JP2011225452A - Method and device for manufacturing glass plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize a temperature distribution in the width direction of a glass ribbon, namely, a viscosity distribution, and to prevent a shape failure of the end of the glass ribbon.SOLUTION: The glass ribbon is formed by fusing molten glass at the lower end 4e of a glass plate forming device 4, and a glass plate is manufactured by a down-draw method for conveying the glass ribbon 9 downward along a plurality of rollers 6 arranged under the glass plate forming device 4. A heater 8 is provided in a space between the lower end 4e of the glass plate forming device 4 and a roller 6a positioned nearest from the glass plate forming device 4, and the glass ribbon 9 is formed and conveyed, while heating locally the end of the glass ribbon 9 just after being fused by the heater 8.

Description

  The present invention relates to a glass plate manufacturing method and a manufacturing apparatus. The present invention particularly relates to a technique for manufacturing a glass plate by a downdraw method.

  The down draw method is a glass ribbon in which the molten glass overflowing from the upper groove of the wedge-shaped glass plate forming apparatus flows downward along the side wall of the glass plate forming apparatus and is fused at the lower end (root) of the glass plate forming apparatus. Is a method of continuously molding. The glass ribbon proceeds through the furnace while being supported by a roll disposed below the glass plate forming apparatus, is gradually cooled, and is cut so as to obtain a glass plate of a desired size.

  The downdraw method is suitable for manufacturing a large area and thin glass plate, for example, a glass substrate for a flat panel display. For example, Japanese Patent Application Laid-Open No. 2008-133174 describes a technique for stably manufacturing an extremely thin glass plate (for example, 0.5 mm or less). Specifically, after reducing the thickness of the glass ribbon to the initial thickness directly under the molded body (glass plate forming apparatus), the glass ribbon is reheated (heater) disposed below the regulating means (cooling roller). Is heated to a temperature equal to or higher than the softening point and softened, and the softened glass ribbon is stretched downward to further reduce the plate thickness.

  Moreover, in order to shape | mold a high quality glass ribbon, the temperature control of the width direction of the molten glass in the side wall of a glass plate shaping | molding apparatus is important. For example, in Japanese Patent Application Laid-Open No. 2007-112665, a heater in which the heating elements are arranged in a dense manner is provided at a position facing the side wall of the molded body (glass plate molding apparatus). A technique for homogenizing the temperature distribution is described. Japanese Patent Application Laid-Open No. 2008-69024 describes a technique for making the temperature distribution in the width direction of molten glass uniform by energizing and heating a platinum coating on the surface of a fusion cell (glass plate forming apparatus).

JP 2008-133174 A JP 2007-112665 A JP 2008-69024 A

  By the way, the end of the glass ribbon formed by the downdraw method is usually in the form shown in FIG. However, the end of the glass ribbon does not always have this shape and may have a bifurcated shape. The end portion having a bifurcated shape makes it difficult to cut the glass ribbon or causes the glass ribbon to break. Furthermore, due to the end portion having a bifurcated shape, the thickness of the central portion (product portion) varies, and the yield may be reduced.

  An object of the present invention is to prevent a defective shape of an end portion of a glass ribbon.

  The present inventors investigated in detail the cause of the shape defect at the end of the glass ribbon. As a result, the present invention has been completed by paying attention to the fact that the viscosity of the glass ribbon immediately after the fusion is the main factor determining the final shape of the end of the glass ribbon.

That is, the present invention
The glass sheet is formed by a down draw method in which molten glass is fused at the lower end of the glass plate forming apparatus to form a glass ribbon, and the glass ribbon is conveyed downward along a plurality of rolls arranged below the glass plate forming apparatus. A manufacturing method comprising:
A heater is provided in a space between the lower end of the glass plate forming apparatus and the roll located closest to the glass plate forming apparatus,
Provided is a method for producing a glass plate, wherein the glass ribbon is molded and conveyed while locally heating the end of the glass ribbon immediately after fusion with the heater.

