Improved Slot Drop Process

Abstract

An improved slot downdraw process is provided for forming glass sheets having thicknesses of less than 200 μm from glass formulations having melting points near or above 1200° C. The improvement facilitates maintenance of the slot assembly and better manages the thermal expansion experienced by some components of the slot downdraw system.

Description

Cross - reference to related applications

[0001] This application claims the benefit of priority under 35 U.S.C.§ 119 to U.S. Provisional Patent Application No. 63 / 034,053, filed on June 3, 2020, the content of which is relied upon and incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates to a method for manufacturing a glass sheet, particularly a glass sheet having a thickness of less than 200 μm.

Background Art

[0003] Many of the latest applications of sheet glass require not only improved toughness but also ultra - thin (less than 200 μm thick) glass sheets. The production of such thin glass sheets requires a glass composition that is significantly different from those previously used. Sometimes, such new glass compositions are high - temperature compositions generally having a melting temperature exceeding 1200 °C and cannot generally be produced on a single platform such as fusion draw.

[0004] The slot - draw process is a down - draw process in which glass is supplied from an orifice in the shape of a machined slot and then pulled downward until the target thickness is reached, enabling more appropriate production of ultra - thin glass sheets.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in applications with increasingly stringent requirements, significant improvements in product characteristics that cannot be achieved with the functions of existing slot - draw apparatuses are required. Therefore, an improved slot - draw process is needed.

Means for Solving the Problems

[0006] An improved slot down-draw glass forming system is provided. The slot down-draw glass forming system includes a molten glass feeding section; a glass conditioner diffusion section connected to and in fluid communication with the molten glass feeding section; a glass conditioner vertical section; and a terminal slot assembly including an upper lip and a lower lip, wherein the lower lip is removably coupled to the upper lip and is configured to be removed from the terminal slot assembly without removing the upper lip.

[0007] A slot down-draw glass forming system according to another embodiment is provided. The system includes a molten glass feeding section; a glass conditioner connected to and in fluid communication with the molten glass feeding section, the glass conditioner including a diffusion section, a vertical section, an elbow section connecting the diffusion section and the vertical section, and a platinum passage for carrying molten glass extending through the diffusion section, the elbow section, and the vertical section; a first casing portion surrounding the platinum passage in the conditioner diffusion section; a second casing portion surrounding the platinum passage in the conditioner vertical section; an elbow-shaped casing portion surrounding the platinum passage in the elbow section; wherein the first casing portion and the elbow-shaped casing portion are arranged in a linear alignment with the platinum passage in the conditioner diffusion section, and the first casing portion and the elbow-shaped casing portion are configured to be controllably moved away from the first casing portion so as to maintain the linear alignment while accommodating the thermal expansion of the platinum passage in the conditioner diffusion section when the slot down-draw glass forming system is heated from ambient temperature to the glass processing temperature; the system further includes a terminal slot assembly.

[0008] According to another embodiment, a slot down-draw glass forming system includes a molten glass feed section; a glass conditioner connected to and in fluid communication with the molten glass feed section; a platinum passage for carrying the flow of molten glass through the glass conditioner to a terminal slot assembly; and a casing surrounding the platinum passage near the terminal slot assembly, where the terminal slot assembly defines a slot through which a glass ribbon is vertically downwardly extended, and the terminal slot assembly includes an upper lip and a lower lip. The slot has a width, and the upper lip extends beyond the width of the slot to define a first end and a second end, where the casing includes two independently laterally movable parts, the first movable part and the second movable part corresponding to the first end and the second end of the upper lip, the first end of the upper lip being connected to the first movable part of the casing, the second end of the upper lip being connected to the second movable part of the casing, and the upper lip and the casing being configured to controllably move the first movable part of the casing laterally relative to the first end of the upper lip and the second movable part of the casing laterally relative to the second end of the upper lip to accommodate the thermal expansion of the upper lip when the slot down-draw glass forming system is heated from ambient temperature to glass processing temperature, where the lower lip also extends beyond the width of the slot to define a first end and a second end, each of the two ends of the lower lip being connected to a lower lip support frame including independently laterally movable first and second movable parts, and the two ends of the lower lip and the two movable parts of the lower lip support frame being configured to controllably move the first movable part laterally relative to the first end of the lower lip and the second movable part laterally relative to the second end of the lower lip to accommodate the thermal expansion of the lower lip when the slot down-draw glass forming system is heated from ambient temperature to glass processing temperature.

[0009] These drawings are provided for illustrative purposes, and it is understood that the embodiments disclosed and discussed herein are not limited to the configurations and means shown. The figures are schematic and not to scale. It is not intended to indicate dimensions or actual ratios.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Modes for Carrying Out the Invention

[0011] This specification may include details, but these should not be construed as limitations on the scope and should be construed as descriptions of features that may be specific to particular embodiments.

[0012] Various embodiments of an improved glass-forming process are described with reference to the drawings, and like elements are given like numbers for ease of understanding.

[0013] Also, unless otherwise specified, terms such as "upper", "lower", "outward", "inward", etc. are for convenience and should not be construed as limiting terms. Additionally, when a group is described as including at least one of a group of elements and combinations thereof, that group always includes any number of the elements listed, either individually or in combination with each other, consists essentially of them, or consists of them.

