TWI458689B - Method and apparatus for producing glass sheet - Google Patents

Description

Glass plate manufacturing method and manufacturing device

The present invention relates to a method and apparatus for producing a glass sheet. The present invention is particularly directed to a technique for producing a glass sheet by a down draw method.

The down-draw method refers to a method in which molten glass overflowing from a groove in the upper portion of the wedge-shaped glass sheet forming apparatus flows down along the side wall of the glass sheet forming apparatus, and then fused at the lower end (bottom) of the glass sheet forming apparatus to continuously form A method of glass ribbon. The glass ribbon is supported by a roller disposed under the glass sheet forming apparatus, enters the furnace while being slowly cooled, and then cut to obtain a glass sheet of a desired size.

The down-draw method is suitable for manufacturing large-area and thin glass sheets, such as glass substrates for flat panel displays. For example, Japanese Laid-Open Patent Publication No. 2008-133174 describes a technique for stably producing an extremely thin glass plate (for example, 0.5 mm or less). Specifically, after the thickness of the glass ribbon is reduced to the initial thickness immediately below the molded body (glass plate forming apparatus), the glass ribbon is further heated by a reheating means (heater) provided under the control means (cooling roller). Heat to a temperature above the softening point to soften it, then stretch the softened glass ribbon down to make the sheet thickness thinner.

Further, in order to form a high-quality glass ribbon, temperature control in the width direction of the molten glass on the side wall of the glass sheet forming apparatus is important. For example, Japanese Laid-Open Patent Publication No. 2007-112665 discloses that a heater provided with a high-density heating element is disposed at a position facing a side wall of a molded body (glass sheet forming apparatus), thereby making molten glass A technique for uniformizing the temperature distribution in the width direction. Japanese Laid-Open Patent Publication No. 2008-69024 discloses that the platinum film on the surface of a fusion cell (glass plate forming apparatus) is electrically heated to uniformize the temperature distribution in the width direction of the molten glass. Technology.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-133174

[Patent Document 2] Japanese Time 2007-112665

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-69024

Further, the end portion of the glass ribbon formed by the following drawing method is usually in the shape shown in Fig. 7. However, the ends of the glass ribbon are not often shaped for this purpose, and sometimes they are also separated into two sides. The end portion having a branching shape will make the cutting step of the glass ribbon difficult or cause cracks in the glass ribbon. Moreover, sometimes the end portion having a branching shape also causes the thickness of the central portion (which becomes a part of the product) to be uneven, and the yield is lowered.

It is an object of the present invention to prevent the shape of the end portion of the glass ribbon from being defective.

The inventors of the present invention have studied in detail the causes of the occurrence of a shape defect at the end portion of the glass ribbon. As a result, the present invention has been made in view of the fact that the viscosity of the just-fused glass ribbon is the main factor determining the final shape of the end portion of the glass ribbon.

That is, the present invention provides a method for producing a glass sheet, which is a method for producing a glass sheet by a down-draw method, that is, a molten glass is fused at a lower end of a glass sheet forming apparatus, formed into a glass ribbon, and then set along the glass sheet. A plurality of rollers under the glass sheet forming apparatus transport the glass ribbon to the lower side, and a heater is disposed at a lower end of the glass sheet forming apparatus and a space between the rollers closest to the glass sheet forming apparatus, and the heater is provided The glass ribbon is formed and conveyed while partially heating the end portion of the glass ribbon that has just been fused.

In another aspect, the present invention provides a glass sheet manufacturing apparatus comprising: a glass sheet forming apparatus having a wedge-shaped cross section; and a plurality of rolls disposed under the glass sheet forming apparatus for transporting the glass ribbon to the glass sheet a glass sheet forming apparatus, wherein the glass ribbon is formed by fusing molten glass overflowing from a groove of an upper portion of the glass sheet forming apparatus at a lower end of the glass sheet forming apparatus; and a heater The end portion of the glass ribbon which has just been fused is heated locally, and is disposed at a lower end of the glass sheet forming apparatus and a space between the rolls closest to the glass sheet forming apparatus.

