WO2015093432A1

WO2015093432A1 - Apparatus for manufacturing float glass and method for manufacturing float glass

Info

Publication number: WO2015093432A1
Application number: PCT/JP2014/083120
Authority: WO
Inventors: 信之伴; 白石　喜裕; 海郡司
Original assignee: 旭硝子株式会社
Priority date: 2013-12-18
Filing date: 2014-12-15
Publication date: 2015-06-25
Also published as: CN105612130A; KR20160098163A; JP2017030978A

Abstract

[Solution] An apparatus for manufacturing float glass, provided with a forming device for forming a sheet-shaped glass ribbon on a molten metal in a bath, an annealing device for annealing the glass ribbon, and an interface device for connecting the forming device and the annealing device, the interface device having a lift-out roller for drawing the glass ribbon up from the molten metal and conveying the glass ribbon toward the annealing device, a cooling member for cooling the downstream end part of the bath, and a heat-insulating member for blocking cold radiation of the glass ribbon by the cooling member.

Description

Float glass manufacturing apparatus and float glass manufacturing method

The present invention relates to a float glass manufacturing apparatus and a float glass manufacturing method.

The float glass manufacturing apparatus includes a forming apparatus for forming a plate-shaped glass ribbon on the molten metal in the bathtub, and a slow cooling apparatus for gradually cooling the glass ribbon (for example, see Patent Document 1). The glass ribbon has a flat portion between both side edges. Since both side edges of the glass ribbon are thicker than the flat part of the glass ribbon, they are cut off after slow cooling. Thereby, the float glass of substantially uniform board thickness is obtained.

Japanese Unexamined Patent Publication No. 6-227831

The float glass manufacturing apparatus includes an interface device that connects a molding apparatus and a slow cooling apparatus. The interface device has a lift-out roll that pulls the glass ribbon from the molten metal and conveys the glass ribbon toward the slow cooling device.

Since the molten metal stores heat, the glass ribbon is difficult to cool while it is in contact with the molten metal, but it is likely to cool away from the molten metal. Since the flat part of the glass ribbon is thinner than both side edges of the glass ribbon, it is easier to cool. Therefore, temperature unevenness in the width direction of the glass ribbon occurs. Moreover, this temperature unevenness is also a cause of temperature unevenness in the flow direction of the glass ribbon.

In the interface device, the temperature of the glass ribbon is near the transition point. In general, the linear expansion coefficient of glass changes greatly at the transition point of glass. Conventionally, in an interface device, since the temperature irregularity of the glass ribbon was large, the glass ribbon was largely deformed, and the glass ribbon was sometimes broken.

The present invention has been made in view of the above problems, and its main object is to provide a float glass manufacturing apparatus capable of preventing the glass ribbon from cracking in the interface device.

In order to solve the above problems, according to one aspect of the present invention,
A molding apparatus for molding a plate-shaped glass ribbon on the molten metal in the bathtub;
A slow cooling device for slowly cooling the glass ribbon;
An interface device for connecting the molding device and the slow cooling device;
The interface device
A lift-out roll that pulls up the glass ribbon from the molten metal and conveys it toward the slow cooling device,
A cooling member for cooling the downstream end of the bathtub;
There is provided a float glass manufacturing apparatus including a heat insulating member that blocks cold radiation of the glass ribbon by the cooling member.

According to the present invention, there is provided a float glass manufacturing apparatus capable of preventing the glass ribbon from being broken in the interface device.

It is a figure which shows the float glass manufacturing apparatus by one Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted. In the following description, “˜” representing a numerical range means a range including numerical values before and after that.

FIG. 1 is a diagram showing a float glass manufacturing apparatus according to an embodiment of the present invention. The float glass manufacturing apparatus includes a forming apparatus 10, a slow cooling apparatus 20, and an interface apparatus 30.

