JP7415252B2 - Method for manufacturing glass articles - Google Patents

Description

The present invention relates to a method for manufacturing glass articles.

Examples of methods for manufacturing glass articles include down-draw methods such as overflow down-draw method, slot down-draw method, and redraw method.

The manufacturing method of glass articles using such a down-draw method involves a forming process in which a glass ribbon is formed by flowing molten glass from a molded object in a forming furnace, and a heat treatment furnace placed below the forming furnace. and a heat treatment step of performing heat treatment (slow cooling treatment) on the glass ribbon to reduce warpage and distortion while conveying the formed glass ribbon downward (see, for example, Patent Document 1). After the heat treatment step, the glass ribbon cooled to around room temperature is cut into a predetermined length to produce a glass plate, or wound into a roll to produce a glass roll.

Japanese Patent Application Publication No. 2014-122124

In the above-mentioned forming process, a process of cooling the surface of the glass ribbon that has flowed down from the molded body may be performed separately from the heat treatment process. In this cooling step, the glass ribbon is cooled by radiating heat from the glass ribbon to the outside of the furnace using a lower refractory brick of the forming furnace that faces the surface of the glass ribbon in the thickness direction of the glass ribbon.

By the way, in consideration of ease of replacement, the lower firebrick may be divided into a plurality of parts in the width direction of the glass ribbon. However, in the case of this structure, there is a possibility that a streak-like convex defect extending along the conveyance direction may be formed on the surface of the glass ribbon at a position facing the joint between adjacent lower firebricks. When such streak-like convex defects are formed, the surface smoothness of the manufactured glass article is lost, and there is a problem that it becomes impossible to manufacture a high-quality glass article.

Here, it is thought that the streaky convex defect was caused by the following reason. That is, gas can easily flow into and out of the forming furnace through the joints of the lower refractory bricks. As a result, heat dissipation from the glass ribbon increases at positions facing the joints of the lower firebrick, and only predetermined portions of the glass ribbon tend to be locally cooled. It is thought that when such local cooling occurs, the surface of the glass ribbon locally contracts and bulges, resulting in streak-like convex defects.

An object of the present invention is to prevent the formation of streaky convex defects on the surface of a glass ribbon and to provide a high-quality glass article.

The present invention, which was devised to solve the above problems, includes a forming process in which a glass ribbon is formed by flowing down molten glass from a formed body in a forming furnace, and a forming process in which the glass ribbon formed in the forming process is moved along the conveyance direction. In the method of manufacturing a glass plate, the forming process is performed by heating the glass ribbon in a forming furnace that faces the surface of the glass ribbon flowing down from the formed body in the thickness direction of the glass ribbon. It includes a step of cooling the glass ribbon using a lower refractory brick, and the lower refractory brick is divided into a plurality of parts in the width direction of the glass ribbon, and when observed from the upstream side in the conveying direction, the adjacent lower refractory brick It is characterized in that the position of the joint in the width direction changes in the thickness direction of the glass ribbon. In this way, it is possible to prevent gas from flowing inside and outside the forming furnace through the joints of the lower refractory bricks, and the sealing performance of the joints of the lower refractory bricks is improved. Therefore, a situation in which only a predetermined portion of the glass ribbon is locally cooled at a position facing the joint of the lower firebrick can be suppressed, and it is possible to prevent streak-like convex defects from being formed on the surface of the glass ribbon.

In the above configuration, it is preferable that the joint between adjacent lower refractory bricks has a bent part when observed from the upstream side in the conveyance direction. In this way, the joints of the lower firebrick are bent by the bent portions, and the sealing performance thereof is further improved. Therefore, it is possible to more reliably prevent a situation in which only a predetermined member of the glass ribbon is locally cooled at a position facing the joint.

In the above configuration, when observed from the glass ribbon side, it is preferable that the position in the width direction of the joint between adjacent lower refractory bricks changes in the conveyance direction. In this way, since the position where the glass ribbon and the joint of the lower refractory brick face each other changes, it is possible to more reliably suppress a situation where only a predetermined portion of the glass ribbon is locally cooled.