[0014] Similarly, when a group is described as consisting of at least one of a group of elements or combinations thereof, that group can always be composed of any number of the elements listed, either individually or in combination with each other. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range. As used herein, the indefinite articles "a" and "an", and the corresponding definite article "the" mean "at least one" or "one or more" unless otherwise specified.

[0015] Those skilled in the art will recognize that many changes can be made to the described embodiments while achieving the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the described features without using other features. Thus, those skilled in the art will recognize that many modifications and adaptations are possible and may even be desirable in certain situations and are part of the present disclosure. Therefore, the following description is provided as an illustration of the principles of the present disclosure and is not intended to limit the present disclosure.

[0016] Disclosed herein are various embodiments of an improved slot down-draw process for forming an ultra-thin glass sheet (i.e., having a thickness of less than 200 μm) from a glass formulation having a forming temperature (i.e., feed temperature) in the range of 800 - 1200°C. The improved slot down-draw process can also handle glass formulations having a forming temperature in the range of 600 - 1400°C.

[0017] Figure 1 is a schematic overview showing the general concept of the slot down-draw process. In the slot down-draw process, molten glass is fed from a slot 12 at the end of a platinum channel 10 as shown. The slot 12 can be formed by a lip made of platinum or a platinum alloy. The glass ribbon R dispensed from the slot is drawn downward as a continuous sheet into an annealing zone.

[0018] Referring to Figure 2, an improved slot down-draw glass forming system 100 for forming a glass sheet from molten glass is described herein. The improved system is particularly suitable for the production of glass sheets having a thickness of less than 200 μm.

[0019] Removable two-part assembly slot: In some embodiments, the improved slot down draw glass forming system 100 includes a molten glass feed section 132 configured to feed a continuous supply of molten glass to the glass conditioner 130 section. Referring to FIG. 3, the glass conditioner 130 includes a glass conditioner diffusion section 134 connected to and in fluid communication with the molten glass feed section 132, a glass conditioner vertical section 135, an elbow type section 134a connecting the diffusion section 134 and the vertical section 135, and a terminal slot assembly 120. The glass conditioner diffusion section 134 converts the supply of molten glass received as a tubular flow into a substantially rectangular molten glass flow having a cross-sectional shape of approximately (500 - 1000 mm) wide × (5 - 20 mm) deep. The diffusion process converts the geometry of the molten glass flow to match the geometry of the downstream terminal slot assembly 120. The glass conditioner vertical section 135 is configured to turn the molten glass flow from the glass conditioner diffusion section in a vertical direction and flow downward toward the downstream terminal slot assembly 120.

[0020] Referring to FIG. 4, unlike conventional slot down draw systems, the terminal slot assembly 120 according to some embodiments of the present disclosure includes an upper lip 121 and a lower lip 122. The upper lip 121 forms a wider slot, does not need to be removed during maintenance procedures, and can generally be attached to a section of the platinum passage 10 within the glass conditioner vertical section 135. The upper lip 121 can be welded to the platinum passage 10.

[0021] The lower lip 122 forms a slot narrower than the upper lip 121 and distributes a glass ribbon R of a desired thickness for the downstream down-draw process step. The lower lip 122 is removably coupled to the upper lip 121 such that the lower lip 122 can be removed from the terminal slot assembly 120 without removing the upper lip 121. A refractory insulation support frame 146 supports the lower lip 122. The support frame 146 is clamped to the upper slot support frame 145. A refractory fiber felt layer 147 is inserted between the upper lip 121 and the lower lip 122 as a glass sealing layer to avoid direct contact between the two slots. Making the lower lip 122 removable allows for quick replacement of the lower lip 122 without the need to cool upstream components during maintenance procedures.

[0022] Conditioner and direct combustion zone of the terminal slot: In some embodiments of the slot down-draw glass forming system 100, at least one or both of the upper lip 121 and the lower lip 122 can be configured as (one or more) direct heating elements by Joule heating. To achieve Joule heating, an electric current is applied to the particular slot structure to be heated. Next, the temperature is controlled by controlling the amount of current flowing through the structure. Thereby, the temperature of the molten glass flow passing through the lips 121, 122 can be accurately controlled, and the optimum flow rate can be maintained by controlling the glass viscosity. Similar to most components in direct contact with molten glass, the upper and lower lips 121, 122 are made of platinum or a platinum alloy and are suitable for Joule heating. By directly heating the down-draw system components themselves, accurate temperature control becomes possible, and the ability to process glass compositions at significantly higher melting temperatures compared to conventional slot down-draw glass forming systems is obtained.

[0023] The glass conditioner diffusion section 134 has a molten glass receiving end 134a and a molten glass discharging end 134b. In some embodiments, the molten glass receiving end 134a is configured as a heating element by Joule heating. The molten glass receiving end 134a section can be connected to a current source for Joule heating. In some embodiments, a direct heating flange 134f element can be attached to the molten glass receiving end 134a for electrical connection.

