JP7498893B2 - Glass article manufacturing method and manufacturing device - Google Patents

Description

The present invention relates to a method and apparatus for manufacturing glass articles such as glass plates.

The overflow downdraw method is a well-known method for producing glass plates for panel displays such as liquid crystal displays and organic electroluminescence displays.

In the overflow downdraw method, molten glass is poured into an overflow groove provided at the top of a forming body with a roughly wedge-shaped cross section, and the molten glass that flows out on both sides of the overflow groove is allowed to flow down along the two sides of the forming body, and these molten glasses are fused and integrated at the lower end of the forming body, thereby continuously forming a single glass ribbon (see, for example, Patent Document 1). As a result of this fusion and integration, a mating surface is formed in the middle part of the glass ribbon in the thickness direction.

International Publication No. 2014/163063

In the conventional overflow downdraw method, the front and back surfaces of the formed glass ribbon are formed without coming into contact with any part of the formed body during the forming process, resulting in a smooth fire-polished surface without scratches.

However, because the molten glass flowing along the two sides of the forming body is fused together, it is difficult to reduce the thickness of the glass ribbon directly below the forming body. As a result, the cooling rate of the glass ribbon is insufficient after the forming body is separated (detached), and the glass is prone to devitrification. In other words, the first problem is that it is difficult to mold molten glass that is prone to devitrification.

In addition, if the thickness dimension of the molten glass flowing along the side of the molded body is reduced, the molten glass becomes less likely to flow to both ends of the molded body in the longitudinal direction. This leads to a second problem in that the molten glass stagnates or devitrifies at both ends of the molded body in the longitudinal direction.

The technical objective of the present invention is to overcome the first and/or second problems in the conventional overflow downdraw method.

The present invention is intended to solve the above problems, and is a method for manufacturing a glass article, comprising a forming step in which molten glass is turned into a sheet shape by a forming body to form a glass ribbon, and a cooling step in which the glass ribbon formed by the forming body is cooled while being conveyed along the vertical direction, the forming body comprises an overflow groove to which the molten glass is supplied, and a side surface through which the molten glass flowing out of the overflow groove flows downward, and the forming step is characterized in that the glass ribbon is formed such that one surface is a forming surface formed by the side surface and the other surface is a fire polished surface.

As described above, the glass ribbon produced by this method has one surface formed by the side of the forming body, and the other surface formed as a fire-polished surface. In this method, one surface of the glass ribbon is a forming surface formed without fusing with other molten glass, which makes it possible to reduce the thickness dimension of the glass ribbon directly below the forming body (when separated from the forming body) compared to the conventional overflow downdraw method in which molten glass flowed down two sides is fused to form a glass ribbon. This makes it possible to increase the cooling rate of the glass ribbon after separation from the forming body. As a result, even glass that is prone to devitrification and difficult to form by the conventional overflow downdraw method can be formed while suppressing devitrification according to this method.

In addition, if the thickness dimension of the glass ribbon directly below the forming body (when separated from the forming body) is the same, this method can increase the thickness dimension of the molten glass flowing down the side of the forming body compared to the conventional overflow downdraw method. This makes it easier for the molten glass to flow to both ends of the longitudinal direction of the forming body. As a result, problems such as stagnation and devitrification of the molten glass at both ends of the longitudinal direction of the forming body can be suppressed.

In the above manufacturing method, the side surface may extend vertically, and the forming body may have a separation portion that is connected to the lower end of the side surface and separates the molten glass from the forming body.

In conventional glass article manufacturing methods, in order to fuse the molten glass flowing along the two side surfaces of the molded body, it is necessary to incline the lower portion of each side surface so that the two side surfaces meet at the lower end of the molded body. In this way, when a portion of the side surface is inclined, it becomes difficult to control the width and thickness dimensions of the molten glass flowing along each side surface. In contrast, according to the present method, the side surface of the molded body is made to extend vertically, which makes it possible to easily control the dimensions of the molten glass. Therefore, it is possible to mold a glass ribbon with high dimensional accuracy. In addition, by using the separating portion to separate the molten glass from the lower end of the side surface of the molded body without leaving it at this lower end, it is possible to prevent the occurrence of defective molding of the molten glass.

The lower part of the molded body may be supported by a support member. By supporting the lower part of the molded body by a support member, it is possible to prevent creep deformation of the molded body during the molding process.