In the above configuration, when observed from the glass ribbon side, it is preferable that the joints between adjacent lower refractory bricks extend in a direction oblique to the conveying direction. In this way, since the position where the glass ribbon and the joint of the lower refractory brick face each other changes continuously, it is possible to more reliably suppress a situation where only a predetermined portion of the glass ribbon is locally cooled.

In the above configuration, the forming furnace is arranged such that the upper refractory brick facing the formed body and the lower refractory brick are closer to the glass ribbon side than the upper refractory brick, and the lower end of the upper refractory brick and the upper end of the lower refractory brick. It may also be equipped with a fireproof brick for connection. In this way, the lower refractory brick can be brought closer to the glass ribbon and the space between them can be reduced, so the lower refractory brick can be used to efficiently cool the glass ribbon that has flowed down from the molded body.

In the above configuration, the connecting refractory bricks are divided into a plurality of parts in the width direction, and when observed from the upstream side in the conveyance direction, the position of the joint between adjacent connecting refractory bricks in the width direction is It is preferable that the thickness changes in the thickness direction. In this way, the sealing performance of the joints of the connecting refractory bricks is improved. Therefore, it becomes difficult for the gas inside and outside the forming furnace to directly flow through the joints of the connecting refractory bricks. Therefore, a situation in which only a predetermined member of the glass ribbon is locally cooled at a position facing the joint of the connecting firebrick can be suppressed, and the formation of streak-like convex defects can be prevented.

In the above configuration, it is preferable that the joint between adjacent connecting firebricks has a bent part when observed from the upstream side in the conveyance direction. In this way, the joints of the connecting refractory bricks are bent by the bent portions, and the sealing performance thereof is further improved. Therefore, it is possible to more reliably prevent a situation in which only a predetermined member of the glass ribbon is locally cooled at a position facing the joint.

In the above configuration, when observed from the glass ribbon side, it is preferable that the position in the width direction of the joint between adjacent connecting refractory bricks changes in the conveying direction. In this way, since the position where the glass ribbon and the joint of the connecting refractory brick face each other changes, it is possible to more reliably suppress a situation where only a predetermined portion of the glass ribbon is locally cooled.

In the above configuration, when observed from the glass ribbon side, it is preferable that the joints between adjacent connecting refractory bricks extend in a direction oblique to the conveying direction. In this way, since the position where the glass ribbon and the joint of the connecting refractory brick face each other changes continuously, it is possible to more reliably prevent a situation where only a predetermined portion of the glass ribbon is locally cooled.

The present invention, which was devised to solve the above problems, includes a forming process in which a glass ribbon is formed by flowing down molten glass from a formed body in a forming furnace, and a forming process in which the glass ribbon formed in the forming process is moved along the conveyance direction. A method for manufacturing a glass article includes a heat treatment step of heat-treating the glass ribbon while conveying the glass ribbon. It includes a step of cooling the glass ribbon using a lower refractory brick, and the lower refractory brick is divided into a plurality of parts in the width direction of the glass ribbon, and when observed from the glass ribbon side, there is a difference between adjacent lower refractory bricks. It is characterized in that the position of the joint in the width direction changes in the conveyance direction. In this way, since the position where the glass ribbon and the joint of the lower refractory brick face each other changes, a situation in which only a predetermined portion of the glass ribbon is locally cooled can be suppressed. Therefore, it is possible to prevent streaky convex defects from being formed on the surface of the glass ribbon.

According to the present invention, it is possible to prevent streaky convex defects from being formed on the surface of a glass ribbon, and to provide a high-quality glass article.