In another aspect, the present invention provides:
A glass plate forming apparatus having a wedge-shaped cross section;
The glass ribbon formed by fusing molten glass overflowing from the upper groove of the glass plate forming apparatus at the lower end of the glass plate forming apparatus is disposed below the glass plate forming apparatus. A plurality of rolls transported downward;
The space between the lower end of the glass plate forming apparatus and the roll located closest to the glass plate forming apparatus so that the end in the width direction of the glass ribbon immediately after fusion can be locally heated. A heater provided in
An apparatus for producing a glass plate, comprising:

  The glass ribbon immediately after the fusion is not completely solidified and is in a viscous fluid state, and thus is easily affected by the ambient temperature. Usually, the edge part of a glass ribbon cools faster than the center part of a glass ribbon. If the temperature drop at the end is too fast compared to the temperature drop at the center, the viscosity varies in the width direction, and the shape of the end tends to be poor.

  On the other hand, according to the said invention, the edge part of the glass ribbon immediately after fusion is locally heated with a heater. That is, only the end portion of the glass ribbon is prevented from being rapidly cooled immediately after leaving the glass plate forming apparatus. Thereby, the temperature distribution in the width direction of the glass ribbon, that is, the viscosity distribution is made uniform, and the shape defect of the end portion is less likely to occur. Since the present invention can be implemented by diverting an existing apparatus, the present invention is excellent in terms of cost.

  In order to obtain the same effect as that of the present invention, it is conceivable to increase the atmospheric temperature in the furnace in the vicinity of the lower end of the glass plate forming apparatus. By doing so, the same effect as the present invention may be obtained. However, the present invention is quite advantageous in terms of power consumption because it is sufficient to locally heat the ends of the glass ribbon. Further, it is not preferable to raise the atmosphere in the furnace to a high degree because deterioration of various parts proceeds rapidly and the life of the apparatus is shortened.

  In addition, "the edge part of a glass ribbon" refers to the area | region to the position advanced about 50 mm inside from the side surface of the glass ribbon, for example.

The schematic front view of the manufacturing apparatus of the glass plate concerning one Embodiment of this invention. 1 is a schematic longitudinal sectional view taken along line II-II of the glass plate manufacturing apparatus shown in FIG. Partial enlarged view showing the detailed position of the heater Schematic diagram showing dimensional relationship between guide and heater Schematic showing a modification of the heater Schematic showing the positional relationship between the glass ribbon and roll Sectional drawing which shows one shape of the edge part of a glass ribbon

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIGS. 1 and 2, a glass plate manufacturing apparatus 100 according to the present embodiment includes a furnace 2, a glass plate forming apparatus 4 disposed in an upper part of the furnace 2, and a lower side of the glass plate forming apparatus 4. Are provided with a plurality of rolls 6 and a heater 8 disposed in the vicinity of the lower end 4 e (root) of the glass plate forming apparatus 4. According to this apparatus 100, a glass plate can be manufactured by the down draw method which fuse | melts the molten glass overflowed from the glass plate forming apparatus 4 by the lower end 4e, and shape | molds the glass ribbon 9. FIG.

  The furnace 2 is usually made of refractory bricks. A plurality of heaters 10 are arranged on the inner wall of the furnace 2 along the vertical direction. The heater 10 has a long shape extending in parallel with the longitudinal direction of the glass plate forming apparatus 4 and is suitable for heating a relatively wide range. The temperature inside the furnace 2 can be adjusted by controlling the heater 10. Specifically, a temperature gradient is formed along the vertical direction so that the glass ribbon 9 is gradually cooled when proceeding downward in the furnace 2.

  The glass plate forming apparatus 4 is usually made of refractory bricks. As shown in FIG. 2, in the cross section orthogonal to the longitudinal direction LD of the glass plate forming apparatus 4, the glass plate forming apparatus 4 has a wedge shape. The longitudinal direction LD of the glass plate forming apparatus 4 coincides with the width direction of the glass ribbon 9. A groove 4k for holding molten glass is formed in the upper part of the glass plate forming apparatus 4 so as to extend in the longitudinal direction LD. As shown in FIG. 1, a supply pipe 11 is connected to the groove 4k so that molten glass can be continuously supplied to the groove 4k from one side in the longitudinal direction LD.

  As shown in FIG. 2, the glass plate forming apparatus 4 has a pair of side walls 4j in the direction perpendicular to the longitudinal direction LD and the vertical direction. The side wall 4j forms a flow path of molten glass overflowing from the groove 4k. These side walls 4j form a ridge line at the lower end 4e so that the molten glass flowing through each side wall 4j is fused at the lower end 4e. As shown in FIG. 1, guides 7 that prevent the molten glass from protruding from the side walls 4j are attached to both ends of the glass plate forming apparatus 4 in the longitudinal direction LD. As shown in FIG. 4, the guide 7 has a wedge shape in a plan view, and is made of a plate material having a size that can cover the entire end surface of the glass plate forming apparatus 4. With respect to the vertical direction, the position of the tip of the guide 7 coincides with the lower end 4 e of the glass plate forming apparatus 4. By the action of the guide 7, it is possible to flow all of the molten glass along the side wall 4j.