The glass ribbon that has just been fused is in a state of a viscous fluid because it is not completely cured, and thus is easily affected by the ambient temperature. Typically, the ends of the ribbon will cool faster than the center of the ribbon. If the temperature at the end portion drops much faster than the temperature at the center portion, the unevenness of the viscosity in the width direction is intensified, and the shape of the end portion is liable to occur.

On the other hand, according to the present invention described above, the end portion of the just-fused glass ribbon is partially heated by a heater. That is, only the end portion of the glass ribbon just leaving the glass sheet forming apparatus is prevented from being rapidly cooled. Thereby, the temperature distribution in the width direction of the glass ribbon, that is, the viscosity distribution can be made uniform, and the shape defect of the end portion is hard to occur. Since the present invention can be implemented by using an existing device, the present invention is also excellent in cost.

In order to obtain the same effects as the present invention, it is also considered to increase the temperature of the ambient atmosphere in the furnace near the lower end of the glass sheet forming apparatus. If it is in the form, it is possible to obtain the same effect as the present invention. However, since the present invention is sufficient to locally heat the end portion of the glass ribbon, it is advantageous in terms of power consumption. Moreover, if the ambient atmosphere in the furnace is made high temperature, the deterioration of various components is accelerated, and the life of the device is shortened, which is not preferable.

Further, the "end portion of the glass ribbon" means, for example, a region from the side of the glass ribbon to the inner side at a position of about 50 mm.

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

As shown in FIG. 1 and FIG. 2, the apparatus 100 for manufacturing a glass sheet according to the present embodiment includes a furnace 2, a glass sheet forming apparatus 4 provided in an upper portion of the furnace 2, and a glass plate forming apparatus 4 disposed below the glass sheet forming apparatus 4. The plurality of rolls 6, and the heater 8 disposed near the lower end 4e (bottom) of the glass sheet forming apparatus 4. According to this apparatus 100, a glass plate can be manufactured by forming a glass ribbon 9 by fusing a molten glass which overflows from the glass plate forming apparatus 4 at the lower end 4e.

Furnace 2 is usually made of refractory bricks. On the inner wall of the furnace 2, a plurality of heaters 10 are disposed along the vertical direction. The heater 10 is a long shape extending parallel to the longitudinal direction of the glass sheet forming apparatus 4, and is suitable for heating a wide range. By controlling the heater 10, the temperature inside the furnace 2 can be adjusted. Specifically, when advancing downward in the furnace 2, a temperature gradient is formed along the vertical direction to slowly cool the glass ribbon 9.

The glass sheet forming apparatus 4 is usually made of refractory bricks. As shown in Fig. 2, the glass sheet forming apparatus 4 has a wedge shape in a cross section orthogonal to the longitudinal direction LD of the glass sheet forming apparatus 4. The longitudinal direction LD of the glass sheet forming apparatus 4 coincides with the width direction of the glass ribbon 9. In the upper portion of the glass sheet forming apparatus 4, a groove 4k for holding the molten glass extending in the longitudinal direction LD is formed. As shown in Fig. 1, the supply pipe 11 is connected to the groove 4k so that the 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 sheet forming apparatus 4 has a pair of side walls 4j in a direction orthogonal to both the longitudinal direction LD and the vertical direction. The side wall 4j forms a flow path of the molten glass overflowed from the groove 4k. These side walls 4j form a ridge line at the lower end 4e so that the molten glass flowing through the side walls 4j is fused at the lower end 4e. As shown in Fig. 1, a guide 7 for blocking the molten glass from overflowing the side wall 4j is attached to both ends of the longitudinal direction LD of the glass sheet forming apparatus 4, respectively. As shown in Fig. 4, the guide member 7 has a wedge shape in plan view and is made of a sheet material which covers the entire size of the end surface of the glass sheet forming apparatus 4. In the vertical direction, the position of the front end of the guide member 7 coincides with the lower end 4e of the glass sheet forming apparatus 4. By the action of the guide 7, all of the molten glass can flow along the side wall 4j.