The molded body may have a guide portion that guides the widthwise end of the plate-shaped molten glass, and the side surface and the guide portion may be provided in the same refractory material.

When the side surface and the guide member are made of different materials, a gap occurs between the side surface and the guide portion, and the molten glass penetrates into this gap. This molten glass may drip from the guide portion and cause defective molten glass forming. In the present invention, by providing the side surface and the guide portion from the same refractory material, the gap between the side surface and the guide portion is eliminated, and the occurrence of defective forming can be effectively prevented.

In the molding process, the spaced portions of the side surfaces may be heated by a heating device.

This configuration can reduce the temperature difference between the front and back surfaces of the glass ribbon formed by the forming body. This makes it possible to prevent warping of the glass ribbon. It also makes it possible to prevent devitrification of the glass ribbon. Furthermore, it makes it possible to reduce the viscosity of the molten glass as much as possible, making it easier for the molten glass to separate from the lower end of the side surface.

In this method, the side surface may include a first side surface located on one side of the molded body and a second side surface located on the opposite side of the first side surface, and the glass ribbon may include a first glass ribbon having a formed surface formed by the first side surface and a second glass ribbon having a formed surface formed by the second side surface.

This configuration makes it possible to simultaneously mold two glass ribbons. This allows glass articles to be manufactured efficiently.

The present invention is intended to solve the above problems, and is characterized in that in a glass article manufacturing apparatus that includes a forming body that shapes molten glass into a sheet shape to form a glass ribbon, the forming body includes an overflow groove to which the molten glass is supplied and a side surface that allows the molten glass that flows out of the overflow groove to flow downward, and the forming body is configured to form the glass ribbon in which one surface is a forming surface formed by the side surface and the other surface is a fire-polished surface.

According to this configuration, by forming the molten glass using the side surfaces formed on the forming body, it is possible to produce a glass ribbon in which one surface is a surface formed by the side surfaces and the other surface is a fire-polished surface. This makes it possible to reduce the thickness dimension of the glass ribbon directly below the forming body (when separated from the forming body) compared to the conventional overflow downdraw method in which molten glass flowed down two side surfaces is fused. This makes it possible to increase the cooling rate of the glass ribbon after it is separated from the forming body. As a result, even glass that is prone to devitrification and difficult to form using the conventional overflow downdraw method can be formed while suppressing devitrification according to this method.

In addition, if the thickness dimension of the glass ribbon directly below the forming body (when separated from the forming body) is the same, this method can increase the thickness dimension of the molten glass flowing down the side of the forming body compared to the conventional overflow downdraw method. This makes it easier for the molten glass to flow to both ends of the longitudinal direction of the forming body. As a result, problems such as stagnation and devitrification of the molten glass at both ends of the longitudinal direction of the forming body can be suppressed.

According to the present invention, even glass that is prone to devitrification and difficult to form using the conventional overflow downdraw method can be formed while suppressing devitrification of the glass. In addition, problems such as stagnation and devitrification of the molten glass at both ends in the longitudinal direction of the formed body can be suppressed.

FIG. 2 is a cross-sectional view of the manufacturing apparatus for a glass article according to the first embodiment. FIG. 1 is a flowchart showing a method for manufacturing a glass article. FIG. 5 is a cross-sectional view of a glass article manufacturing apparatus according to a second embodiment. FIG. FIG. 4 is a cross-sectional view of a glass article manufacturing apparatus according to a third embodiment. FIG. 11 is a cross-sectional view of a glass article manufacturing apparatus according to a fourth embodiment.

Hereinafter, the embodiment of the present invention will be described with reference to the drawings. Figures 1 to 3 show a first embodiment of a manufacturing method and manufacturing apparatus for a glass article according to the present invention.

Figure 1 shows a manufacturing apparatus for a glass article. In this embodiment, a manufacturing apparatus for manufacturing a transparent glass ribbon and a glass sheet as a glass article is illustrated. The manufacturing apparatus 1 mainly includes a forming furnace 2 for forming a glass ribbon GR from molten glass GM, and an annealing furnace 3 for cooling the formed glass ribbon GR.

The forming furnace 2 includes a forming body 4, a support member 5 that supports the forming body 4, a heating device 6 that heats the forming body 4, and edge rollers 7 that clamp the molten glass GM formed by the forming body 4. In addition, the forming furnace 2 includes a furnace wall (not shown) that surrounds the forming body 4. The furnace wall is provided with a heating device for heating the forming body 4 and the space around it.

