JP6810909B2 - Glass plate manufacturing equipment and manufacturing method - Google Patents

Description

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

As is well known, the manufacturing process of a glass plate may include a step of forming a long glass ribbon which is a base of the glass plate. Here, Patent Document 1 discloses an example of a mode in which a glass ribbon is molded by an overflow down draw method (referred to as a fusion draw method in the same document).

In the same embodiment, the molten glass is poured into a groove formed at the top of the wedge-shaped molded body, and each of the molten glass overflowing from the groove on both sides is allowed to flow down along the side surface of the molded body, and then the molded body is formed. A glass ribbon is generated by fusing and integrating at the lower end. After that, the widthwise end of the glass ribbon descending from the molded body is sandwiched by edge rollers from both the front and back sides and sent downward to stretch the glass ribbon for molding.

Inside the edge roller, a flow path for circulating the coolant (inflow line 152 and outflow line 154 in the same document) is formed. With this coolant, it is possible to cool the edge roller and also to cool the glass ribbon in contact with the edge roller.

Japanese Unexamined Patent Publication No. 2011-178657

However, under the above aspects, the following problems to be solved have occurred when molding a glass ribbon made of glass satisfying a specific condition.

That is, a problem occurs when molding a glass ribbon made of glass having a low molding temperature, a large change in viscosity with respect to a unit temperature change, and a large coefficient of thermal expansion. Examples of the glass having these conditions include phosphate-based glass. Then, when molding a glass ribbon made of such glass, the glass ribbon is rapidly shrunk and cracked as the glass ribbon is rapidly cooled by contact with a conventional cooled edge roller. There is a problem that the viscosity of the glass ribbon rapidly increases and stretching becomes difficult.

In view of the above circumstances, the present invention establishes a technique capable of suitably molding a glass ribbon composed of glass having a low molding temperature, a large change in viscosity with respect to a unit temperature change, and a large coefficient of thermal expansion. With the goal.

The apparatus according to the present invention, which was devised to solve the above problems, is an apparatus for manufacturing a glass plate provided with an edge roller that feeds downward while sandwiching the widthwise end portions of the glass ribbon descending from the molded body from both the front and back sides. It is characterized by having a heating mechanism for heating the edge roller.

According to such a configuration, by providing a heating mechanism for heating the edge roller, the heated edge roller can be brought into contact with the glass ribbon, and the glass ribbon is rapidly cooled by the contact with the edge roller. You can avoid that. Therefore, when molding a glass ribbon composed of glass having a low molding temperature, a large change in viscosity with respect to a unit temperature change, and a large coefficient of thermal expansion (hereinafter referred to as specific glass), the glass ribbon that accompanies quenching is used. It is possible to prevent sudden shrinkage and sudden increase in viscosity. As a result, it is possible to prevent the glass ribbon from breaking or becoming difficult to stretch, and the glass ribbon can be suitably molded.

In the above configuration, the heating mechanism may be a heater arranged inside the edge roller.

In this way, the edge roller is heated from the inside by the heater, so that the edge roller can be heated efficiently.

In the above configuration, the edge roller has a rotating shaft and a roller body attached to the outer periphery of the rotating shaft and in contact with the glass ribbon, and the heater is arranged inside the portion of the rotating shaft to which the roller body is attached. It is preferable that it is.

In this way, since the heater is arranged inside the portion of the rotating shaft to which the roller body is attached, only the periphery of the roller body that actually contacts the glass ribbon can be heated, and wasteful heat energy is consumed. Can be prevented. Further, since only the periphery of the roller body is heated, it is not necessary to adopt a heat-resistant structure equivalent to that of the roller body for parts other than the periphery, and the cost can be suppressed accordingly.

In the above configuration, the heating mechanism may include a flow path through which the fluid flows inside the edge roller and a fluid heating means for heating the fluid flowing into the flow path.

Even in this way, since the edge roller is heated from the inside, the edge roller can be heated efficiently.

In the above configuration, the edge roller has a rotating shaft and a roller body attached to the outer periphery of the rotating shaft and in contact with the glass ribbon, and the flow path allows the fluid flowing into the inside from the outside of the rotating shaft to flow into the roller body. It is preferable to have an outward path for sending to the side and a return path for returning the fluid flowing out from the inside of the rotating shaft to the outside from the roller body side.

