TWI540107B - Apparatus and methods for fusion drawing a glass ribbon - Google Patents

Description

Apparatus and method for fusing a traction glass ribbon

The present invention generally relates to apparatus and methods for fusing a glazing glass ribbon, and in particular, to an apparatus and method for fusing a glazing glass ribbon with a heating device and a cooling device.

Glass manufacturing systems are commonly used to form various glass articles, such as LCD sheet glass. It is known to produce sheet glass by flowing a molten glass downward through a wedge and pulling a glass ribbon from the root of the wedge. Edge guides are often provided at opposite ends of the forming wedge to assist in achieving the desired ribbon width and edge characteristics.

To provide a basic understanding of some of the example aspects described in the Detailed Description of the Invention, a simplified summary of the disclosure is presented below.

In an exemplary aspect, the fusion splicing method comprises the steps of: flowing molten glass through a forming surface portion of a pair of downwardly inclined wedges, and forming a downwardly inclined forming surface portion to meet in a downstream direction to form Root. The method further includes the steps of flowing the molten glass through the edge guide, the edge guide intersecting at least one of the pair of downwardly inclined forming surface portions. The method also includes the steps of: drawing a glass ribbon from the root, wherein the edges of the glass ribbon are formed by the flow of molten glass away from the edge guide. The method further includes the steps of: heating the interface of the molten glass with the edge guide using a heating device and using a cooling device to extract heat from a portion of the glass ribbon that is flowing away from the edge guide.

In another exemplary aspect, an apparatus for fusing a traction glass ribbon includes forming a wedge having a pair of downwardly inclined forming surface portions, the downwardly inclined forming surface portions meeting in a downstream direction, To form the roots. The apparatus further includes an edge guide that intersects at least one of the pair of downwardly inclined forming surface portions. The apparatus also includes a heating device configured to heat the interface of the molten glass contact edge guide and a cooling device configured to extract heat from a portion of the glass ribbon that is flowing away from the edge guide.

Embodiments of the present invention will now be fully described in the following description with reference to the accompanying drawings. Wherever possible, the same reference numerals are in the However, the invention may be embodied in many different forms and should not be construed as being limited to the specific embodiments set forth herein.

Figure 1 is a schematic illustration of an apparatus 101 for fusing a glazing glass ribbon 103 for subsequent processing of the glass ribbon into a glass sheet. Apparatus 101 can include a melting tank 105 configured to receive batch 107 from storage bin 109. Batch 107 can be introduced by batch delivery device 111, which is driven by motor 113. The optional controller 115 can be configured to drive the motor 113 to direct a desired amount of batch 107 into the melt tank 105 as indicated by arrow 117. The glass metal probe 119 can be used to measure the level of the glass melt 121 in the riser 123, and the glass metal probe 119 transmits the measured information to the controller 115 via the communication line 125.

The apparatus 10 may also include a finishing vessel 127, such as a refining tube, located downstream of the melting tank 105 and coupled to the melting tank 105 by a first connecting tube 129. A mixing tank 131, such as a mixing chamber, may also be located downstream of the refining tank 127, and a delivery tank 133, such as a crucible, may be located downstream of the mixing tank 131. As shown, the second connecting tube 135 can couple the refining groove 127 to the mixing tank 131, and the third connecting tube 137 can couple the mixing tank 131 to the delivery trough 133. As further illustrated, a downflow tube 139 can be placed to deliver the glass melt 121 from the delivery trough 133 to the inlet 141 that forms the trough 143. As shown, the melting tank 105, the refining tank 127, the mixing tank 131, the delivery tank 133, and the forming tank 143 are examples of glass melting stations that can be disposed in series along the apparatus 101.

The melting tank 105 is typically fabricated from a refractory material such as a refractory (e.g., ceramic) brick. Apparatus 101 may further comprise several components, typically made of platinum or a platinum-containing metal, such as platinum-ruthenium, platinum-ruthenium, and combinations thereof, but may also include, for example, molybdenum, palladium, rhodium, iridium, titanium, tungsten, Refractory materials such as lanthanum, cerium, zirconium, and alloys thereof and/or zirconia. The platinum-containing member may include a first connecting pipe 129, a refining groove 127 (eg, a refiner tube), a second connecting pipe 135, a standpipe 123, a mixing tank 131 (eg, a stirring chamber), a third connecting pipe 137, One or more of a delivery tank 133 (eg, helium), a downcomer 139, and an inlet 141. The forming groove 143 can also be made of a refractory material and designed to form the glass ribbon 103.