FIG. 1 is a schematic vertical cross-sectional view of a glass article manufacturing apparatus. FIG. 2 is a sectional view taken along the line AA in FIG. 1, showing the state of the joints of the lower refractory brick and the connecting refractory brick when observed from the glass ribbon side. FIG. 2 is a sectional view taken along line BB in FIG. 1, showing the state of the joints of the lower firebrick when observed from the upstream side in the conveyance direction. FIG. 2 is a cross-sectional view taken along the line CC in FIG. 1, showing the state of the joints of the connecting refractory bricks when observed from the upstream side in the conveyance direction. It is a sectional view showing a modification of the joint of the lower refractory brick when observed from the upstream side in the conveyance direction. It is a sectional view showing a modification of the joint of the lower refractory brick when observed from the upstream side in the conveyance direction. It is a sectional view showing a modification of the joint of the lower refractory brick when observed from the upstream side in the conveyance direction. It is a sectional view showing a modification of the joint of the lower refractory brick when observed from the upstream side in the conveyance direction. FIG. 2 is a sectional view taken along the line AA in FIG. 1, showing a modified example of the joints of the lower firebrick when observed from the glass ribbon side.

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. Note that XYZ in the figure is an orthogonal coordinate system. The X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. While the glass ribbon G is conveyed in a vertical position, the X direction is the thickness direction of the glass ribbon G (hereinafter also simply referred to as the "thickness direction"), and the Y direction is the width direction of the glass ribbon G (hereinafter simply referred to as the "width direction"). The Z direction is the transport direction of the glass ribbon G (hereinafter also simply referred to as the "transport direction").

As shown in FIG. 1, a glass article manufacturing apparatus for embodying the glass article manufacturing method according to the present embodiment is an apparatus that continuously forms a glass ribbon G. Glass articles manufactured from the glass ribbon G include glass plates and glass rolls.

The glass article manufacturing apparatus includes a forming furnace 1 that forms a glass ribbon G, a heat treatment furnace 2 that heat-treats the glass ribbon G, a cooling zone 3 that cools the glass ribbon G to around room temperature, a heat treatment furnace 2, and a cooling zone. Each of the rollers 3 is provided with a pair of rollers 4 provided in a plurality of upper and lower stages.

Here, the glass article manufacturing apparatus includes, on the downstream side of the cooling zone 3, a cutting device that cuts the glass ribbon G to obtain a glass plate, an end surface processing device that processes the end surface of the glass plate, and a cleaning device that cleans the glass plate. , an inspection device for inspecting the glass plate, etc. may be further provided. Alternatively, on the downstream side of the cooling zone 3, the glass article manufacturing apparatus includes a cutting device that cuts and removes both ends of the glass ribbon G in the width direction, and a winding device that winds up the glass ribbon G into a roll shape to obtain a glass roll. It may further include a collecting device or the like.

A molded body 5 for molding a glass ribbon G from molten glass Gm by an overflow down-draw method is arranged in the internal space of the molding furnace 1. The molten glass Gm supplied to the molded body 5 overflows from the groove 5a formed at the top of the molded body 5, and the overflowing molten glass Gm flows onto both side surfaces 5b of the molded body 5, which have a wedge-shaped cross section. By passing along the glass ribbons and merging at the lower end, a plate-shaped glass ribbon G is continuously formed. The glass ribbon G to be formed is in a vertical position (preferably in a vertical position).

The forming furnace 1 includes an upper refractory brick 6, a lower refractory brick 7, and a connecting refractory brick 8 that connects the lower end of the upper refractory brick 6 and the upper end of the lower refractory brick 7. The connecting refractory brick 8 connects the upper refractory brick 6 and the lower refractory brick 7 such that the lower refractory brick 7 is closer to the glass ribbon G side than the upper refractory brick 6 is. Note that the connecting refractory brick 8 may be omitted.

At a position corresponding to the upper firebrick 6, the temperature of the molten glass Gm flowing down the surface of the molded body 5 is adjusted. The temperature of the molten glass Gm flowing down the surface of the molded body 5 can be adjusted, for example, by a heating device (not shown) such as a heater provided at a position corresponding to the upper refractory brick 6. The heating device can be provided inside or outside the furnace of the upper refractory brick 6. Alternatively, the heating device can be embedded inside the upper refractory brick 6.

The lower refractory brick 7 faces the surface of the glass ribbon G flowing down from the molded body 5 in the thickness direction, and the lower refractory brick 7 is used to cool the glass ribbon G. This cooling is aimed at adjusting the uneven thickness of the glass ribbon G, and is performed by radiating the heat of the glass ribbon G to the outside of the furnace via the lower refractory brick 7. That is, the lower refractory brick 7 corresponds to a heat radiation zone. Note that a heating device such as a heater is not provided at a position corresponding to the lower refractory brick 7.