The forming body 4 forms the glass ribbon GR by forming the molten glass GM into a thin plate shape. The forming body 4 is composed of dense zircon, alumina-based, zirconia-based, or other refractory bricks. The forming body 4 may be provided with a coating of a precious metal (e.g., platinum). The coating of the precious metal may be formed, for example, by thermal spraying. The coating of the precious metal may be formed, for example, on the entire surface of the forming body 4, or may be formed only on the portion that comes into contact with the molten glass GM. The forming body 4 includes an upper portion 4a, a side portion 4b, and a lower portion 4c.

The upper portion 4a of the molding 4 includes an upper surface 8, an overflow groove 9 to which the molten glass GM is supplied, and a supply section 10 that supplies the molten glass GM to the overflow groove 9.

The upper surface 8 is located between the overflow groove 9 and the side portion 4b. The upper surface 8 may be configured to be horizontal, or may be configured as an inclined surface that slopes downward from the overflow groove 9 toward the side portion 4b.

The overflow groove 9 includes an edge portion 11 that allows the molten glass GM to flow out, and an outflow prevention wall portion 12 that prevents the outflow of the molten glass GM. The edge portion 11 is configured in a straight line, but is not limited to this shape. The edge portion 11 is connected to the upper surface 8. The outflow prevention wall portion 12 has a wall surface 13 that extends above the edge portion 11 and the upper surface 8.

The supply unit 10 is made of a metal such as platinum or a platinum alloy. As shown in FIG. 2, the supply unit 10 is configured in a tubular shape. The supply unit 10 has an opening 14 for discharging the molten glass GM. The opening 14 is connected to one end of the overflow groove 9 in the longitudinal direction.

The side portion 4b of the forming body 4 has a side surface 15 that guides the molten glass GM flowing out of the overflow groove 9 downward, and guide portions 16a, 16b that guide (restrict) the widthwise ends of the molten glass GM downward.

As shown in Figures 1 and 2, the side surface 15 is composed of a single flat surface extending in the vertical direction, but the shape of the side surface 15 is not limited to this embodiment. The side surface 15 may be a vertical surface formed along the vertical direction, a surface that is inclined within a range of ±40° with respect to the vertical direction, or a combination of a vertical surface and an inclined surface.

The guide portions 16a and 16b are made of the same refractory material as the side surface 15. That is, like the side surface 15, the guide portions 16a and 16b are formed by cutting or otherwise processing the firebricks that make up the molded body 4. The guide portions 16a and 16b include a first guide portion 16a that regulates the flow of the molten glass GM at one end in the width direction, and a second guide portion 16b that regulates the flow of the molten glass GM at the other end in the width direction.

The lower portion 4c of the molded body 4 has a support surface 19 supported by the support member 5 and a separation portion 20 formed between the lower end portion 18 of the side surface 15 and the support surface 19.

The support surface 19 is formed below the overflow groove 9. The support surface 19 is located above the lower end 18 of the side surface 15. The support surface 19 is a flat surface facing downward, but the shape of the support surface 19 is not limited to this embodiment. The support surface 19 is formed from one end to the other end in the width direction of the molded body 4. In other words, the support surface 19 is formed not only at one end and the other end in the width direction of the molded body 4, but also in the intermediate portion between them.

The separation portion 20 is for moving the molten glass GM away from the lower end 18 of the side surface 15. The separation portion 20 includes a first surface 21 connected to the lower end 18 of the side surface 15, and a second surface 22 connected to the first surface 21. The first surface 21 is configured as an arc-shaped curved surface (relief portion) that is convex downward. The second surface 22 is configured as a flat surface that is inclined at a predetermined angle with respect to the vertical direction. By configuring the second surface 22 to be inclined, a space is formed between the support member 5 that supports the support surface 19 and the second surface 22, in which a heating device 6 can be placed.

The support member 5 is configured in a rectangular prism shape, but is not limited to this shape. The support member 5 is configured, for example, from a refractory material. The support member 5 supports the formed body 4 by contacting a support surface 19 formed on the lower part 4c of the formed body 4. Specifically, the support member 5 supports the formed body 4 by contacting not only one end and the other end of the support surface 19 in the width direction of the formed body 4, but also the intermediate part between them.