  The roll 6 plays a role of conveying the glass ribbon 9 below the glass plate forming apparatus 4. The rotation speed of the roll 6 is adjusted so that the glass ribbon 9 having a desired thickness is formed. As shown in FIG. 2, the roll 6 is disposed symmetrically with respect to the vertical plane including the lower end 4 e of the glass plate forming apparatus 4 so as to sandwich the glass ribbon 9 in the thickness direction. The rolls 6 are arranged at predetermined intervals in the vertical direction. The glass ribbon 9 is conveyed downward while being sandwiched between these rolls 6.

  As shown in FIG. 1, the heaters 8 are provided on one side and the other side in the longitudinal direction LD of the glass plate forming apparatus 4. Specifically, the heater 8 is provided in a space between the lower end 4 e of the glass plate forming device 4 and the roll 6 a located closest to the glass plate forming device 4 in the vertical direction. By locally heating the end portion in the width direction of the glass ribbon 9 immediately after the fusion with the heater 8, the viscosity of the end portion of the glass ribbon 9 immediately after the fusion is prevented from becoming too high compared to the viscosity at the center portion. . In other words, the viscosity variation in the width direction of the glass ribbon 9 is reduced. As a result, the shape defect of the edge part of the glass ribbon 9 can be prevented. Furthermore, devitrification of the glass is also prevented.

  As is well known, devitrification is a phenomenon in which crystal grains are formed in glass and the transparency of the glass is lowered. When a glass plate is manufactured by the down draw method, devitrification tends to occur at the end of the glass ribbon 9. The reason is not necessarily clear, but it is thought that one reason is that the molten glass flow rate decreases in the vicinity of the guide 7 and the molten glass is held for a long time in a temperature range where devitrification is likely to occur.

  When the heater 8 is disposed in the vicinity of the guide 7, not only the end portion of the glass ribbon 9 but also the guide 7 is heated by the heater 8. It is possible to prevent the heat of the guide 7 from being transmitted to the molten glass in the vicinity of the guide 7 and to keep only the molten glass in the vicinity of the guide 7 for a long time in a temperature range where devitrification easily occurs. In particular, when the molten glass contains tin as a fining agent, tin oxide is crystallized in the glass and devitrification is likely to occur. Therefore, the present invention is particularly recommended when the molten glass contains tin.

In the present embodiment, the heater 8 is not in contact with any of the glass plate forming apparatus 4, the guide 7 and the furnace 2. The position of the heater 8 is adjusted so that the end of the glass ribbon 9 immediately after the fusion can be effectively heated. The detailed position of the heater 8 will be described with reference to FIG. The heater 8 is provided in a space outside the guides 7 attached to both ends in the longitudinal direction LD of the glass plate forming apparatus 4 and facing the side surface 9p of the glass ribbon 9. More specifically, with respect to the vertical direction, the heater 8 in the space between the lower end 4e of the glass sheet forming apparatus 4, the position P ₁ where the width of the glass ribbon 9 is constant gradually decreases is provided.

As shown in FIG. 3, at the time of molding, the width of the glass ribbon 9 gradually decreases from the lower end 4e of the glass plate forming device 4 to the position P _1. That is, the side surface 9p curves gently. The heater 8 faces the curved portion of the side surface 9p. By providing the heater 8 at such a position, the end of the glass ribbon 9 immediately after the fusion can be efficiently heated. The vertical distance H ₁ from the lower end 4e of the glass plate forming apparatus 4 (the lower end of the guide 7) to the heater 8 is, for example, 0 to 500 mm, preferably depending on the output and dimensions of the heater 8. 0 to 100 mm. The horizontal distance L ₁ from the inner wall surface 7g of the guide 7 to the heater 8 is, for example, −10 to 100 mm, preferably 0 to 100 mm, and more preferably 0 to 30 mm. However, care should be taken that the heater 8 does not contact the glass ribbon 9. When the distance L ₁ is −10 mm or more and less than 0 mm, a part or all of the heater 8 is present on the side where the glass ribbon 9 is present with reference to the inner wall surface 7 g of the guide 7.