In this way, since the flow path has an outward path and a return path, the fluid can be circulated between the inside and the outside of the rotating shaft. This is advantageous in keeping the temperature of the roller body constant.

In the above configuration, a fluid cooling means for cooling the fluid flowing into the flow path may be provided.

In this way, instead of the fluid heated by the fluid heating means, the fluid cooled by the fluid cooling means flows into the flow path, so that the glass plate manufacturing apparatus according to the present invention can be made of a glass plate other than the specified glass. It can also be used when molding a glass ribbon composed of the above glass (a glass ribbon that needs to be brought into contact with a cooled edge roller). That is, the edge roller can be switched between a heated state and a cooled state according to the type of glass to be molded, and various types of glass can be manufactured with one device.

Further, the method according to the present invention, which was devised to solve the above problems, includes a step of feeding the end portion of the glass ribbon descending from the molded body downward while being sandwiched from both the front and back sides by edge rollers. A method of making a plate, characterized by heating the edge rollers during the execution of the process.

According to such a method, it is possible to obtain the same action / effect as the above-mentioned action / effect for the above-mentioned glass plate manufacturing apparatus.

In the above method, it is preferable to heat the edge roller so that the temperature is higher than the ambient temperature around the edge roller and lower than the temperature of the portion of the glass ribbon in contact with the edge roller.

If the temperature of the heated edge roller is within the above range, the temperature of the glass ribbon can be gradually lowered by contact with the edge roller, and it is possible to reliably avoid quenching of the glass ribbon. Become.

In the above method, in the temperature range of 30 ° C. to 300 ° C., the value of the coefficient of thermal expansion of the glass constituting the glass ribbon is within the range of 80 × ^10-7 / ° C. to 150 × ^10-7 / ° C. May be good.

When the specific glass having a coefficient of thermal expansion within the above range is formed, when the glass ribbon is formed of the specific glass, the glass ribbon is rapidly shrunk and easily broken. Therefore, when the glass ribbon made of such a specific glass is molded, if the method for producing a glass plate according to the present invention is applied, the effect can be utilized more effectively.

In the above method, the value of the viscosity of the glass constituting the glass ribbon may be in the range of 10 ^2.2 dPa · s to ^5.5 dPa · s in the temperature range of 600 ° C. to 800 ° C. ..

A specific glass having a viscosity value within the above range tends to be difficult to stretch if the glass ribbon is rapidly cooled when forming a glass ribbon composed of the specific glass. Therefore, if the method for producing a glass plate according to the present invention is applied when molding a glass ribbon made of such a specific glass, the effect can be utilized more effectively.

In the above method, the glass constituting the glass ribbon may be phosphate-based glass.

Phosphate-based glass is liable to break and difficult to stretch when the glass ribbon is rapidly cooled when forming a glass ribbon composed of the glass. Therefore, when the glass ribbon made of phosphate-based glass is formed, if the method for producing a glass plate according to the present invention is applied, the effect can be utilized more effectively.

According to the glass plate manufacturing apparatus and manufacturing method according to the present invention, a glass ribbon composed of glass having a low molding temperature, a large change in viscosity with respect to a unit temperature change, and a large coefficient of thermal expansion is suitably molded. Is possible.

It is a front view which shows the manufacturing apparatus of the glass plate which concerns on 1st Embodiment of this invention. FIG. 2A is a cross-sectional plan view showing the periphery of an edge roller in the glass plate manufacturing apparatus according to the first embodiment of the present invention, and FIG. 2B is AA of FIG. 2A. It is a longitudinal side view which shows the cross section. FIG. 3A is a cross-sectional plan view showing the periphery of the edge roller in the glass plate manufacturing apparatus according to the second embodiment of the present invention, and FIG. 3B is BB of FIG. 3A. It is a longitudinal side view which shows the cross section.

Hereinafter, the glass plate manufacturing apparatus and manufacturing method according to the embodiment of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
First, the glass plate manufacturing apparatus according to the first embodiment of the present invention will be described.

