JP6708970B2 - Method for manufacturing glass article - Google Patents

Description

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

As a method for manufacturing a glass article, a downdraw method is widely used in which a glass ribbon is continuously formed from glass that has flowed down from a molded body during production (production process). The downdraw method includes, for example, an overflow downdraw method, a slot downdraw method, a redraw downdraw method, and the like.

In the above-mentioned production process, in order to reduce the warp and internal strain of the glass ribbon, it is common to gradually cool the glass ribbon in the lower region of the molded body while sandwiching the glass ribbon between upper and lower annealing rollers while conveying it downward. (For example, see Patent Document 1).

JP, 2013-216526, A

The above-mentioned method for manufacturing a glass article may include a preparation step for preparing a glass ribbon before the production step. In this preparatory step, the glass flowed down from the molded body is sandwiched in order by an anneal roller. As a result, the glass that has flowed down from the molded body is thinly drawn and gradually approaches the shape of the glass ribbon.

In the above-described preparation process and production process, the annealing roller may be internally cooled in order to prevent problems such as bending of the annealing roller due to thermal deformation and winding of glass around the annealing roller. However, if the anneal roller is excessively cooled, a new problem may occur that the glass ribbon is rapidly cooled in the production process, for example, and the glass ribbon is easily broken. Therefore, the internal cooling of the annealing roller still has a problem in each step of the preparation step and the production step.

An object of the present invention is to optimize internal cooling of an annealing roller in each step of a preparation step and a production step.

The present invention, which was devised to solve the above-mentioned problems, is a method for manufacturing a glass article using a downdraw method, in which a glass ribbon formed by a formed body is sandwiched between upper and lower tiers of annealer rollers and is moved downward. The production step of gradually cooling while conveying to, and before the production step, the glass flowed down from the molded body is sandwiched in order by an annealing roller, and a preparation step of approaching the shape of the glass ribbon is provided. A second roller provided with a first roller arranged in a first temperature region above the strain point of the glass ribbon and a second roller arranged in a second temperature region below the strain point of the glass ribbon in the production process. Is characterized in that the internal cooling temperature in the production process is higher than the internal cooling temperature in the preparation process.

The inventors of the present application focused on the difference between the heat amount of glass (glass ribbon) in the production process and the heat amount of glass in the preparation process. That is, in the preparatory step, the glass has a large thickness since it is in a state before it becomes a glass ribbon. Therefore, the amount of heat that glass has is inevitably large. On the other hand, in the production process, since the thickness of the glass ribbon is small, the heat amount of the glass ribbon is necessarily small. Therefore, in the production process, if the annealing roller is cooled under the same temperature condition as in the preparation process, the glass ribbon may be rapidly cooled and the glass ribbon may be broken. Such rapid cooling of the glass ribbon is unlikely to occur in the first temperature region above the strain point where the glass ribbon temperature or the ambient temperature is high, and is likely to occur in the second temperature region below the strain point where the glass ribbon temperature or the ambient temperature is low. .. Therefore, in the present invention, the internal cooling temperature of the second roller (the annealing roller arranged in the second temperature region) in the production process becomes higher than the internal cooling temperature of the second roller in the preparation process as in the above configuration. Was set. This prevents the glass ribbon from being rapidly cooled by the internal cooling of the annealing roller in the production process, so that the glass ribbon can be reliably prevented from cracking due to the internal cooling of the annealing roller. Therefore, it can be said that the internal cooling of the annealing roller was optimized in each of the preparation process and the production process.

In the above configuration, it is preferable that the internal cooling temperature of the first roller is lower than the internal cooling temperature of the second roller in the production process. Even in the production process, since the glass temperature and the ambient temperature are high in the first temperature region above the strain point, the first roller arranged in the region may be thermally deformed or the glass may be wrapped around. Therefore, in order to prevent thermal deformation of the first roller and wrapping of glass in the production process, it is preferable to adopt the above configuration.

In the above configuration, the first roller includes a first shaft portion having a passage through which a cooling fluid can flow, and a first roller body provided on the first shaft portion, and the second roller is A second shaft portion having a passage through which a cooling fluid can flow, and a second roller body provided on the second shaft portion may be provided. With this configuration, the first roller and the second roller are internally cooled by passing the cooling fluid through the passage of each shaft portion.

