WO2020085297A1

WO2020085297A1 - Glass article manufacturing method

Info

Publication number: WO2020085297A1
Application number: PCT/JP2019/041294
Authority: WO
Inventors: 周作玉村; 畑野　達也
Original assignee: 日本電気硝子株式会社
Priority date: 2018-10-26
Filing date: 2019-10-21
Publication date: 2020-04-30
Also published as: KR20210082443A; JPWO2020085297A1; CN112867697B; TWI799659B; TW202106636A; JP7415252B2; CN112867697A

Abstract

The present invention addresses the problem of preventing the formation of stripe-shaped protrusion defects on the surface of a glass ribbon so as to provide a high quality glass article. This glass article manufacturing method comprises: a molding step in which a molten glass (Gm) is made to flow down from a molding body (5) within a molding furnace (1) so as to mold a glass ribbon (G); and a heat treatment step in which the glass ribbon (G) which was molded in the molding step is subjected to a heat treatment while being conveyed along a conveyance direction. The molding step includes a step in which the glass ribbon (G) is cooled using a lower refractory brick (7) of the molding furnace (1), the lower refractory brick opposing, in the thickness direction of the glass ribbon (G), the surface of the glass ribbon (G) that has flowed down from the molding body (5). The lower refractory brick (7) is divided into multiple bricks in the width direction of the glass ribbon (G), and when observed from the upstream side in the conveyance direction, the position in the width direction of a joint (9) between adjacent lower refractory bricks (7) changes in the thickness direction.

Description

Method for manufacturing glass article

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

As a method of manufacturing glass articles, there are downdraw methods such as an overflow downdraw method, a slot downdraw method, and a redraw method.

The method of manufacturing a glass article using such a downdraw method includes a forming step of forming a glass ribbon by flowing molten glass from a formed body in a forming furnace, and a heat treatment furnace arranged below the forming furnace. Then, a heat treatment step of performing heat treatment (gradual cooling treatment) for reducing the warp or distortion of the glass ribbon while the formed glass ribbon is conveyed downward (see, for example, Patent Document 1). Then, after the heat treatment step, the glass ribbon cooled to around room temperature is cut into a predetermined length to manufacture a glass plate, or wound into a roll shape to manufacture a glass roll.

JP, 2014-122124, A

In the above molding process, a process of cooling the surface of the glass ribbon flowing down from the molded body may be carried out separately from the heat treatment process. In this cooling step, the glass ribbon is cooled by radiating the heat of the glass ribbon to the outside of the furnace by using the lower refractory brick of the forming furnace which faces the surface of the glass ribbon in the thickness direction of the glass ribbon.

By the way, the lower refractory bricks may be divided into multiple pieces in the width direction of the glass ribbon in consideration of ease of replacement. However, in the case of this structure, a streak-like convex defect extending along the transport direction may be formed on the surface of the glass ribbon at a position facing a joint between adjacent lower refractory bricks. When such streak-shaped convex defects are formed, there is a problem in that the smoothness of the surface of the glass article to be manufactured is lost and a high-quality glass article cannot be manufactured.

▽ Here, it is considered that the streak-shaped convex defects were caused by the following reasons. That is, the gas easily flows in and out of the forming furnace through the joints of the lower refractory bricks. As a result, the heat dissipation of the glass ribbon increases at the position facing the joint of the lower refractory brick, and only a predetermined portion of the glass ribbon is likely to be locally cooled. Then, when such local cooling occurs, it is considered that the surface of the glass ribbon contracts locally and rises to form streak-shaped convex defects.

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

The present invention, which was devised to solve the above-mentioned problems, has a forming step of forming a glass ribbon by flowing molten glass from a formed body in a forming furnace, and a glass ribbon formed in the forming step along a conveying direction. In a method for manufacturing a glass plate, which comprises heat-treating a glass ribbon while conveying the glass ribbon, the forming step includes a forming furnace facing a surface of the glass ribbon flowing down from the formed body in a thickness direction of the glass ribbon. Using the lower refractory brick, comprising a step of cooling the glass ribbon, the lower refractory brick is divided into a plurality in the width direction of the glass ribbon, when observed from the upstream side of the transport direction, adjacent lower refractory bricks The position of the joint in the width direction changes in the thickness direction of the glass ribbon. By doing so, it is possible to prevent the gas inside and outside the forming furnace from flowing through the joint of the lower refractory brick, and the sealing property of the joint of the lower refractory brick is improved. Therefore, it is possible to prevent the situation where only a predetermined portion of the glass ribbon is locally cooled at a position facing the joint of the lower refractory brick, and it is possible to prevent the formation of streak-shaped convex defects on the surface of the glass ribbon.