[0024] In some embodiments, the glass conditioner vertical section 135 can be configured to heat the side surface of the vertical section by Joule heating. This feature can be used to develop a temperature gradient from the side surface to the center of the molten glass flowing down through the glass conditioner vertical section 135.

[0025] Controlled atmosphere: Some glass compositions benefit from providing a controlled environment (e.g., oxygen, hydrogen, humidity, temperature, gas flow, pressure, etc.) that surrounds various parts of the slot down draw glass forming system 100. It is generally not easy to do this. According to one aspect of the present disclosure, an airtight stainless steel housing structure 200 encloses a part of the slot down draw glass forming system 100 with a closed loop control system that provides a controlled environment. Preferably, the housing structure 200 encloses the glass conditioner 130 portion. For example, the controlled environment within the housing structure 200 is controlled to limit the level of hydrogen around the outer (surface not in contact with the glass) of the components of the glass conditioner 130 to suppress the formation of gaseous inclusions and surface bulges in the glass sheet. Additionally, the closed loop control system and the housing structure 200 maintain an atmosphere with minimal oxygen around the noble metal components in contact with the glass to prevent unwanted oxidation. The noble metal components in contact with the glass can be made of platinum or a platinum alloy. Some examples of noble metal components in contact with the glass are the platinum passages 10 for carrying molten glass through the glass forming system 100 and the upper and lower lips 121, 122. Referring to FIG. 5, in some embodiments, the housing 200 is configured to surround and enclose the glass conditioner diffusion section 134, the glass conditioner vertical section 135, and the terminal slot assembly 140.

[0026] Vertical and Horizontal Thermal Expansion Management System: Higher melting point glass compositions required to form ultra-thin glass sheets require the glass conditioner 130 to experience large temperature gradients in different sections of the conditioner 130, which results in significant thermal expansion of the conditioner components, many of which are made of platinum and / or platinum alloy. To manage the thermal expansion of the components, a system with an adjustable mechanical configuration is provided.

[0027] The mechanical configuration disclosed herein forms a thermal expansion management system that adapts the glass conditioner assembly 130 to the thermal expansion of platinum components caused by temperature changes from the ambient temperature to the nominal processing temperature of the glass conditioner components, reducing unwanted mechanical stresses in the different components of the glass conditioner assembly 130. The nominal processing temperature of the glass conditioner components depends on the specific composition of the molten hot glass. Generally, the nominal processing temperature is between about 90°C and about 1200°C. The thermal expansion management system prevents mechanical deformation of the components of the glass forming system resulting from mismatches in thermal expansion between components.

[0028] When there is a large temperature gradient between two adjacent components of the glass conditioner assembly 130, the components can expand by different amounts, causing mechanical stress. The problem can be exacerbated when the adjacent components are made of different materials with different coefficients of thermal expansion (CTEs) and the component with the larger CTE is at a higher temperature. This is the situation in the glass conditioner assembly 130. The platinum passage 10 that carries the molten glass becomes hotter than the surrounding components of the glass conditioner assembly 130, and the platinum components have a higher CTE than the surrounding components.

[0029] The thermal expansion management system according to the present disclosure includes placing two non-uniformly expanding adjacent parts on one or more guide rails to allow relative movement between the two non-uniformly expanding adjacent parts. The non-uniform expansion between the two adjacent parts is due to the temperature gradient that exists during the operation of the slot down draw glass forming process. The thermal expansion management system also controllably moves the component experiencing less thermal expansion to accommodate the thermal expansion of the adjacent part experiencing greater thermal expansion.

[0030] A slot-down draw glass forming system incorporating such a thermal expansion management function is disclosed. Referring to FIGS. 3 and 6A, a glass conditioner section 130 and a molten glass feed section 132 are shown. The glass conditioner 130 is connected to and in fluid communication with the molten glass feed section 132. The glass conditioner 130 includes a diffusion section 134, a vertical section 135, an elbow section 134a connecting the diffusion section 134 and the vertical section 135, and a platinum passage 10 for carrying molten glass extending through the diffusion section 134, the elbow section 134a, and the vertical section 135. A first casing portion 310 surrounds the platinum passage 10 within the conditioner diffusion section 134. A second casing portion 330 surrounds the platinum passage 10 within the conditioner vertical section 135. An elbow casing portion 320 surrounds the platinum passage 10 within the elbow section 134a. The first casing portion 310 and the elbow casing portion 320 are arranged in linear alignment with the platinum passage 10 within the conditioner diffusion section 134. The first casing portion 310 and the elbow casing portion 320 are configured to controllably move the elbow casing portion 320 away from the first casing portion 310 while maintaining a linear alignment to accommodate thermal expansion of the platinum passage 10 within the conditioner diffusion section 134 as the slot-down draw glass forming system heats from ambient temperature to glass processing temperature. A terminal slot assembly 140 provided at the end of the glass conditioner vertical section 135 is also shown.