As shown in FIG. 2, the heater 8 extends in the horizontal direction orthogonal to both the longitudinal direction LD and the vertical direction of the glass plate forming apparatus 4, that is, in the thickness direction of the glass ribbon 9. As shown in FIG. 4, the dimension W ₁ of the heater 8 in the thickness direction of the glass ribbon 9 is larger than the dimension W ₂ of the glass plate forming apparatus 4 and the dimension W _{3 of the} guide 7 in the direction. According to such a structure, since an edge part can be uniformly heated from both the front surface side and the back surface side of the glass ribbon 9, shape defects can be prevented more effectively. Further, since the heater 8 has a sufficient dimension W ₁ , the lower portion of the guide 7 can be sufficiently heated, so that the effect of preventing devitrification is enhanced.

  The energization (set temperature) of the heater 8 is appropriately controlled in consideration of the glass composition, the distance from the heater 8 to the glass ribbon 9, and the like. For example, in the composition of the glass plate for flat panel displays, the set temperature of the heater 8 can be arbitrarily adjusted in the range of 800 to 1300 ° C.

  Moreover, as shown in FIG. 4, you may provide the temperature sensor 12 which detects the temperature of the molten glass in the side wall 4j of the glass plate forming apparatus 4, and the controller 14 which acquires the signal from the temperature sensor 12. As shown in FIG. The temperature sensor 12 is attached to the lower part of the guide 7, for example, and indirectly detects the temperature of the molten glass. For example, a thermocouple can be used as the temperature sensor 12. The controller 14 controls energization to the heater 8 based on the detection result of the temperature sensor 12. For example, the temperature detected by the temperature sensor 12 and the set temperature of the heater 8 are made equal. In this way, the heater 8 can be appropriately controlled regardless of the glass composition, and the defective shape of the end of the glass ribbon 9 can be reliably prevented.

  Note that the output of the heater 8 may be manually adjusted based on the detection result of the temperature sensor 12. Moreover, when detecting the temperature of the center part of the width direction of the molten glass in the lower end 4e of the glass plate forming apparatus 4, a non-contact type infrared sensor can be used as the temperature sensor 12.

  The heater 8 is not particularly limited as long as it can be used even at an atmospheric temperature exceeding 1000 ° C. Specifically, as the heater 8, a linear heating element or a linear heating element in a coil shape can be used. Further, a radial heater such as a ceramic heater, a halogen heater, or a silicon carbide heating element can be used. The shape of the heater 8 is not particularly limited, and may be a rod shape as shown in FIGS. 1 to 4 or a U shape as shown in FIG. 5. As described above, since the width of the end portion of the glass ribbon 9 is about 50 mm, the heater 8 having the shape shown in FIGS. Further, it is not necessary to secure the space occupied by the heater 8. On the other hand, according to the U-shaped heater 18 shown in FIG. 5, the end 9t of the glass ribbon 9 can be surrounded by the heater 18 from three directions and heated.

  According to the present embodiment, since the end of the glass ribbon 9 is heated by the heater 8, the end of the glass ribbon 9 keeps the property of the viscous fluid stronger until it reaches the roll 6a. Therefore, as shown in FIG. 6, the glass ribbon 9 can be conveyed with the end 9t sandwiched between rolls 6a. In other words, the roll 6a is disposed at a position sandwiching the end 9t. With respect to the width direction of the glass ribbon 9, the roll 6 a crosses the side surface of the glass ribbon 9. On the other hand, the other rolls 6 below the roll 6a do not sandwich the end portion 9t, but sandwich the portion inside the end portion 9t.

  For example, as shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2008-133174, the positions of these rolls can be determined so that all the rolls do not sandwich the end portion of the glass ribbon. When the viscosity of the end is high, it is wise to avoid pinching the end with a roll from the viewpoint of carrying out stable conveyance and preventing the glass ribbon from cracking.