As shown in FIG. 1, the glass plate manufacturing apparatus 1 (hereinafter, simply referred to as manufacturing apparatus 1) according to the first embodiment of the present invention forms a glass ribbon 3 from the molten glass 2 by an overflow downdraw method. It is configured as follows.

The manufacturing apparatus 1 has a wedge shape and sandwiches a molded body 4 that produces a glass ribbon 3 from the molten glass 2 and a widthwise end portion 3a (ear portion) of the glass ribbon 3 that descends from the molded body 4 from both the front and back sides. It is provided with an edge roller 5 that stretches and forms the glass ribbon 3 by feeding the glass ribbon 3 downward.

After the molten glass 2 that overflows from the groove 4aa formed in the top portion 4a to both sides (front side and back side with respect to the paper surface in FIG. 1) flows down along the side surface 4b of the molded body 4. , It is possible to generate the glass ribbon 3 by fusing and integrating at the lower end portion 4c.

The edge roller 5 is provided for holding the one side end portion 3aa in the width direction of the glass ribbon 3 and for holding the other side end portion 3ab, and both 5 and 5 are centered in the width direction of the glass ribbon 3. Are arranged symmetrically with respect to. Further, for both the edge rollers 5 for sandwiching the one side end portion 3aa and for sandwiching the other side end portion 3ab, the glass ribbon 3 is arranged in a plurality of upper and lower stages along the path descending from the molded body 4. (In FIG. 1, only the uppermost edge roller 5 and the second-stage edge roller 5 from the top are shown).

As shown in FIGS. 2A and 2B, the edge roller 5 includes a first roller 6 arranged on the front surface 3b side and a second roller 5 arranged on the back surface 3c side with the glass ribbon 3 sandwiched in the thickness direction. It consists of a roller 7. Each of the first roller 6 and the second roller 7 has a rotating shaft 8 and a roller body 9 attached to the outer periphery of the rotating shaft 8 and in contact with the glass ribbon 3.

The rotating shaft 8 is formed in a cylindrical shape (hollow shape). The rotating shaft 8 is connected to a drive source (not shown) such as a motor, and can rotate as the drive source operates. The roller body 9 is attached to the tip of the rotating shaft 8. The roller body 9 is formed in a cylindrical shape, and the inner peripheral surface 9a of the roller body 9 is fitted along the outer peripheral surface 8a of the rotating shaft 8 by caulking.

Inside the rotating shaft 8, a heater 10 as a heating mechanism for heating the roller body 9 of the first roller 6 (second roller 7), a lead wire 11 electrically connected to the heater 10, and a lead A cylindrical insulating protective tube 12 that surrounds the wire 11 is provided. In the following description, these three parties 10, 11 and 12 are collectively referred to as a "heater unit". The heater unit may be configured to rotate together with the rotating shaft 8 or may be configured to stand still independently of the rotating shaft 8.

Here, the edge roller 5 (first roller 6 and second roller 7) provided with the heater unit may be only the uppermost edge roller 5 of the upper and lower plurality of stages, or one continuous from the uppermost stage. The edge roller 5 of the step (for example, from the uppermost step to the third step among the upper and lower ten steps) may be used. Further, the edge rollers 5 in all the upper and lower stages may be provided with a heater unit.

The heater 10 is arranged inside a portion of the rotating shaft 8 to which the roller body 9 is attached. The heater 10 can locally heat only the periphery of the roller body 9. Further, the heater 10 is a sheathed heater and has an outer diameter such that a gap is formed between the heater 10 and the inner peripheral surface 8b of the rotating shaft 8. As the heater 10, for example, a SiC heater may be used instead of the sheathed heater.

Similar to the heater 10, the insulating protective tube 12 has an outer diameter such that a gap is formed between the insulating protective tube 12 and the inner peripheral surface 8b of the rotating shaft 8.

Here, the rotating shaft 8 can be made of, for example, an alloy containing iron or nickel, or ceramic. In this embodiment, the rotating shaft 8 is made of stainless steel.

