4b, when the actuator 252 performs a first bend on the glass ribbon 210, the actuator 252 can apply a first average stress to the glass ribbon 210 by moving the center rod 254 a first average displacement in the direction D2, such that the glass ribbon bends a first average displacement in the direction D2 from the second surface to the first surface from the position where the glass ribbon 210 is received. When the actuator 252 performs a second bend on the glass ribbon 210, the actuator 252 can apply a second average stress to the glass ribbon 210 by moving the center rod 254 a second average displacement, such that the glass ribbon bends a second average displacement in the direction D2 from the second surface to the first surface from the position where the glass ribbon 210 is received. The second average displacement can be greater than the first average displacement. Referring to FIG. 4b, the displacement (d) can affect the stress applied for the bending of the glass ribbon 210. Therefore, when the displacement (d) is too small, the crack may not fully expand. When the displacement (d) is too large, multiple cracks can be generated in the glass ribbon 210, specifically in its weld bead.

[0057] The overhang (the distance between the center of the first clamping rod 255 and the center of the second clamping rod 256) is indicated by OH in Figure 4A and Figure 4B As the overhang increases, the process window with process tolerances can become wider. However, as the overhang decreases, the curvature of the bent portion of the glass ribbon 210 is affected during bending, and the stress applied to the glass ribbon 210 increases.

[0058] According to some embodiments, the scribing device 253 can include at least one of, for example, a cutting wheel or a laser device, but the present disclosure is not limited thereto, and any device capable of creating a scribe mark on the glass ribbon 210 can thus be used. Additionally, the scribing device 253 can be connected to another actuator (e.g., a servo motor) to move the scribing device along a predetermined cutting path of the glass ribbon 210 to another position.

[0059] Figure 5It is a schematic diagram showing a cutting pattern according to a change in the displacement of opposite end portions of the center rod 254 in the direction D2 during primary bending and secondary bending in a method of manufacturing a glass sheet from a glass ribbon. Refer to Figure 5 (a) of, according to some embodiments, during primary bending, the center rod 254 can be moved to have a displacement d of the first end portion of the center rod 254 F and a displacement d of the second end portion of the center rod 254 R , where the displacement d F is less than the displacement d R , so as to press the glass ribbon 210 forward asymmetrically in the direction D2 toward the clamping rods 255 and 256. Therefore, in this case, the stress applied to the first end portion of the first end portion of the center rod 254 in contact with the predetermined cutting path of the glass ribbon 210 can be less than the stress applied to the second end portion of the second end portion of the center rod 254 in contact with the predetermined cutting path of the glass ribbon 210.

[0060] Furthermore, referring to Figure 5 (b) of, during secondary bending after scribing, conversely, the displacement d F ' of the first end portion of the center rod 254 can be set to be greater than the displacement d R ' of the second end portion, such that the center rod 254 presses the glass ribbon 210 forward asymmetrically in the direction D2 toward the clamping rods 255 and 256. Therefore, in this case, the stress applied to the first end portion of the predetermined cutting path of the glass ribbon 210 can be greater than the stress applied to its second end portion. According to the configuration as described above, compared with the corresponding first end of the first end portion of the center rod 254 in contact with the glass ribbon, a smaller stress is applied to the corresponding second end of the second end portion of the center rod 254 in contact with the glass ribbon along the predetermined cutting path. In this case, the internal stress applied to the bead of the second end portion of the glass ribbon can be reduced, thereby minimizing the multiple cracks generated on the second bead of the glass ribbon.

[0061] For example, during primary bending, when the displacement d F of the front end portion of the center rod 254 is set to 0.8 mm and the displacement d R of the rear end portion of the center rod 254 is set to 1.2 mm, the center rod 254 can press the glass ribbon 210 in the direction D2. During secondary bending, when the displacement H 1F ' of the front end portion of the center rod 254 is set to 2.8 mm and the displacement H 1R ' of the rear end portion of the center rod 254 is set to 1.2 mm, the center rod 254 can press the glass ribbon 210 in the direction D2.