[0031] Since the molten glass flows through the platinum passage 10, a substantial temperature gradient is formed between the platinum passage 10 and the surrounding casings (the first casing part 310, the elbow-shaped casing part 320, and the second casing part 330) during the startup of the slot-down draw system starting from the ambient temperature (the platinum passage 10 is at a substantially higher (exceeding 100 °C) temperature). Due to the temperature gradient, the platinum passage 10 immediately expands and expands more than the casing. This effect is amplified by the fact that the platinum passage 10 has a larger CTE than the casing material, the surrounding structure such as the casing is made of a non-precious metal, and some parts are made of refractory materials with a smaller CTE. The first casing part 310 and the elbow-shaped casing part 320, which are configured to be controllably moved away from the first casing part 310, extend to the combined length of the first casing part 310 and the elbow-shaped casing part 320 in the diffusion section 134 so as to match the thermal expansion of the platinum passage 10 in the diffusion section 134. The first casing part 310 and the elbow-shaped casing part 320 need to be maintained in a linear alignment with the platinum passage 10 so that they do not interfere with or damage the structure of the platinum passage 10 when the two casing parts move apart.

[0032] In some embodiments, the step of controllably moving the elbow-shaped casing part 320 away from the first casing part 310 is achieved by one or more adjustable push rods 410 disposed between the first casing part 310 and the elbow-shaped casing part 320. The adjustable push rod 410 can comprise a threaded bolt and sleeve configuration that can push or pull the elbow-shaped casing part 320, and the position of the elbow-shaped casing part 320 relative to the first casing part 310 can be adjusted by turning the threaded bolt or the threaded sleeve depending on the specific implementation of such a configuration.

[0033] In some embodiments, one or more adjustable push rods 410 can be manually rotated to control and adjust the position of the elbow-shaped casing portion 320. In some embodiments, one or more adjustable push rods 410 can be remotely operated by a stepping motor, for example, to control and adjust the position of the elbow-shaped casing portion 320.

[0034] In some embodiments, one or more sets of rails and linear bearings 510 can be provided on a movable part (in this case, the elbow-shaped casing portion 320) so that a linear alignment between the first casing portion 310 and the elbow-shaped casing portion 320 can be maintained while the elbow-shaped casing portion 320 is moving.

[0035] In some embodiments, the amount of thermal expansion of the platinum passage 10 in the conditioner diffusion section 134 is determined by monitoring the temperature of the platinum passage 10 in the conditioner diffusion section 134. Since the CTE of the platinum passage is known, the amount by which the platinum passage 10 expands linearly can be calculated. For temperature monitoring, a suitable thermocouple or other suitable device can be used.

[0036] Referring to FIG. 6B, to manage the thermal expansion of the components within the vertical section 135 of the conditioner 130, the elbow-shaped casing portion 320 and the second casing portion 330 are configured to be controllably moved so that the second casing portion 330 moves away from the elbow-shaped casing portion 320 to accommodate the thermal expansion of the platinum passage 10 within the conditioner vertical section 135 when the slot-down drogue glass forming system 100 is heated from the ambient temperature to the glass processing temperature. The elbow-shaped casing portion 320 and the second casing portion 330 are arranged in linear alignment with the platinum passage 10 within the conditioner vertical section 135, and this linear alignment is maintained while the second casing portion 330 is controllably moving.

[0037] In some embodiments, the controllable movement of the second casing portion 330 is achieved by one or more adjustable push rods disposed between the elbow-shaped casing portion 320 and the second casing portion 330. In some embodiments, the position of the second casing portion 330 can be controlled and adjusted by manually turning one or more adjustable push rods 410a. In some embodiments, one or more adjustable push rods 410a can be remotely operated by a stepping motor, for example, to control and adjust the position of the second casing portion 330.

[0038] In some embodiments, while the second casing portion 330 is moving, one or more sets of rails and linear bearings 510a can be provided for the movable second casing portion 330 so as to maintain a linear alignment between the elbow-shaped casing portion 320 and the second casing portion 330.

[0039] In some embodiments, the amount of thermal expansion of the platinum passage 10 within the conditioner vertical section 135 is determined using one or more stacks 520 of Belleville washers. In the illustrated example shown in FIG. 6B, two stacks of Belleville washers 520 are utilized, one on each side of the conditioner vertical section 135. Each stack of Belleville washers 520 is positioned such that as the platinum passage 10 within the conditioner vertical section 135 expands as the hot molten glass passes through, the expanding platinum passage 10 exerts a compressive force on the stack of Belleville washers 520. Thus, by monitoring the compression of the Belleville washers within each stack 520, the amount of thermal expansion due to the platinum passage can be determined. This information is used to adjust one or more adjustable push rods 410a and move the second casing portion 330 an appropriate amount away from the elbow-shaped casing portion 320 to accommodate the expansion of the platinum passage 10. An example of a Belleville washer is a Belleville disk, also known as a conical spring washer.

[0040] For the stack of dish spring washers 520 to operate as described, the dish spring washer 520 is captured between a fixture or bracket 330a attached to the second casing portion 330 and a compression cap 522 attached to the upper lip 121 of the terminal slot assembly 140. A flange 121f extends from each end of the upper lip 121, extends beyond the width of the slot 12, and the compression cap 522a is connected to the flange 121f. The upper lip 121 is attached to the platinum passage 10. Thus, when the platinum passage 10 expands relative to the second casing portion 330, since the elbow-shaped section 134a of the conditioner 130 is fixed in the vertical direction, the platinum passage 10 expands downward in the view shown in FIG. 6B. Next, due to this downward movement, the compression cap 522a is pulled downward and the dish spring washer 520 is compressed. Therefore, by monitoring an increase in the compression of one or more stacks of dish spring washers 520, the amount of thermal expansion of the platinum passage in the conditioner vertical section can be determined.