Here, for example, the upper refractory brick 6 and the lower refractory brick 7 are formed of silicon carbide (SiC) bricks, and the connecting refractory brick 8 is formed of an alumina zircon brick or the like.

The internal space of the heat treatment furnace 2 has a predetermined temperature gradient downward. As the glass ribbon G in the vertical position moves downward through the interior space of the heat treatment furnace 2, it is gradually cooled (annealed) so that its temperature becomes lower. This slow cooling is for adjusting (reducing) warpage and distortion of the glass ribbon G. The temperature gradient in the internal space of the heat treatment furnace 2 can be adjusted, for example, by a heating device (not shown) such as a heater provided at a position corresponding to the heat treatment furnace 2. The heating device can be provided inside or outside the heat treatment furnace 2. Alternatively, the heating device can be embedded inside the furnace wall of the heat treatment furnace 2.

The plurality of roller pairs 4 are configured to clamp each of the widthwise ends of the glass ribbon G in the vertical position from both the front and back sides. Note that the roller pair 4 is not provided in the region from the lower end of the molded body 5 to the lower end of the lower refractory brick 7.

The uppermost roller pair 4a of the plurality of roller pairs 4 is provided near the upper end of the heat treatment furnace 2, and is composed of cooling rollers (edge rollers) that cool both ends of the glass ribbon G in the width direction. There is. This cooling roller is for suppressing shrinkage of the glass ribbon G in the width direction.

In addition, in the internal space of the heat treatment furnace 2, etc., the plurality of roller pairs 4 may include rollers that do not sandwich the widthwise ends of the glass ribbon G. In other words, the spacing between the pair of rollers 4 may be made larger than the thickness of the ends of the glass ribbon G in the width direction, so that the glass ribbon G can pass between the pair of rollers 4.

As shown in FIG. 2, the lower refractory brick 7 and the connecting refractory brick 8 are divided into a plurality of parts in the width direction. Therefore, joints 9 and 10 are formed between each of the bricks 7 and 8 adjacent in the width direction. Note that the connecting firebrick 8 may have an integral structure without being divided into a plurality of parts in the width direction and without joints.

When observed from the glass ribbon G side, the joints 9 of the lower refractory brick 7 are straight lines inclined with respect to the conveyance direction, and the position in the width direction changes in the conveyance direction. Similarly, when observed from the glass ribbon G side, the joints 10 of the connecting refractory bricks 8 are also straight lines inclined with respect to the conveyance direction, and the position in the width direction changes in the conveyance direction. As a result, the position in the width direction where the glass ribbon G and the joints 9 and 10 face each other changes sequentially in the conveyance direction, so it is possible to prevent a situation in which only a predetermined part in the width direction of the glass ribbon G continues to be locally cooled. . In the illustrated example, the inclination direction of the joint 9 and the inclination direction of the joint 10 are opposite to each other, but they may be in the same direction. Furthermore, some of the joints 9 (or joints 10) may have different inclination directions. Furthermore, as long as the positions of the joints 9 and 10 in the width direction change in the conveying direction when observed from the glass ribbon G side, the manner in which the joints 9 and 10 change is not limited to a linear shape. However, if it is straight, it has the advantage that the bricks 7 and 8 can be easily processed.

As shown in FIG. 3, when observed from the upstream side in the conveyance direction, the joint 9 of the lower refractory brick 7 has a bent part 9a, and the position in the width direction changes in the thickness direction. Similarly, as shown in FIG. 4, when observed from the upstream side in the conveyance direction, the joints 10 of the connecting refractory bricks 8 also have bent portions 10a, and the position in the width direction changes in the thickness direction. There is. This improves the sealing performance of the joints 9 and 10, making it difficult for gas to flow directly inside and outside the forming furnace 1 through the joints 9 and 10. Therefore, it is possible to suppress a situation in which a predetermined portion of the glass ribbon G in the width direction is locally cooled at a position where the glass ribbon G and the joints 9 and 10 face each other.