The heating device 6 is, for example, configured with a rod-shaped heater, but the configuration of the heating device 6 is not limited to this embodiment and may be configured with multiple panel-shaped heaters. The heating device 6 has a length dimension greater than the length dimension in the width direction of the formed body 4. The heating device 6 is disposed between the support member 5 and the separation portion 20 of the formed body 4. The heating device 6 heats the separation portion 20 in the formed body 4 and the molten glass GM immediately after it leaves the lower end portion 18.

The edge rollers 7 are made up of a pair of rollers. The edge rollers 7 are used to pinch and pull out the widthwise end of the glass ribbon GR formed by the forming body 4.

The annealing furnace 3 slowly cools the glass ribbon GR that is transported downward through the forming furnace 2, thereby suppressing the occurrence of internal distortion. In other words, multiple heaters are arranged vertically within the annealing furnace 3, and a predetermined temperature gradient is formed within the annealing furnace 3 by each heater. As a result, in the annealing furnace 3, the temperature gradually decreases as the glass ribbon GR descends, suppressing the occurrence of internal distortion in the glass ribbon GR.

The annealing furnace 3 is disposed below the forming furnace 2. The annealing furnace 3 has multiple stages of conveying rollers 23 arranged at intervals in the vertical direction. The conveying rollers 23 are a pair of rollers capable of clamping the glass ribbon GR. The conveying rollers 23 rotate while clamping the glass ribbon GR formed by the forming furnace 2, thereby conveying the glass ribbon GR downward in a vertical position.

Below, we will explain how to manufacture glass articles (glass ribbon GR, glass plate) using the manufacturing device 1 configured as described above.

As shown in FIG. 3, this method includes a preparation step S1, a molding step S2, a cooling step S3, and a cutting step S4.

In the preparation step S1, glass raw materials are heated in a glass melting furnace to produce molten glass GM. If necessary, the molten glass GM is subjected to fining, stirring, and condition adjustment processes. The molten glass GM is supplied to the forming furnace 2 through a glass supply path.

In the forming step S2, molten glass GM is supplied to the overflow groove 9 of the formed body 4 through the supply section 10. The molten glass GM supplied to the overflow groove 9 flows out of the overflow groove 9 beyond the edge 11. The molten glass GM that has exceeded the edge 11 flows along the upper surface 8 of the formed body 4 toward the side surface 15.

When the molten glass GM moves from the upper surface 8 to the side surface 15, it flows downward along the side surface 15. At this time, the widthwise ends of the molten glass GM flow downward while being restricted by the guide portions 16a and 16b. The side surface 15 causes the molten glass GM to flow downward from the upper end portion 17 to the lower end portion 18. The molten glass GM becomes plate-shaped while flowing along the side surface 15.

The plate-shaped molten glass GM continues to move downward even after it reaches the lower end 18 of the side surface 15, and separates (detaches) from the forming body 4 at the separation section 20. As a result, a thin plate-shaped glass ribbon GR is formed from the molten glass GM. The edge rollers 7 convey the formed glass ribbon GR downward while clamping the widthwise ends of the glass ribbon GR.

The cooling process S3 includes a slow cooling process using the slow cooling furnace 3 and a natural cooling process in which the molten glass GM that has passed through the slow cooling furnace 3 is naturally cooled (allowed to cool).

In the annealing process, the glass ribbon GR that has passed through the forming furnace 2 is annealed in the annealing furnace 3 while being conveyed downward in a vertical position by the conveying rollers 23. Then, in the natural cooling process, the glass ribbon GR passes through a cooling chamber located below the annealing furnace 3. This allows the glass ribbon GR to be naturally cooled to room temperature.

In the cutting process S4, the glass ribbon GR that has passed through the cooling chamber is cut by a cutting method such as laser cutting or scribe cutting. This forms a rectangular glass plate. If necessary, an edge processing process for grinding and polishing the edge of the glass plate, a cleaning process, an inspection process, and a packaging process may be provided. In each of these processes, the same aspects as those used in the manufacture of display glass substrates and cover glass by the conventional overflow method or float method can be adopted.