Figure 2 is a cross-sectional perspective view of the apparatus 101 along line 2-2 of Figure 1. As shown, forming the groove 143 includes forming a wedge 201 that includes a pair of downwardly inclined forming surface portions 207, 209 extending between opposite ends of the forming wedge 201. The pair of downwardly inclined forming surface portions 207, 209 meet in the downstream direction 211 to form a root portion 213. The traction plane 215 extends through the root 213 where the glass ribbon 103 can be drawn in the downstream direction 211 along the traction plane 215. As shown, although the drag plane 215 may extend in other orientations of the corresponding root 213, the drag plane 215 may equally divide the root 213.

The forming groove 143 may include one or more edge guides that intersect at least one of the pair of downwardly inclined forming surface portions 207, 209. In a further example, one or more edge guides can intersect both of the downwardly sloped forming surface portions 207, 209. In a further example, the edge guides can be disposed at opposite ends of the forming wedge 201, wherein the edges of the glass ribbon 103 can be formed from molten glass that flows away from the edge director. For example, as shown in FIG. 2, the edge guide 217 can be disposed at the first opposite end 203, and the second identical edge guide (not shown) can be disposed at the second opposite end (not shown) Show). Each edge guide can be configured to intersect both of the downwardly sloping formation surface portions 207, 209. Although the edge guides may have different features in further examples, each edge guide 217 may be substantially identical to each other. A variety of wedge and edge guide configurations can be used in accordance with the teachings of the present disclosure. For example, the disclosure of the disclosure of the present invention is disclosed in U.S. Patent No. 3,451,798, U.S. Patent No. 3,537,834, U.S. Patent No. 7,409,839, and/or U.S. Provisional Patent Application Serial No. 61/155,669, filed on Jan. 26, which is incorporated herein by reference.

FIG. 2 illustrates only one example of an edge guide 217 that can be used in the context of the present disclosure. The first edge guide 217 will be discussed before it is understood that the second edge guide (not shown) in some examples may be similar or identical to the first edge guide 217. While the edge guides may have different characteristics to provide various glass sheet features and/or accommodate various grooved configurations, providing the same edge guide may be beneficial to provide a consistent glass ribbon.

FIG. 2 illustrates a first side of the first edge guide 217 disposed corresponding to the first downwardly inclined formation surface portion 207 forming the wedge 201. Although not shown, the first edge guide 217 further includes a second side that is disposed corresponding to the second downwardly sloped formation surface portion 209 that forms the wedge 201. The second side of the first edge guide 217 is a mirror image of the first side to the traction plane 215 of the aliquoting root 213. As shown, the first side includes a first surface 219 that intersects the first downwardly sloped forming surface portion 207 that forms the wedge 201. Although not shown, the second side of the first edge guide 217 also includes substantially the same surface that intersects the second downwardly sloped forming surface portion 207 that forms the wedge 201.

Retaining blocks 221 may be provided at opposite ends of the forming wedge 201 to assist in laterally positioning the corresponding first and second edge guides 217. Optionally, as shown, the first edge guide 217 can include an upper portion 223 and a lower portion 225. In some examples, the lower portion 225 can engage the first edge guide 217 with the first opposite end 203 and the second edge guide for engagement with the second opposite end (not shown). Joining the edge guides 217 together may be beneficial to simplify assembly of the edge guides 217 to form the wedges 201. In a further example, the upper portion 223 of the edge guide 217 can be provided separately. For example, the first edge guide 217 can be separated from the second edge guide and independently assembled to form the pair of downwardly inclined forming surface portions 207, 209 forming the wedge 201. In such a configuration, providing the unjoined upper portion 223 simplifies the manufacture of the edge guide 217. Each edge guide 217 can be provided with a variety of orientations and geometries by providing different surfaces associated with forming the wedge 201.