In the above configuration, it is preferable that the joint between the lower refractory bricks adjacent to each other has a bent portion when observed from the upstream side in the transport direction. By doing so, the joint portion of the lower refractory brick is bent by the bent portion, and the sealing property thereof is further improved. Therefore, it is possible to more reliably suppress the situation where only the predetermined member of the glass ribbon is locally cooled at the position facing the joint.

In the above structure, 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 transport direction. With this configuration, 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 the 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 joint between adjacent lower refractory bricks extends in a direction inclined with respect to the transport direction. With this configuration, since the position where the glass ribbon and the joint of the lower refractory brick face each other continuously changes, it is possible to more reliably suppress the situation where only a predetermined portion of the glass ribbon is locally cooled.

In the above configuration, the forming furnace, the upper refractory bricks facing the molded body, as the lower refractory bricks closer to the glass ribbon side than the upper refractory bricks, the lower end of the upper refractory bricks and the upper end of the lower refractory bricks And a refractory brick for connection that connects the two. In this way, the lower refractory bricks can be brought closer to the glass ribbon and the space between the two can be reduced, so that the glass ribbon flowing down from the molded body can be efficiently cooled using the lower refractory bricks.

In the above configuration, the connection refractory brick is divided into a plurality in the width direction, when viewed from the upstream side in the transport direction, the position in the width direction of the joint between adjacent connection refractory bricks, the glass ribbon It is preferable that the thickness changes in the thickness direction. By doing so, the sealing property of the joint of the refractory brick for connection is improved. Therefore, it becomes difficult for the gas inside and outside the forming furnace to directly flow through the joints of the refractory bricks for connection. Therefore, it is possible to suppress the situation where only a predetermined member of the glass ribbon is locally cooled at a position facing the joint of the refractory brick for connection, and it is possible to prevent the formation of streak-shaped convex defects.

In the above configuration, it is preferable that the joint between adjacent refractory bricks for connection has a bent portion when observed from the upstream side in the transport direction. By doing so, the joint of the refractory brick for connection is bent by the bent portion, and the sealing property thereof is further improved. Therefore, it is possible to more reliably suppress the situation where only the predetermined member of the glass ribbon is locally cooled at the position facing the joint.

In the above structure, when observed from the glass ribbon side, it is preferable that the position in the width direction of the joint between adjacent refractory bricks for connection changes in the transport direction. With this configuration, since the position where the glass ribbon and the joint of the refractory brick for connection face each other changes, it is possible to more reliably suppress the 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 joint between adjacent refractory bricks for connection extends in a direction inclined with respect to the transport direction. With this configuration, since the position where the glass ribbon and the joint of the refractory brick for connection face each other continuously changes, it is possible to more reliably suppress the situation where only a predetermined portion of the glass ribbon is locally cooled.

The present invention, which was devised to solve the above-mentioned problems, has a forming step of forming a glass ribbon by flowing molten glass from a formed body in a forming furnace, and a glass ribbon formed in the forming step along a conveying direction. In a method for manufacturing a glass article, which comprises heat-treating a glass ribbon while conveying the glass ribbon, the forming step includes a forming furnace facing a surface of the glass ribbon flowing down from the formed body in a thickness direction of the glass ribbon. Using the lower refractory bricks, comprising a step of cooling the glass ribbon, the lower refractory brick is divided into a plurality in the width direction of the glass ribbon, when observed from the glass ribbon side, between the adjacent lower refractory bricks. The position of the joint in the width direction changes in the transport direction. By doing so, the position where the glass ribbon and the joint of the lower refractory brick face each other changes, so that it is possible to suppress the situation where only a predetermined portion of the glass ribbon is locally cooled. Therefore, it is possible to prevent the formation of streak-shaped convex defects on the surface of the glass ribbon.

According to the present invention, it is possible to prevent the formation of streak-shaped convex defects on the surface of the glass ribbon and provide a high-quality glass article.

