Method of manufacturing high strength glass fibers in a direct melt operation and products formed there from

Patent metadata

Field	Value
Publication number	US-9656903-B2
Application number	US-64341109-A
Country	US
Kind code	B2
Filing date	Dec 21, 2009
Priority date	Nov 4, 2005
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A method of forming high strength glass fibers in a glass melter substantially free of platinum or other noble metal materials, products made there from and batch compositions suited for use in the method are disclosed. One glass composition for use in the present invention includes 50-75 weight % SiO 2 , 13-30 weight % Al 2 O 3 , 5-20 weight % MgO, 0-10 weight % CaO, 0 to 5 weight % R 2 O where R 2 O is the sum of Li 2 O, Na 2 O and K 2 O, has a higher fiberizing temperature, e.g. 2400-2900° F. (1316-1593° C.) and/or a liquidus temperature that is below the fiberizing temperature by as little as 45° F. (25° C.). Another glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO 2 , 16-24 weight percent Al 2 O 3 , 8-12 weight percent MgO and 0.25-3 weight percent R 2 O, where R 2 O equals the sum of Li 2 O, Na 2 O and K 2 O, has a fiberizing temperature less than about 2650° F. (1454° C.), and a ΔT of at least 80° F. (45° C.). A forehearth for transporting molten glass from the glass melter to a forming position is disclosed. By using furnaces and/or forehearths substantially free of platinum or other noble metal materials, the cost of production of glass fibers is significantly reduced in comparison with the cost of fibers produced using a melting furnace lined with noble metal materials. High strength composite articles including the high strength glass fibers are also disclosed.

First claim

We claim:

1. A method of forming high strength glass fibers in a continuous system having a glass melting furnace, a forehearth, and a bushing, the method comprising:
supplying a glass batch to the furnace, wherein at least a portion of the furnace is lined with a material substantially free of noble metals thereby forming a furnace glass contact surface,
the glass batch being capable of forming a fiberizable molten glass having a fiberizing temperature from 2,400° F. to 2,900° F. and comprising;
65-75 weight percent SiO 2 ;
15-30 weight percent Al 2 O 3 ;
5-20 weight percent MgO;
0-4 weight percent CaO;
1.0-3 weight percent Li 2 O; and trace impurities;

melting the glass batch in the furnace by providing heat from a furnace heat source and forming a pool of molten glass in contact with the furnace glass contact surface;
transporting the molten glass from the furnace to the bushing via the forehearth, wherein the forehearth is heated from a forehearth heat source, and wherein the forehearth is at least partially lined with a material substantially free of noble metal materials, forming a forehearth glass contact surface;
discharging the molten glass from the forehearth into the bushing at a predetermined viscosity; and
forming the molten glass into continuous glass fibers, the fibers having a pristine tensile strength greater than 700 kPsi.

2. The method of claim 1 , wherein the transporting step includes flowing the molten glass through the forehearth at a depth of less than 8 inches.

3. The method of claim 2 , wherein the transporting step includes flowing the molten glass through the forehearth at a depth of less than 3.5 inches.

4. The method of claim 1 , wherein at least a portion of the furnace is lined with an oxide-based refractory material.

5. The method of claim 4 , wherein at least a portion of the furnace is lined with a material selected from the group consisting of chromic oxide materials and zircon.

6. The method of claim 1 , wherein at least a portion of the furnace is lined with externally cooled walls.

7. The method of claim 1 , wherein at least a portion of the forehearth is lined with an oxide-based refractory material.

8. The method of claim 7 , wherein at least a portion of the forehearth is lined with a material selected from the group consisting of chromic oxide materials and zircon.

9. The method of claim 1 , wherein the furnace heat source comprises one or more oxy-fuel burners disposed in a roof, a sidewall, an endwall, or a bottom of the furnace, or combinations thereof.

10. The method of claim 1 , wherein the forehearth heat source further comprises one or more oxy-fuel burners disposed in a roof, a sidewall, or an endwall of the forehearth, or combinations thereof.

11. The method of claim 1 , wherein the forehearth heat source further comprises one or more air-fuel burners disposed in a roof, a sidewall, or an endwall of the furnace, or combinations thereof, at a spacing sufficient to prevent devitrification of the molten glass in the forehearth.

12. The method of claim 11 , wherein the air-fuel burners are spaced at least 4 inches apart.

13. The method of claim 1 , wherein the furnace includes one or more bubblers, electric boost electrodes, and combinations thereof.

14. The method of claim 1 , wherein the forehearth includes one or more bubblers, electric boost electrodes, and combinations thereof.

15. The method of claim 1 , wherein the predetermined viscosity is 1000 poise.

16. The method of claim 1 , wherein the predetermined viscosity is 316 poise.

17. The method of claim 1 , wherein the glass fibers have a density of 2.434-2.520 g/cc.

18. The method of claim 1 , wherein the glass fibers have a measured modulus greater than 12.7 MPsi.

19. The method of claim 1 , wherein the glass fibers have a density of 2.434-2.520 g/cc and a measured modulus greater than 12.7 MPsi.

20. The method of claim 1 , wherein the glass fibers have a density of 2.434-2.486 g/cc.

Assignees

• Mcginnis Peter Bernard
• Hofmann Douglas
• Baker David J
• Wingert John W
• Bemis Byron
• Ocv Intellectual Capital Llc

Inventors

• Mcginnis Peter Bernard
• Hofmann Douglas
• Baker David J
• Wingert John W
• Bemis Byron

Classifications

• C03B37/02 Primary

  by drawing or extruding, {e.g. direct drawing of molten glass from nozzles; Cooling fins therefor (C03B37/04 takes precedence; sizing of the fibres C03C25/00)} · CPC title

• C03B5/2353 Primary

  by combustion with pure oxygen or oxygen-enriched air, e.g. using oxy-fuel burners or oxygen lances · CPC title

• C03B5/43

  Use of materials for furnace walls, e.g. fire-bricks · CPC title

• C03B7/065

  by combustion with pure oxygen or oxygen-enriched air · CPC title

• C03B7/06

  Means for thermal conditioning or controlling the temperature of the glass · CPC title