Further, the roller body 9 can be made of, for example, an alloy containing iron or nickel, and can be formed by spraying tungsten carbide on the outer peripheral surface 9b (contact surface with the glass ribbon 3). In addition to this, the roller body 9 can be made of ceramic. In the present embodiment, the roller main body 9 is made of stainless steel and has tungsten carbide sprayed on the outer peripheral surface 9b thereof.

Next, a method for manufacturing a glass plate according to the first embodiment of the present invention using the above-mentioned manufacturing apparatus 1 (hereinafter, simply referred to as a manufacturing method) will be described.

In this manufacturing method, a glass ribbon 3 made of glass having a low molding temperature, a large change in viscosity with respect to a unit temperature change, and a large coefficient of thermal expansion (hereinafter referred to as specific glass) is molded. In the present embodiment, the glass ribbon 3 made of phosphate-based glass, which is a kind of specific glass, is molded.

Here, as an example of the composition of the phosphate-based glass, in mass%, P ₂ O ₅ : 25 to 60%, Al ₂ O ₃ : _{2 to} 19%, RO (where R is Mg, Ca, At least one selected from Sr and Ba): 10 to 45%, ZnO: 0 to 13%, K ₂ O: 12 to 20% (however, 12% and 20% are not included), Na ₂ O: 0 to 0 Examples thereof include a composition containing 12% and CuO: 0.3 to 20%.

Further, as another example of the composition of the phosphate-based glass, P ⁵⁺ : 5 to 50%, Al ³⁺ : 2 to 30%, R' ⁺ (however, R'is Li, Na) in cation% representation. And K (at least one selected from): 10-40% and R ²⁺ (where R ²⁺ is at least one selected from Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , and Zn ²⁺ ): 20 Examples thereof include a composition containing F ⁻ : 5 to 80% and O ² : 20 to 95% in terms of ~ 50% and anion%, and substantially free of Pb component and As component.

As the still another example of the composition of the phosphate type glass, in mole percent on the oxide _{basis, P 2 O 5: 5~40%} , SO 3: 1~35%, R '2 O ( where R'is Li, Na or K): 10 to 30%, RO (where R is Mg, Ca, Sr, Ba or Zn): 20 to 50%, and CuO + Fe ₂ O ₃ + CoO + CeO ₂ : 0. A composition containing 001 to 15% can be mentioned.

The phosphate-based glass having the above composition may have the conditions (1) to (4) listed below.

(1) The molding temperature is 600 ° C. to 800 ° C. (2) In the temperature range of 600 ° C. to 800 ° C., the viscosity value is 10 ^2.2 dPa · s-10 ^5.5 dPa · s, preferably 10 ^3.5 dPa · s-10 ^5.5 dPa · s. Is. (3) The amount of change in viscosity with respect to a unit temperature change is 0.1 Pa · s / ° C or more. (4) In the temperature range of 30 ° C to 300 ° C, the value of the coefficient of thermal expansion is 80 × ^10-7 / ° C to 150 × ^10-7 / ° C, preferably 100 × ^10-7 / ° C to 150 × ^10-7. / ° C.

In this manufacturing method, when molding a glass ribbon 3 made of phosphate-based glass having the conditions (1) to (4), the edge roller 5 (first roller 6 and second roller 7) is used to form the glass ribbon. During the execution of the step of feeding 3 downward, the roller body 9 of the edge roller 5 provided with the heater unit is heated.

At this time, when the edge roller 5 provided with the heater unit is only the uppermost edge roller 5, the roller body 9 is heated for the edge roller 5 as follows. That is, the temperature is higher than the ambient temperature around the roller body 9 and lower than the temperature of the portion of the glass ribbon 3 in contact with the roller body 9 (hereinafter, the temperature range satisfying this condition is referred to as a specific temperature range). The roller body 9 is heated so as to be.

On the other hand, when the edge roller 5 provided with the heater unit is arranged in a part of the continuous stages from the uppermost stage, or when it is arranged in all the upper and lower stages, the rollers are as follows. The main body 9 is heated. That is, for all the edge rollers 5 provided with the heater unit, in addition to heating the roller body 9 so as to be in a specific temperature range, the temperature of the roller body 9 of the edge roller 5 arranged on the lower stage side is lowered. Heat to.