In the above configuration, the internal cooling temperature of the second roller may be adjusted by changing the supply flow rate of the cooling fluid to the second shaft portion in the preparation process and the production process. As a method of adjusting the internal cooling temperature, a method of changing the supply temperature of the cooling fluid itself can be considered, but the method of changing the supply flow rate itself can be realized by a simpler mechanism.

In the above configuration, the supply of the cooling fluid to the second shaft portion may be stopped in the production process.

In the above structure, the second shaft portion is made of metal supported on both sides, the second roller body is provided on both axial sides of the second shaft portion, and the second shaft portion is You may have a metal exposure part between the 2nd rollers in an axial direction.

In the above structure, the second shaft portion may be cantilevered and made of metal, and the second roller body may be provided on one axial side of the second shaft portion.

In the above configuration, the preparation step includes an adjustment step for adjusting the thickness of the glass and the direction of the warp, and after the adjustment step, the internal cooling temperature of the second roller is changed from the internal cooling temperature in the preparation step to the production step. It is preferable to switch to the internal cooling temperature.

In the above configuration, as well as detect the state of the glass ribbon in the production process, when the production defects of the glass ribbon is detected based on the detection result, internal cooling temperature of the second roller, the internal cooling temperature in the production process To the internal cooling temperature in the preparation step. With this configuration, when the production failure of the glass ribbon occurs in the production process, the internal cooling temperature of the second roller can be automatically switched to the internal cooling temperature in the preparation process.

In the above configuration, the glass ribbon that has been gradually cooled in the production process may be wound into a roll. In this way, a roll-shaped glass article (glass roll) can be manufactured.

According to the present invention as described above, the internal cooling of the annealing roller can be optimized in each of the preparation process and the production process.

It is a front view of the glass article manufacturing apparatus which shows the production process of the glass article manufacturing method. It is an AA sectional view of FIG. It is sectional drawing of the 1st roller and 1st shaft part shown in FIG. It is sectional drawing of the 2nd roller and 2nd shaft part shown in FIG. It is a front view of the manufacturing apparatus of a glass article which shows the preparation process of the manufacturing method of a glass article. FIG. 6 is a sectional view taken along line BB of FIG. 5. It is a front view of the modification of the manufacturing apparatus of a glass article.

One Embodiment of the manufacturing method of the glass article which concerns on this invention is described.

As shown in FIGS. 1 and 2, a glass article manufacturing apparatus 1 used in a glass article manufacturing method mainly includes a molding furnace 2 and an annealing furnace 3 located below the molding furnace 2. The glass article manufacturing apparatus 1 forms the glass ribbon GR in the forming furnace 2 from the molten glass GM supplied from the melting furnace provided on the upstream side, and then removes the warp and internal strain of the glass ribbon GR in the annealing furnace 3. To do. In addition, in the figure, the furnace walls of the forming furnace 2 and the slow cooling furnace 3 are not shown.

The forming furnace 2 includes a formed body 4 that executes an overflow downdraw method inside a furnace wall, and edge rollers 5 that cool both widthwise ends of the glass ribbon GR formed by the formed body 4.

The molded body 4 is formed in an elongated shape and has an overflow groove 6 formed along the longitudinal direction (the width direction of the glass ribbon GR) at the top. Further, the molded body 4 includes a vertical surface portion 7 and an inclined surface portion 8 that form a pair of side wall portions facing each other. An inclined surface portion 8 is formed at the lower end of the vertical surface portion 7 so as to be connected thereto. The pair of inclined surface portions 8 intersect each other by gradually approaching downward, and form a lower end portion 9 of the molded body 4.

As shown in FIG. 1, the edge rollers 5 are configured as a pair of right and left in a front view so as to sandwich each end portion in the width direction of the glass ribbon GR just below the molded body 4. In addition, as shown in FIG. 2, the edge roller 5 is configured as a roller pair arranged in parallel in the plate thickness direction of the glass ribbon GR so as to sandwich the widthwise end of the glass ribbon GR. The edge roller 5 is a cantilever type roller and is always internally cooled in each step of a preparation step and a production step described later. The edge roller 5 may be provided in a plurality of stages (for example, two stages) in the vertical direction. For example, in the case of two upper and lower stages, it is preferable that the upper edge roller is a driving roller and the lower edge roller is a free roller.