The apparatus 101 for fusing the glazing glass ribbon may also include at least one edge roller assembly including a pair of edge rollers configured to engage corresponding ones when the glass ribbon is drawn away from the root 213 forming the wedge 201 Glass belt edge. The pair of edge rollers facilitate proper finishing of the edges of the ribbon. The edge roller trim provides the desired edge features and proper fusion of the edge portions of the molten glass, wherein the molten glass edge portions are pulled away from the edge guides associated with the pair of downwardly sloped forming surface portions 207, 209 The opposite surface. As shown in FIG. 2, the first edge roller assembly 227 is associated with the first edge guide 217, and the second edge roller assembly (not shown) is associated with the second edge guide. Each edge roller assembly 227 can be substantially identical to one another, although the pair of edge rollers can have different features in further examples.

Figure 2 depicts an exemplary edge roller assembly that can be used in the context of the present disclosure. The first edge roller assembly 227 will be discussed before it is understood that the second edge roller assembly (not shown) in some examples may be similar or identical to the first edge roller assembly 227. As shown in FIG. 2, the first edge roller assembly 227 includes a first pair of edge rollers 229, and the first pair of edge rollers 229 includes a first edge roller 231 and a second edge roller 233. The edge rollers 231, 233 are configured to simultaneously engage the first side and the second side of the glass ribbon 103. The first edge roller assembly 227 further includes a first shaft 235 to which the first shaft 235 is attached and a second shaft 237 to which the second edge roller 233 is attached. The first and second shafts 235, 237 are configured to be rotatably drivable by a motor (not shown).

As shown schematically in FIG. 2, device 101 may also include one or more heating devices 239. The heating device 239 is configured to heat the interface of the molten glass in contact with the first edge guide 217. In the illustrated example, the first heating device 239 can be positioned adjacent the edge guide 217 as an external heating device. In one example, the external heating device can be configured to heat the rear side of the lower portion 225 of the first edge guide 217. As shown in Fig. 3, the heating device 339 can also be positioned inside the edge guide, although the heating device can be positioned on the edge guide or at other locations in further examples. In fact, the heating device can be positioned in various three-dimensional positions relative to the edge guide 217. As shown, a single heating device can be provided, although a plurality of heating devices can be provided in further examples.

The heating means heats the interface of the molten glass in contact with the first edge guide 217 to be higher than the liquidus temperature of the molten glass. The liquidus temperature corresponds to a lower temperature range in which the glass remains molten without crystal formation. If a part of the molten glass is lower than the liquidus temperature, crystallized glass may be developed. The portion of the crystallized glass, commonly referred to as devit in the molten glass, tends to accumulate at a rate proportional to the temperature difference below the liquidus temperature of the glass. Thus, in one example, the heating device 239 is configured to heat the interface of the molten glass with the first edge guide to reduce the rate at which devitation builds up on the edge guide. In another example, the edge guide 217 is maintained above the liquidus temperature to substantially reduce or even eliminate any devitation buildup on the edge guide. Eliminating any devitation buildup can result in a devitrification-free edge guide device.

Although it is desirable to reduce the accumulation of devitation on the edge guides, the operation of the heating device 239 may also tend to reduce the viscosity of the molten glass. As noted by the symbol 245 in Figure 2, the reduced viscosity may undesirably reduce the width of the glass ribbon 103.

Apparatus 101 may also include one or more cooling devices 241 to counteract an undesired reduction in the width of glass ribbon 103. As schematically illustrated in FIG. 2, the cooling device 241 is configured to extract heat from a portion of the molten glass that flows away from the first edge guide 217. Cooling device 241 can include various devices including, but not limited to, fluid dispensing devices (eg, holes that form an air jet stream), relatively cold objects that are held near the edge of the glass ribbon, radiant coolers, and/or a plurality of fluid nozzles.

The cooling device can be configured to operate in one or more of a variety of modes of operation. For example, the cooling device 241 can be configured to preferentially extract heat from the edge of the glass ribbon 103 below the root 213 such that the temperature of the edge of the glass ribbon 103 decreases at a higher rate than the temperature of the inner portion of the ribbon. In such an example, the inner portion may include an intermediate portion, such as an intermediate portion disposed between opposite lateral edges of the glass ribbon 103. Additionally or alternatively, the cooling device 241 can be configured such that the cooling device 241 extracts more heat from the edge of the glass ribbon 103 below the root portion 213 than the heating device 239 provides to the interface of the molten glass and the edge guide.

The operation of the cooling device 241 at a location below the root 213 helps to counteract the undesirable reduction in ribbon width that may occur due to the separate operation of the heating device 239. Thus, a heating device 239 can be used to reduce the formation of devitation on the edge guide while using the cooling device 241 to offset the molten glass that may have left the edge guide due to the use of the heating device 239 and without cooling therewith. Unexpected loss of ribbon width occurs.