[0041] In some embodiments, the amount of thermal expansion of the platinum passage 10 in the conditioner vertical section 135 can be determined by monitoring the temperature of the platinum passage 10 in the conditioner diffusion section 134. For temperature monitoring, a suitable thermocouple or other suitable device can be used.

[0042] Thermal expansion management system for the upper and lower lips of the slot assembly: In some embodiments, the slot down-draw glass forming system 100 includes a terminal slot assembly 140 that defines a slot 12 through which a glass ribbon R is vertically and downwardly extended. The terminal slot assembly 140 includes an upper lip 121 and a lower lip 122. The slot 12 has a width W, and the upper lip 121 extends beyond the width W of the slot 12. The upper lip 121 defines a first end 121' and a second end 121". The second casing portion 330 includes a first movable portion 330' and a second movable portion 330" that are two independently laterally movable portions corresponding to the first end 121' and the second end 121" of the upper lip 121. The first end 121' of the upper lip 121 is connected to the first laterally movable portion 330', and the second end 121" of the upper lip 121 is connected to the second laterally movable portion 330". Laterally movable means that the two movable portions 330' and 330" are movable in a direction parallel to the length of the upper lip 121 (i.e., substantially horizontal in the figure shown in FIG. 6C).

[0043] When the slot down-draw glass forming system is heated from the ambient temperature to the glass processing temperature, the upper lip 121 and the second casing portion 330 are configured to controllably move the first movable portion 330' laterally with respect to the first end 121' of the upper lip 121 and controllably move the second movable portion 330" laterally with respect to the second end 121" of the upper lip 121 to accommodate the thermal expansion of the upper lip 121. The upper lip 121 and the lower lip 122 are platinum or platinum alloy structures. Thus, even at the same temperature, the upper lip 121 and the lower lip 122 expand substantially more than the surrounding casing and frame components made of non-noble metals and refractory materials.

[0044] In some embodiments, to controllably move two movable parts 330', 330" laterally relative to two respective ends 121', 121" of the upper lip, one or more adjustable push rods 410b are disposed between each of the two ends 121', 121" of the upper lip 121 and the respective first and second movable parts 330', 330" of the second casing. In some embodiments, one or more adjustable push rods 410b can be manually controlled. In some embodiments, one or more adjustable push rods 410b are remotely controlled using, for example, a stepping motor. In some embodiments, one or more sets of rails and linear bearings 510b are provided to facilitate the movement of the two movable parts 330', 330".

[0045] The amount of thermal expansion experienced by the upper lip 121 can be detected by one or more stacked disc spring washers 520a. As shown in FIG. 6C, each stack of disc spring washers 520a is configured to be disposed between the casing 330 and an adjustable push rod 410b connected to one end 121', 121" of the upper lip 121. As the upper lip 121 expands, it moves outward from the structure of the slot 12 as represented by arrow A. Thereby, the push rod 410b is biased in the same outward direction, and the compression against the stack of disc spring washers 520a is reduced. Accordingly, by monitoring the reduction in compression in the stack of disc spring washers 520a, the amount of thermal expansion experienced by the upper lip 121 can be determined, and corresponding adjustments are made to accommodate the thermal expansion by moving the movable parts 330', 330" of the casing 330 in the outward direction A using the push rod 410b.

[0046] In some embodiments, the lower lip 122 also extends beyond the width W of the slot 12, and the lower lip 122 defines a first end 122' and a second end 122". The lower lip 122 is attached to the lower lip support frame 340. The lower lip support frame 340 includes a first movable part 340' and a second movable part 340", which are two separate laterally movable parts corresponding to the first end 122' and the second end 122" of the lower lip 122. Laterally movable means that the two movable parts 340' and 340" are movable in a direction parallel to the length of the lower lip 122.

[0047] When the slot down-draw glass forming system is heated from ambient temperature to the glass processing temperature, the lower lip 122 and the lower lip support frame 340 are configured to controllably move the first movable part 340' laterally relative to the first end 122' of the lower lip 122 and to controllably move the second movable part 340" laterally relative to the second end 122" of the lower lip 122 to accommodate the thermal expansion of the lower lip 122.

[0048] In some embodiments, one or more adjustable push rods 410c are disposed between each of the two ends 122', 122" of the lower lip 122 and the two movable parts 340', 340" of the lower lip support frame 340, respectively, to controllably move the two movable parts 340', 340" laterally relative to the first end 122' and the second end 122" of the lower lip 122, respectively. In some embodiments, one or more adjustable push rods 410c can be manually controlled. In some embodiments, one or more adjustable push rods 410c are remotely controlled using, for example, a stepping motor. In some embodiments, one or more sets of rails and linear bearings 510c are provided to facilitate the movement of the two movable parts 340', 340".

