Method of manufacturing S-glass fibers in a direct melt operation and products formed therefrom
View Patent ↗A method of forming high strength glass fibers in a continuous system is provided. The method includes supplying a glass batch to a glass melting furnace lined with a material substantially free of noble metals. The glass batch comprises about 50-about 75 weight percent SiO 2 , about 15-about 30 weight percent Al2O3, about 5-about 20 weight percent MgO, about 0-about 10 weight percent CaO, about 0.25-about 5 weigh percent R 2 O. The method further includes melting the glass batch in the furnace 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 using a forehearth that is at least partially lined with a material substantially free of noble metal materials, discharging the molten glass from the forehearth into the bushing; and forming the molten glass into continuous fibers.
1. A method of forming high strength glass fibers in a continuous system having a furnace, a forehearth, and a bushing, the method comprising:
supplying a glass batch to a glass melting furnace, wherein at least a portion of said glass melting furnace is lined with a material substantially free of noble metals, the materials thereby forming a furnace glass contact surface, the glass batch being capable of forming a fiberizable molten glass having a fiberizing ΔT greater than 45° F. (25° C.) and comprising;
about 50-about 75 weight percent SiO 2 ;
about 15-about 30 weight percent Al2O3;
about 5-about 20 weight percent MgO;
0 to 2 weight percent CaO;
about 1.75 to about 5 weigh percent R 2 O, where R 2 O equals the sum of Li 2 O, Na 2 O and K 2 O;
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 said molten glass from the furnace to the bushing using a forehearth heated from a forehearth heat source, wherein said 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 temperature of about 2400° F. (1316° C.) to about 2650° F. (1454° C.) and a predetermined viscosity; and
forming the molten glass into continuous fibers, wherein said fibers have a pristine strength of at least 688 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 about 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 about 3.5 inches.
4. The method of claim 1 , wherein at least a portion of the furnace is lined with an oxide-based furnace 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 forehearth 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 said 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 said 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 said 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 said air-fuel burners are spaced about 4 inches apart.
13. The method of claim 1 , wherein said glass melting furnace includes one or more bubblers, electric boost electrodes, and combinations thereof.
14. The method of claim 1 , wherein said forehearth includes one or more bubblers, electric boost electrodes, and combinations thereof.
15. The method of claim 1 , wherein the predetermined viscosity is about 1000 poise.
16. The method of claim 1 , wherein the predetermined viscosity is about 316 poise.
17. The method of claim 1 , wherein the glass fibers produced have a density of 2.434-2.520 g/cc.
18. The method of claim 1 , wherein the glass fibers produced have a measured strength greater than 700 KPsi.
19. The method of claim 1 , wherein the glass fibers produced 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 produced have a density of 2.434-2.486 g/cc and a measured strength of 688-737 KPsi.
21. A method of forming high strength glass fibers in a continuous system having a furnace, a forehearth, and a bushing, the method comprising:
supplying a glass batch to a glass melting furnace, wherein at least a portion of said glass melting furnace is lined with a material substantially free of noble metals, the materials thereby forming a furnace glass contact surface, the glass batch being capable of forming a fiberizable molten glass having a fiberizing ΔT greater than 45° F. (25° C.) 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;
1.75-about 5 weigh percent R 2 O, where R 2 O equals the sum of Li 2 O, Na 2 O and K 2 O;
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 said molten glass from the furnace to the bushing using a forehearth heated from a forehearth heat source, wherein said 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 temperature of about 2400° F. (1316° C.) to about 2650° F. (1454° C.) and a predetermined viscosity; and
forming the molten glass into continuous fibers, wherein said fibers have a density of 2.434-2.520 g/cc.