The forming apparatus 10 forms a plate-like glass ribbon G on the molten metal M in the bathtub 11. The glass ribbon G gradually hardens while flowing on the molten metal M. The glass ribbon G is pulled up from the molten metal M in the downstream region of the bathtub 11 and sent toward the slow cooling device 20. The molding apparatus 10 includes a bathtub 11, a roof 15, a heater 16, a pipe 17, and the like.

The bathtub 11 accommodates the molten metal M. The molten metal M may be a common one, and may be, for example, molten tin or a molten tin alloy. The bathtub 11 is composed of, for example, a metal casing 12 and a brick layer 13.

The metal casing 12 suppresses mixing of outside air into the bathtub 11. The metal casing 12 is formed by welding a plurality of metal plates, for example.

The brick layer 13 covers the inner surface of the metal casing 12. The brick layer 13 may be an assembly in which a plurality of bricks are assembled in a box shape, and contains the molten metal M therein.

The roof 15 is disposed above the bathtub 11 and covers the upper space of the bathtub 11. In the upper space of the bathtub 11, reducing gas or the like is supplied from the through hole 15 a of the roof 15 in order to prevent the molten metal M from being oxidized. As the reducing gas, for example, a mixed gas of nitrogen gas and hydrogen gas is used. The upper space of the bathtub 11 is set to a positive pressure higher than the atmospheric pressure in order to prevent outside air from being mixed.

The heater 16 is inserted into the through hole 15a of the roof 15, protrudes downward from the roof 15, and heats the glass ribbon G and the like. The heater 16 may be a general one, for example, a SiC heater.

A plurality of heaters 16 are arranged at intervals in the width direction of the glass ribbon G (the vertical direction in FIG. 1) and the flow direction of the glass ribbon G (the left-right direction in FIG. 1).

The pipe 17 forms an airflow film at the outlet of the molding apparatus 10 by injecting an inert gas such as nitrogen gas. The outflow of reducing gas can be suppressed. A partition plate may be provided instead of the pipe 17. The partition plate is disposed above the glass ribbon G and forms a slight gap with the glass ribbon G.

The slow cooling device 20 cools the glass ribbon G slowly. The slow cooling device 20 includes a slow cooling furnace 21, a transport roll 22, and the like. The transport roll 22 is rotatable about its center line, is driven to rotate by a motor or the like, and transports the glass ribbon G horizontally in the slow cooling furnace 21. The glass ribbon G is gradually cooled while being conveyed. The glass ribbon G has a flat part between both side edge parts. Since both side edges of the glass ribbon G are thicker than the flat part of the glass ribbon G, they are cut off after slow cooling. Thereby, the float glass of substantially uniform board thickness is obtained.

The interface device 30 connects the molding device 10 and the slow cooling device 20 to limit the temperature drop of the glass ribbon G away from the molten metal M. Since the molten metal M stores heat, the glass ribbon G is difficult to cool while being in contact with the molten metal M, but is likely to be cooled away from the molten metal M.

The interface device 30 includes a dross box 31, a sealing 32, lift-out rolls 33-1 to 33-3, drapes 34-1 to 34-3, seal blocks 35-1 to 35-3, a cooling member 36, a heat insulating member 37, And heaters 38-1 to 38-8.

The dross box 31 is disposed below the glass ribbon G and collects molten metal M debris (called dross) adhering to the bottom surface of the glass ribbon G. The inner surface of the dross box 31 is covered with a heat insulating material 41, and heat radiation from the dross box 31 to the outside is limited.

The dross box 31 may connect the downstream end portion 11 a of the bathtub 11 and the upstream end portion of the slow cooling furnace 21. When a slight gap is formed between the dross box 31 and the upstream end portion of the slow cooling furnace 21, the gap may be filled with a heat insulating material.

The sealing 32 is disposed above the glass ribbon G. The upper surface of the ceiling 32 is covered with a heat insulating material 42, and heat radiation from the ceiling 32 to the outside is limited.

The sealing 32 may connect the downstream end of the roof 15 and the upstream end of the slow cooling furnace 21. When a slight gap is formed between the sealing 32 and the upstream end of the slow cooling furnace 21, the gap may be filled with a heat insulating material.

