WO2021183291A1

WO2021183291A1 - Systems and methods for separating glass substrates

Info

Publication number: WO2021183291A1
Application number: PCT/US2021/019541
Authority: WO
Inventors: Hsin-Lin CHEN; Chih-Chin PENG; Yichun Wang
Original assignee: Corning Incorporated
Priority date: 2020-03-12
Filing date: 2021-02-25
Publication date: 2021-09-16
Also published as: KR20220152305A; CN115427364A; TW202206384A; JP2023516498A

Abstract

A method for separating a glass sheet includes engaging a first surface of a glass sheet with a scribing wheel, the glass sheet defining the first surface and a sheet thickness, moving the scribing wheel along the glass sheet at a scribing speed of at least 35 meters per minute, applying a force on the glass sheet with the scribing wheel, maintaining the force within 1.0 Newtons of a predetermined force, and forming, with the scribing wheel, a median crack extending along a length of the first surface and extending into the glass sheet, the median crack defining a crack depth extending into the glass sheet, where the crack depth extending into the glass sheet varies less than 2.0% along the length of the median crack on the first surface.

Description

SYSTEMS AND METHODS FOR SEPARATING GLASS SUBSTRATES

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 62/988,606, filed on March 12, 2020, the content of which is relied upon and incorporated herein by reference in its entirety.

BACKGROUND

Field

[0002] The present specification generally relates to methods and systems for separating glass substrates, and in particular, methods and systems for forming a median crack in a glass substrate.

Technical Background

[0001] Thin, flexible glass substrates can be used in various applications, including so-called “e-paper,” color filters, photovoltaic cells, displays, OLED lighting, and touch sensors. The glass for such substrates can be quite thin. The processing of the substrates can be performed on an individual glass sheet basis, or by conveying the substrate as a long glass web, which can be wound on a roll or spool. In either instance, individual glass sheets or discrete portions of the glass web may be cut into glass sheets for further processing or for preparation for installation to a final product.

SUMMARY

[0002] To cut the glass sheets or glass web, the glass sheets or glass web may be scored, for example with a scribing wheel, forming a crack along the glass sheet or glass web. Tensile force may then be applied to the glass sheet or web to separate the glass sheet or glass web along the crack. Variability in crack depth may result in undesirable separation and/or breakage of the glass sheet or glass web, thereby increasing defects and manufacturing costs. Accordingly, it is desirable to maintain consistent crack depth, and there is a need for apparatuses and methods for forming consistent median cracks in glass sheets to facilitate desirable separation along the median cracks.

[0003] In a first aspect Al, a method for separating a glass sheet according to the present disclosure includes engaging a first surface of a glass sheet with a scribing wheel, the glass sheet including a second surface opposite the first surface, and a sheet thickness between the first surface and the second surface, moving the scribing wheel along the first surface of the glass sheet at a scribing speed of at least about 35 meters per minute, applying and maintaining, with the scribing wheel, a force on the first surface of the glass sheet that is within about 1.0 Newtons of a predetermined force as the scribing wheel moves along the first surface of the glass sheet, and forming, with the scribing wheel, a median crack extending along a length of the first surface and extending into the glass sheet, the median crack defining a crack depth extending into the glass sheet that is less than the sheet thickness and varies less than about 2.0% along the length of the median crack on the first surface.

[0004] In a second aspect A2, the present disclosure provides the method aspect Al, where applying the force includes maintaining a position of the scribing wheel in a first direction transverse to the first surface of the glass sheet with an air cylinder coupled to the scribing wheel.

[0005] In a third aspect A3, the present disclosure provides the method of aspect A2, further including restricting movement of a rod of the air cylinder with a linear motion guide rail engaged with the rod of the air cylinder, where the linear motion guide rail permits movement of the rod in the first direction and restricts movement of the rod in a direction transverse to the first direction.

[0006] In a fourth aspect A4, the present disclosure provides the method of either of aspects A2 or A3, where applying the force includes maintaining the position of the scribing wheel in the first direction with a first actuator coupled to the scribing wheel through the air cylinder.

[0007] In a fifth aspect A5, the present disclosure provides the method of any of aspects Al- A4, where the crack depth of the median crack varies less than about 1.5% along the length of the median crack on the first surface. [0008] In a sixth aspect A6, the present disclosure provides the method of any of aspects Al- A5, where the crack depth of the median crack varies less than about 1.0% along the length of the median crack on the first surface.

[0009] In a seventh aspect A7, the present disclosure provides the method of any of aspects A1-A6, where the scribing speed is at least about 40 meters per minute.