The roller 6 has a function for conveying the glass ribbon 9 below the glass sheet forming apparatus 4. The rotational speed of the roller 6 is adjusted to form a glass ribbon 9 having a desired thickness. As shown in Fig. 2, the roller 6 is symmetrically disposed on a vertical surface including the lower end 4e of the glass sheet forming apparatus 4 so that the glass ribbon 9 can be sandwiched in the thickness direction. Further, the rollers 6 are disposed in the vertical direction at specific intervals. The glass ribbon 9 is conveyed to the lower side in the state clamped by the roller 6.

As shown in Fig. 1, the heater 8 is provided on one side and the other side in the longitudinal direction LD of the glass sheet forming apparatus 4. Specifically, the heater 8 is provided in a space between the lower end 4e of the glass sheet forming apparatus 4 and the roller 6a closest to the glass sheet forming apparatus 4 in the vertical direction. By partially heating the end portion of the just-fused glass ribbon 9 in the width direction by the heater 8, it is possible to prevent the viscosity of the end portion of the glass ribbon 9 which is just fused from being much higher than the viscosity of the central portion. In other words, the unevenness of the viscosity in the width direction of the glass ribbon 9 can be reduced. As a result, the shape of the end portion of the glass ribbon 9 can be prevented from being poor. Moreover, it is also possible to prevent devitrification of the glass.

As is well known, the phenomenon of loss of transparency refers to a phenomenon in which crystal grains are formed in the glass to lower the transparency of the glass. When the glass plate is produced by the following drawing method, the phenomenon of devitrification is likely to occur at the end of the glass ribbon 9. Although the reason is not necessarily clear, it is considered that one of the reasons is that the flow rate of the molten glass in the vicinity of the guide 7 is lowered, so that the molten glass is kept in a temperature region where the phenomenon of devitrification is likely to occur for too long.

If the heater 8 is provided in the vicinity of the guide 7, not only the end of the glass ribbon 9, but also the guide 7 is heated by the heater 8. The heat of the guide member 7 is conducted to the molten glass in the vicinity of the guide member 7, and it is prevented that only the molten glass in the vicinity of the guide member 7 is kept in a temperature region where the phenomenon of devitrification is likely to occur for too long. In particular, when the molten glass contains tin as a clarifying agent, tin oxide crystallizes in the glass to easily cause depolarization. Therefore, the present invention is particularly recommended when the molten glass contains tin.

In the present embodiment, the heater 8 is not connected to any one of the glass sheet forming apparatus 4, the guide 7 and the furnace 2. The position of the heater 8 is adjusted to effectively heat the end of the glass ribbon 9 that has just been fused. The detailed position of the heater 8 will be described with reference to Fig. 3 . The heater 8 is provided outside the guide 7 attached to both ends of the longitudinal direction LD of the glass sheet forming apparatus 4 and is a space faced by the side surface 9p of the glass ribbon 9. And more particularly to, a heater 8, lines in the vertical direction is provided lower glass sheet 4 forming means 4E, and 9 of the decreasing width of the glass ribbon becomes constant the position P of _a space.

As shown in FIG. 3, at the time of forming the glass ribbon width coefficient from the glass plate 9 of the lower end of the forming device 4 4e decreasing to position P _1. That is, the side surface 9p is gently curved. The heater 8 is a portion that is curved toward the side surface 9p. By providing the heater 8 at such a position, the end portion of the glass ribbon 9 that has just been fused can be efficiently heated. Further, although depending on the output, size, and the like of the heater 8, the distance H ₁ from the lower end 4e of the glass sheet forming apparatus 4 (the lower end of the guide 7) to the vertical direction of the heater 8 is, for example, 0 to 500 mm. It is preferably 0 to 100 mm. The distance L ₁ from the inner wall surface 7g of the guide member 7 to the horizontal direction of the heater 8 is, for example, -10 to 100 mm, more preferably 0 to 100 mm, still more preferably 0 to 30 mm. However, it should be noted that the heater 8 does not come into contact with the glass ribbon 9. Further, when the distance L ₁ is -10 mm or more and less than 0 mm, part or all of the heater 8 is present on the side where the glass ribbon 9 is located with the inner wall surface 7g of the guide 7 as a reference.