As shown in FIG. 3, a side view of a second exemplary device 301 including the forming wedge 201 and the edge guide 217 of FIG. 2 is shown therein. In the example of FIG. 3, the heating device 339 is located within the edge guide 271. As further shown in FIG. 3, apparatus 301 can include a pair of edge gates 305 and a pair of center gates 307. Since the other of the pairs of gates is located on the opposite side of the molten glass, only one of the edge gates 305 and one of the center gates 307 is shown in this view. The edge gate 305 and the center gate 307 are located below the lower portion 225 of the edge guide 217 to assist in directing the flow of molten glass. Since the central portion of the molten glass is thinner than the edge portion of the molten glass, the center gates 307 can be closer together than the edge gates 305. The edge gate 305 cannot be so in close proximity due to the additional molten glass flow from the edge guide 217.

As further shown in FIG. 3, the first and second rollers 231, 233 can be actively cooled to assist in reducing the likelihood of molten glass depositing on the edge rollers 231, 233. For example, as shown in FIG. 3, configurable inlet line 309 extends through each shaft 235 to provide a cooling fluid (ie, gas or liquid) to first and second rollers 231, 233. The outlet line 311 also extends through the shafts 235, 237 to allow the heated liquid to flow back to the liquid source 313. The hydraulic pump 315 can draw fluid from the liquid source and pass through the heat exchanger 317 to be transferred from the first and second rollers 231, 233 before circulating back into the line 309 to continue cooling the first and second rollers 231, 233. Hot removal. Cooling can help reduce the likelihood of glass sticking to the rollers. In a further example, the rollers can be cooled at a higher rate to assist in cooling device 241.

A third example device 401 is shown in FIG. As described above, the heating device 239 heats the interface where the molten glass contacts the first edge guide 217. Cooling device 241 is configured to extract heat from a portion of the molten glass that flows away from first edge guide 217. The third example device 401 may also further include a structure to cool the rollers 231, 233, or any other structure from other examples.

In a third example of FIG. 4, a heat shield device can be provided with the illustrated heat shield 411 as appropriate. If a heat shield 411 is provided, the heat shield 411 can be configured to shield the heated region associated with the heating device 239 and the cooling region associated with the cooling device 241. As further illustrated, a control system 419 can be provided to control at least one of the heating device 239 and the cooling device 241. Control system 419 can operate at least one of heating device 239 and cooling device 241 according to various states including, but not limited to, monitoring the temperature of the molten glass at different locations and monitoring the width of glass ribbon 103. In one example, control system 419 can be configured to control cooling device 241 to preferentially extract heat from the edge of glass ribbon 103 below root 213 such that the temperature of the edge of glass ribbon 103 is higher than the temperature of the inner portion of glass ribbon 103. The rate is reduced. Additionally or alternatively, the control system 419 can be configured to operate at least one of the heating device 239 and the cooling device 241 such that the cooling device 241 draws more heat from the edge of the glass ribbon 103 below the root portion 213 than the heating device 239 provides to the molten glass. The heat of the interface in contact with the edge guide.

In one example, control system 419 can further include a controller 421 and at least one inductor 423. In this example, at least one of the inductors 423 is located on the edge guide 217, although it may be located at other locations in further embodiments. Still further, the inductor can include an infrared sensor configured to sense a temperature condition associated with the edge guide. At least one inductor 423 is configured to sense the temperature associated with the molten glass adjacent the edge guide 217 and to provide feedback control to the heating device 239 and the cooling device 241 using the sensed temperature. At least one sensor 423 can transmit the sensed temperature to the controller 421 via a wired connection or through a wireless connection. Controller 421 is then configured to adjust the operation of heating device 239 and/or cooling device 241 in response to the sensed temperature. Additionally or alternatively, another inductor 425 may be associated with the cooling device 241 to sense the temperature state of the edge of the glass ribbon 103. The inductor may comprise an infrared sensor, although other sensing devices may be provided in further examples. The inductor 425 is configured to sense the temperature associated with the edge of the glass ribbon 103 and provide feedback to the controller 421 using the sensed temperature. Based on the sensed feedback, controller 421 can then operate cooling device 241 to provide an appropriate cooling state.