According to the manufacturing method and manufacturing apparatus 1 for a glass article according to the present embodiment described above, in the forming step S2, the molten glass GM is formed by the side surface 15 formed on the forming body 4, which makes it possible to reduce the thickness dimension of the glass ribbon GR directly below the forming body 4 (when separated from the forming body 4) compared to the conventional manufacturing method in which the molten glass is fused by the two side surfaces of the forming body. Therefore, the cooling rate of the glass ribbon GR after separation from the forming body 4 can be increased. As a result, even if the glass is prone to devitrification and difficult to form by the conventional overflow downdraw method, this method makes it possible to form the glass while suppressing devitrification of the glass.

In addition, if the thickness dimension of the glass ribbon directly below the forming body 4 (when separated from the forming body 4) is the same, in this method, the thickness dimension of the molten glass GM flowing down the side surface 15 of the forming body 4 can be increased (e.g., doubled) compared to the conventional overflow downdraw method. This makes it easier for the molten glass GM to flow to both ends of the longitudinal direction of the forming body 4. As a result, problems such as stagnation or devitrification of the molten glass GM can be suppressed at both ends of the longitudinal direction of the forming body 4.

The glass ribbon GR produced by this method has a first main surface GRa as a fire-polished surface formed without contacting the side surface 15 of the formed body 4, and a second main surface GRb as a formed surface formed by contacting the side surface 15. In the process of forming the glass ribbon GR, the molten glass is not fused and integrated, so there is no mating surface in the middle part in the thickness direction. The surface roughness (arithmetic mean roughness) Ra of the first main surface GRa is 1 to 0.2 nm. The surface roughness Ra of the second main surface GRb is 1 to 0.2 nm. Thus, although the second main surface GRb (formed surface) is an unpolished surface, it has surface properties comparable to those of the first main surface GRa (fire-polished surface). The surface roughness Ra of the second main surface GRb changes depending on the surface roughness Ra of the side surface 15 of the formed body 4. From the viewpoint of setting the surface roughness of the second main surface GRb in the above-mentioned range, it is preferable to set the surface roughness Ra of the side surface 15 to 1 to 0.6 nm.

The thickness dimension of the glass ribbon GR produced by this method (after passing through the cooling chamber) is, for example, 3000 to 25 μm, but is preferably 500 to 100 μm.

In this method, the glass ribbon GR in a vertical position is cooled while being transported vertically in the cooling step S3, so that the glass ribbon GR can be transported without the intermediate portion in the width direction of the glass ribbon GR coming into contact with the edge rollers 7 or the transport rollers 23. By removing both ends in the width direction of the glass ribbon GR that are in contact with the edge rollers 7, etc. by cutting or the like, a glass article in which damage caused by transport is suppressed can be manufactured.

In this method, in the forming step S2, the separation portion 20 of the formed body 4 and the molten glass GM immediately after leaving the lower end portion 18 of the side surface 15 are heated by the heating device 6, so that the temperature difference between the surface (the surface not in contact with the formed body 4, corresponding to the first main surface GRa) and the back surface (the surface in contact with the formed body 4, corresponding to the second main surface GRb) of the molten glass GM can be reduced. This makes it possible to prevent warping of the glass ribbon GR after forming. In addition, it is possible to prevent devitrification of the glass ribbon GR, making it possible to manufacture a high-quality glass article. Furthermore, the viscosity of the molten glass GM can be reduced as much as possible by heating with the heating device 6. This makes it easier for the molten glass GM to separate from the lower end portion 18 of the side surface 15, and it is possible to reliably prevent the molten glass GM from remaining at the lower end portion 18 or the molten glass GM from remaining on the first surface 21 of the separation portion 20.

In addition, by supporting the lower part 4c (support surface 19) of the molded body 4 at its widthwise middle part with the support member 5, it is possible to prevent creep deformation of the molded body 4 during the molding process S2.

Figures 4 and 5 show a second embodiment of the present invention. The manufacturing apparatus 1 according to this embodiment differs from the first embodiment in the configuration of the forming furnace 2. In this embodiment, the molded body 4 in the forming furnace 2 has a first side 15a located on one side of the molded body 4 and a second side 15b located on the opposite side of the first side 15a.

The overflow groove 9 of the molded body 4 includes a first edge 11a that supplies the molten glass GM to the first side 15a, and a second edge 11b that supplies the molten glass GM to the second side 15b. The upper surface 8 of the molded body 4 includes a first upper surface 8a that connects the first edge 11a and the first side 15a, and a second upper surface 8b that connects the second edge 11b and the second side 15b. The upper portion 4a of the molded body 4 does not include the outflow prevention wall portion 12 in the first embodiment.