[0062] Figure 6 is a view showing the stress distribution of the glass ribbon 210 when performing a single bend on the glass ribbon 210 according to the present disclosure. In Figure 6 , during a single bend, the stress applied to the beads 212 and 216 at the edges of the glass ribbon 210 is greater than the stress applied to the mass region 214 which is the middle part of the glass ribbon 210.

[0063] Figure 6 shows the stress distribution according to some embodiments when applying an asymmetric stress by applying a greater stress to the bead portion 216 at the other end portion of the glass ribbon compared to the bead 212 at one end portion of the bent portion of the glass ribbon 210 during a single bend. Accordingly, the bead portion at the other end portion of the glass ribbon shows the maximum stress ST max .

[0064] Figure 7 is a view showing that the radius of curvature R of the bent portion of the glass ribbon 210 changes according to the overhang amount OH in the cutting unit 250 according to the present disclosure. In Figure 7 , according to some embodiments, the displacements of the center rod 254 and the clamping rods 255 and 256 are set to the same conditions in (a) and (b), and only the overhang amount between the first clamping rod 255 and the second clamping rod 256 is set to 40 mm in (a) and 30 mm in (b), respectively. Then, the radius of curvature R of the bent portion of the glass ribbon 210 becomes R1 = 192.5 mm (a) and R2 = 105 mm (b), in which case the bending level of (b) is greater than that of (a). Accordingly, as the overhang amount decreases, the applied stress increases. In contrast, as the overhang amount increases, the process window (the tolerance range of the process) regarding the change in the thickness of the glass ribbon can be widened.

[0065] However, since the overhang amount OH affects the curvature of the bent portion of the glass ribbon 210 during bending, thereby affecting the stress applied to the bent portion of the glass ribbon 210. Refer to Figure 6 and Figure 7, when the overhang OH increases by more than 40 mm, the quality region 214 between the beads (212, 216) at the two edges in the width direction of the glass ribbon 210 does not receive sufficient stress to propagate the crack. Therefore, the overhang OH can be in the range of 0 mm to 40 mm, in the range of 10 mm to 40 mm, in the range of 20 mm to 40 mm, in the range of 28 mm to 40 mm, or in the range of 32 mm to 40 mm. By way of example, when the thickness of the glass ribbon 210 is 75 micrometers (μm), the widest process window can be obtained when the overhang (OH) is in the range of 28 mm to 40 mm. When the thickness of the glass ribbon is 100 μm, the widest process window can be obtained when the overhang (OH) is in the range of 32 mm to 40 mm.

[0066] Figure 8 is a schematic flowchart of a method for manufacturing a glass sheet from a glass ribbon according to the present disclosure. According to some embodiments, the method for manufacturing a glass sheet from a glass ribbon may include: in operation S810, providing a glass ribbon 210 to a singulation device 250; performing a first bending S820 on the glass ribbon 210 along its predetermined cutting path by applying a first average stress to the glass ribbon 210; using a scribing device 253 to scribe at least one point of the bent portion of the glass ribbon 210 S830; and performing a second bending S840 on the glass ribbon by applying a second average stress to the bent portion of the glass ribbon 210.

[0067] The second average stress may be greater than the first average stress. The method may further include: cutting the second bent portion of the glass ribbon 210 S850. Refer to Figure 2 and Figure 8 , in operation S810, the glass ribbon 210 may be provided from a reel unwind machine 220 to the singulation device 250 by guiding rollers 230, and during the cutting process, the position and tension of the glass ribbon 210 may be maintained. In this state, the glass ribbon 210 is provided into the space between a center rod 254 and at least two clamping rods 255 and 256.

[0068] In operation S820, the center rod 254 is set to have a first average displacement H 11 , and presses the glass ribbon 210 toward the clamping rods 255 and 256, thereby applying stress to the glass ribbon and performing a first bending. According to some embodiments, in operation S820, during the first bending, the center rod 254 may apply stress for bending to one end portion (e.g., the front end portion) of the predetermined cutting path of the glass ribbon 210, and the stress is less than the stress applied to the other end portion (e.g., the rear end portion) of the predetermined cutting path.

[0069] In operation S830, a scribing device 253 can be used to scribe at least one point on the bent portion of the glass ribbon 210. For example, at least one of a cutting wheel or a laser device can be used as the scribing device 253, but the present disclosure is not limited thereto. For example, at least one of a cutting wheel or a laser device can be used as the scribing device 253, but the present disclosure is not limited thereto.