As shown in Fig. 2, the heater 8 extends in a horizontal direction orthogonal to both the longitudinal direction LD and the vertical direction of the glass sheet forming apparatus 4, that is, the thickness direction of the glass ribbon 9. 4, the dimension W of the glass ribbon heater 8 to 9 in the thickness direction of _1, the glass sheet is greater than the dimension W means the direction dimension W _{3 2} 4 and the guide member 7 is formed. According to this configuration, since both sides from the front side and the back side of the glass ribbon 9 can be uniformly heated, it is possible to more effectively prevent the shape from being defective. Further, by providing the heater 8 with a sufficient size W ₁ , the lower portion of the guide member 7 can be sufficiently heated, so that the effect of preventing the loss of transparency can be improved.

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

Further, as shown in FIG. 4, a temperature sensor 12 for detecting the temperature of the molten glass of the side wall 4j of the glass sheet forming apparatus 4, and a controller 14 for obtaining a signal from the temperature sensor 12 may be provided. The temperature sensing device 12, for example, can be mounted under the guide 7 to indirectly detect the temperature of the molten glass. The temperature sensor 12 can be, for example, a thermocouple. The controller 14 controls the energization of the heater 8 based on the detection result of the temperature sensor 12. For example, the temperature detected by the temperature sensor 12 is made equal to the set temperature of the heater 8. According to the above aspect, the heater 8 can be appropriately controlled without depending on the composition of the glass, and the shape of the end portion of the glass ribbon 9 can be surely prevented from being defective.

Alternatively, the output of the heater 8 can be manually adjusted based on the detection result of the temperature sensor 12. Further, when it is desired to detect the temperature of the central portion in the width direction of the molten glass of the lower end 4e of the glass sheet forming apparatus 4, a non-contact infrared sensor can be used as the temperature sensor 12.

The heater 8 is not particularly limited as long as it is a user who can exceed the ambient temperature of 1000 ° C. Specifically, a linear heating element or a wire-shaped heating element may be used as the heater 8 . Further, a radiant heater such as a ceramic heater, a halogen heater, or a tantalum carbide heating element may be used. The shape of the heater 8 is also 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. 1 to 4 is necessary for local heating. Moreover, it is not necessary to intentionally ensure the space occupied by the heater 8. On the other hand, according to the U-shaped heater 18 shown in Fig. 5, the heater 18 can be heated by enclosing the end portion 9t of the glass ribbon 9 from the three directions.

According to the present embodiment, since the end portion of the glass ribbon 9 is heated by the heater 8, the end of the glass ribbon 9 reaches the roller 6a, and the property of the viscous fluid can be further enhanced. Therefore, as shown in Fig. 6, the glass belt 9 can be conveyed by sandwiching the end portion 9t with the roller 6a. In other words, the roller 6a is disposed at the position of the grip end portion 9t. In the width direction of the glass ribbon 9, the roller 6a passes through the side of the glass ribbon 9. On the other hand, the other roller 6 located below the lower roller 6a does not sandwich the end portion 9t but sandwiches the portion closer to the inner side than the end portion 9t.

For example, as shown in FIG. 2 of Japanese Laid-Open Patent Publication No. 2008-133174, the positions of the rollers may be defined such that all the rollers do not sandwich the end portions of the glass ribbon. When the viscosity of the end portion is high, it is preferable to avoid the end portion being sandwiched by the roller from the viewpoint of performing stable conveyance and preventing cracks of the glass ribbon.

On the other hand, according to the present embodiment, since the increase in the viscosity of the end portion 9t immediately after the fusion is suppressed, the glass belt 9 can be conveyed by sandwiching the end portion 9t with the roller 6a. Further, before the glass ribbon 9 is sufficiently cured, as shown in Fig. 6, a pressure may be applied to the end portion 9t by the roller 6a to make the end portion 9t flat (to some extent). When the end portion 9t is flat, the step of cutting the glass ribbon 9 can be facilitated. Although it is also possible to sandwich the end portion 9t with the other roller 6 located below the roller 6a, if the end portion 9t is sandwiched by the roller 6a closest to the glass sheet forming device 4, the end portion 9t is flattened. highest. Further, when the other portion of the end portion 9t is sandwiched by the other roller 6, the problem such as the crack of the glass ribbon 9 is not caused, and stable conveyance can be realized. In this way, according to the present embodiment, it is possible to have an effect of adjusting the shape of the end portion 9t and an effect of stably conveying the glass ribbon 9.