It is a schematic longitudinal cross-sectional view of a glass article manufacturing apparatus. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, showing a joint state 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 of FIG. 1, showing a joint state of the lower refractory brick when observed from the upstream side in the transport direction. FIG. 2 is a cross-sectional view taken along line CC of FIG. 1, showing a joint joint refractory brick state when observed from the upstream side in the transport direction. It is sectional drawing which shows the modification of the joint of a lower refractory brick when it observes from the upstream of a conveyance direction. It is sectional drawing which shows the modification of the joint of a lower refractory brick when it observes from the upstream of a conveyance direction. It is sectional drawing which shows the modification of the joint of a lower refractory brick when it observes from the upstream of a conveyance direction. It is sectional drawing which shows the modification of the joint of a lower refractory brick when it observes from the upstream of a conveyance direction. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, showing a modified example of joints of the lower refractory brick when observed from the glass ribbon side.

An embodiment of the present invention will be described below with reference to the accompanying drawings. XYZ in the figure is an orthogonal coordinate system. The X and Y directions are horizontal, and the Z direction is vertical. While the glass ribbon G is being conveyed in the vertical posture, the X direction is the thickness direction of the glass ribbon G (hereinafter also simply referred to as “thickness direction”) and the Y direction is the width direction of the glass ribbon G (hereinafter simply referred to as “width”). The “direction”) and the Z direction are the conveyance direction of the glass ribbon G (hereinafter, also simply referred to as “conveyance 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 for continuously forming a glass ribbon G. The glass article manufactured from the glass ribbon G includes a glass plate and a glass roll.

The glass article manufacturing apparatus includes a molding furnace 1 for molding a glass ribbon G, a heat treatment furnace 2 for heat-treating the glass ribbon G, a cooling zone 3 for cooling the glass ribbon G to around room temperature, a heat treatment furnace 2 and a cooling zone. Each of the rollers 3 has 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 apparatus for cutting the glass ribbon G to obtain a glass plate, an end surface processing apparatus for processing the end surface of the glass plate, and a cleaning apparatus for cleaning the glass plate. An inspection device for inspecting the glass plate may be further provided. Alternatively, the glass article manufacturing apparatus is a cutting apparatus that cuts and removes both ends of the glass ribbon G in the width direction on the downstream side of the cooling zone 3, and winds the glass ribbon G into a roll to obtain a glass roll. It may further be provided with a picking device or the like.

A molding 5 for molding the glass ribbon G from the molten glass Gm by the 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 overflowed molten glass Gm has a wedge-shaped cross section on both sides 5b. The plate-shaped glass ribbon G is continuously formed by flowing along the flow path and joining at the lower end. The formed glass ribbon G has a vertical posture (preferably a vertical posture).

The forming furnace 1 includes an upper refractory brick 6, a lower refractory brick 7, and a connecting refractory brick 8 connecting the lower end of the upper refractory brick 6 and the upper end of the lower refractory brick 7. The connection refractory bricks 8 connect the upper refractory bricks 6 and the lower refractory bricks 7 so that the lower refractory bricks 7 are closer to the glass ribbon G side than the upper refractory bricks 6. The connecting refractory brick 8 may be omitted.

At the position corresponding to the upper refractory brick 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 by, for example, 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 the furnace or outside the upper refractory brick 6. Alternatively, the heating device can be embedded inside the upper refractory brick 6.

The lower refractory brick 7 is opposed to 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 intended to adjust 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 dissipation zone. 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 bricks 6 and the lower refractory bricks 7 are made of silicon carbide (SiC) -based bricks or the like, and the connection refractory bricks 8 are made of alumina zircon-based bricks or the like.

The internal space of the heat treatment furnace 2 has a predetermined temperature gradient downward. The glass ribbon G in the vertical posture is gradually cooled (annealed) so that the temperature thereof becomes lower as the glass ribbon G moves downward in the internal space of the heat treatment furnace 2. This gradual cooling is for adjusting (reducing) warpage or distortion of the glass ribbon G. The temperature gradient in the internal space of the heat treatment furnace 2 can be adjusted by, for example, 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 designed to sandwich both ends of the glass ribbon G in the vertical position in the width direction from the front and back sides. 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 in the vicinity of the upper end of the heat treatment furnace 2 and is composed of a cooling roller (edge roller) that cools both ends of the glass ribbon G in the width direction. There is. This cooling roller is for suppressing the shrinkage of the glass ribbon G in the width direction.