  On the other hand, according to this embodiment, since the increase in the viscosity of the end portion 9t immediately after the fusion is suppressed, the glass ribbon 9 can be conveyed with the end portion 9t sandwiched between the rolls 6a. Further, before the glass ribbon 9 is sufficiently cured, as shown in FIG. 6, it is also possible to apply pressure to the end portion 9t with the roll 6a so that the end portion 9t becomes flat to some extent. When the end 9t is flat, the process of cutting the glass ribbon 9 is facilitated. Although it is possible to sandwich the end 9t with another roll 6 below the roll 6a, if the end 9t is sandwiched between the roll 6a closest to the glass plate forming apparatus 4, the end 9t is flattened. The effect to become the highest. And if the part inside the edge part 9t is pinched | interposed with the other roll 6, stable conveyance can be implement | achieved, without causing malfunctions, such as a crack of the glass ribbon 9. FIG. Thus, according to this embodiment, both the effect of adjusting the shape of the end portion 9t and the effect of stably transporting the glass ribbon 9 can be enjoyed.

  The operation of the glass plate manufacturing apparatus 100 will be briefly described. When the amount of molten glass supplied to the groove 4k of the glass plate forming apparatus 4 exceeds a certain amount, the molten glass overflows from the groove 4k and flows downward along the side wall 4j. The molten glass on the side wall 4j is heated by a heater 10 disposed around the glass plate forming apparatus 4 in order to maintain viscosity. The molten glass flowing through each side wall 4j is fused at the lower end 4e, whereby a glass ribbon 9 is formed. The glass ribbon 9 is guided between the roll 6 and the roll 6 facing each other, and is conveyed downward while being gradually cooled. The temperature of the glass ribbon 9 becomes lower as it goes downward, and the solidification of the glass ribbon 9 proceeds accordingly. If the glass ribbon 9 conveyed outside the furnace 2 is cut into a desired size, a glass plate is obtained.

  According to this embodiment, since the end portion 9t of the glass ribbon 9 is heated by the heater 8, the viscosity of the end portion 9t of the glass ribbon 9 in the vicinity of the roll 6a is too high compared to the viscosity of the central portion. Can be prevented. The glass ribbon 9 is cooled to the temperature range of the glass transition point and solidifies in the middle of the furnace 2 as a guide.

  The viscosity of the molten glass at the lower end 4e of the glass plate forming apparatus 4 varies depending on the glass composition and production conditions. For example, when manufacturing the glass plate for flat panel displays, the viscosity of the molten glass in the lower end 4e is adjusted to the range of 10000-60000 Pa.s. The viscosity of the molten glass is controlled by the temperature of the molten glass. If the temperature of a molten glass is adjusted to the range of 800-1000 degreeC, the viscosity of a molten glass will settle in the said range. Specifically, the atmospheric temperature in the furnace 2 is adjusted by controlling the heater 10 so that the temperature of the molten glass becomes 800 to 1000 ° C. at the lower end 4e.

  Particularly in recent years, the demand for large-area glass plates is increasing. For example, the size of the glass substrate for 10th generation liquid crystal display is 2850 mm × 3050 mm. As the width of the glass ribbon becomes wider, the viscosity in the width direction tends to vary, so the effect obtained by applying the present invention increases. In addition, the typical glass composition of the glass substrate for flat panel displays is shown below.

SiO _2: 57~70 mass%
Al ₂ O ₃ : 13 to 19% by mass
B ₂ O ₃ : 8 to 13% by mass
MgO: 0 to 2% by mass
CaO: 4 to 6% by mass
SrO: 2 to 4% by mass
BaO: 0 to 2% by mass
Na ₂ O: 0 to 1% by mass
K ₂ O: 0 to 1% by mass
As ₂ O ₃ : 0 to 1% by mass
Sb ₂ O ₃ : 0 to 1% by mass
SnO ₂ : 0 to 1% by mass
Fe ₂ O ₃ : 0 to 1% by mass
ZrO ₂ : 0 to 1% by mass

  Using a continuous melting apparatus equipped with a refractory brick melting tank and a platinum adjustment tank (tank for carrying out the refining process), the glass raw material prepared to have the following composition was melted at 1550 ° C., The glass was clarified at 1600 ° C. and stirred at 1550 ° C. to obtain a molten glass. The total mass exceeds 100 because an error due to rounding is included.