The function of the glass plate manufacturing apparatus 100 will be briefly explained. When the amount of molten glass supplied to the groove 4k of the glass sheet forming apparatus 4 exceeds a certain amount, the molten glass overflows from the groove 4k and flows down along the side wall 4j. The molten glass of the side wall 4j is heated by the heater 10 provided around the glass plate forming apparatus 4 in order to maintain adhesiveness. The molten glass flowing through each side wall 4j is fused at the lower end 4e, whereby the glass ribbon 9 is formed. The glass ribbon 9 is guided between the rollers 6 and the rollers 6 opposed to each other, and is conveyed downward while being slowly cooled. The lower the temperature of the glass ribbon 9 is, the lower the lower the glass ribbon 9 is cured. When the glass ribbon 9 conveyed outside the furnace 2 is cut into a desired size, a glass plate can be obtained.

According to the present embodiment, since the end portion 9t of the glass ribbon 9 is heated by the heater 8, it is possible to prevent the viscosity of the end portion 9t of the glass ribbon 9 in the vicinity of the roller 6a from being much higher than the viscosity of the central portion. The glass ribbon 9 is cooled to a temperature region where the glass transition point is solidified, which is a rough target in the vicinity of the middle of the furnace 2.

The viscosity of the molten glass at the lower end 4e of the glass sheet forming apparatus 4 varies depending on the composition of the glass and the manufacturing conditions. For example, when manufacturing a glass plate for a flat panel display, the viscosity of the molten glass at the lower end 4e is adjusted in the range of 10,000 to 60,000 Pa s. The viscosity of the molten glass is controlled by the temperature of the molten glass. When the temperature of the molten glass is adjusted in the range of 800 to 1000 ° C, the viscosity of the molten glass will fall within the above range. Specifically, the heater 10 is controlled to adjust the ambient temperature in the furnace 2 such that the temperature of the molten glass is 800 to 1000 ° C at the lower end 4e.

Especially in recent years, the demand for large-area glass plates is gradually increasing. For example, the size of the glass substrate for the liquid crystal display of the 10th generation is 2850 mm × 3050 mm. On the other hand, since the width of the glass ribbon is wider, the viscosity in the width direction is more likely to be uneven, and the effect obtained by the application of the present invention is also improved. In addition, the following shows a typical glass composition of a glass substrate for a flat panel display.

SiO ₂ : 57 to 70% by 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 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

[Examples]

Using a continuous melting device equipped with a refractory brick melting tank and a platinum plating tank (a tank for carrying out the clarification step), the glass raw material having the following composition was melted at 1550 ° C to be lyophilized, and clarified at 1600 ° C. Then, the mixture was stirred at 1,550 ° C to obtain molten glass. In addition, the total mass exceeds 100% due to the inclusion of errors caused by rounding.

SiO ₂ : 60.9 mass%

Al ₂ O ₃ : 16.9 mass%

B ₂ O ₃ : 11.6% by mass

MgO: 1.7 mass%

CaO: 5.1% by mass

SrO: 2.6 mass%

BaO: 0.7% by mass

K ₂ O: 0.25 mass%

Fe ₂ O ₃ : 0.15 mass%

SnO ₂ : 0.13 mass%

Next, the molten glass is supplied to the manufacturing apparatus 100 of the glass plate described with reference to FIG. The set temperature of the heater 8 was set to 1110 °C. The viscosity of the molten glass flowing into the glass sheet forming apparatus 4 is estimated to be equivalent to about 5,000 Pa s because the temperature of the molten glass is 1200 °C.

The molten glass is continuously supplied, and the molten glass is overflowed from the glass sheet forming apparatus 4 to be formed into a glass ribbon. The glass ribbon is cut to a specific size to obtain a plurality of glass sheets. After examining the shape of the ends of the glass sheets, they were not divided into two sides. Moreover, there is no obvious loss of transparency in these glass plates. Further, a molten glass having another composition which is easily formed at a high viscosity during molding is used to form a glass ribbon by the same procedure. As a result, a glass plate having a good-shaped end portion was obtained.