[0010] In an eighth aspect A8, the present disclosure provides the method of any of aspects A1-A7, where the scribing speed is at least about 45 meters per minute.

[0011] In a ninth aspect A9, the present disclosure provides the method of any of aspects Al- A8, where the crack depth varies less than about 5 micrometers along the length of the median crack on the first surface.

[0012] In a tenth aspect A10, the present disclosure provides the method of any of aspects Al- A9, where the sheet thickness is less than about 0.5 millimeters.

[0013] In an eleventh aspect A11, the present disclosure provides the method of any of aspects A1-A9, where the sheet thickness is about 0.30 millimeters.

[0014] In a twelfth aspect A12, the present disclosure provides the method of any of aspects Al-Al 1, where applying the force on the first surface of the glass sheet with the scribing wheel further includes maintaining the force within about 0.2 Newtons of the predetermined force.

[0015] In a thirteenth aspect A13, the present disclosure provides a glass cutting system including a scribing wheel, a regulator, an air cylinder coupled to the scribing wheel and in communication with the regulator, a second actuator coupled to the air cylinder, and a controller communicatively coupled to the regulator and the second actuator, the controller including a processor and a memory including a computer readable and executable instruction set, which, when executed by the processor, causes the processor to direct the regulator to apply and maintain a force on a first surface of a glass sheet with the scribing wheel within about 1.0 Newtons of a predetermined force with the air cylinder, and direct the second actuator to move the scribing wheel along the glass sheet at a scribing speed of at least about 35 meters per minute, thereby forming a median crack extending along a length of the first surface and extending into the glass sheet, the median crack defining a crack depth extending into the glass sheet that is less than a sheet thickness of the glass sheet and varies less than about 5 micrometers along the length of the median crack on the first surface.

[0016] In a fourteenth aspect A14, the present disclosure provides the system of aspect A13, further including a first actuator coupled to the air cylinder.

[0017] In a fifteenth aspect A15, the present disclosure provides the system of aspect A14, where the first actuator is communicatively coupled to the controller, and where the computer readable and executable instruction set, when executed by the processor, further causes the processor to direct the first actuator to move the air cylinder toward the first surface of the glass sheet.

[0018] In a sixteenth aspect A16, the present disclosure provides the system of any of aspects A13-A15, further including a linear motion guide rail engaged with a rod of the air cylinder, where the linear motion guide rail permits movement of the rod in a first direction and restricts movement of the rod in a direction transverse to the first direction.

[0019] In a seventeenth aspect A17, the present disclosure provides the system of any of aspects A13-A16, where the computer readable and executable instruction set, when executed by the processor, causes the processor to direct the second actuator to move the scribing wheel along the glass sheet at a scribing speed of at least about 40 meters per minute.

[0020] In an eighteenth aspect A18, the present disclosure provides the system of any of aspects A13-A17, where the computer readable and executable instruction set, when executed by the processor, further causes the processor to direct the regulator to apply and maintain the force on the first surface of the glass sheet with the scribing wheel within about 0.2 Newtons of the predetermined force with the air cylinder.

[0021] In a nineteenth aspect A19, the present disclosure provides the system of any of aspects A13-A18, where the crack depth of the median crack varies less than about 1.5% along the length of the median crack on the first surface.

[0022] In a twentieth aspect A20, the present disclosure provides the system of any of aspects A13-A19, where applying the force on the first surface of the glass sheet with the scribing wheel includes maintaining the force within about 0.2 Newtons of the predetermined force. [0023] Additional features and advantages of the embodiments will be set forth in the detailed description that follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description that follows, the claims, as well as the appended drawings.

[0024] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 schematically depicts a perspective view of a glass cutting system, according to one or more embodiments shown or described herein;

[0026] FIG. 2 schematically depicts a control diagram of the glass cutting system of FIG. 1, according to one or more embodiments shown or described herein;

[0027] FIG. 3 schematically depicts the glass cutting system of FIG. 1 and a glass sheet, according to one or more embodiments shown or described herein;

[0028] FIG. 4 schematically depicts the glass sheet of FIG. 3 with a median crack extending into the glass sheet, according to one or more embodiments shown or described herein;

[0029] FIG. 5 A schematically depicts a perspective view of the glass sheet of FIG. 4 and the median crack, according to one or more embodiments shown or described herein;

[0030] FIG. 5B schematically depicts a glass sheet with an uneven median crack; and