SiO ₂ : 60.9% by mass,
Al ₂ O ₃ : 16.9% by mass
B ₂ O ₃ : 11.6% by mass
MgO: 1.7% by mass
CaO: 5.1 mass%
SrO: 2.6% by mass
BaO: 0.7 mass%
K ₂ O: 0.25% by mass
Fe ₂ O ₃ : 0.15% by mass
SnO ₂ : 0.13 mass%

  Next, the molten glass was supplied to the glass plate manufacturing apparatus 100 described with reference to FIG. The set temperature of the heater 8 was set to 1110 ° C. It can be inferred that the viscosity of the molten glass poured into the glass plate forming apparatus 4 corresponds to about 5000 Pa · s since the temperature of the molten glass was 1200 ° C.

  The molten glass was continuously supplied, and the molten glass overflowed from the glass plate forming apparatus 4 to form a glass ribbon. The glass ribbon was cut into a predetermined size to obtain a number of glass plates. When the shape of the edge part of these glass plates was investigated, there was no thing opened to the fork. In addition, no obvious devitrification occurred in these glass plates. In addition, the glass ribbon was shape | molded in the same procedure using the molten glass of another composition which becomes high viscosity easily at the time of shaping | molding. As a result, a glass plate having an end with a good shape was obtained.

2 Furnace 4 Glass plate forming device 4e Lower end (root)
4j Side wall 6, 6a Roll 7 Guide 8 Heater 9 Glass ribbon 9t End 12 Temperature sensor 14 Controller 100 Glass plate manufacturing apparatus

Claims (10)

The glass sheet is formed by a down draw method in which molten glass is fused at the lower end of the glass plate forming apparatus to form a glass ribbon, and the glass ribbon is conveyed downward along a plurality of rolls arranged below the glass plate forming apparatus. A manufacturing method comprising:
A heater is provided in a space between the lower end of the glass plate forming apparatus and the roll located closest to the glass plate forming apparatus,
While forming and conveying the glass ribbon while locally heating the end of the glass ribbon immediately after the fusion with the heater,
The said heater is the manufacturing method of the glass plate each arrange | positioned in the position facing the side surface of the said glass ribbon so that a heat ray may be irradiated toward the side surface of the said glass ribbon.   The manufacturing method of the glass plate of Claim 1 whose said space is a space outside the guide attached to the both ends of the longitudinal direction of the said glass plate forming apparatus.   The manufacturing method of the glass plate of Claim 1 or 2 whose said space is a space between the lower end of the said glass plate forming apparatus, and the position where the width | variety of the said glass ribbon reduces gradually and becomes constant.   Among the plurality of rolls, the roll located closest to the glass plate forming apparatus sandwiches the end of the glass ribbon at a position crossing the side surface of the glass ribbon in the width direction of the glass ribbon. The manufacturing method of the glass plate of any one of Claims 1-3.   The manufacturing method of the glass plate of any one of Claims 1-4 with which the said molten glass contains tin. A glass plate forming apparatus having a wedge-shaped cross section;
The glass ribbon formed by fusing molten glass overflowing from the upper groove of the glass plate forming apparatus at the lower end of the glass plate forming apparatus is disposed below the glass plate forming apparatus. A plurality of rolls transported downward;
The space between the lower end of the glass plate forming apparatus and the roll located closest to the glass plate forming apparatus so that the end in the width direction of the glass ribbon immediately after fusion can be locally heated. A heater provided in
With
The said heater is the manufacturing apparatus of the glass plate each arrange | positioned in the position facing the side surface of the said glass ribbon so that a heat ray may be irradiated toward the side surface of the said glass ribbon. A guide that prevents the molten glass from protruding from the side wall of the glass plate forming apparatus is attached to an end in the longitudinal direction of the glass plate forming apparatus,
The glass plate manufacturing apparatus according to claim 6, wherein the space is a space outside the guide.   The glass plate manufacturing apparatus according to claim 6 or 7, wherein a dimension of the heater with respect to a direction orthogonal to a longitudinal direction and a vertical direction of the glass sheet forming apparatus is larger than a dimension of the glass plate forming apparatus with respect to the direction.   Of the plurality of rolls, a position where the roll located closest to the glass plate forming apparatus crosses a side surface of the glass ribbon with respect to a width direction of the glass ribbon so as to sandwich an end portion of the glass ribbon The manufacturing apparatus of the glass plate of any one of Claims 6-8 arrange | positioned. A temperature sensor for detecting the temperature of the molten glass at the side wall of the glass plate forming apparatus;
A controller for controlling energization to the heater based on the detection result of the temperature sensor;
The apparatus for manufacturing a glass plate according to any one of claims 6 to 9, further comprising:

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