The lift-out rolls 33-1 to 33-3 pull up the glass ribbon G from the molten metal M and convey it toward the slow cooling device 20. The lift-out rolls 33-1 to 33-3 are rotatable around the center line, and are driven to rotate by a motor or the like.

The drapes 34-1 to 34-3 are suspended from the ceiling 32 and block the gas flow above the glass ribbon G. Thereby, mixing of the hydrogen gas from the shaping | molding apparatus 10 can be suppressed, and the temperature fluctuation by combustion of hydrogen gas can be suppressed. The drapes 34-1 to 34-3 are provided above the lift-out rolls 33-1 to 33-3.

The seal blocks 35-1 to 35-3 come into contact with the lift-out rolls 33-1 to 33-3, thereby blocking the gas flow below the glass ribbon G and the lift-out rolls 33-1 to 33-3. Scrape off the dross attached to the surface. The dross is collected in the dross box 31. The seal blocks 35-1 to 35-3 are made of carbon, for example.

The cooling member 36 forms a refrigerant flow path 36a. The refrigerant in the refrigerant flow path 36a may be either gas or liquid. The cooling member 36 cools the downstream end portion 11 a of the bathtub 11. Melting of the metal casing 12 at the downstream end 11a can be prevented.

The cooling member 36 may be attached to the inner surface of the dross box 31, for example, and may form a refrigerant flow path 36 a between the inner surface of the dross box 31. The cooling member 36 may cool the downstream end portion 11 a of the bathtub 11 through the dross box 31.

The heat insulating member 37 covers the cooling member 36 from the downstream side and blocks the cold radiation of the glass ribbon G by the cooling member 36. Cold radiation means that heat is taken away. The temperature drop of the flat portion of the glass ribbon G from the take-off position P1 where the glass ribbon G is separated from the molten metal M to the contact position P2 where the glass ribbon G contacts the most upstream lift-out roll 33-1 is moderate. Become. Therefore, the temperature unevenness due to the difference in thickness between the flat portion and both side edge portions of the glass ribbon G can be reduced between the take-off position P1 and the contact position P2, and the deformation of the glass ribbon G due to the temperature unevenness can be reduced. The glass ribbon G can be prevented from cracking to some extent.

The thermal conductivity of the heat insulating member 37 is, for example, 1.0 W / mK or less, preferably 0.4 W / mK or less, and more preferably 0.05 W / mK or less. The thickness of the heat insulating material can be set as appropriate according to the equipment, but is preferably 5 mm to 50 mm.

The heat insulating member 37 may have a fine porous structure in order to prevent heat transfer due to gas flow. For example, the heat insulating member 37 may be an aggregate of fine particles, and a void may be formed between the fine particles. Since heat transfer by air convection is limited and the heat transfer path is thin and long, heat insulation is good. As the fine particles, for example, silica fine particles are used, and preferably amorphous silica fine particles are used. The heat insulating member 37 may have a flexible heat-resistant exterior, and the exterior may hold fine particles.

Each heater 38-1 to 38-8 heats the glass ribbon G. The plurality of heaters 38-1 to 38-8 may be controlled independently.

Each heater 38-1 to 38-8 may be divided into a plurality of heating elements in the width direction of the glass ribbon G in order to adjust the temperature distribution in the width direction of the glass ribbon G. The plurality of divided heating elements may be controlled independently.

At least one of the plurality of heaters 38-1 to 38-8 (two heaters 38-1 and 38-2 in the present embodiment) is upstream of the center line of the most upstream lift-out roll 33-1 ( It may be arranged in the left direction in FIG.

In the present embodiment, heaters 38-1 and 38-2 are disposed upstream of the center line of the most upstream lift-out roll 33-1. Thereby, the temperature drop of the flat part of the glass ribbon G between the take-off position P1 and the contact position P2 is further moderated. Therefore, the deformation of the glass ribbon G due to temperature unevenness can be further reduced, and the occurrence of fine deformation such as wrinkles, waviness and warpage can be suppressed.