[0031] FIG. 5C schematically depicts another glass sheet with an uneven median crack. DETAILED DESCRIPTION

[0032] Reference will now be made in detail to embodiments of apparatuses and methods for separating glass sheets. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. Glass cutting systems according to embodiments described herein generally include a scribing wheel and an air cylinder that maintains a position of the scribing wheel in a first direction transverse to a glass sheet. In particular, the air cylinder may maintain the position of the scribing wheel in the first direction such that the scribing wheel can maintain a constant or nearly constant force on a glass sheet to form a median crack in the glass sheet. By maintaining a constant or nearly constant force on the glass sheet, variation of a crack depth of the median crack can be minimized. By minimizing variation in the crack depth, undesirable and/or unpredictable separation of the glass sheet along the median crack can be minimized, thereby reducing scrap and reducing manufacturing costs. These and other embodiments will be described in more detail herein with specific reference to the appended drawings.

[0033] The phrase “communicatively coupled” is used herein to describe the interconnectivity of various components of the glass cutting system and means that the components are connected either through wires, optical fibers, or wirelessly such that electrical, optical, and/or electromagnetic signals may be exchanged between the components.

[0034] Referring now to FIG. 1, an example glass cutting system 100 is schematically depicted. In embodiments, the glass cutting system 100 generally includes a cutting device, depicted as a scribing wheel 140. The glass cutting system 100 is operable to move the scribing wheel 140 in a first direction (/. ., in the y-direction as depicted) toward or away from a glass sheet, as described in greater detail herein. The glass cutting system 100 is also operable to move the scribing wheel 140 in at least a second direction (/. ., in the x-direction as depicted), and/or in a third direction (/. ., in the z-direction as depicted) that are transverse to the first direction. In embodiments, the scribing wheel 140 includes a wheel with an appropriately selected geometry to initiate controlled mechanical damage to a glass sheet. The scribing wheel 140 may include an abrasive scoring wheel such as a serrated scoring wheel, a diamond scoring wheel, or the like. [0035] In the embodiment depicted in FIG. 1, the glass cutting system 100 can include an air cylinder 120 coupled to the scribing wheel 140. The air cylinder 120 may generally include a body 122 and a rod 124 that is movably engaged with the body 122. In particular, the rod 124 may be extended outward from the body 122, or drawn toward the body 122, moving the rod 124. In embodiments, the air cylinder 120 is in communication with a regulator 115 that can regulate a pressure of air supplied to the air cylinder 120. By regulating the pressure of air supplied to the air cylinder 120, the rod 124 can be moved with respect to the body 122 and a position of the rod 124 with respect to the body 122 can be maintained, for example, in the first direction. As the scribing wheel 140 is coupled to the rod 124, a position of the scribing wheel 140 in the first direction can be maintained by maintaining a position of the rod 124 with respect to the body 122 via the regulator 115. The air cylinder 120 and the regulator 115 may assist in maintaining a position of the scribing wheel 140 to apply force to a glass sheet with the scribing wheel 140, as described in greater detail herein.

[0036] In some embodiments, the glass cutting system 100 may include one or more sensors that detect a position of the scribing wheel 140. For example, in the embodiment depicted in FIG. 1, the glass cutting system 100 includes a displacement sensor 117 that is structurally configured to detect a position of the cutting wheel 140 in the first direction (/. ., in the y- direction as depicted). While in the embodiment depicted in FIG. 1 the glass cutting system 100 includes the displacement sensor 117, it should be understood that the glass cutting system 100 may include any suitable sensor for detecting a position of the cutting wheel 140 in the first direction, for example and without limitation, a hall effect sensor, an eddy-current sensor, an inductive sensor, a laser sensor, a piezo-electric transducer, or the like.

[0037] In some embodiments, the glass cutting system 100 can include a linear motion guide rail 130 engaged with the rod 124 of the air cylinder 120. The linear motion guide rail 130 generally permits movement of the rod 124 in the first direction (/. ., in the y-direction as depicted), while restricting movement of the rod 124 in directions transverse to the first direction, such as the second and/or the third directions (i.e., in the x-direction and the z- direction as depicted, respectively). By restricting movement of the rod 124 in directions transverse to the first direction, the linear motion guide rail 130 may assist in minimizing movement of the scribing wheel 140 in other directions, such as the second and the third directions (i.e., in the x-direction and the z-direction as depicted, respectively) as the scribing wheel 140 moves along a glass sheet, as described in greater detail herein.