Note that, in the internal space of the heat treatment furnace 2 or the like, the plurality of roller pairs 4 may include one that does not sandwich the widthwise end of the glass ribbon G. In other words, the facing distance between the pair of rollers 4 may be made larger than the thickness of the end portion in the width direction of the glass ribbon G so that the glass ribbon G passes between the pair of rollers 4.

As shown in FIG. 2, the lower refractory bricks 7 and the connecting refractory bricks 8 are divided into a plurality in the width direction. Therefore, joints 9 and 10 are formed between the

bricks

7 and 8 that are adjacent to each other in the width direction. The connecting refractory brick 8 may have a joint structure that is not divided into a plurality in the width direction and has no joint.

When observed from the glass ribbon G side, the joint 9 of the lower refractory brick 7 is a straight line inclined with respect to the transport direction, and the position in the width direction changes in the transport direction. Similarly, when observed from the glass ribbon G side, the joint 10 of the refractory brick 8 for connection is also a straight line inclined with respect to the transport direction, and the position in the width direction changes in the transport direction. As a result, the positions in the width direction where the glass ribbon G and the

joints

9 and 10 face each other are sequentially changed in the transport direction, so that it is possible to suppress the situation where only a predetermined portion in the width direction of the glass ribbon G is continuously cooled. . In the illustrated example, the joint 9 and the joint 10 are inclined in opposite directions, but may be in the same direction. Further, the joints 9 (or the joints 10) may include those having different inclination directions. Further, when observed from the glass ribbon G side, if the widthwise positions of the

joints

9 and 10 change in the transport direction, the manner of change of the

joints

9 and 10 is not limited to a linear shape. However, the straight shape has an advantage that the

bricks

7 and 8 can be easily processed.

As shown in FIG. 3, when observed from the upstream side in the conveying direction, the joint 9 of the lower refractory brick 7 has a bent portion 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 transport direction, the joint 10 of the refractory brick 8 for connection also has a bent portion 10a, and the position in the width direction changes in the thickness direction. There is. As a result, the sealability of the

joints

9 and 10 is improved, and it becomes difficult for the gas inside and outside the molding furnace 1 to directly flow through the

joints

9 and 10. Therefore, at a position where the glass ribbon G and the

joints

9 and 10 face each other, it is possible to suppress a situation where a predetermined portion in the width direction of the glass ribbon G is locally cooled.

In this embodiment, the joint 9 of the lower refractory brick 7 has two bent portions 9a. Due to the bent portions 9a, the joint 9 has two first portions 9b extending in the thickness direction and a second portion 9c extending in the width direction between the first portions 9b, and has a step shape as a whole. (Hook-like). Similarly, the joint 10 of the connecting refractory brick 8 also has two bent portions 10a. Due to these bent portions 10a, the joint 10 has two first portions 10b extending in the thickness direction and a second portion 10c extending in the width direction between the first portions 10b, and has a step shape as a whole. (Hook-like). That is, the

joints

9 and 10 have a relatively simple shape, but the

second portions

9c and 10c extending along the width direction have a large resistance to the gas passing through the

joints

9 and 10, so that the gas flows. It is a structure that is difficult to do.

Here, in this embodiment, when observed from the upstream side in the transport direction, the position P1 (or the position P2) facing the inside of the joint 9 of the lower refractory brick 7 shown in FIG. 3 and the connection shown in FIG. It differs from the position Q1 (or the position Q2) of the joint 10 of the refractory brick 8 facing the inside of the furnace without overlapping in the width direction. That is, at the position P1 (or position P2) of the joint 9 of the lower refractory brick 7, a portion without the joint 10 of the connecting refractory brick 8 is located, and the position Q1 of the joint 10 of the connecting refractory brick 8 (or At the position Q2), the portion of the lower refractory brick 7 without the joint 9 is located. As a result, 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, a formation region over the entire length of the joint 9 of the lower refractory brick 7 in the transport direction and a formation region over the entire length of the joint 10 of the joint refractory brick 8 in the transport direction. Exemplifies a mode in which there is no overlap in the width direction.