The separation portions 20a, 20b include a first separation portion 20a that separates the molten glass GM from the lower end portion 18 of the first side surface 15a, and a second separation portion 20b that separates the molten glass GM from the lower end portion 18 of the second side surface 15b.

The support surface 19 formed on the lower part 4c of the molded body 4 is between the first spaced part 20a and the second spaced part 20b, and is formed below the overflow groove 9.

The heating devices 6a and 6b include a first heating device 6a that heats the first separation portion 20a of the molding body 4 and the molten glass GM immediately after it leaves the lower end 18 of the first side surface 15a, and a second heating device 6b that heats the second separation portion 20b of the molding body 4 and the molten glass GM immediately after it leaves the lower end 18 of the second side surface 15b.

The edge rollers 7a, 7b include a first edge roller 7a that clamps the widthwise end of the molten glass GM formed by the first side surface 15a, and a second edge roller 7b that clamps the widthwise end of the molten glass GM formed by the second side surface 15b.

Hereinafter, the glass ribbon formed from the molten glass GM by the first side 15a is referred to as the first glass ribbon GR1, and the glass ribbon formed from the molten glass GM by the second side 15b is referred to as the second glass ribbon GR2.

The annealing furnace 3 includes a first conveying roller 23a that conveys the first glass ribbon GR1 in a vertical position, and a second conveying roller 23b that conveys the second glass ribbon GR2 in a vertical position.

In the manufacturing method of the glass article according to the present embodiment, in the forming step S2, the plate-shaped molten glass GM flowing through the first side surface 15a and the plate-shaped molten glass GM flowing through the second side surface 15b do not fuse. That is, the first side surface 15a of the forming body 4 can form the first glass ribbon GR1 by forming the molten glass GM flowing out from the first edge portion 11a of the overflow groove 9. The second side surface 15b can form the second glass ribbon GR2 by forming the molten glass GM flowing out from the second edge portion 11b of the overflow groove 9. Each of the glass ribbons GR1 and GR2 includes a first main surface GRa that serves as a fire-polished surface and a second main surface GRb that serves as a forming surface formed by each of the side surfaces 15a and 15b.

According to the present embodiment described above, it is possible to simultaneously mold two glass ribbons GR using one molding body 4. This allows glass articles to be manufactured efficiently.

Figure 6 shows a third embodiment of the present invention. The glass article manufacturing apparatus 1 according to this embodiment differs from the first embodiment in the configuration of the formed body 4 and the heating device 6 in the forming furnace 2. The heating device 6 is inserted into a hole 24 formed through the formed body 4. The hole 24 in the formed body 4 is formed in a position near the lower end 18 of the side surface 15. The hole 24 penetrates the entire width of the formed body 4.

Compared to the first embodiment, the heating device 6 can heat the lower end 18 of the side 15 of the forming body 4 at a position close to the lower end 18, the separation portion 20, and the molten glass GM immediately after it leaves the lower end 18.

Figure 7 shows a fourth embodiment of the present invention. The manufacturing apparatus 1 according to this embodiment differs from the second embodiment in the configuration of the forming furnace 2.

The upper portion 4a of the molded body 4 has a first overflow groove 9a and a second overflow groove 9b separated by an overflow prevention wall portion 12.

The outflow prevention wall portion 12 includes a first wall surface 13a that prevents the outflow of molten glass GM from the first overflow groove 9a, and a second wall surface 13b that prevents the outflow of molten glass GM from the second overflow groove 9b. The first wall surface 13a prevents the molten glass GM supplied to the first overflow groove 9a from flowing into the second overflow groove 9b. The second wall surface 13b prevents the GM supplied to the second overflow groove 9b from flowing into the first overflow groove 9a.

The heating devices 6a1, 6a2, 6b1, and 6b2 include a plurality of first heating devices 6a1, 6a2 and a plurality of second heating devices 6b1, 6b2.

The first heating devices 6a1, 6a2 include an upper heating device 6a1 that mainly heats the first separation portion 20a of the forming body 4, and a lower heating device 6a2 that mainly heats the molten glass GM immediately after it leaves the lower end portion 18 of the first side surface 15a.

The second heating devices 6b1, 6b2 include an upper heating device 6b1 that mainly heats the second separated portion 20b of the forming body 4, and a lower heating device 6b2 that mainly heats the molten glass GM immediately after it leaves the lower end portion 18 of the second side surface 15b.