[0049] The amount of thermal expansion experienced by the lower lip 122 can be detected by one or more stacks of disc spring washers 520b. As shown in FIG. 6C, each stack of disc spring washers 520b is configured to be disposed between the lower lip support frame 340 and an adjustable push rod 410c connected to one end 122’, 122” of the lower lip 122. As the lower lip 122 expands, it moves outward from the structure of the slot 12 as represented by arrow A. Thereby, the push rod 410c is biased in the same outward direction, and the compression against the stack of disc spring washers 520a is reduced. Therefore, by monitoring the reduction in compression in the stack of disc spring washers 520b, the amount of thermal expansion experienced by the lower lip 122 can be determined, and corresponding adjustments are made to accommodate thermal expansion by moving the movable parts 340’, 340” of the lower lip support frame 340 in the outward direction A using the push rod 410c.

[0050] Those skilled in the art will recognize that many modifications can be made to the exemplary embodiments described herein without departing from the spirit and scope of the present disclosure. Accordingly, the description is not intended to be limiting and should not be construed as being limited to the given examples, and the full scope of protection afforded by the appended claims and their equivalents should be recognized. Additionally, some features of the present disclosure can be used without the corresponding use of other features. Accordingly, the foregoing description of exemplary or illustrative embodiments is not intended to limit the principles of the present disclosure, but is provided for illustrative purposes and can include modifications and permutations thereof.

[0051] Although the preferred embodiments of the present disclosure have been described, the described embodiments are merely illustrative, and the scope of the present invention is defined only by the appended claims, and it should be understood that many variations and modifications that would occur naturally to those skilled in the art from a thorough reading of this specification are included when full scope of equivalence is given.

[0052] Hereinafter, preferred embodiments of the present invention will be described item by item.

[0053] Embodiment 1 A slot-down draw glass forming system, a molten glass feeding section, a glass conditioner diffusion section connected to and in fluid communication with the molten glass feeding section, a glass conditioner vertical section, and a terminal slot assembly, an upper lip, and a lower lip including a terminal slot assembly is provided with, the lower lip is removably coupled to the upper lip, and the lower lip is configured to be removed from the terminal slot assembly without removing the upper lip. A slot-down draw glass forming system.

[0054] Embodiment 2 The slot-down draw glass forming system according to Embodiment 1, wherein the lower lip is connected to the upper lip by a support frame.

[0055] Embodiment 3 The slot-down draw glass forming system according to Embodiment 1, further including a layer of refractory fiber felt provided between the upper lip and the lower lip.

[0056] Embodiment 4 The slot-down draw glass forming system according to Embodiment 1, wherein the lower lip is configured as a heating element by Joule heating.

[0057] Embodiment 5 The slot-down draw glass forming system according to Embodiment 4, wherein the upper lip is configured as a heating element by Joule heating.

[0058] Embodiment 6 The slot-down draw glass forming system according to Embodiment 5, wherein the glass conditioner diffusion section has a molten glass receiving end and a molten glass discharging end, and the molten glass receiving end is configured as a heating element by Joule heating.

[0059] Embodiment 7 The glass conditioner diffusion section, the glass conditioner vertical section, and the terminal slot assembly are in a controlled atmosphere Enclosure A housing structure that reduces oxidation of the platinum components of the glass conditioner diffusion section, the glass conditioner vertical section, and the terminal slot assembly The slot-down draw glass forming system according to Embodiment 1, further comprising the same.

[0060] Embodiment 8 A slot-down draw glass forming system, comprising: A molten glass feeding section, A glass conditioner connected to the molten glass feeding section and in fluid communication with the molten glass feeding section, the glass conditioner including a diffusion section, a vertical section, an elbow-shaped section connecting the diffusion section and the vertical section, and a platinum passage for carrying the molten glass extending through the diffusion section, the elbow-shaped section, and the vertical section. A first casing portion surrounding the platinum passage in the conditioner diffusion section, A second casing portion surrounding the platinum passage in the conditioner vertical section, An elbow-shaped casing portion surrounding the platinum passage in the elbow-shaped section wherein The first casing part and the elbow-shaped casing part are arranged in a linear alignment with the platinum passage in the conditioner diffusion section. The first casing part and the elbow-shaped casing part are configured to move the elbow-shaped casing part away from the first casing part in a controllable manner while maintaining the linear alignment to accommodate the thermal expansion of the platinum passage in the conditioner diffusion section when the slot-down draw glass forming system is heated from the ambient temperature to the glass processing temperature. Terminal slot assembly A slot-down draw glass forming system further comprising.

[0061] Embodiment 9 The elbow-shaped casing part and the second casing part are arranged in a linear alignment with the platinum passage and the elbow-shaped casing part in the conditioner vertical section. The second casing part is configured to move the second casing part away from the elbow-shaped casing part in a controllable manner while maintaining the linear alignment to accommodate the thermal expansion of the platinum passage in the conditioner vertical section when the slot-down draw glass forming system is heated from room temperature to the glass processing temperature. The slot-down draw glass forming system according to Embodiment 8.