As described above, the glass ribbon 3 is stretched while being fed downward, and at the same time, its temperature is lowered to cool and harden the glass ribbon 3. Then, when the glass ribbon 3 is solidified, the molding is completed. Here, the speed at which the glass ribbon 3 is fed downward (plate pulling speed) is preferably in the range of 1 m / min to 7 m / min.

Next, the main actions / effects of the above-mentioned manufacturing apparatus 1 and the manufacturing method will be described.

According to the above-mentioned manufacturing apparatus 1 and manufacturing method, the heated edge roller 5 (roller body 9) can be brought into contact with the glass ribbon 3, and it is possible to prevent the glass ribbon 3 from being rapidly cooled by the contact. Therefore, when molding the glass ribbon 3 made of the specific glass (phosphate-based glass or the like), it is possible to prevent the glass ribbon 3 from suddenly shrinking or rapidly increasing in viscosity due to quenching. As a result, it is possible to prevent the glass ribbon 3 from cracking or becoming difficult to stretch, and the glass ribbon 3 can be suitably molded.

<Second embodiment>
Hereinafter, the glass plate manufacturing apparatus according to the second embodiment of the present invention and the glass plate manufacturing method according to the second embodiment of the present invention using the apparatus will be described. The second embodiment will be described only with respect to the differences from the first embodiment described above. Regarding the common points with the first embodiment, the same reference numerals are given to the drawings referred to in the description of the second embodiment, and duplicate description will be omitted.

As shown in FIGS. 3 (a) and 3 (b), the manufacturing apparatus 1 according to the second embodiment is different from the manufacturing apparatus 1 according to the first embodiment (A). The heating mechanism for heating the fluid 13 is not the heater 10, but includes a flow path 14 for flowing the fluid 13 inside the rotating shaft 8 and a fluid heating means 15 for heating the fluid 13 flowing into the flow path 14. (B) A fluid cooling means 16 for cooling the fluid 13 flowing into the flow path 14 is provided.

The flow path 14 returns the outbound path 14a for sending the fluid 13 flowing into the inside from the outside of the rotating shaft 8 to the roller body 9 side and the fluid 13 flowing out from the inside of the rotating shaft 8 to the outside from the roller body 9 side. It has a return route 14b for the purpose. The fluid 13 flows in from the outside to the inside at the base end portion (not shown) of the rotating shaft 8 and flows out from the inside to the outside. As the fluid 13, a gas (for example, air or the like) may be used, or a liquid (for example, water or the like) may be used.

The outward path 14a is formed inside the cylindrically formed tube 17. The outer diameter of the pipe 17 is smaller than the inner diameter of the rotating shaft 8, and a gap is formed between the inner peripheral surface 8b of the rotating shaft 8 and the outer peripheral surface 17a of the pipe 17. This gap constitutes the return route 14b. The pipe 17 may be configured to rotate together with the rotating shaft 8 or may be configured to stand still independently of the rotating shaft 8.

Both the fluid heating means 15 and the fluid cooling means 16 are arranged outside the rotating shaft 8. Both 15 and 16 are connected to the outbound route 14a, and when one is in operation, the other is stopped. As a result, when the fluid heating means 15 is in operation, the heated fluid 13 can be circulated inside the rotating shaft 8 to heat the roller body 9, and when the fluid cooling means 16 is in operation, the cooled fluid 13 is passed through the rotating shaft 8. The roller body 9 can be cooled by circulating the inside of the roller body 9.

Here, as the fluid heating means 15, for example, a heat pump system or a heater can be used. Further, as the fluid cooling means 16, for example, a general-purpose cooling facility or a refrigerator can be used.

Next, the manufacturing method according to the second embodiment using the manufacturing apparatus 1 described above will be described.

The difference between the manufacturing method according to the second embodiment and the manufacturing method according to the first embodiment is that the roller is not driven by the heater 10 but by the heated fluid 13 flowing in the flow path 14. The point of heating the main body 9 and (D) the glass ribbon 3 composed of glass other than the specific glass (for example, glass having a relatively high molding temperature such as non-alkali glass) when the fluid cooling means 16 is operated. The point is that it can be molded.