[0070] In operation S840, the center rod 254 moves a second average displacement and presses the glass ribbon 210 toward the clamping rods 255 and 256, thereby applying stress to the glass ribbon, and thus performing secondary bending. According to some embodiments, in operation S840, during secondary bending, the center rod 254 can apply stress for bending to one end portion (e.g., the front end portion) of a predetermined cutting path of the glass ribbon 210, and the stress is greater than the stress applied to the other end portion (e.g., the rear end portion) of the predetermined cutting path. During secondary bending, a crack can extend from a weld bead at one end portion of the predetermined cutting path of the glass ribbon 210 to another weld bead portion at the other end portion. Then, in operation S850, cutting along the predetermined cutting path of the glass ribbon 210 can be performed. During operation S850, the glass ribbon 210 can be cut along the predetermined cutting path by applying a stress greater than the stress applied to the glass ribbon 210 during operation S840 for secondary bending of the glass ribbon 210 through the center rod 254.

[0071] Figure 9 is a graph schematically showing a crack propagation mode of the average displacement H1 set during primary bending on the Y-axis and secondary bending on the X-axis in a method of manufacturing a glass sheet from a glass ribbon according to the center rod 254. Figure 9 Shows the results of the crack propagation mode with respect to the coordinates of the Y-axis indicating the displacement of the center rod during primary bending and the X-axis indicating the displacement of the center rod during secondary bending for a glass ribbon having a thickness of 100 μm in the quality region in the middle of the glass ribbon. In Figure 9 the case, cracks start to occur when the displacement d of the center rod on the Y-axis during primary bending is about 0.8 mm. However, since multiple cracks M.C. may also occur, a displacement d of about 1.0 mm or more may be appropriate.

[0072] In addition, when the displacement d of the center rod on the Y-axis during primary bending exceeds 1.4 mm, cracks initiate without secondary bending, so a displacement d of 1.4 mm or less may be appropriate. In addition, it can be seen that the displacement d of the center rod on the X-axis during secondary bending can be 0.8 mm or more, at which time the generation of cracks stops, and it may be appropriate to set the displacement to 1.8 mm or less, at which time multiple cracks occur.

[0073] Figure 10It is a graph showing the correlation of the tensile stress σ generated in each of two glass ribbons with thicknesses of 75 μm and 100 μm according to the displacement of the center rod 254 when a bending stress is applied to each of the glass ribbons. Figure 10 The figure of Figure 10 shows different stresses generated in the bead at both side edge portions of each of the two glass ribbons and in the quality region 214 which is the middle portion between the beads 212 and 216. In the singulation device 250 according to some embodiments, when the glass ribbon with a thickness of 75 μm is pressed and bent with the average displacement d of the center rod 254 set to 1 mm, the maximum bending stress σ max of the quality region as the middle portion is 20.0 Mpa, and the maximum bending stress σ max of the bead region is 60.0 Mpa. Further, when the glass ribbon with a thickness of 100 μm is pressed and bent with the average displacement d a of the center rod 254 set to 0.75 mm, the maximum bending stress σ max of the quality region as the middle portion is 20.0 Mpa, and the maximum bending stress σ max of the bead region is 60.0 Mpa.

[0074] It can be seen that when the bending stress σ max applied to the quality region of the glass ribbon exceeds 20.0 Mpa (in this case, the maximum bending stress σ max of the bead region can be 60.0 Mpa), cracks initiate and begin to propagate along a predetermined cutting path transverse to the receiving direction of the glass ribbon 210. In this state, the average displacement of the center rod 254 on the graph is between about 0.75 mm and about 1 mm.

[0075] Further, when the bending stress σ max applied to the bead region of the glass ribbon is greater than 100 Mpa, multiple cracks and multiple notches can be generated in the bead region. Therefore, it can be seen that in order to prevent the generation of multiple cracks and notches and the propagation of cracks by generating an appropriate tensile stress σ in the bead region of the glass ribbon, a stress of about 60 MPa to about 100 MPa is applied to the bead region.