[0038] In some embodiments, the air cylinder 120 can be coupled to a first actuator 110 that is operable to move the air cylinder 120 toward or away from a glass sheet. For example, in the embodiment depicted in FIG. 1, the air cylinder 120 can be coupled to a cylinder plate 114, which can be coupled to an actuator plate 112. The actuator plate 112, in embodiments, can be engaged with a first guide 116 and is movable along the first guide 116. The first actuator 110 is coupled to the actuator plate 112 and is generally operable to move the actuator plate 112, and accordingly the cylinder plate 114 and the air cylinder 120. By moving the air cylinder 120 in the first direction (i.e., in the y-direction as depicted), the first actuator 110 may position the air cylinder 120, and accordingly the scribing wheel 140 on a glass sheet. For example, the first actuator 110 may operate to move the scribing wheel 140 to engage a glass sheet, while the air cylinder 120 may assist in maintaining contact between the scribing wheel 140 and the glass sheet as the scribing wheel 140 moves along the glass sheet. For example, the air cylinder 120 may allow the scribing wheel 140 to move in the first direction (i.e., in the y-direction as depicted) to accommodate variations of the glass sheet in the first direction, such that contact between the scribing wheel 140 and the glass sheet is maintained as the scribing wheel 140 moves along the glass sheet.

[0039] In embodiments, the first actuator 110 may include any actuator suitable to move the air cylinder 120, such as and without limitation, a direct current (DC) motor, an alternating current (AC) motor, or the like, and may be a servomotor including a positional encoder. While in the embodiment depicted in FIG. 1, the glass cutting system 100 includes the actuator plate 112 and the cylinder plate 114, this is merely an example. In embodiments, the first actuator 110 may be coupled to the air cylinder 120 in any suitable manner that allows the first actuator

110 to move the air cylinder 120, and accordingly the scribing wheel 140.

[0040] In some embodiments, the glass cutting system 100 further includes one or more linear actuators that are operable to move the air cylinder 120 and accordingly the scribing wheel 140 in the second and the third directions (i.e., in the x-direction and the y-direction, respectively). In the embodiment depicted in FIG. 1, the glass cutting system 100 includes a second actuator

111 coupled to the air cylinder 120 and/or the first actuator 110. The second actuator 111 is operable to move the air cylinder 120, and accordingly the scribing wheel 140, in at least the second direction (/. ., in the x-direction as depicted). In some embodiments, the glass cutting system 100 further includes a third actuator 113 that is operable to move the air cylinder 120 and accordingly the scribing wheel 140 in the third direction ( i.e ., in the z-direction as depicted). The second and third actuators 111, 113 may include any suitable actuator to move the air cylinder 120, and accordingly the scribing wheel 140. For example and without limitation the second and third actuators 111, 113 may each be linear actuators including a DC motor, an AC motor, or the like, and may each be a servomotor including a positional encoder. In the embodiment depicted in FIG. 1, the second and third actuators 111, 113 are coupled to the air cylinder 120 through the actuator plate 112 and the cylinder plate 114, however, this is merely an example. In embodiments, the second and third actuators 111, 113 may be coupled to the air cylinder 120 in any suitable manner to move the air cylinder 120 and the scribing wheel 140.

[0041] Referring to FIG. 2, a control diagram of the glass cutting system 100 is schematically depicted. In embodiments, the glass cutting system 100 includes a controller 160 including a processor 162, a data storage component 164, and/or a memory component 166. The memory component 166 may be configured as volatile and/or nonvolatile memory and as such, may include random access memory (including SRAM, DRAM, and/or other types of RAM), flash memory, secure digital (SD) memory, registers, compact discs (CD), digital versatile discs (DVD), and/or other types of non-transitory computer-readable mediums. Depending on the particular embodiment, these non-transitory computer-readable mediums may reside within the controller 160 and/or external to the controller 160.

[0042] The memory component 166 may store operating logic, analysis logic, and communication logic in the form of one or more computer-readable and executable instruction sets. The analysis logic and the communication logic may each include a plurality of different pieces of logic, each of which may be embodied as a computer program, firmware, and/or hardware, as an example. A local interface is also included in the controller 160 and may be implemented as a bus or other communication interface to facilitate communication among the components of the controller 160.

[0043] The processor 162 may include any processing component operable to receive and execute instructions (such as from a data storage component 164 and/or the memory component 166). While the components in FIG. 2 are illustrated as residing within the controller 160, this is merely an example, and in some embodiments, one or more of the components may reside external to the controller 160. Additionally, while the controller 160 is illustrated as a single device, this is also merely an example, and the controller 160 may include any suitable number of devices.