In this forming furnace 2, the molten glass GM is poured into the overflow groove 6 of the formed body 4, and the molten glass GM overflowing from the overflow groove 6 to both sides is made to flow down along the vertical surface portion 7 and the inclined surface portion 8 while the lower end portion 9 is formed. Are fused and integrated with each other to continuously form one glass ribbon GR. The molded body 4 is not limited to the above-described configuration, and may be configured to execute a downdraw method other than the overflow downdraw method such as a slot downdraw method or a redraw downdraw method.

As shown in FIGS. 1 and 2, the annealing furnace 3 includes an annealing roller 10 configured in a plurality of stages (six stages in the illustrated example) in the vertical direction. The anneal roller 10 includes a first roller (first anneal roller) 11 arranged in a first temperature region X that exceeds the strain point of the glass ribbon GR in the production process, and a second roller that is equal to or lower than the strain point of the glass ribbon GR in the production process. A second roller (second anneal roller) 12 arranged in the temperature region Y.

As shown in FIG. 1, the first roller 11 includes a first shaft portion 13 supported by both ends, and a first roller body 14 continuously provided in a portion of the first shaft portion 13 overlapping the glass ribbon GR. Equipped with. The first shaft portion 13 is made of metal, penetrates the shaft center of the first roller body 14, and projects from each end of the first roller body 14.

The first roller body 14 has a large-diameter contact portion 14a that contacts the glass ribbon GR and a small-diameter non-contact portion 14b that does not contact the glass ribbon GR. As shown in FIG. 2, the contact portion 14a is configured as a roller pair that holds the glass ribbon GR in the plate thickness direction. Further, the contact portions 14a are configured to be a pair of left and right in a front view (see FIG. 1) so as to sandwich each end portion in the width direction of the glass ribbon GR. The non-contact portion 14b functions as a cover portion that covers the first shaft portion 13 that overlaps the glass ribbon GR in a front view.

On the other hand, as shown in FIG. 1, the second roller 12 includes a second shaft portion 15 supported on both sides and second roller main bodies 16 provided on both sides of the second shaft portion 15 in the width direction. The second shaft portion 15 is made of metal, penetrates the shaft center of the second roller body 16, and protrudes from each end portion of each second roller body 16.

The second roller body 16 functions as a contact portion that contacts the glass ribbon GR. As shown in FIG. 2, the second roller body 16 is configured as a roller pair that holds the glass ribbon GR in the plate thickness direction. In addition, the second roller main body 16 is configured to be a pair of right and left in a front view (see FIG. 1) so as to sandwich each end of the glass ribbon GR in the width direction. A portion of the second shaft portion 15 between the pair of left and right second roller bodies 16 is a metal exposed portion 15a where the metal portion of the second shaft portion 15 is exposed. The metal exposed portion 15a overlaps the glass ribbon GR in a front view.

Each of the roller bodies 14 and 16 is made of, for example, ceramics, and is configured by impregnating an inorganic filler to a predetermined depth from the surface thereof. As the ceramic, for example, silica, more preferably sintered amorphous is used. As the inorganic filler, a colloidal suspension of a heat resistant oxide such as colloidal silica or colloidal alumina is suitable. The material of each roller body 14, 16 is not particularly limited as long as it has heat resistance.

As shown in FIGS. 3 and 4, cooling devices 17 and 18 are provided on the shaft portions 13 and 15 of the rollers 11 and 12, respectively. As shown in FIG. 3, the first cooling device 17 includes a first cooling pipe 19 arranged inside a hollow first shaft portion 13. The first cooling pipe 19 has a plurality of holes 20 through which a cooling medium such as air is discharged. The cooling medium discharged from the plurality of holes 20 circulates inside the first shaft portion 13 to internally cool the first shaft portion 13 and the first roller body 14. Here, the internal cooling means cooling the member to be cooled from the inside. As shown in FIG. 4, the second cooling device 18 has substantially the same configuration as the first cooling device 17. That is, the second cooling device 18 also includes the second cooling pipe 21 having a plurality of holes 22 through which the cooling medium is discharged, inside the second shaft portion 15 which is hollow. As shown in FIG. 1, valves 23 and 24 are provided in the cooling pipes 19 and 21, respectively, so that the flow rate of the cooling medium can be adjusted. The adjustment of the flow rate of the cooling medium includes the case where the valves 23 and 24 are completely closed to stop the supply of the cooling medium. The configurations of the cooling devices 17 and 18 are not particularly limited as long as the cooling fluid can flow inside the shaft portions 13 and 15 and/or inside the roller bodies 14 and 16.