Further, in the present embodiment, when observed from the upstream side in the transport direction, the position P1 of the joint 9 of the one lower refractory brick 7 facing the one surface of the glass ribbon G facing the inside of the furnace, and the position of the glass ribbon G. A position P2 of the joint 9 of the lower refractory brick 7 facing the other surface facing the inside of the furnace differs from the other surface without overlapping in the width direction. That is, the joint 9 of the lower refractory brick 7 on one side faces the inside of the furnace, and the portion of the other lower refractory brick 7 without the joint 9 faces in the thickness direction. Similarly, when observed from the upstream side in the transport direction, the position Q1 facing the inside of the joint 10 of the connecting refractory brick 8 facing one surface of the glass ribbon G and the other surface of the glass ribbon G. The position Q2 facing the inside of the joint 10 of the other connecting refractory brick 8 that faces is different from the position Q2 without overlapping in the width direction. That is, at a position of the joint 10 of the connecting refractory brick 8 facing the inside of the furnace, a portion of the other connecting refractory brick 8 without the joint 10 faces in the thickness direction. As a result, the influence of the

joints

9 and 10 is dispersed on both surfaces of the glass ribbon G. In addition, in FIGS. 3 and 4, when observed from the upstream side in the transport direction, the formation regions over the entire length in the thickness direction of the joints 9 of both lower refractory bricks 7 facing each other do not overlap each other in the width direction. , A mode in which the formation regions of the joints 10 of the connecting refractory bricks 8 across the entire thickness in the thickness direction do not overlap each other in the width direction.

Furthermore, in the present embodiment, the bent portion 10a (or the 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. Thus, the portion of the joint 10 facing the inside of the furnace is configured only by the linear first portion 10b along the thickness direction, and the shape of the joint 10 facing the inside of the furnace is simplified. The bent portion 10a (or the second portion 10c) of the joint 10 in the connecting refractory brick 8 may be located below the upper refractory brick 6 or in the furnace inside the upper refractory brick 6. You may have.

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

As shown in FIG. 1, a glass article manufacturing method includes a forming step of forming a glass ribbon G by flowing 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 G along the transport direction, and cooling the glass ribbon G to near room temperature while transporting the glass ribbon G heat-treated in the cooling zone 3 along the transport direction. And a cooling step.

The forming process includes an adjusting process of adjusting (reducing) the uneven thickness of the glass ribbon G by cooling the glass ribbon G flowing down from the formed body 5 using the lower refractory brick 7 of the forming furnace 1. In the adjusting step, the glass ribbon G is cooled by radiating the heat of the glass ribbon G to the outside of the furnace through the lower refractory brick 7.

Here, the cooling in the adjusting step is intended to adjust the uneven thickness of the glass ribbon G, and the cooling (gradual cooling) in the heat treatment step is intended to adjust the warpage and distortion of the glass ribbon G. Has different purposes. The temperature of the glass ribbon G in the adjusting step is, for example, 1000 to 1300 ° C., and the temperature of the glass ribbon G in the heat treating step is, for example, 500 to 1000 ° C. The viscosity of the glass ribbon G in the adjusting step is, for example, 20,000 to 300,000 poise, and the viscosity of the glass ribbon G in the heat treating step is, for example, 10 ⁵ to 10 ¹⁶ poise.

In the adjusting step, as described above, the

joints

9 and 10 of the lower refractory bricks 7 and the connecting refractory bricks 8 have their widthwise positions changed in the carrying direction when observed from the glass ribbon G side, and the carrying direction. The position in the width direction changes in the thickness direction when observed from the upstream side of. Therefore, in the adjustment step, 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 streaky convex defects are formed on the surface of the glass ribbon G. It can be prevented from being formed. Therefore, a high-quality glass article having excellent surface smoothness can be provided.

It should be noted that the present invention is not limited to the above-described embodiment at all, and may be carried out in various forms without departing from the gist of the present invention.

In the above-described embodiment, the

joints

9 and 10 of the lower refractory brick 7 and the connecting refractory brick 8 have two

bent portions

9a and 10a when viewed from the upstream side in the transport direction, and have a step-like shape as a whole. Although the case has been described, the number of

bent portions

9a and 10a is not particularly limited. For example, the joint 9 of the lower refractory brick 7 may have one bent portion 9a as shown in FIG. 5 or may be one bent portion 9a as shown in FIG. 6 when observed from the upstream side in the transport direction. May be three or four or more bent portions 9a may be provided as shown in FIG. Of course, for example, as shown in FIG. 8, when observed from the upstream side in the transport direction, the joint 9 may have a linear shape inclined with respect to the thickness direction, or may have a shape without a bent portion. These matters can be similarly applied to the joint 10 of the refractory brick 8 for connection.

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 width direction 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 position of 9e in the width direction. By doing so, it is possible to more reliably suppress the situation of local cooling.