[0044] In embodiments, the controller 160 is communicatively coupled to one or more components of the glass cutting system 100. For example, in the embodiment depicted in FIG. 2, the controller 160 is communicatively coupled to the first actuator 110, the second actuator 111, the third actuator 113, and the regulator 115. In embodiments, the controller 160 may direct the first actuator 110, the second actuator 111, the third actuator 113, and the air cylinder 120 (via the regulator 115) to move such that the glass cutting system 100 forms a crack in a glass sheet, as described in greater detail herein.

[0045] For example, and referring to FIG. 3, a side view of the glass cutting system 100 and a glass sheet 200 is schematically depicted. In the embodiment depicted in FIG. 3, the glass sheet 200 defines a first edge 206 and a second edge 208 positioned opposite the first edge 206. While in the embodiment depicted in FIG. 3 the glass sheet 200 is a discrete sheet that defines the first edge 206 and the second edge 208, this is merely an example, and the glass sheet 200 may be a continuous web.

[0046] In embodiments, the glass sheet 200 defines a first surface 202 and a second surface 204 positioned opposite the first surface 202, and the glass sheet 200 defines a sheet thickness St evaluated between the first surface 202 and the second surface 204. As depicted and referred to herein the first direction (/. ., the y-direction) is transverse to the first surface 202 of the glass sheet 200. In some embodiments, the sheet thickness St is less than 0.5 millimeters. In some embodiments, the sheet thickness St is between 0.25 millimeters and 0.5 millimeters, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the sheet thickness St is about 0.25 millimeters. In some embodiments, the sheet thickness is about 0.30 millimeters. In some embodiments, the sheet thickness St is about 0.4 millimeters. In some embodiments, the sheet thickness St is about 0.5 millimeters.

[0047] To separate portions of the glass sheet 200, the scribing wheel 140 of the glass cutting system 100 engages the first surface 202 of the glass sheet 200. For example and referring to FIGS. 1-3, in some embodiments, the controller 160 directs the regulator 115 to move the air cylinder 120, moving the scribing wheel 140 toward the first surface 202 to engage ( e.g ., contact) the first surface 202 of the glass sheet 200.

[0048] In some embodiments, the controller 160 additionally or alternatively directs the first actuator 110 to move the air cylinder 120 toward the first surface 202 of the glass sheet 200. For example, in some embodiments, the controller 160 may direct the first actuator 110 to move the air cylinder 120 toward the first surface 202 of the glass sheet 200 such that the scribing wheel 140 engages the first surface 202 of the glass sheet 200.

[0049] With the scribing wheel 140 engaged with the first surface 202 of the glass sheet 200, the scribing wheel 140 moves along the first surface 202 of the glass sheet 200 at a scribing speed. For example, in embodiments, the controller 160 directs the second actuator 111 and/or the third actuator 113 to move the air cylinder 120, accordingly moving the scribing wheel 140 along the first surface 202 of the glass sheet 200.

[0050] In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 along the first surface 202 of the glass sheet 200 at a scribing speed of at least about 35 meters per minute. In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 between about 35 meters per minute and about 60 meters per minute, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 along the first surface 202 of the glass sheet 200 at a scribing speed of at least about 40 meters per minute. In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 along the first surface 202 of the glass sheet 200 at a scribing speed between about 40 meters per minute and about 60 meters per minute, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 along the first surface 202 of the glass sheet 200 at a scribing speed of at least about 45 meters per minute. In some embodiments, the second actuator 111 and/or the third actuator 113 moves the scribing wheel 140 along the first surface 202 of the glass sheet 200 at a scribing speed between about 45 meters per minute and about 60 meters per minute, inclusive of the endpoints and including all ranges between the endpoints. [0051] As the scribing wheel 140 moves along the first surface 202 of the glass sheet 200, the scribing wheel 140 applies a force on the first surface 202 of the glass sheet 200. For example, in embodiments, the controller 160 directs the air cylinder 120 (via the regulator 115) and/or the first actuator 110 to maintain the position of the scribing wheel 140 such that the scribing wheel 140 applies a force to the first surface 202 of the glass sheet 200. In embodiments, the scribing wheel 140 maintains a force on the first surface 202 of the glass sheet 200 within 1.0 Newtons of a predetermined force as the scribing wheel 140 moves along the first surface 202 of the glass sheet 200. In some embodiments, the scribing wheel 140 maintains a force on the first surface 202 of the glass sheet 200 within about 0.75 Newtons of a predetermined force as the scribing wheel 140 moves along the first surface 202 of the glass sheet 200. In some embodiments, the scribing wheel 140 maintains a force on the first surface 202 of the glass sheet 200 within about 0.5 Newtons of a predetermined force as the scribing wheel 140 moves along the first surface 202 of the glass sheet 200. In some embodiments, the scribing wheel 140 maintains a force on the first surface 202 of the glass sheet 200 within about 0.2 Newtons of a predetermined force as the scribing wheel 140 moves along the first surface 202 of the glass sheet 200.