In this embodiment, the joint 9 of the lower refractory brick 7 has two bent portions 9a. Due to these bent portions 9a, the joint 9 has two first portions 9b extending along the thickness direction and a second portion 9c extending along the width direction between these first portions 9b, and has a stepped shape as a whole. (hook shape). Similarly, the joint 10 of the connecting firebrick 8 also has two bent portions 10a. Due to these bent portions 10a, the joint 10 has two first portions 10b extending along the thickness direction and a second portion 10c extending along the width direction between these first portions 10b, and has a stepped shape as a whole. (hook shape). That is, although the joints 9 and 10 have a relatively simple shape, the second portions 9c and 10c extending along the width direction provide a large resistance to the gas passing through the joints 9 and 10, so that the gas does not flow. It has a difficult structure.

Here, in this embodiment, when observed from the upstream side in the conveyance direction, the position P1 (or position P2) of the joint 9 of the lower refractory brick 7 facing the inside of the furnace shown in FIG. The position Q1 (or position Q2) of the joint 10 of the refractory brick 8 facing the inside of the furnace differs from the position Q1 (or position Q2) without overlapping in the width direction. That is, the joint 10 of the connecting firebrick 8 is located at position P1 (or position P2) of the joint 9 of the lower firebrick 7, and the joint 10 of the connecting firebrick 8 is located at position Q1 (or position P2). At position Q2), a portion of the lower refractory brick 7 without joints 9 is located. Thereby, the influence of the joints 9 and 10 is dispersed in the width direction of the glass ribbon G. In addition, in FIG. 2, when observed from the glass ribbon G side, the formation region spanning the entire length of the joint 9 of the lower refractory brick 7 in the transport direction, and the formation region spanning the entire length of the joint 10 of the connecting firebrick 8 in the transport direction. exemplifies a mode in which there is no overlap in the width direction.

Further, in this embodiment, when observed from the upstream side in the conveying direction, the position P1 of the joint 9 of one lower refractory brick 7 facing the inside of the furnace facing the one surface of the glass ribbon G, and the position P1 of the joint 9 of the glass ribbon G facing the inside of the furnace The position P2 facing the inside of the furnace of the joint 9 of the other lower refractory brick 7 facing the other surface does not overlap in the width direction, but is different. That is, the position where the joint 9 of one lower refractory brick 7 faces the inside of the furnace is opposed in the thickness direction by the portion without the joint 9 of the other lower refractory brick 7. Similarly, when observed from the upstream side in the conveyance direction, the position Q1 facing the inside of the furnace of the joint 10 of one connecting refractory brick 8 facing one surface of the glass ribbon G, and the other surface of the glass ribbon G The position Q2 of the joint 10 of the other connecting refractory brick 8 facing the inside of the furnace does not overlap in the width direction, but is different. That is, the position where the joint 10 of one connecting refractory brick 8 faces the inside of the furnace is opposed in the thickness direction by the portion of the other connecting refractory brick 8 that does not have the joint 10. Thereby, the influence of the joints 9 and 10 is dispersed on both surfaces of the glass ribbon G. In addition, in FIG. 3 and FIG. 4, when observed from the upstream side in the conveyance direction, the formation area over the entire length of the joint 9 of both opposing lower refractory bricks 7 in the thickness direction does not overlap with each other in the width direction. , and a mode in which the forming regions over the entire thickness direction of the joints 10 of both opposing connecting refractory bricks 8 do not overlap with each other in the width direction.

Furthermore, in this embodiment, the bent portion 10a (or second portion 10c) of the joint 10 in the connecting refractory brick 8 is located outside the upper refractory brick 6, that is, outside the furnace. Thereby, the portion of the joint 10 facing the inside of the furnace is configured with only the first linear portion 10b along the thickness direction, thereby simplifying the shape of the joint 10 facing the inside of the furnace. Note that the bent portion 10a (or second portion 10c) of the joint 10 in the connecting refractory brick 8 may be located below the upper refractory brick 6, or may be located inside the furnace than the upper refractory brick 6. You may do so.