Still further, the controller can transmit a signal along line 417 to drive a motor (not shown) to control the position of the thermal shield 411 to provide a heated region associated with the heating device 239 and a cooling region associated with the cooling device 241. Thermal control is desired.

A method for forming glass will now be described with respect to device 401, which includes an example edge guide 217. It will be appreciated that similar or identical method steps can be performed with further examples, for example, as described throughout the application. Moreover, the example methods of the present invention may omit and/or add additional steps. Also, unless noted, such steps may be performed in a simultaneous, sequential or different order depending on the particular application.

As shown in FIGS. 1 to 2 and 4, a method of forming glass by the example apparatus 401 including the edge guide 217 is schematically illustrated therein. In the first exemplary method, a fusion screed for making the glass ribbon 103 is provided. The method includes the steps of flowing molten glass through a pair of downwardly inclined forming surface portions 207, 209 comprising wedges 201, wherein the pair of downwardly sloped forming surface portions 207, 209 are formed at the bottom of the wedge 201 The roots 213 meet. The method further includes the steps of flowing the molten glass through the first edge guide 217, the first edge guide 217 intersecting at least one of the pair of downwardly inclined forming surface portions 207, 209, and self-forming The root 213 of the wedge 201 drags the molten glass to form a glass ribbon 103. The method further includes the steps of: using a heating device 239 to heat the interface of the molten glass in contact with the first edge guide 217, and using the cooling device 241 to self-flow away from the molten glass of the edge guide 217 Extract heat. Therefore, the heating device 239 heats the interface of the molten glass in contact with the first edge guide 217 to reduce devitation accumulation, and the cooling device 241 extracts heat from the position below the edge guide 217 to offset the possibility by offsetting The width of the glass ribbon 103 is preserved by the loss of width that occurs only by the use of the heating device 239. In one example, the heating device 239 heats the interface of the molten glass with the first edge guide 217 by using an external heater that operates outside of the edge guide 217. In another example, the heating device 239 heats the interface of the molten glass with the first edge guide 217 by using an internal heater that operates inside the edge guide 217. In one example, the cooling device 241 can extract heat from the molten glass below the edge guide 217 by using a fluid nozzle.

An exemplary method can include using a heating device 239 to heat the interface of the molten glass in contact with the first edge guide 217 to be above the liquidus temperature of the molten glass. The liquidus temperature corresponds to the temperature at which the crystalline phase begins to develop. Thus, in one example, the heating device 239 is configured to heat the interface of the molten glass with the first edge guide 217 to slow the rate at which devitation builds up on the edge guide 217. In another example, the edge guide 217 is maintained above the liquidus temperature to substantially reduce or even eliminate any devitation buildup on the edge guide 217. The additional heat flux required to completely eliminate the devitation buildup ensures that no portion of the surface of the edge guide 217 operates at a lower liquid phase temperature than the formed glass. Thus, aspects of the present disclosure can reduce or eliminate devitation buildup that may affect the quality of the ribbon. In fact, when the devit layer becomes too thick, the flowing glass "bridges" the fixed objects in the vicinity and causes serious operational problems. The devitation stack can also interfere with the fusion of the two molten glass ribbons that are drawn away from the root 213 from the downwardly sloped forming surfaces 207,209. The fusion interference at the edges can cause bubbles to form in the beads or cause other defects in the glass ribbon.

An exemplary method can include using a cooling device 241 to draw a significant amount of heat flux to counteract the use of the heating device 239. The step of using the heating means 239 to heat the interface of the molten glass in contact with the first edge guide 217 will cause a loss in width or a contraction of the glass ribbon 103. Cooling device 241 can be operated to extract a substantial amount of heat flux corresponding to the amount of heat flux applied by heating device 239 and to restore a portion of the width loss. In one example, the amount of heat flux applied and then extracted can be assessed by a glass ribbon forming model. The glass ribbon forming model provides guidance on the size of the glass sheets produced by the various temperatures of the molten glass.

In another example, the amount of heat flux applied and extracted can be measured during operation of the device. In one example, the cooling device 241 can operate at different cooling rates to achieve different width losses of the glass ribbon due to different narrowing of the molten glass. Based on the model building technique, it has been determined that operating the cooling device 241 at different rates can result in a reduction in the width loss of the resulting glass ribbon to approximately 57 mm. In another model setup example using a relatively high cooling rate, it has been determined that the width loss of the resulting glass ribbon can be reduced to approximately 6 mm. In yet another model setup example using a relatively high cooling rate, the model building results indicate that the glass ribbon has a width gain of approximately 11 mm.