[0052] In embodiments, the predetermined force is associated with a predetermined cutting pressure. Without being bound by theory, pressure applied to the first surface 202 of the glass sheet 200 by the scribing wheel 140 depends on the force applied to the first surface 202 and the geometry of the scribing wheel 140. In some embodiments the predetermined force is associated with a predetermined cutting pressure of about 0.09 Megapascals. In some embodiments, the predetermined force is associated with a predetermined cutting pressure of about 0.12 Megapascals. In some embodiments, the predetermined force is associated with a predetermined cutting pressure between about 0.09 Megapascals and about 0.12 Megapascals, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the predetermined force is associated with a predetermined cutting pressure between about 0.05 Megapascals and about 0.15 Megapascals, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the predetermined force is associated with a predetermined cutting pressure between about 0.05 Megapascals and about 0.20 Megapascals, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the predetermined force is associated with a predetermined cutting pressure between about 0.05 Megapascals and about 0.25 Megapascals, inclusive of the endpoints and including all ranges between the endpoints. In some embodiments, the predetermined force is associated with a predetermined cutting pressure between about 0.05 Megapascals and about 0.30 Megapascals, inclusive of the endpoints and including all ranges between the endpoints.

[0053] As the scribing wheel 140 moves along the first surface 202 of the glass sheet 200 at the scribing speed applying the force, the scribing wheel 140 forms a median crack extending into the first surface 202. For example and referring to FIG. 4, a side view of the glass sheet 200 is depicted with a median crack 210 formed in the glass sheet 200. The scribing wheel 140 forms the median crack 210 extending along a length Le of the first surface 202, and extending into the glass sheet 200. While in the embodiment depicted in FIG. 4, the length Le is depicted as extending between and terminating at the first edge 206 and the second edge 208, it should be understood that this is merely an example. For example, in some embodiments, the median crack 210 may be bounded between the first edge 206 and/or the second edge 208. Further, while in the embodiment depicted in FIG. 4 the glass sheet 200 is depicted as including the first edge 206 and the second edge 208, it should be understood that the glass sheet 200 may be a continuous glass web, and the median crack 210 may extend the length Le along the continuous glass web.

[0054] The median crack 210 defines a crack depth Cd extending into the glass sheet 200, and the crack depth Cd is less than the sheet thickness St. In some embodiments, the crack depth Cd < about 0.75 St. In some embodiments, the crack depth Cd < about 0.5 St. In some embodiments the crack depth Cd < 0.4 St. In some embodiments, the crack depth Cd < about 0.3 St. In some embodiments the target crack depth Td < abut 0.25 St. In some embodiments the crack depth Cd < about 0.2 St.

[0055] In embodiments, the crack depth Cd of the median crack 210 varies ( e.g ., in the y- direction as depicted) by a variation v along the length Le of the median crack 210 that can be expressed as a percentage of the crack depth Cd. In some embodiment, the crack depth Cd varies less than 2.0% along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200, for example in embodiments in which the sheet thickness St (FIG. 3) is greater than or equal to 0.3 millimeters. In embodiments, the crack depth Cd of the median crack 210 varies less than 1.5% along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200, for example in embodiments in which the sheet thickness St (FIG. 3) is greater than or equal to 0.3 millimeters. In embodiments, the crack depth Cd of the median crack 210 varies less than 1.0% along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200, for example in embodiments in which the sheet thickness St (FIG. 3) is greater than or equal to 0.3 millimeters.

[0056] Characterized another way, in embodiments, the variation v of the crack depth is less than about 5 micrometers along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200. In some embodiments, the variation v of the crack depth is less than about 4 micrometers along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200. In some embodiments, the variation v of the crack depth is less than about 3 micrometers along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200. In some embodiments, the variation v of the crack depth is less than about 2 micrometers along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200. In some embodiments, the variation v of the crack depth is between about 2 micrometers and about 5 micrometers along the length Le of the median crack 210 on the first surface 202 of the glass sheet 200, inclusive of the endpoints and including all ranges between the endpoints. By minimizing variation of the crack depth Cd, undesirable separation of the glass sheet 200 along the median crack 210 may be minimized.