The heater 38-1 is disposed below the glass ribbon G, like the cooling member 36. Contact between the cold air of the cooling member 36 and the glass ribbon G can be suppressed.

Unlike the cooling member 36, the heater 38-2 is disposed above the glass ribbon G. The glass ribbon G cooled from below by the cooling member 36 can be heated from above.

At least one of the plurality of heaters 38-1 to 38-8 (two heaters 38-7 and 38-8 in the present embodiment) is located downstream of the center line of the most downstream liftout roll 33-3 ( It may be arranged in the right direction in FIG. The heater 38-7 is disposed below the glass ribbon G, and the heater 38-8 is disposed above the glass ribbon G.

In the present embodiment, the heaters 38-7 and 38-8 are disposed downstream of the center line of the most downstream lift-out roll 33-3. Thereby, the rapid temperature drop of the glass ribbon G in the vicinity of the inlet of the slow cooling furnace 21 can be restricted, and the occurrence of fine deformation can be further suppressed.

Next, with reference to FIG. 1 again, a float glass manufacturing method using the float glass manufacturing apparatus having the above configuration will be described.

The float glass manufacturing method has a forming step of forming a plate-shaped glass ribbon G on the molten metal M in the bathtub 11 and a slow cooling step of gradually cooling the glass ribbon G. The glass ribbon G gradually hardens while flowing on the molten metal M. The glass ribbon G is pulled up from the molten metal M in the downstream area of the bathtub 11 and is conveyed toward the slow cooling furnace 21 on the lift-out rolls 33-1 to 33-3. Thereafter, the glass ribbon G is gradually cooled while being transported on the transport roll 22 in the slow cooling furnace 21. The glass ribbon G has a flat part between both side edge parts. Since both side edges of the glass ribbon G are thicker than the flat part of the glass ribbon G, they are cut off after slow cooling. Thereby, the float glass of substantially uniform board thickness is obtained.

By the way, between the take-off position P1 where the glass ribbon G is separated from the molten metal M and the contact position P2 where the glass ribbon G is in contact with the most upstream lift-out roll 33-1, the flat portion and both side edge portions of the glass ribbon G are used. Temperature unevenness due to the difference in thickness between the two. The temperature of the glass ribbon G between the take-off position P1 and the contact position P2 is a temperature near the glass transition point. In general, the linear expansion coefficient of glass changes greatly at the transition point of glass.

The temperature unevenness caused by the difference in thickness between the flat portion and both side edge portions of the glass ribbon G causes the heat insulating member 37 to block the cooling radiation of the glass ribbon G by the cooling member 36, so that the contact position P2 from the take-off position P1. The temperature drop of the flat portion of the glass ribbon G during the period becomes moderate. Therefore, temperature unevenness due to the difference in thickness between the flat portion and both side edge portions of the glass ribbon G can be reduced, deformation of the glass ribbon G due to temperature unevenness can be reduced to some extent, and cracking of the glass ribbon G can be prevented. .

In addition, since at least one (two in the present embodiment) heaters 38-1 and 38-2 are disposed upstream of the center line of the most upstream lift-out roll 33-1, contact is made from the take-off position P1. The temperature drop of the flat portion of the glass ribbon G until the position P2 is further moderated. Therefore, the deformation of the glass ribbon G due to temperature unevenness can be further reduced, and the occurrence of fine deformation can be suppressed.

At the take-off position P1, the viscosity of the flat portion of the glass ribbon G is, for example, 10 ^10.7 dPa · s to 10 ^12.3 dPa · s. Both the hardness that can pull the glass ribbon G from the molten metal M and the softness that the glass ribbon G is not broken by the pulling from the molten metal M are obtained. The viscosity of the flat portion of the glass ribbon G is represented by the viscosity at the center in the width direction of the glass ribbon G.