[0076] The range of the average displacement d a of the center rod 254 for applying the bending stress corresponding to the average displacement d a is about 1 mm to about 1.7 mm for the glass ribbon with a thickness of 75 μm, and about 0.75 mm to about 1.25 mm for the glass ribbon with a thickness of 100 μm.

[0077] According to Figure 8In the method of manufacturing a glass sheet from a glass ribbon, during at least one of a first bending operation S820 and a second bending operation S840, the internal stress generated in the weld bead 212 of the glass ribbon is in the range of about 60 Mpa to about 100 Mpa.

[0078] When manufacturing a glass sheet from a glass ribbon according to the present disclosure, a glass sheet without multiple cracks can be manufactured with a high yield and at low cost through a simplified and efficient process.

[0079] Although one or more embodiments have been described with reference to the drawings, those of ordinary skill in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims.

Claims

1. An apparatus for manufacturing glass sheets from a glass ribbon, the apparatus comprising: a roller; an actuator positioned behind the roller in the receiving direction of the glass ribbon from the roller, the actuator being configured to receive the glass ribbon from the roller, bend the glass ribbon along a predetermined cutting path transverse to the receiving direction of the glass ribbon by applying a first average stress to the glass ribbon, and further bend the bent portion of the glass ribbon by applying a second average stress to the glass ribbon after scribing the glass ribbon; and a scribing device positioned near a first surface of the glass ribbon at the actuator and configured to scribe at least one point of the first surface of the bent portion of the glass ribbon; wherein the second average stress is greater than the first average stress.

2. The apparatus according to claim 1, wherein the actuator comprises a central rod positioned near a second surface of the glass ribbon and at least two clamping rods positioned near the first surface of the glass ribbon, the second surface of the glass ribbon being opposite to the first surface of the glass ribbon; wherein when bending the glass ribbon, the actuator applies the first average stress to the glass ribbon by moving the central rod a first average displacement such that the glass ribbon bends the first average displacement from the position of the glass ribbon in a direction from the second surface to the first surface; wherein when further bending the bent portion of the glass ribbon, the actuator applies the second average stress to the bent portion of the glass ribbon by moving the central rod a second average displacement such that the glass ribbon bends the second average displacement from the position of the glass ribbon in the direction from the second surface to the first surface; and wherein the second average displacement is greater than the first average displacement.

3. The apparatus according to claim 2, wherein a first clamping rod of the at least two clamping rods is positioned in front of the central rod in the receiving direction of the glass ribbon at the actuator, and a second clamping rod of the at least two clamping rods is positioned behind the central rod in the receiving direction of the glass ribbon at the actuator; wherein when bending the glass ribbon, the central rod moves perpendicular to the receiving direction of the glass ribbon towards the first surface of the glass ribbon to contact and press a predetermined cutting path of the second surface of the glass ribbon such that the glass ribbon bends the first average displacement from the position of the glass ribbon towards the first surface, and the at least two clamping rods move perpendicular to the receiving direction of the glass ribbon towards the second surface of the glass ribbon to hold the glass ribbon; and When the bent portion of the glass ribbon is further bent, the center rod moves perpendicular to the receiving direction of the glass ribbon toward the first surface of the glass ribbon to press a predetermined cutting path on the second surface of the glass ribbon, such that the glass ribbon bends a second average displacement from the position of the glass ribbon toward the first surface.

4. The apparatus according to claim 1, wherein when the glass ribbon is bent along the predetermined cutting path, the actuator applies a smaller stress to a first end of the predetermined cutting path than to a second end of the predetermined cutting path.

5. The apparatus according to claim 4, wherein when the bent portion of the glass ribbon is further bent, the actuator applies a greater stress to a first end of the predetermined cutting path of the glass ribbon than to a second end of the predetermined cutting path of the glass ribbon.

6. The apparatus according to claim 2 or 3, wherein when the glass ribbon is bent, a first end of the center rod in a direction transverse to the receiving direction of the glass ribbon has a smaller displacement in a direction from the second surface to the first surface than a second end of the center rod.