Next, a method for manufacturing a glass article using the manufacturing apparatus configured as described above will be described.

As shown in FIG. 1, the method for manufacturing a glass article includes a forming process in which a glass ribbon G is formed by flowing down molten glass Gm from a formed body 5 in a forming furnace 1, and a glass ribbon formed in a heat treatment furnace 2. A heat treatment step of heat-treating the glass ribbon G while transporting the glass ribbon G along the transport direction, and cooling the glass ribbon G to around room temperature while transporting the heat-treated glass ribbon G in the cooling zone 3 along the transport direction. It is equipped with a cooling process.

The molding process includes an adjustment process in which the glass ribbon G flowing down from the molded body 5 is cooled using the lower refractory brick 7 of the molding furnace 1, and the uneven thickness of the glass ribbon G is adjusted (reduced). In the adjustment process, the glass ribbon G is cooled by dissipating the heat of the glass ribbon G to the outside of the furnace via the lower refractory brick 7.

Here, the purpose of the cooling in the adjustment process is to adjust the uneven thickness of the glass ribbon G, and the purpose of the cooling (slow cooling) in the heat treatment process is to adjust the warpage and distortion of the glass ribbon G. have different purposes. The temperature of the glass ribbon G in the conditioning process is, for example, 1000 to 1300°C, and the temperature of the glass ribbon G in the heat treatment process is, for example, 500 to 1000°C. Further, the viscosity of the glass ribbon G in the adjustment step is, for example, 20,000 to 300,000 poise, and the viscosity of the glass ribbon G in the heat treatment step is, for example, 10 ⁵ to 10 ¹⁶ poise.

In the adjustment process, as described above, the joints 9 and 10 of the lower refractory brick 7 and the connecting refractory brick 8 change in width direction position when observed from the glass ribbon G side, and When observed from the upstream side, the position in the width direction changes in the thickness direction. Therefore, in the adjustment process, a situation in which only a predetermined portion in the width direction of the glass ribbon G is locally cooled at a position facing the joints 9 and 10 is suppressed, and streak-like convex defects are prevented from occurring on the surface of the glass ribbon G. can be prevented from forming. Therefore, a high-quality glass article with excellent surface smoothness can be provided.

Note that the present invention is not limited to the above-described embodiments, and may be implemented in various forms without departing from the spirit of the present invention.

In the above embodiment, the joints 9 and 10 of the lower refractory brick 7 and the connecting refractory brick 8 have two bent parts 9a and 10a and have a step-like shape as a whole when observed from the upstream side in the conveyance direction. However, the number of bent portions 9a and 10a is not particularly limited. For example, when observed from the upstream side in the conveyance direction, the joint 9 of the lower refractory brick 7 may have one bent portion 9a as shown in FIG. 5, or may have one bent portion 9a as shown in FIG. The number of bent portions 9a may be three, or the number of bent portions 9a may be four or more as shown in FIG. Of course, for example, as shown in FIG. 8, when observed from the upstream side in the conveyance direction, the joints 9 may have a linear shape that is inclined with respect to the thickness direction, and may have a shape without a bent portion. These matters can be similarly applied to the joints 10 of the connecting firebrick 8.

In the above embodiment, as shown in FIG. 9, when the joint 9 of the lower refractory brick 7 is observed from the glass ribbon G side, the widthwise position of the upper end point 9d of the joint 9 is the lower end point of the adjacent joint 9. It may be the same as the width direction position of 9e. In this way, localized cooling can be more reliably suppressed.

In the above embodiment, a case has been described in which the bent portions 9a and 10a are formed from corners where two straight lines intersect, but the bent portions 9a and 10a may be formed from curved portions such as circular arcs.