The manufacturing apparatus 1 and the manufacturing method according to the second embodiment can also obtain the same main actions and effects as those of the manufacturing apparatus 1 and the manufacturing method according to the first embodiment.

Here, the glass plate manufacturing apparatus and manufacturing method according to the present invention are not limited to the configurations and modes described in the above embodiments. For example, in the above embodiment, the glass ribbon is formed from the molten glass by the overflow down draw method, but this is not the case. Even when the glass ribbon is molded by a molding method other than the overflow down draw method, the molding method is a form in which the widthwise end portion of the glass ribbon descending from the molded body is sandwiched by edge rollers from both the front and back sides and fed downward. In some cases, the present invention can be applied.

Further, in the above embodiment, the roller body is heated from the inside of the rotating shaft, but this is not the case. For example, a heating means such as a heater may be installed around the roller body, and the roller body may be heated from the outside by the heating means.

1 Glass plate manufacturing equipment 3 Glass ribbon 3a Width direction end 3b Front surface 3c Back surface 4 Molded body 5 Edge roller 8 Rotating shaft 9 Roller body 10 Heater 13 Fluid 14 Flow path 14a Outward route 14b Return route 15 Fluid heating means 16 Fluid cooling means

Claims (10)

A glass plate manufacturing apparatus equipped with an edge roller that holds the widthwise end of a glass ribbon descending from a molded body from both the front and back sides and sends it downward.
A heating mechanism for heating the edge roller is provided .
A glass plate manufacturing apparatus , wherein the heating mechanism is a heater arranged inside the edge roller . The edge roller has a rotating shaft and a roller body attached to the outer periphery of the rotating shaft and in contact with the glass ribbon.
The glass plate manufacturing apparatus according to claim 1 , wherein the heater is arranged inside a portion of the rotating shaft to which the roller body is attached. A glass plate manufacturing apparatus equipped with an edge roller that holds the widthwise end of a glass ribbon descending from a molded body from both the front and back sides and sends it downward.
A heating mechanism for heating the edge roller is provided.
A glass plate manufacturing apparatus, wherein the heating mechanism includes a flow path for flowing a fluid inside the edge roller and a fluid heating means for heating the fluid flowing into the flow path. The edge roller has a rotating shaft and a roller body attached to the outer periphery of the rotating shaft and in contact with the glass ribbon.
The flow path has an outward path for sending the fluid flowing into the inside from the outside of the rotating shaft to the roller body side, and a return path for returning the fluid flowing out from the inside of the rotating shaft to the outside from the roller body side. The glass plate manufacturing apparatus according to claim 3 . The glass plate manufacturing apparatus according to claim 3, further comprising a fluid cooling means for cooling the fluid flowing into the flow path. A glass plate including a step of feeding the end portion of the glass ribbon descending from the molded body downward while being sandwiched from both the front and back sides by an edge roller provided in the glass plate manufacturing apparatus according to any one of claims 1 to 5 . It ’s a manufacturing method,
A method for manufacturing a glass plate, which comprises heating the edge roller by a heating mechanism provided in the manufacturing apparatus during execution of the step. A method for manufacturing a glass plate, which includes a step of sandwiching the widthwise end of a glass ribbon descending from a molded body from both the front and back sides with an edge roller and sending it downward.
During the execution of the step, the edge roller is heated so as to be higher than the ambient temperature around the edge roller and lower than the temperature of the portion of the glass ribbon in contact with the edge roller. A method for manufacturing a glass plate. In the temperature range of 30 ° C. to 300 ° C., the value of the coefficient of thermal expansion of the glass constituting the glass ribbon is in the range of 80 × 10 ^-7 / ° C. to 150 × 10 ^-7 / ° C. The method for manufacturing a glass plate according to claim 6 or 7 . The claim is characterized in that, in the temperature range of 600 ° C. to 800 ° C., the value of the viscosity of the glass constituting the glass ribbon is within the range of 10 ^2.2 dPa · s to ^5.5 dPa · s. The method for producing a glass plate according to any one of 6 to 8 . The method for producing a glass plate according to any one of claims 6 to 9 , wherein the glass constituting the glass ribbon is a phosphate-based glass.

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