Here, in FIG. 1, reference numeral 25 is a sensor that detects the torque and/or the rotational speed of the edge roller 5, and in FIG. 2, reference numeral 26 is the presence or absence of the glass ribbon GR and/or the crack of the glass ribbon GR ( For example, it is a sensor (for example, a laser sense) that detects the presence or absence of vertical cracks. Although not shown, a sensor (for example, a laser sensor) that detects the facing distance between the edge roller 5 and the annealing roller 10 is also provided. Note that these sensors may be omitted.

Next, a method for manufacturing a sheet glass as a glass article (glass article manufacturing method) by the glass article manufacturing apparatus 1 having the above configuration will be described.

The manufacturing method includes a preparation step for forming the glass ribbon GR and a production step for forming the glass ribbon GR.

In the preparation process and the production process, the molten glass GM supplied from the melting furnace is injected into the overflow groove 6 of the molded body 4, overflows from the overflow groove 6 and propagates through the vertical surface portion 7 and the inclined surface portion 8 to reach the lower end. Join at Part 9.

As shown in FIG. 4, in the preparation step, the molten glass GM merged at the lower end portion 9 of the molded body 4 has a glass GB having a plate thickness larger than that of the glass ribbon GR immediately below the lower end portion 9 of the molded body 4. Become. The glass GB may sometimes become a lump and form a glass lump.

As shown in FIG. 5, the glass GB is sandwiched by the edge rollers 5. Next, the glass GB whose both ends in the width direction are supported by the edge roller 5 is stretched in the width direction and the up-down direction, and is passed between the annealing rollers 10 waiting in the open state. After that, the anneal roller 10 is changed from the open state to the closed state, and the glass GB is sandwiched by the anneal roller 10. Here, the open state refers to a state in which the facing distance between the roller pairs arranged to face each other in the plate thickness direction of the glass GB is maintained larger than the plate thickness of the glass GB, and the closed state refers to the facing distance between the roller pairs. Is maintained at the same level as the plate thickness of the glass GB (preferably not more than the plate thickness). The above-mentioned clamping operation is sequentially performed from the uppermost first roller 11. As a result, the shape of the glass GB gradually approaches the glass ribbon GR. Here, the stretching of the glass GB in the vertical direction may be performed by pulling the glass GB downward by the annealing roller 10 in addition to the action of gravity, or by a pulling roller (not shown) provided outside the annealing furnace 3, for example. ), the glass GB may be pulled downward. Further, between the edge roller 5 and the uppermost anneal roller 10, a roller (not shown) that holds the glass GB and expands it in the width direction may be separately provided. It is preferable that the roller is separated from the glass GB after the glass GB is expanded in the width direction in the initial stage of the preparation process.

After the glass GB is sandwiched by the plurality of annealing rollers 10, an adjusting step of adjusting the plate thickness and the warp direction of the glass GB is performed. The adjustment process is performed at the end of the preparation process. In the adjusting step, the plate thickness of the glass GB is adjusted by adjusting the temperatures of the forming furnace 2 and the annealing furnace 3, for example. In the adjusting step, for example, the glass GB is pressed by the rod-shaped body in the annealing furnace 3 to adjust the warp direction of the glass GB.

When the preparation process is completed, the production process is started as shown in FIG. In the production process, the glass ribbon GR is continuously molded from the molten glass GM joined at the lower end 9 of the molded body 4. The formed glass ribbon GR is annealed in the annealing furnace 3 and then cut to a predetermined size by a cutting device (not shown) on the downstream side in the carrying direction of the annealing furnace 3. As a result, plate glass as a glass article is manufactured from the glass ribbon GR. The sheet glass thus manufactured is stacked on a pallet in a state where a plurality of glass sheets are stacked in a vertical posture or a horizontal posture, and is transported to a customer or the like. When the plate glasses are stacked and packed, it is preferable to interpose a protective sheet such as a slip sheet or a resin sheet between the plate glasses.

As shown in FIG. 5, in the preparation step, the valves 23 and 24 for supplying the cooling medium (water, air, etc.) to the rollers 11 and 12 are opened. On the other hand, as shown in FIG. 1, in the production process, the cooling medium is supplied to the second roller 12 while the first valve 23 for supplying the cooling medium to the first roller 11 is kept open. The second valve 24 is closed. That is, the supply of the cooling medium to the second roller 12 is stopped.