The supply section includes a first supply section that supplies molten glass GM to the first overflow groove 9a, and a second supply section that supplies molten glass GM to the second overflow groove 9b.

In the manufacturing method of the glass article according to this embodiment, in the forming step S2, the first glass ribbon GR1 and the second glass ribbon GR2 are formed by supplying molten glass GM to the first overflow groove 9a and the second overflow groove 9b individually via the first supply section and the second supply section. This makes it possible to form, for example, the first glass ribbon GR1 and the second glass ribbon GR2 having different compositions.

The present invention is not limited to the configuration of the above embodiment, nor is it limited to the above-mentioned effects. Various modifications of the present invention are possible without departing from the gist of the present invention.

In the above embodiment, the side surfaces 15, 15a, and 15b of the molded body 4 are configured as flat surfaces from the upper end 17 to the lower end 18, but the present invention is not limited to this configuration. The side surfaces 15, 15a, and 15b of the molded body 4 may be configured as curved surfaces or other shapes.

In the above embodiment, a cutting step S4 for cutting the glass ribbon GR is exemplified, but the present invention is not limited to this configuration. The manufacturing method of a glass article according to the present invention may include a winding step for winding the glass ribbon GR into a roll, instead of the cutting step S4. The winding step makes it possible to manufacture a glass roll by winding the glass ribbon GR into a roll.

Description of the Reference Signs 1 Manufacturing apparatus 4 Molded body 4c Lower part of molded body 5 Support member 6 Heating device 6a First heating device 6a1 First heating device 6a2 First heating device 6b Second heating device 6b1 Second heating device 6b2 Second heating device 9 Overflow groove 9a First overflow groove 9b Second overflow groove 15 Side surface 15a First side surface 15b Second side surface 16a First guide portion 16b Second guide portion 18 Lower end portion of side surface 20 Separation portion GM Molten glass GR Glass ribbon GR1 First glass ribbon GR2 Second glass ribbon GRa First main surface of glass ribbon (fire polished surface)
GRb: second main surface (forming surface) of the glass ribbon
S2 Molding process S3 Cooling process

Claims (7)

A method for manufacturing a glass article, comprising: a forming step of forming a glass ribbon by converting molten glass into a plate shape using a forming body; and a cooling step of cooling the glass ribbon formed by the forming body while transporting it in a vertical direction,
The forming body includes an overflow groove to which the molten glass is supplied, and a side surface through which the molten glass flowing out of the overflow groove flows downward,
In the forming step, the glass ribbon is formed such that one surface is a formed surface formed by the side surface and the other surface is a fire-polished surface ,
A method for producing a glass article, comprising obtaining a glass article from the glass ribbon, one surface of which is a formed surface formed by the side surface and the other surface of which is a fire-polished surface . The side surface extends in a longitudinal direction,
The method for manufacturing a glass article according to claim 1 , wherein the forming body has a separation portion that is connected to a lower end of the side surface and separates the molten glass from the forming body. The method for manufacturing a glass article according to claim 1 or 2, wherein the lower part of the molded body is supported by a support member. The method for manufacturing a glass article according to any one of claims 1 to 3, wherein the molded body has a guide portion that guides the end portion in the width direction of the plate-like molten glass, and the side surface and the guide portion are provided in the same refractory material. The method for manufacturing a glass article according to claim 2, wherein in the forming step, the spaced portion of the side surface is heated by a heating device. The side surface includes a first side surface located on one side of the molded body and a second side surface located on the opposite side of the first side surface,
The method for manufacturing a glass article according to any one of claims 1 to 5, wherein the glass ribbon includes a first glass ribbon having a formed surface by the first side surface, and a second glass ribbon having a formed surface by the second side surface. An apparatus for manufacturing a glass article, comprising a forming body for forming molten glass into a plate shape to form a glass ribbon,
The forming body includes an overflow groove to which the molten glass is supplied, and a side surface through which the molten glass flowing out of the overflow groove flows downward,
the forming body is configured to form the glass ribbon having one surface which is a formed surface formed by the side surface and the other surface which is a fire-polished surface ,
A glass article manufacturing apparatus configured to obtain a glass article from the glass ribbon, one surface of which is a formed surface formed by the side surface and the other surface of which is a fire-polished surface .

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