Method for forming molten glass, forming apparatus, and method for producing glass product

Patent metadata

Field	Value
Publication number	US-12291475-B2
Application number	US-201916529306-A
Country	US
Kind code	B2
Filing date	Aug 1, 2019
Priority date	Feb 15, 2017
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

To provide a method for forming molten glass, capable of easily improving the forming accuracy of molten glass. One embodiment of the method for forming molten glass of the present invention comprises a supplying in which molten glass having a temperature of at least the softening point is discharged in a strip shape and supplied on the surface of molten metal, and a transporting the glass ribbon supplied on the surface of the molten metal, wherein the transporting includes a cooling the glass ribbon being transported, in a region on the upstream side in the transport direction, so that the temperature of the glass ribbon becomes lower than the softening point in the entire width direction.

First claim

What is claimed is:

1. A method for forming molten glass, comprising:
adjusting a temperature of a portion of molten metal where a glass ribbon makes first contact with the molten metal such that a temperature of the portion of the molten metal is brought to be lower than a softening point of the molten glass and higher than an annealing point of the molten glass;
setting a temperature of the molten glass in a supply device having a discharge section that discharges the molten glass in a strip shape and supplies the molten glass in a form of the glass ribbon such that a viscosity n of the molten glass become within a range of 1.5≤log η≤5 where η is in dPa·s;
discharging the molten glass in the strip shape on a surface of the molten metal such that the molten glass is supplied in the form of the glass ribbon on a surface of the portion of the molten metal where the temperature is kept lower than the softening point of the molten glass and higher than the annealing point of the molten glass; and
transporting the glass ribbon comprising the molten glass and supplied on the surface of the portion of the molten metal from an upstream side to a downstream side in a transport direction such that a thickness of the glass ribbon is maintained on the surface of the molten metal during the transporting,
wherein the discharging comprises dropping the molten glass having a temperature of at least the softening point in the form of the glass ribbon vertically downward such that during the dropping, the glass ribbon is cooled by a cooling device configured to cool the glass ribbon, has a temperature of at least the softening point of the molten glass and is stretched by an own weight of the glass ribbon and adjusted to the thickness for the transporting, and said transporting includes cooling the glass ribbon being transported on the molten metal in a region on the upstream side in the transport direction such that the temperature of the glass ribbon becomes lower than the softening point of the molten glass in an entire width direction.

2. The forming method according to claim 1 , wherein the cooling in the transporting the glass ribbon includes cooling the glass ribbon such that the temperature of the glass ribbon becomes higher than the annealing point in the entire width direction.

3. The forming method according to claim 2 , wherein the adjusting includes lowering the temperature of the portion of the molten metal by a cooling device positioned to cool the portion of the molten metal and maintaining the temperature of the portion of the molten metal to be at least 560° C. and at most 750° C.

4. The forming method according to claim 2 , wherein the temperature of the portion of the molten metal is at most 900° C.

5. The forming method according to claim 2 , wherein the discharging includes shielding at least part of radiant heat radiated from the glass ribbon toward the molten metal.

6. The forming method according to claim 1 , wherein the adjusting includes lowering the temperature of the portion of the molten metal by a cooling device positioned to cool the portion of the molten metal and maintaining the temperature of the portion of the molten metal to be at least 560° C. and at most 750° C.

7. The forming method according to claim 1 , wherein the temperature of the portion of the molten metal is at most 900° C.

8. The forming method according to claim 1 , wherein the discharging includes shielding at least part of radiant heat radiated from the glass ribbon toward the molten metal.

9. The forming method according to claim 1 , wherein at least one of the discharging and the transporting includes shielding at least part of radiant heat radiated from a discharge section that discharges the molten glass toward the molten metal and the glass ribbon.

10. The forming method according to claim 1 , wherein the cooling in the transporting the glass ribbon includes cooling the glass ribbon from an opposite side to a molten metal side.

11. The forming method according to claim 1 , wherein a viscosity n of the glass ribbon in the dropping is adjusted such that the viscosity n of the glass ribbon does not become log η<1.5 where η is in dPa·s.

12. The forming method according to claim 1 , wherein the transporting includes not exerting a force which deforms the glass ribbon.

13. The forming method according to claim 1 , wherein the discharging includes discharging the molten glass from a slit at a discharge section such that the molten glass is formed into the glass ribbon.

14. The forming method according to claim 1 , wherein the discharging includes discharging the molten glass from a discharge section having a declined surface such that the declined surface is declined in a vertical direction from the upstream side in the transport direction and declining toward the downstream side in the transport direction, and the discharging includes transmitting the molten glass along said declined surface such that the molten glass is formed into the glass ribbon.

15. The forming method according to claim 1 , wherein the discharging includes discharging the molten glass from a discharge section having a first surface and a second surface such that the molten glass is transmitted on the first surface and the second surface, and that a lower end of the first surface and a lower end of the second surface are connected to each other, and the discharging includes laminating a first glass ribbon from the first surface and a second glass ribbon from the second surface such that the molten glass is discharged in the strip shape and supplied in the form of the glass ribbon.

16. A method for producing a glass product, comprising:
annealing the glass ribbon which is formed by the method of claim 1 .

Assignees

• Agc Inc

Inventors

• Iga Motoichi
• Kamihori Toru
• Nakano Masanori

Classifications

• C03B18/12

  Making multilayer, coloured or armoured glass (chemical aspects C03C) · CPC title

• C03B18/18

  Controlling or regulating the temperature of the float bath; Composition or purification of the float bath · CPC title

• C03B25/093

  being in a horizontal position on a fluid support, e.g. a gas or molten metal · CPC title

• C03B17/06 Primary

  Forming glass sheets · CPC title

• C03B18/02

  Forming sheets · CPC title