[0062] Embodiment 10 One or more adjustable push rods are arranged between the first casing part and the elbow-shaped casing part to move the elbow-shaped casing part away from the first casing part in a controllable manner. The slot-down draw glass forming system according to Embodiment 8.

[0063] Embodiment 11 The one or more adjustable push rods are remotely controllable. The slot-down draw glass forming system according to Embodiment 10.

[0064] Embodiment 12 The slot down draw glass forming system according to embodiment 10, further comprising one or more sets of rails and linear bearings for maintaining the linear alignment between the first casing part and the elbow-shaped casing part while the elbow-shaped casing part is moving.

[0065] Embodiment 13 The thermal expansion of the platinum passage in the conditioner diffusion section is determined by monitoring the temperature of the platinum passage in the conditioner diffusion section. The slot down draw glass forming system according to embodiment 8.

[0066] Embodiment 14 One or more adjustable push rods are arranged between the elbow-shaped casing part and the second casing part to controllably move the second casing part away from the elbow-shaped casing part. The slot down draw glass forming system according to embodiment 9.

[0067] Embodiment 15 The one or more adjustable push rods of the slot down draw glass forming system according to embodiment 14 are remotely controllable.

[0068] Embodiment 16 The slot down draw glass forming system according to embodiment 14, further comprising one or more sets of rails and linear bearings for maintaining the linear alignment between the elbow-shaped casing part and the second casing part while the elbow-shaped casing part is moving.

[0069] Embodiment 17 Further comprising one or more stacks of disc spring washers for determining the thermal expansion of the platinum passage in the conditioner vertical section. One or more stacks of said dish spring washers are configured to experience an increase in compression when the platinum passageway within said conditioner vertical section expands relative to said second casing portion, and the thermal expansion of said platinum passageway within said conditioner vertical section is determined by monitoring said increase in compression of one or more stacks of said dish spring washers. The slot down draw glass forming system according to Embodiment 14.

[0070] Embodiment 18 A slot down draw glass forming system, comprising: A molten glass feeding section, A glass conditioner connected to and in fluid communication with said molten glass feeding section, A platinum passageway for carrying the flow of said molten glass through said glass conditioner to a terminal slot assembly, and A casing surrounding the platinum passageway near said terminal slot assembly wherein: Said terminal slot assembly defines a slot through which a glass ribbon is vertically extended downwardly, and said terminal slot assembly comprises: An upper lip, and A lower lip wherein: Said slot has a width, said upper lip extends beyond said width of said slot and defines a first end and a second end, Said casing includes a first movable part and a second movable part corresponding to said first end and said second end of said upper lip, which are two independently laterally movable parts, Said first end of said upper lip is connected to said first movable part of said casing, and said second end of said upper lip is connected to said second movable part of said casing, When the slot down-draw glass forming system is heated from ambient temperature to the glass processing temperature, the upper lip and the casing are configured to controllably move the first movable part of the casing laterally with respect to the first end of the upper lip and the second movable part of the casing laterally with respect to the second end of the upper lip in order to accommodate the thermal expansion of the upper lip. The lower lip also extends beyond the width of the slot, defining a first end and a second end, and each of the two ends of the lower lip is connected to a lower lip support frame including a first movable part and a second movable part that are independently movable laterally. When the slot down-draw glass forming system is heated from ambient temperature to the glass processing temperature, the two ends of the lower lip and the two movable parts of the lower lip support frame are configured to controllably move the first movable part laterally with respect to the first end of the lower lip and the second movable part laterally with respect to the second end of the lower lip in order to accommodate the thermal expansion of the lower lip. Slot down-draw glass forming system.

[0071] Embodiment 19 The slot down-draw glass forming system according to Embodiment 18, wherein one or more adjustable push rods are disposed between each of the two ends of the upper lip and the respective first and second movable parts of the casing to controllably move the movable parts of the casing.

[0072] Embodiment 20 The slot down-draw glass forming system according to Embodiment 19, wherein the one or more adjustable push rods are remotely controllable.

[0073] Embodiment 21 The slot down-draw glass forming system according to Embodiment 19, wherein the one or more adjustable push rods are manually controllable.

[0074] Embodiment 22 The slot-down draw glass forming system according to Embodiment 19, further comprising one or more sets of rails and linear bearings for facilitating the movement of the two movable parts of the casing.

[0075] Embodiment 23 The slot-down draw glass forming system according to Embodiment 18, wherein one or more adjustable push rods are arranged between each of the two ends of the lower lip and the respective movable parts of the lower lip support frame to controllably move the movable parts of the lower lip support frame.

[0076] Embodiment 24 The slot-down draw glass forming system according to Embodiment 23, wherein the one or more adjustable push rods are remotely controllable.

[0077] Embodiment 25 The slot-down draw glass forming system according to Embodiment 23, wherein the one or more adjustable push rods are manually controllable.

[0078] Embodiment 26 The slot-down draw glass forming system according to Embodiment 23, further comprising one or more sets of rails and linear bearings provided on each of the two movable parts of the lower lip support frame for facilitating the movement of the two movable parts of the lower lip support frame.