When the type of float glass to be produced is non-alkali glass, the viscosity of the flat portion of the glass ribbon G at the take-off position P1 is preferably 10 ^11.3 dPa · s to 10 ^12.3 dPa · s. The temperature range of the alkali-free glass corresponding to this viscosity range is, for example, 740 ° C. to 770 ° C.

When the type of float glass produced is soda lime glass, the viscosity of the flat part of the glass ribbon G at the take-off position P1 is preferably 10 ^10.7 dPa · s to 10 ^11.8 dPa · s. The temperature range of soda lime glass corresponding to this viscosity range is, for example, 590 ° C. to 620 ° C.

The temperature change width of the flat portion of the glass ribbon G between the take-off position P1 and the contact position P2 is, for example, 40 ° C. or less, preferably 20 ° C. or less, more preferably 10 ° C. or less. The temperature change width may be zero degrees Celsius. If the said temperature change width is 40 degrees C or less, the crack of the glass ribbon G can be prevented. If the temperature change width is 30 ° C. or less, there is almost no occurrence of fine deformation.

The temperature of the flat part of the glass ribbon G may gradually decrease from the take-off position P1 to the contact position P2.

Conventionally, the temperature of the flat portion of the glass ribbon G has been too low at the contact position P2 and tends to increase from the contact position P2 toward the downstream, but gradually decreases from the contact position P2 to the inlet of the slow cooling furnace 21 in this embodiment. It may be. This is because the temperature change width of the flat portion of the glass ribbon G between the take-off position P1 and the contact position P2 is small and the temperature of the flat portion of the glass ribbon G is high at the contact position P2.

The thickness of the manufactured float glass is, for example, 0.8 mm or less. In this case, the thickness of the flat part of the glass ribbon G is 0.8 mm or less. On the other hand, the plate thickness of general-purpose float glass is about 2 mm to 6 mm. In this case, the thickness of the flat portion of the glass ribbon is about 2 mm to 6 mm.

The glass ribbon G having a flat portion thickness of 0.8 mm or less has a smaller heat capacity than a glass ribbon having a flat portion thickness of about 2 mm to 6 mm. Therefore, the sensible heat (amount of heat) that the glass ribbon G brings into the interface device 30 from the molding apparatus 10 is small, and the glass ribbon G has conventionally been easy to cool. For this reason, the float glass having a flat portion thickness of 0.8 mm or less has a remarkable effect of suppressing the temperature drop of the flat portion of the glass ribbon G between the take-off position P1 and the contact position P2. That is, temperature unevenness due to the difference in thickness between the flat portion and both side edge portions of the glass ribbon G can be suppressed. The smaller the plate thickness of the manufactured float glass, the more remarkable the above-mentioned effects. The plate thickness is more preferably 0.6 mm or less, and further preferably 0.3 mm or less.

The manufactured float glass is used as a glass substrate for display, a cover glass for display, and a window glass, for example.

The float glass produced may be alkali-free glass when used as a glass substrate for a display. The alkali-free glass is a glass that does not substantially contain an alkali metal oxide such as Na ₂ O, K ₂ O, or Li ₂ O. The alkali-free glass may have a total content of alkali metal oxides of 0.1% by mass or less.

The alkali-free glass is, for example, expressed by mass% based on oxide, SiO ₂ : 50% to 73%, Al ₂ O ₃ : 10.5% to 24%, B ₂ O ₃ : 0% to 12%, MgO : 0% to 10%, CaO: 0% to 14.5%, SrO: 0% to 24%, BaO: 0% to 13.5%, MgO + CaO + SrO + BaO: 8% to 29.5%, ZrO ₂ : 0% Contains ~ 5%.

When the alkali-free glass has both a high strain point and a high solubility, it is preferable that SiO ₂ : 58% to 66%, Al ₂ O ₃ : 15% to 22%, expressed by mass% based on oxide. B ₂ O ₃ : 5% to 12%, MgO: 0% to 8%, CaO: 0% to 9%, SrO: 3% to 12.5%, BaO: 0% to 2%, MgO + CaO + SrO + BaO: 9% to Contains 18%.