In the above embodiment, the case where the

bent portions

9a and 10a are formed by the corners where the two straight lines intersect has been described, but the

bent portions

9a and 10a may be formed by the curved portions such as arcs.

In the above embodiment, the

joints

9 and 10 of the lower refractory bricks 7 and the connecting refractory bricks 8 have a position in the width direction that changes in the transport direction when (1) the glass ribbon G side is observed, and (2) ) The case where the position in the width direction changes in the thickness direction when observed from the upstream side in the transport direction has been described, but at least the position in the width direction of the joint 9 of the lower refractory brick 7 is the same as the above (1) and (2). ) It is sufficient if either one of them is satisfied. When only the above (1) is satisfied, the joint is linear along the thickness direction when observed from the upstream side in the transport direction, and when only the above (2) is satisfied, the joint is from the glass ribbon G side. When observed, it becomes a straight line along the transport direction.

In the above embodiment, the case where the glass ribbon G is formed by the overflow downdraw method has been described, but the glass ribbon G may be formed by another downdraw method such as a slot downdraw method or a redraw method.

1 Forming Furnace 2 Heat Treatment Furnace 3 Cooling Zone 4 Roller Pair 5 Molded Body 6 Upper Refractory Bricks 7 Lower Refractory Bricks 8 Connection Refractory Bricks 9 Lower Refractory Bricks Joints 10 Connection Refractory Bricks Joints G Glass Ribbon Gm Molten Glass

Claims

A forming step of forming a glass ribbon by flowing molten glass from a formed body in a forming furnace, and a heat treatment for heat-treating the glass ribbon while conveying the glass ribbon formed in the forming step in a conveying direction. In a method of manufacturing a glass article, which comprises a step,
The forming step includes a step of cooling the glass ribbon by using a lower refractory brick of the forming furnace facing the surface of the glass ribbon flowing down from the formed body in the thickness direction of the glass ribbon,
The lower refractory brick is divided into a plurality in the width direction of the glass ribbon,
The method for manufacturing a glass article, wherein the position in the width direction of the joint between the adjacent lower refractory bricks changes in the thickness direction when observed from the upstream side in the transport direction.
The method for manufacturing a glass article according to claim 1, wherein the joint between the lower refractory bricks adjacent to each other has a bent portion when observed from the upstream side in the transport direction.
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 transport direction, the manufacturing of the glass article according to claim 1 or 2. Method.
The method for manufacturing a glass article according to claim 3, wherein the joint between the lower refractory bricks adjacent to each other extends in a direction inclined with respect to the transport direction when observed from the glass ribbon side.
The forming furnace, the upper refractory bricks facing the molded body, as the lower refractory bricks closer to the glass ribbon side than the upper refractory bricks, the lower end of the upper refractory bricks and the lower refractory bricks. The method for manufacturing a glass article according to any one of claims 1 to 4, further comprising: a refractory brick for connection that connects upper end portions.
The connection refractory bricks are divided into a plurality in the width direction, when viewed from the upstream side of the transport direction, the width direction position of the joint between the adjacent connection refractory bricks, the thickness. The method for producing a glass article according to claim 5, wherein the glass article changes in direction.
The method for manufacturing a glass article according to claim 6, wherein the joint between the refractory bricks for connection has a bent portion when observed from the upstream side in the transport direction.
The position in the width direction of the joint between the adjacent refractory bricks for connection, when observed from the glass ribbon side, changes in the transport direction, the glass article according to claim 6 or 7. Production method.
The method for manufacturing a glass article according to claim 8, wherein, when observed from the glass ribbon side, joints between adjacent refractory bricks for connection extend in a direction inclined with respect to the transport direction.
A forming step of forming a glass ribbon by flowing molten glass from a formed body in a forming furnace, and a heat treatment for heat-treating the glass ribbon while conveying the glass ribbon formed in the forming step in a conveying direction. In a method of manufacturing a glass article, which comprises a step,
The forming step includes a step of cooling the glass ribbon by using a lower refractory brick of the forming furnace facing the surface of the glass ribbon flowing down from the formed body in the thickness direction of the glass ribbon,
The lower refractory brick is divided into a plurality in the width direction of the glass ribbon,
The method for manufacturing a glass article, wherein the position of the joint between the lower refractory bricks adjacent to each other changes in the width direction when observed from the glass ribbon side.