[0057] For example and referring to FIGS. 5A, 5B, and 5C, perspective views of glass sheets 200, 200’, and 200” including median cracks 210, 210’, and 210” are depicted, respectively. In the example depicted in FIG. 5 A, the median crack 210 defines a generally uniform crack depth Cd extending into the first surface 202 of the glass sheet 200. Because the crack depth Cd is generally uniform, separation of the glass sheet 200 along the median crack 210 is also generally uniform, and undesired breakage is minimized.

[0058] By contrast and referring to FIG. 5B, a perspective view of a glass sheet 200’ including an uneven median crack 210’ is depicted. In FIG. 5B, the median crack 210’ of the glass sheet 200’ defines a crater 230’ that extends from the median crack 210’ (/. ., in the y-direction as depicted). The crater 230’ may be formed, for example, through the variation in force ( e.g ., an undesired increase in force) applied to the glass sheet 200’ by a cutting device, such as scribing wheel. The crater 230’ interrupts the uniformity of the median crack 210’, and may cause uneven or undesired separation of the glass sheet 200’ along the median crack 210’. [0059] Similarly and referring to FIG. 5C, a perspective view of another glass sheet 200” including an uneven median crack 210” is depicted. In FIG. 5C, the median crack 210” of the glass sheet 200” defines a gap 232” that extends from the median crack 210” ( i.e ., in the y- direction as depicted). The gap 232” may be formed, for example, through a variation in force e.g ., an undesired decrease in force) applied to the glass sheet 200” by a cutting device, such as a scribing wheel. Like the crater 230’ (FIG. 5B), the gap 232” interrupts the uniformity of the median crack 210”, and may cause uneven or undesired separation of the glass sheet 200” along the median crack 210”.

[0060] Referring again to FIGS 1-4, by minimizing variation in the crack depth Cd, uneven separation of the glass sheet 200 may be minimized. As outlined above, variation in the crack depth Cd may be minimized by maintaining consistent force on the glass sheet 200 with the scribing wheel 140, for example through the air cylinder 120.

[0061] Moreover, by maintaining consistent force with the scribing wheel 140, the scribing speed may be increased while maintaining acceptable variation in the crack depth Cd. In particular, as scribing speed increases, the impact of inconsistent force by the scribing wheel 140 on the crack depth Cd is amplified, resulting in greater variation in the crack depth Cd. By maintaining consistent force on the glass sheet 200 with the scribing wheel 140, for example with the air cylinder 120, the scribing speed of the scribing wheel 140 may be increased while minimizing the variation in the crack depth Cd. By increasing the scribing speed, glass sheets 200 may be separated more quickly, thereby increasing manufacturing throughput.

[0062] Accordingly, it should now be understood that glass cutting systems according to embodiments described herein generally include a scribing wheel and an air cylinder that maintains a position of the scribing wheel in a first direction that is transverse to a glass sheet. In particular, the air cylinder may maintain the position of the scribing wheel in the first direction such that the scribing wheel can maintain a constant or nearly constant force on the glass sheet to form a median crack in the glass sheet. By maintaining a constant or nearly constant force on the glass sheet, variation of a crack depth of the median crack can be minimized. By minimizing variation in the crack depth, undesirable and/or unpredictable separation of the glass sheet along the median crack can be minimized, thereby reducing scrap and reducing manufacturing costs. [0063] It is noted that recitations herein of a component of the present disclosure being "structurally configured" in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is "structurally configured" denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.

[0064] It is noted that terms like “preferably,” “commonly,” and “typically,” when utilized herein, are not utilized to limit the scope of the claims or to imply that certain features are critical, essential, or even important to the structure or function of the claims. Rather, these terms are merely intended to identify particular aspects of an embodiment of the present disclosure or to emphasize alternative or additional features that may or may not be utilized in a particular embodiment of the present disclosure.

[0065] For the purposes of describing and defining the present disclosure, the terms “substantially” and “about” are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms “substantially” and “about” are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0066] One or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present disclosure, this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open- ended preamble term “comprising.”