In the above embodiment, the joints 9 and 10 of the lower refractory brick 7 and the connecting refractory brick 8 (1) when observed from the glass ribbon G side, the position in the width direction changes in the conveying direction, and (2 ) The case where the position in the width direction changes in the thickness direction when observed from the upstream side in the conveyance direction has been described, but at least the position in the width direction of the joint 9 of the lower refractory brick 7 changes as described in (1) and (2) above. ) may be satisfied. In addition, when only the above (1) is satisfied, the joint will be a straight line along the thickness direction when observed from the upstream side in the conveying direction, and when only the above (2) is satisfied, the joint will be a straight line from the glass ribbon G side. When observed, it appears to be a straight line along the conveyance direction.

In the above embodiment, a case has been described in which the glass ribbon G is formed by the overflow downdraw method, but the glass ribbon G may be formed by other downdraw methods such as the slot downdraw method and the redraw method.

1 Molding furnace 2 Heat treatment furnace 3 Cooling zone 4 Roller pair 5 Molded body 6 Upper refractory brick 7 Lower refractory brick 8 Connection refractory brick 9 Lower refractory brick joint 10 Connecting refractory brick joint G Glass ribbon Gm Molten glass

Claims (10)

A molding process in which a glass ribbon is formed by flowing down molten glass from a molded body in a molding furnace, and a heat treatment in which the glass ribbon formed in the molding process is subjected to heat treatment while being conveyed along the conveyance direction. In a method for manufacturing a glass article, the method includes the steps of:
The forming step includes a step of cooling the glass ribbon using a lower refractory brick of the forming furnace that faces the surface of the glass ribbon that has flowed down from the molded body in the thickness direction of the glass ribbon,
The lower refractory brick is divided into a plurality of parts in the width direction of the glass ribbon,
A method for manufacturing a glass article, characterized in that the position in the width direction of the joint between the adjacent lower refractory bricks changes in the thickness direction of the glass ribbon when observed from the upstream side in the conveyance direction. 2. The method for manufacturing a glass article according to claim 1, wherein a joint between the adjacent lower refractory bricks has a bent portion when observed from the upstream side in the conveyance direction. Manufacturing the glass article according to claim 1 or 2, characterized in that, when observed from the glass ribbon side, the position in the width direction of the joint between the adjacent lower refractory bricks changes in the conveyance direction. Method. 4. The method for manufacturing a glass article according to claim 3, wherein when observed from the glass ribbon side, joints between the adjacent lower refractory bricks extend in a direction oblique to the conveyance direction. The forming furnace is arranged such that the upper refractory brick facing the molded body and the lower refractory brick are closer to the glass ribbon side than the upper refractory brick, and the lower end of the upper refractory brick and the lower refractory brick are connected to each other. 5. The method for manufacturing a glass article according to claim 1, further comprising a connecting refractory brick that connects the upper end portions. The connecting refractory brick is divided into a plurality of parts in the width direction, and when observed from the upstream side in the conveyance direction, the position of the joint between adjacent connecting refractory bricks in the width direction is 6. The method for manufacturing a glass article according to claim 5, wherein the thickness varies in the thickness direction of the ribbon . 7. The method for manufacturing a glass article according to claim 6, wherein a joint between the adjacent connecting refractory bricks has a bent portion when observed from the upstream side in the conveying direction. The glass article according to claim 6 or 7, characterized in that, when observed from the glass ribbon side, a position in the width direction of a joint between the adjacent connecting firebricks changes in the conveying direction. Production method. 9. The method for manufacturing a glass article according to claim 8, wherein when observed from the glass ribbon side, a joint between the adjacent connecting refractory bricks extends in a direction oblique to the conveying direction. A forming process in which a glass ribbon is formed by flowing molten glass from a molded body in a forming furnace, and a heat treatment in which the glass ribbon formed in the forming process is subjected to heat treatment while being conveyed along the conveying direction. In a method for manufacturing a glass article, the method includes the steps of:
The forming step includes a step of cooling the glass ribbon using a lower refractory brick of the forming furnace that faces the surface of the glass ribbon that has flowed down from the molded body in the thickness direction of the glass ribbon,
The lower refractory brick is divided into a plurality of parts in the width direction of the glass ribbon,
A method for manufacturing a glass article, characterized in that, when observed from the glass ribbon side, a position in the width direction of a joint between adjacent lower refractory bricks changes in the conveying direction.

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