As a result, the rollers 11 and 12 are internally cooled in the preparation step. In the preparatory step, the temperature of the glass GB and the ambient temperature tend to be relatively high, but since the rollers 11 and 12 are internally cooled, it is possible to prevent problems such as thermal deformation and winding of the glass GB. can do.

The internal cooling temperature T2p of the second roller 12 in the production process is set higher than the internal cooling temperature T2r of the second roller 12 in the preparation process. Therefore, in the production process, the internal cooling of the second roller 12 is weakened, and the glass ribbon GR cooled to the strain point or less is not easily cooled and broken.

In the production process, the internal cooling temperature T1p of the first roller 11 is set lower than the internal cooling temperature T2p of the second roller 12. Therefore, even in the production process, the internal cooling of the first roller 11 is strong, and it is possible to prevent the first roller 11 from being thermally deformed or the glass ribbon GR being wound. Even in the production process, in the first temperature region X above the strain point where the first roller 11 is arranged, the temperature of the glass ribbon GR and the ambient temperature are likely to be relatively high. Is preferred.

In this manufacturing method, after the adjusting step, the second valve 24 is switched from the open state to the closed state, and the internal cooling temperature of the second roller 12 is changed from the internal cooling temperature T2r in the preparation step to the internal cooling temperature T2p in the production step. To do. That is, the switching of the internal cooling temperature of the second roller 12 is performed immediately before the production process.

Further, in the present manufacturing method, when a production defect occurs in the glass ribbon GR in the production process, production defect information is reported (output). This production defect information is notified in the following cases, for example. (1) When the sensor 25 detects that the torque of the edge roller 5 is less than or equal to a predetermined value, or when the rotational speed of the edge roller 5 is less than or equal to a predetermined value, the glass ribbon Notify the production defect information of GR. Here, for example, when the glass ribbon GR is lost or broken, the torque and the rotation speed of the edge roller 5 become equal to or less than a predetermined value. (2) In addition, when the sensor 26 detects that the glass ribbon GR is absent or when the glass ribbon GR is detected to have a crack, the defective production information of the glass ribbon GR is notified. (3) Further, when the sensor (not shown) detects that the facing distance between the edge roller 5 and the anneal roller 10 has become equal to or less than a predetermined value, the defective production information of the glass ribbon GR is notified. Here, for example, since the edge roller 5 and the anneal roller 10 are urged in the direction of sandwiching the glass ribbon GR, when the glass ribbon GR disappears, the facing distance between the edge roller 5 and the anneal roller 10 becomes a predetermined value or less. Become.

Further, in the present manufacturing method, when the production defect information is notified in any of the above (1) to (3), the second valve 24 is switched from the closed state to the open state, and the internal cooling temperature of the second roller 12 becomes The internal cooling temperature T2p in the production process is changed to the internal cooling temperature T2r in the preparation process. Although the internal cooling temperature of the second roller 12 may be changed manually, it is preferable to automatically change the internal cooling temperature using the production defect information as a trigger signal.

It should be noted that the present invention is not limited to the configurations of the above-described embodiments, and is not limited to the above-described operational effects. The present invention can be variously modified without departing from the scope of the present invention.

In the above-described embodiment, as the second roller 12, the configuration in which the second roller main body 16 is provided on both sides in the axial direction of the second shaft portion 15 supported by both ends is illustrated. As shown in, the roller body 28 may be provided on one side of the second shaft portion 27 supported in a cantilever manner. The second shaft portion 27 is provided with a cooling device (not shown). Similarly, the first roller 11 may also be a cantilever type roller.

In the above embodiment, the case where the supply of the cooling medium to the second roller 12 is stopped in the production process has been described, but the supply of the cooling medium to part or all of the first roller 11 may also be stopped in the production process. You can

In the above embodiment, the case where the internal cooling temperature of the second roller 12 is relatively increased by stopping the supply of the cooling medium to the second roller 12 in the production process has been described. A cooling medium may be supplied to the roller 12. In this case, the flow rate of the cooling medium supplied to the second roller 12 may be reduced or the temperature of the cooling medium may be increased in the production process rather than the preparation process. Of course, in each of the preparation process and the production process, the supply flow rate of the cooling medium to the rollers 11 and 12 may be changed, or the temperature of the cooling medium may be changed. In the former case, it is preferable that the supply flow rate of the cooling medium of the upper roller be relatively large and the supply flow rate of the cooling medium of the lower roller be relatively small. In the latter case, it is preferable that the temperature of the cooling medium of the upper roller is relatively low and the temperature of the cooling medium of the lower roller is relatively high.