7. The apparatus according to claim 6, wherein when the bent portion of the glass ribbon is further bent, the first end of the center rod in the direction transverse to the receiving direction of the glass ribbon has a greater displacement in a direction from the second surface to the first surface than the second end of the center rod.

8. The apparatus according to claim 1, wherein at least one point to be scribed by the scribing device on the first surface of the bent portion is located at an end of a predetermined cutting path on the first surface of the glass ribbon.

9. The apparatus according to claim 3, wherein a distance between a center of the first clamping rod and a center of the second clamping rod is greater than 0 mm but less than or equal to 40 mm.

10. The apparatus according to claim 1, wherein the scribing device includes at least one of a cutting wheel or a laser device.

11. A method of manufacturing glass sheets from a glass ribbon, the method comprising: bending the glass ribbon along a predetermined cutting path by applying a first average stress to the glass ribbon using a singulation device; scribing at least one point of a bent portion of the glass ribbon using a scribing device; and further bending the bent portion of the glass ribbon by applying a second average stress to the glass ribbon using the singulation device, wherein the second average stress is greater than the first average stress.

12. The method according to claim 11, wherein the singulation device includes an actuator, the actuator including a center rod positioned near a second surface of the glass ribbon and at least two clamping rods positioned near a first surface of the glass ribbon, the second surface of the glass ribbon being opposite the first surface of the glass ribbon; Bending the glass ribbon along the predetermined cutting path includes applying the first average stress to the glass ribbon by moving the center rod a first average displacement such that the glass ribbon bends the first average displacement from its position in a direction from the second surface to the first surface; Further bending of the bent portion of the glass ribbon includes applying the second average stress to the bent portion of the glass ribbon by moving the center rod a second average displacement such that the glass ribbon bends the second average displacement from its position in the direction from the second surface to the first surface; And wherein the second average displacement is greater than the first average displacement.

13. The method according to claim 12, wherein a first clamping rod of the at least two clamping rods is located in front of the center rod in the receiving direction of the glass ribbon at the actuator, and a second clamping rod of the at least two clamping rods is located behind the center rod in the receiving direction of the glass ribbon at the actuator; Bending the glass ribbon includes applying the first average stress to the glass ribbon by moving the center rod perpendicular to the receiving direction of the glass ribbon towards the first surface of the glass ribbon to contact and press a predetermined cutting path on the second surface of the glass ribbon such that the glass ribbon bends a first average displacement from its position towards the first surface; Further bending of the bent portion of the glass ribbon includes applying the second average stress to the bent portion of the glass ribbon by moving the center rod perpendicular to the receiving direction of the glass ribbon towards the first surface of the glass ribbon to press a predetermined cutting path on the second surface of the glass ribbon such that the glass ribbon bends a second average displacement from its position towards the first surface.

14. The method according to claim 11, wherein bending the glass ribbon along the predetermined cutting path includes applying a smaller stress to a first end of the predetermined cutting path of the glass ribbon compared to a second end of the predetermined cutting path of the glass ribbon.

15. The method according to claim 14, wherein further bending of the bent portion of the glass ribbon includes applying a greater stress to the first end of the predetermined cutting path of the glass ribbon compared to the second end of the predetermined cutting path of the glass ribbon.

16. The method according to claim 12 or 13, wherein when bending the glass ribbon, a first end of the center rod in a direction transverse to the receiving direction of the glass ribbon has a smaller displacement compared to a second end of the center rod in a direction from the second surface to the first surface.

17. The method according to claim 16, wherein when further bending the bent portion of the glass ribbon, the first end of the center rod in the direction transverse to the receiving direction of the glass ribbon has a greater displacement in the direction from the second surface to the first surface than the second end of the center rod.

18. The method according to claim 11, wherein at least one point to be scribed by the scribing device of the bent portion is located at one end of a predetermined cutting path on the first surface of the glass ribbon.

19. The method according to claim 11, wherein at least one of bending the glass ribbon and further bending the bent portion of the glass ribbon includes generating an internal stress of at least 60 Mpa but less than 100 Mpa in the bead region of the glass ribbon.

20. The method according to claim 13, wherein the distance between the center of the first clamping rod and the center of the second clamping rod is greater than 0 mm but less than or equal to 40 mm.

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