2. . . furnace

4. . . Glass plate forming device

4e. . . Lower end (bottom)

4j. . . Side wall

6,6a. . . Roll

7. . . Guide

8. . . Heater

9. . . Glass belt

9t. . . Ends

12. . . Temperature sensor

14. . . Controller

100. . . Glass plate manufacturing device

Fig. 1 is a schematic front view showing a manufacturing apparatus of a glass sheet according to an embodiment of the present invention.

Fig. 2 is a schematic longitudinal cross-sectional view taken along line II-II of the apparatus for manufacturing a glass sheet shown in Fig. 1.

Figure 3 is a partial enlarged view showing the detailed position of the heater.

Fig. 4 is a schematic view showing the dimensional relationship between the guide and the heater.

Fig. 5 is a schematic view showing a modification of the heater.

Fig. 6 is a schematic view showing the positional relationship between the glass ribbon and the roller.

Figure 7 is a cross-sectional view showing the shape of one end of a glass ribbon.

2. . . furnace

4. . . Glass plate forming device

6,6a. . . Roll

7. . . Guide

8. . . Heater

9. . . Glass belt

11. . . Supply tube

LD. . . Long side direction

100. . . Glass plate manufacturing device

Claims (10)

A method for manufacturing a glass plate, which is a method for manufacturing a glass plate by a down-draw method, that is, a molten glass is fused at a lower end of a glass plate forming device, formed into a glass ribbon, and then disposed along the glass sheet forming device. The lower plurality of rollers convey the glass ribbon to the lower side, and a heater is disposed at a lower end of the glass sheet forming device and a space between the rollers closest to the glass sheet forming device, and the glass ribbon is just fused to the heater The end portion is heated locally, and the glass ribbon is formed and conveyed. The method for producing a glass sheet according to the first aspect of the invention, wherein the space is outside the guide member attached to both ends in the longitudinal direction of the glass sheet forming device and is a space facing the side of the glass ribbon. . The method for producing a glass sheet according to the first aspect of the invention, wherein the space is a space between a lower end of the glass sheet forming apparatus and a width of the glass ribbon to be a constant position. A method of producing a glass sheet according to claim 1, wherein the end of the glass ribbon is sandwiched by the roller closest to the glass sheet forming apparatus. A method of producing a glass sheet according to claim 1, wherein the molten glass contains tin. A glass plate manufacturing apparatus comprising: a glass plate forming device having a wedge-shaped cross section; a plurality of rollers disposed under the glass plate forming device for conveying the glass ribbon under the glass plate forming device, wherein The glass ribbon is formed by fusing molten glass overflowing from a groove of an upper portion of the glass sheet forming apparatus at a lower end of the glass sheet forming apparatus; and a heater so as to be opposite to a width direction of the glass ribbon just fused The end portion is heated locally, and is disposed at a lower end of the glass sheet forming apparatus and a space between the rolls closest to the glass sheet forming apparatus. The apparatus for manufacturing a glass sheet according to claim 6, wherein a guide for blocking the molten glass from overflowing the side wall of the glass sheet forming apparatus is installed at a distal end of the glass sheet forming apparatus, the space , is the outer side of the guide and is the space facing the side of the glass ribbon. The apparatus for manufacturing a glass sheet according to claim 6, wherein the heater has a dimension larger than a direction orthogonal to a longitudinal direction and a vertical direction of the glass sheet forming apparatus, and the glass sheet forming apparatus is larger than the direction. size of. The apparatus for manufacturing a glass sheet according to claim 6, wherein the roller closest to the glass sheet forming apparatus is disposed at a position sandwiching an end portion of the glass ribbon. The apparatus for manufacturing a glass sheet according to claim 6, further comprising a temperature sensor for detecting the temperature of the molten glass of the side wall of the glass sheet forming apparatus, and controlling the detection result according to the temperature sensor A controller that energizes the heater.