The exemplary method may further include the step of maintaining the temperature of the molten glass below the loose deformation temperature of the molten glass at a position below the root 213. The loose deformation temperature represents the maximum allowable temperature on the free glass ribbon before the loose deformation state is observed. The loose deformation temperature can be varied depending on the cooling curve in one of the regions of the molten glass, as well as the local mass flow and the glass composition. The loose deformation is physically interpreted as a state in which the molten glass has a reduced viscosity because the molten glass temperature exceeds the loose deformation temperature. In the loosely deformed state, the viscosity of the molten glass is lowered to such an extent that it can no longer be stretched by a stretched reel (not shown). Still further, in the relaxed state of deformation, the flow of glass exiting the forming wedge can begin to extend beyond the purely rectangular glass sheet by a stretched reel positioned at a much lower position in the plane to a fixed thickness of glass stream. In an exemplary method, heating device 239 maintains the temperature at the edge of the molten glass through edge guide 217 in the range of from about 3010 ° C to about 1200 ° C. The temperature range can correspondingly maintain the molten glass in contact with the first edge guide at a liquidus temperature higher than the molten glass, such as 3010 ° C, while still maintaining the temperature of the molten glass at a position below the root below the loose temperature Deformation temperature, such as 1200 ° C. The exemplary method can maintain the temperature by using one of the heating device 239 and the cooling device 241, or by using both the heating device 239 and the cooling device 241.

In another alternative, the example method may further include the steps of shielding the heating zone of the heating device 239 from the cooling zone of the cooling device 241. The shielding of the heating zone and the cooling zone can be achieved by the heat shield 411 shown in FIG. The heat shield 411 can be configured to assist in controlling heat transfer between the heating zone and the cooling zone.

The example method may further include the step of controlling at least one of the heating device 239 and the cooling device 241 with the control system 419. Control system 419 can operate at least one of heating device 239 and cooling device 241 in various manners depending on various conditions, including the temperature of the molten glass at different locations, and the width of glass ribbon 103. In one example, control system 419 can include the steps of sensing or measuring the temperature with respect to the molten glass and providing feedback control to control system 419 using the sensed temperature.

It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claimed invention.

101. . . device

103. . . Glass belt

105. . . Melting tank

107. . . Batch

109. . . Storage warehouse

111. . . Batch delivery device

113. . . motor

115. . . Controller

117. . . arrow

119. . . Glass metal probe

121. . . Glass melt

123. . . Standpipe

125. . . Communication line

127. . . Refinement slot

129. . . Connecting pipe

131. . . Mixing tank

133. . . Delivery slot

135. . . Connecting pipe

137. . . Connecting pipe

139. . . Downflow tube

141. . . Entrance

143. . . Forming a groove

201. . . Forming a wedge

203. . . Opposite end

207. . . Forming a surface portion

209. . . Forming a surface portion

211. . . Downstream direction

213. . . Root

215. . . Traction plane

217. . . Edge guide

219. . . First surface

221. . . Reserved block

223. . . Upper part

225. . . Lower part

227. . . Edge roller assembly

229. . . Pair of edge rollers

231. . . First edge roller

233. . . Second edge roller

235. . . First shaft

237. . . Second shaft

239. . . heating equipment

241. . . Cooling device

245. . . width

301. . . device

305. . . Edge gate

307. . . Central gate

309. . . Entering the pipeline

311. . . Export pipeline

313. . . Liquid source

315. . . Hydraulic pump

317. . . Heat exchanger

339. . . heating equipment

401. . . device

411. . . Heat shield

417. . . line

419. . . Control System

421. . . Controller

423. . . sensor

425. . . sensor

These and other aspects are more appropriately understood when the detailed description of the invention is read with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of an apparatus for fusing a traction glass ribbon;

Figure 2 is a cross-sectional perspective view of the apparatus along line 2-2 of Figure 1 showing portions of the first exemplary apparatus;

Figure 3 is a side elevational view showing a portion of the second example device;

Figure 4 is a side elevational view of the portion of the third example device.