When it is desired to obtain a particularly high strain point, the alkali-free glass is preferably expressed in terms of mass% based on oxide, SiO ₂ : 54% to 73%, Al ₂ O ₃ : 10.5% to 22.5%, B ₂ O ₃ : 0% to 5.5%, MgO: 0% to 10%, CaO: 0% to 9%, SrO: 0% to 16%, BaO: 0% to 2.5%, MgO + CaO + SrO + BaO: 8 % To 26%.

The manufactured float glass may be a chemically strengthened glass when used as a cover glass for a display. What chemically-strengthened the glass for chemical strengthening is used as a cover glass. In the chemical strengthening treatment, ions having a small ion radius (for example, Li ions or Na ions) among alkali ions contained on the glass surface are replaced with ions having a large ion radius (for example, K ions) to obtain a predetermined depth from the glass surface. A compressive stress layer is formed.

The glass for chemical strengthening is, for example, expressed in mol% based on oxide, SiO ₂ : 62% to 68%, Al ₂ O ₃ : 6% to 12%, MgO: 7% to 13%, Na ₂ O: 9% 17%, K ₂ O: 0% to 7%, the difference of subtracting Al ₂ O ₃ content from the total content of Na ₂ O and K ₂ O is less than 10%, ZrO ₂ When it contains, the content is 0.8% or less.

Another glass for chemical strengthening is expressed in terms of mol% based on oxide, SiO ₂ : 65% to 85%, Al ₂ O ₃ : 3% to 15%, Na ₂ O: 5% to 15%, K ₂ O : 0% to less than 2%, MgO: 0% to 15%, ZrO ₂ : 0% to 1%, the total content of SiO ₂ and Al ₂ O ₃ SiO ₂ + Al ₂ O ₃ is 88% or less It is.

The float glass produced may be soda lime glass when used as a window glass. Soda lime glass is, for example, expressed in terms of mass% based on oxide, SiO ₂ : 65% to 75%, Al ₂ O ₃ : 0% to 3%, CaO: 5% to 15%, MgO: 0% to 15% Na ₂ O: 10% to 20%, K ₂ O: 0% to 3%, Li ₂ O: 0% to 5%, Fe ₂ O ₃ : 0% to 3%, TiO ₂ : 0% to 5% CeO ₂ : 0% to 3%, BaO: 0% to 5%, SrO: 0% to 5%, B ₂ O ₃ : 0% to 5%, ZnO: 0% to 5%, ZrO ₂ : 0% -5%, SnO ₂ : 0% to 3%, SO ₃ : 0% to 0.5%.

[Example 1]
In Example 1, float glass was manufactured using the float glass manufacturing apparatus shown in FIG. The interface device has a heat insulating member that blocks the cold radiation of the cooling member, and a heater that is disposed upstream of the center line of the most upstream lift-out roll. The thickness of the float glass was 0.2 mm, and the type of float glass was non-alkali glass. As the alkali-free glass, AN100 manufactured by Asahi Glass was used.

[Example 2]
In the second embodiment, except that the output of the heater arranged upstream of the center line of the uppermost liftout roll among the plurality of heaters included in the interface device is reduced to 50% of the first embodiment. Float glass was produced in the same manner as in Example 1.

[Example 3]
In the third embodiment, the output of the heater arranged upstream of the center line of the uppermost liftout roll among the plurality of heaters included in the interface device is set to 0% of the first embodiment. Float glass was produced in the same manner as in Example 1.