Description of Reference Numerals

[0079] 10 Platinum passage 12 Slot 100 Glass forming system 120 Terminal slot assembly 121 Upper lip 122 Lower lip 130 Glass conditioner 132 Molten glass feeding section 134 Glass conditioner diffusion section 134a Elbow-shaped section 135 Glass conditioner vertical section 140 Terminal slot assembly 145 Upper slot support frame 146 Support frame 147 Refractory fiber felt layer 200 Housing structure 310 First casing part 320 Elbow-shaped casing part 330 Second casing part 340 Lower lip support frame 410, 410b Push rod 510a, b, c One or more sets of rails and linear bearings 520, 520a, b Dish spring washer 522, 522a Compression cap

Claims

1. A slot down-draw glass forming system comprising: a molten glass feeding section, a glass conditioner diffusion section connected to and in fluid communication with the molten glass feeding section, a glass conditioner vertical section, and a terminal slot assembly comprising an upper lip, and a lower lip wherein the lower lip is removably coupled to the upper lip and is configured to be removed from the terminal slot assembly without removing the upper lip. A slot down-draw glass forming system.

2. The slot down-draw glass forming system of claim 1, wherein the lower lip is connected to the upper lip by a support frame.

3. The slot down-draw glass forming system of claim 1, further comprising a layer of refractory fiber felt provided between the upper lip and the lower lip.

4. The slot down-draw glass forming system of claim 1, wherein the lower lip, the upper lip, or both the lower lip and the upper lip are configured as heating elements by Joule heating.

5. The slot down-draw glass forming system of claim 4, wherein the glass conditioner diffusion section has a molten glass receiving end and a molten glass discharging end, and the molten glass receiving end is configured as a heating element by Joule heating.

6. A housing structure for enclosing the glass conditioner diffusion section, the glass conditioner vertical section, and the terminal slot assembly in a controlled atmosphere to reduce oxidation of platinum components of the glass conditioner diffusion section, the glass conditioner vertical section, and the terminal slot assembly. The slot down-draw glass forming system of claim 1, further comprising the housing structure.

7. A slot down-draw glass forming system comprising: a molten glass feeding section, a molten glass feeding section, A glass conditioner connected to and in fluid communication with the molten glass feeding section, the glass conditioner including a diffusion section, a vertical section, an elbow-shaped section connecting the diffusion section and the vertical section, and a platinum passage for carrying the molten glass extending through the diffusion section, the elbow-shaped section, and the vertical section. A first casing portion surrounding the platinum passage within the conditioner diffusion section. A second casing portion surrounding the platinum passage within the conditioner vertical section. An elbow-shaped casing portion surrounding the platinum passage within the elbow-shaped section. Comprising, wherein The first casing portion and the elbow-shaped casing portion are arranged in linear alignment with the platinum passage within the conditioner diffusion section, and the first casing portion and the elbow-shaped casing portion maintain the linear alignment while adapting to the thermal expansion of the platinum passage within the conditioner diffusion section when the slot-down draw glass forming system is heated from ambient temperature to glass processing temperature, and are configured to controllably move the elbow-shaped casing portion away from the first casing portion. Terminal slot assembly Further comprising a slot-down draw glass forming system.

8. The elbow-shaped casing portion and the second casing portion are arranged in linear alignment with the platinum passage within the conditioner vertical section and the elbow-shaped casing portion, and the second casing portion maintains the linear alignment while adapting to the thermal expansion of the platinum passage within the conditioner vertical section when the slot-down draw glass forming system is heated from room temperature to glass processing temperature, and is configured to controllably move the second casing portion away from the elbow-shaped casing portion. The slot-down draw glass forming system according to claim 7.

9. One or more adjustable push rods are arranged between the first casing portion and the elbow-shaped casing portion to controllably move the elbow-shaped casing portion away from the first casing portion. The slot-down draw glass forming system according to claim 7.

10. The slot down draw glass forming system according to claim 9, further comprising one or more sets of rails and linear bearings for maintaining the linear alignment between the first casing part and the elbow-shaped casing part while the elbow-shaped casing part is moving.

11. The slot down draw glass forming system according to claim 7, wherein the thermal expansion of the platinum passage in the conditioner diffusion section is determined by monitoring the temperature of the platinum passage in the conditioner diffusion section.

12. The slot down draw glass forming system according to claim 8, wherein one or more adjustable push rods are arranged between the elbow-shaped casing part and the second casing part to controllably move the second casing part away from the elbow-shaped casing part.

13. The slot down draw glass forming system according to claim 12, further comprising one or more sets of rails and linear bearings for maintaining the linear alignment between the elbow-shaped casing part and the second casing part while the elbow-shaped casing part is moving.

14. Further comprising one or more stacks of disc spring washers for determining the thermal expansion of the platinum passage in the conditioner vertical section, wherein the one or more stacks of disc spring washers are configured to experience an increase in compression when the platinum passage in the conditioner vertical section expands relative to the second casing part, and the thermal expansion of the platinum passage in the conditioner vertical section is determined by monitoring the increase in compression of the one or more stacks of disc spring washers. The slot down draw glass forming system according to claim 12.

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