101. . . device

103. . . Glass belt

201. . . Forming a wedge

203. . . Opposite end

207. . . Forming a surface portion

209. . . Forming a surface portion

211. . . Downstream direction

213. . . Root

215. . . Traction plane

217. . . Edge guide

219. . . First surface

221. . . Reserved block

223. . . Upper part

225. . . Lower part

227. . . Edge roller assembly

229. . . Pair of edge rollers

231. . . First edge roller

233. . . Second edge roller

235. . . First shaft

237. . . Second shaft

239. . . heating equipment

241. . . Cooling device

245. . . width

Claims (18)

A fusion and traction method comprising the steps of: flowing molten glass through a forming surface portion inclined downwardly by a pair of wedges, the downwardly inclined forming surface portions meeting along a downstream direction to form a molten glass a root portion; the molten glass flows through an edge guide that intersects at least one of the pair of downwardly inclined forming surface portions; a glass ribbon is drawn from the root portion, wherein the glass ribbon An edge is formed by the molten glass flowing away from the edge guide; a heating device is used to heat the interface of the molten glass with the edge guide, wherein the heating device bonds the molten glass to the edge The interface in contact with the guide member is maintained at a temperature above the liquidus of the molten glass; and a cooling device is used to extract heat from a portion of the glass ribbon that has flowed away from the edge guide. The method of claim 1, further comprising the step of maintaining a temperature of one of the molten glass below a loose deformation temperature of the molten glass at a position downstream from the root. The method of claim 1, wherein the cooling device extracts heat from the edge of the glass ribbon in preference to the root portion, such that The temperature of the edge of the glass ribbon is reduced at a rate higher than the temperature of the inner portion of one of the glass ribbons. The method of claim 1, wherein the cooling device draws heat from the edge of the glass ribbon below the root more than the heating device provides the molten glass in contact with the edge guide The heat at the interface. The method of claim 1, further comprising the step of shielding a heating zone of the heating device from a cooling zone of the cooling device. The method of claim 1, wherein the heating device maintains the interface of the molten glass in contact with the edge guide by using an external heater, the external heater being outside the edge guide Operation. The method of claim 1, wherein the heating device maintains the interface of the molten glass in contact with the edge guide by using an internal heater, the internal heater being inside the edge guide Operation. The method of claim 1, wherein the cooling device comprises a fluid nozzle at a position downstream from the edge guide Heat is extracted from the edge of the glass ribbon. The method of claim 1, further comprising the step of controlling the heating device and at least one of the cooling devices with a control system. The method of claim 9, further comprising the steps of: sensing a temperature and using the sensed temperature to provide feedback to the control system. An apparatus for fusing a glass ribbon, comprising: forming a wedge comprising a pair of downwardly inclined forming surface portions, the downwardly inclined forming surface portions meeting along a downstream direction to form a portion; an edge guide intersecting at least one of the pair of downwardly inclined forming surface portions; a heating device configured to heat the molten glass to contact the edge guide An interface, wherein the heating device is configured to maintain the interface of the molten glass in contact with the edge guide at a liquidus temperature above the molten glass; and a cooling device configured to self-flow away from the edge guide A portion of the glass ribbon of one of the leads extracts heat. The apparatus of claim 11, wherein the cooling device is configured such that the cooling device draws heat from the edge of the glass ribbon in preference to the root portion, such that the temperature of the edge of the glass ribbon is higher than the The rate of temperature at the inner portion of one of the glass ribbons is reduced. The apparatus of claim 11, wherein the cooling device is configured such that the cooling device extracts heat from the edge of the glass ribbon below the root more than the heating device provides to the molten glass and the edge The heat at the interface where the guide contacts. The apparatus of claim 11, further comprising a heat shield positioned between a heating zone of the heating device and a cooling zone of the cooling device. The apparatus of claim 11, further comprising: a control system configured to control at least one of the heating device and the cooling device. The device of claim 15 wherein the control system includes a controller and a temperature sensor configured to provide feedback to the controller. The apparatus of claim 15 wherein the control system is configured to control the cooling device to extract heat from the edge of the glass ribbon in preference to the root portion, such that the temperature of the edge of the glass ribbon is higher than The rate of temperature of the inner portion of one of the glass ribbons is reduced. The apparatus of claim 15 wherein the control system is configured to operate at least one of the heating device and the cooling device such that the cooling device draws heat from the edge of the glass ribbon below the root portion More than the heating device provides heat to the interface where the molten glass is in contact with the edge guide.