[0067] Having described the subject matter of the present disclosure in detail and by reference to specific embodiments thereof, it is noted that the various details disclosed herein should not be taken to imply that these details relate to elements that are essential components of the various embodiments described herein, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Further, it will be apparent that modifications and variations are possible without departing from the scope of the present disclosure, including, but not limited to, embodiments defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

What is claimed:

1. A method for separating a glass sheet comprising: engaging a first surface of a glass sheet with a scribing wheel, the glass sheet comprising a second surface opposite the first surface and a sheet thickness between the first surface and the second surface; moving the scribing wheel along the first surface of the glass sheet at a scribing speed of at least about 35 meters per minute; applying and maintaining, with the scribing wheel, a force on the first surface of the glass sheet that is within about 1.0 Newtons of a predetermined force as the scribing wheel moves along the first surface of the glass sheet; and forming, with the scribing wheel, a median crack extending along a length of the first surface and extending into the glass sheet, the median crack defining a crack depth extending into the glass sheet that is less than the sheet thickness and varies less than about 2.0% along the length of the median crack on the first surface.

2. The method of claim 1, wherein applying the force comprises maintaining a position of the scribing wheel in a first direction transverse to the glass sheet with an air cylinder coupled to the scribing wheel.

3. The method of claim 2, further comprising restricting movement of a rod of the air cylinder with a linear motion guide rail engaged with the rod of the air cylinder, wherein the linear motion guide rail permits movement of the rod in the first direction and restricts movement of the rod in a direction transverse to the first direction.

4. The method of claim 2, wherein applying the force comprises maintaining the position of the scribing wheel in the first direction with a first actuator coupled to the scribing wheel through the air cylinder.

5. The method of claim 1, wherein the crack depth of the median crack varies less than about 1.5% along the length of the median crack on the first surface.

6. The method of claim 1, wherein the crack depth of the median crack varies less than about 1.0% along the length of the median crack on the first surface.

7. The method of claim 1, wherein the scribing speed is at least about 40 meters per minute.

8. The method of claim 1, wherein the scribing speed is at least about 45 meters per minute.

9. The method of claim 1, wherein the crack depth varies less than about 5 micrometers along the length of the median crack on the first surface.

10. The method of claim 1, wherein the sheet thickness is less than about 0.5 millimeters.

11. The method of claim 1, wherein the sheet thickness is about 0.30 millimeters.

12. The method of claim 1, wherein applying the force on the first surface of the glass sheet with the scribing wheel further comprises maintaining the force within about 0.2 Newtons of the predetermined force.

13. A glass cutting system comprising: a scribing wheel; a regulator; an air cylinder coupled to the scribing wheel and in communication with the regulator; a second actuator coupled to the air cylinder; and a controller communicatively coupled to the regulator and the second actuator, the controller comprising a processor and a memory comprising a computer readable and executable instruction set, which, when executed by the processor, causes the processor to: direct the regulator to apply and maintain a force on a first surface of a glass sheet with the scribing wheel within about 1.0 Newtons of a predetermined force with the air cylinder; and direct the second actuator to move the scribing wheel along the glass sheet at a scribing speed of at least about 35 meters per minute, thereby forming a median crack extending along a length of the first surface and extending into the glass sheet, the median crack defining a crack depth extending into the glass sheet that is less than a sheet thickness of the glass sheet and varies less than about 5 micrometers along the length of the median crack on the first surface.

14. The glass cutting system of claim 13, further comprising a first actuator coupled to the air cylinder.

15. The glass cutting system of claim 14, wherein the first actuator is communicatively coupled to the controller, and wherein the computer readable and executable instruction set, when executed by the processor, further causes the processor to direct the first actuator to move the air cylinder toward the first surface of the glass sheet.

16. The glass cutting system of claim 13, further comprising a linear motion guide rail engaged with a rod of the air cylinder, wherein the linear motion guide rail permits movement of the rod in a first direction transverse to the glass sheet and restricts movement of the rod in a direction transverse to the first direction.

17. The glass cutting system of claim 13, wherein the computer readable and executable instruction set, when executed by the processor, causes the processor to direct the second actuator to move the scribing wheel along the glass sheet at a scribing speed of at least about 40 meters per minute.

18. The glass cutting system of claim 13, wherein the computer readable and executable instruction set, when executed by the processor, further causes the processor to direct the regulator to apply and maintain the force on the first surface of the glass sheet with the scribing wheel within about 0.2 Newtons of the predetermined force with the air cylinder.

19. The glass cutting system of claim 13, wherein the crack depth of the median crack varies less than about 1.5% along the length of the median crack on the first surface.

20. The glass cutting system of claim 13, wherein applying the force on the first surface of the glass sheet with the scribing wheel comprises maintaining the force within about 0.2 Newtons of the predetermined force.