[Evaluation]
The results of the float glass evaluation are shown in Table 1. In Table 1, “A” indicates that the glass ribbon was not cracked and there was no fine deformation such as wrinkles, and “B” was that the glass ribbon was not cracked, but there was a fine deformation. Respectively. The presence or absence of cracks and fine deformation of the glass ribbon was confirmed visually. Table 1 also shows the results of measuring the temperature in the center of the glass ribbon width direction with a radiation thermometer. In Table 1, “T1” means the temperature in the center of the glass ribbon width direction at the take-off position P1, and “T2” means the temperature in the center of the glass ribbon width direction at the contact position P2 with the most upstream lift-out roll. In addition, since the temperature difference in the flat part of the glass ribbon G is smaller than the temperature difference (temperature unevenness) between the flat part and both side edges, the temperature of the flat part of the glass ribbon G is the temperature at the center in the glass ribbon width direction. Represented.

As is clear from Table 1, in Examples 1 to 3, the interface device has a heat insulating member that blocks the cooling member's cooling radiation, so that the center of the glass ribbon in the width direction between the take-off position P1 and the contact position P2 is used. The temperature change width was 40 ° C. or less. As a result, the glass ribbon was not cracked. Moreover, in Example 1 and Example 2, since the interface apparatus had a heater upstream from the centerline of the most upstream lift-out roll, the said temperature change width was 30 degrees C or less. As a result, the glass ribbon did not crack and there was no fine deformation such as wrinkles. Note that when the float glass was formed under the same conditions as in Example 3 except that the heat insulating member was not used, the take-off position P1 The glass ribbon is very likely to break between the contact point P2 and the contact position P2, and it is difficult to manufacture the glass ribbon under such conditions.

As mentioned above, although embodiment of the float glass manufacturing apparatus and the float glass manufacturing method was described, this invention is not limited to the said embodiment etc., In the range of the summary of this invention described in the claim, various Can be modified and improved.

For example, the heat insulating member 37 of the above embodiment contacts the cooling member 36, but a gap may be formed between the heat insulating member 37 and the cooling member 36.

This application claims priority based on Japanese Patent Application No. 2013-260798 filed with the Japan Patent Office on December 18, 2013. The entire contents of Japanese Patent Application No. 2013-260798 are incorporated herein by reference. To do.

DESCRIPTION OF SYMBOLS 10 Forming apparatus 11 Bath 11a Downstream end 12 Metal casing 13 Brick layer 20 Slow cooling apparatus 30 Interface apparatus 31 Dross box 32 Sealing 33-1 to 33-3 Lift-out roll 36 Cooling member 37 Thermal insulation member 38-1 to 38-8 Heater G Glass ribbon M Molten metal

Claims

A molding apparatus for molding a plate-shaped glass ribbon on the molten metal in the bathtub;
A slow cooling device for slowly cooling the glass ribbon;
An interface device for connecting the molding device and the slow cooling device;
The interface device
A lift-out roll that pulls up the glass ribbon from the molten metal and conveys it toward the slow cooling device,
A cooling member for cooling the downstream end of the bathtub;
A float glass manufacturing apparatus, comprising: a heat insulating member that blocks cold radiation of the glass ribbon by the cooling member.
The interface device has a heater for heating the glass ribbon,
The float glass manufacturing apparatus according to claim 1, wherein at least one of the heaters is disposed upstream of a center line of the most upstream lift-out roll.
A float glass production method for producing float glass using the float glass production apparatus according to claim 1 or 2.
The float glass production according to claim 3, wherein the glass ribbon has a viscosity in the center in the width direction of 10 10.7 dPa · s to 10 12.3 dPa · s at a take-off position where the glass ribbon is separated from the molten metal. Method.
The temperature change width at the center in the width direction of the glass ribbon between the take-off position where the glass ribbon is separated from the molten metal and the contact position where the glass ribbon is in contact with the most upstream lift-out roll is 40 ° C. or less. The float glass manufacturing method according to claim 3 or 4.
The temperature change width at the center in the width direction of the glass ribbon between the take-off position where the glass ribbon is separated from the molten metal and the contact position where the glass ribbon is in contact with the most upstream lift-out roll is 30 ° C. or less. The float glass manufacturing method according to claim 3 or 4.
The float glass manufacturing method according to any one of claims 3 to 6, wherein the thickness of the manufactured float glass is 0.8 mm or less.