In the above-mentioned embodiment, the case where the glass ribbon is manufactured as the glass article from the glass ribbon GR has been described, but the glass article is not limited to the sheet glass. For example, when the glass ribbon GR is thin (in the case of a glass film), the glass ribbon GR may be wound into a roll by a winding device (not shown) on the downstream side in the transport direction of the slow cooling furnace 3. Thereby, the glass roll as a glass article is manufactured from the glass ribbon GR. The glass roll manufactured in this way is stored, for example, in a roll form or transported to a customer or the like. In the case of a glass roll, it is preferable that the glass ribbon GR and the protective sheet are overlapped and wound around the winding core, and the protective sheet is interposed between the glass ribbons GR facing each other in the radial direction.

1 Glass Article Manufacturing Equipment 2 Molding Furnace 3 Annealing Furnace 4 Molded Body 5 Edge Roller 10 Annealer Roller 11 First Roller 12 Second Roller 13 First Shaft 14 First Roller Main Body 14a Contact Part 14b Non-contact Part 15 Second Shaft 15a Metal exposed part 16 Second roller body 17 First cooling device 18 Second cooling device 23 First valve 24 Second valve GM Molten glass GB glass GR Glass ribbon X First temperature range Y Second temperature range

Claims (10)

A method of manufacturing a glass article using a downdraw method,
A production step of gradually cooling while conveying the glass ribbon formed by a molded body while sandwiching it between upper and lower annealing rollers, and before the production step, the glass flowed down from the molded body by the annealing roller. Sandwiching in order, comprising a preparatory step of approaching the shape of the glass ribbon,
The annealer roller is arranged in a first temperature region in which the strain point of the glass ribbon exceeds the strain point of the glass ribbon in the production process, and in a second temperature region of which the strain point is less than or equal to the glass ribbon in the production process. And a second roller,
The method for manufacturing a glass article, wherein the second roller has an internal cooling temperature higher than that in the preparation step in the production step. The method of manufacturing a glass article according to claim 1, wherein the internal cooling temperature of the first roller is lower than the internal cooling temperature of the second roller in the production step. The first roller comprises a first shaft portion having a passage through which a cooling fluid can flow, and a first roller body provided on the first shaft portion,
The second roller includes a second shaft portion having a passage through which a cooling fluid can flow, and a second roller body provided on the second shaft portion. 2. The method for producing a glass article according to item 2. The glass article according to claim 3, wherein an internal cooling temperature of the second roller is adjusted by changing a supply flow rate of the cooling fluid to the second shaft portion in the preparation step and the production step. Manufacturing method. The method for manufacturing a glass article according to claim 3, wherein the supply of the cooling fluid to the second shaft portion is stopped in the production step. The second shaft portion is made of metal supported on both sides,
The second roller main body is provided on both axial sides of the second shaft portion,
The said 2nd axial part has a metal exposure part between the said 2nd roller main bodies in the axial direction of the said 2nd axial part, The manufacturing of the glass article in any one of Claims 3-5 characterized by the above-mentioned. Method. The second shaft portion is made of a cantilevered metal,
The said 2nd roller main body is provided in the axial direction one side of the said 2nd axial part, The manufacturing method of the glass article of any one of Claims 3-5 characterized by the above-mentioned. The preparing step includes an adjusting step of adjusting the thickness of the glass and the direction of the warp, and after the adjusting step, the internal cooling temperature of the second roller is changed from the internal cooling temperature in the preparing step to the production step. The method for producing a glass article according to any one of claims 1 to 7, wherein the internal cooling temperature is switched to the internal cooling temperature. As well as detect the state of the glass ribbon in the production process, when the production defects of the glass ribbon is detected based on the detection result, internal cooling temperature of the second roller, the internal cooling temperature in the production process The method for manufacturing a glass article according to claim 1, wherein the temperature is switched to the internal cooling temperature in the preparation step. The method for producing a glass article according to claim 1, wherein the glass ribbon after being gradually cooled in the production step is wound into a roll.

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