Methods to make glass compositions and fibers made therefrom
View Patent ↗Embodiments of the present invention provides fiberizable glass compositions formed from batch compositions comprising amounts of one or more glassy minerals, including perlite and/or pumice.
1. A method of producing a glass fiber, the method comprising:
(a) providing a batch composition comprising:
at least 10 weight percent of a glassy mineral and at least 5 weight percent of a sodium source, the glassy mineral comprising a combination of SiO 2 and Al 2 O 3 in an amount of at least 80 weight percent;
at least 10 weight percent of an additional source of silicon, aluminum, or both silicon and aluminum; and
a sufficient amount of an alkali metal oxide (R 2 O) component comprising K 2 O, such that the glass fiber produced comprises 8.5 to 18 weight percent of R 2 O and further comprises from 0.5 to 4 weight percent K 2 O;
(b) heating the batch composition to form a molten glass composition; and
(c) extruding the molten glass composition through a bushing to form a glass fiber.
2. The method of claim 1 , wherein the batch composition is heated to a fiber forming temperature ranging from about 1120° C. to about 1300° C.
3. The method of claim 1 , wherein the batch composition is heated to a temperature ranging from about 1400° C. to about 1450° C.
4. The method of claim 1 , wherein the batch composition is heated to a fiber forming temperature which differs from a liquidus temperature of a glass composition from about 45° C. to about 165° C.
5. The method of claim 1 , wherein the batch composition comprises at least 25 weight percent of the glassy mineral.
6. The method of claim 1 , wherein the batch composition comprises at least 40 weight percent of the glassy mineral.
7. The method of claim 1 , wherein the glassy mineral comprises perlite, pumice or mixtures thereof.
8. The method of claim 1 , wherein the batch composition comprises at least 10 weight percent of the sodium source.
9. The method of claim 1 , wherein the batch composition comprises at least 10 weight percent of an additional source of silicon.
10. The method of claim 9 , wherein the source of silicon comprises 34-56 weight percent silica.
11. The method of claim 1 , wherein the batch composition comprises at least 10 weight percent of an additional source of aluminum.
12. The method of claim 11 , wherein the source of aluminum comprises corundum.
13. The method of claim 1 , wherein the batch composition comprises at least 10 weight percent of an additional source of both silicon and aluminum.
14. The method of claim 13 , wherein the source of both silicon and aluminum comprises at least one of kaolinite, dickite, halloysite, nacrite, montmorillonite, or alkali metal aluminosilicates.
15. The method of claim 14 , wherein the source of both silicon and aluminum comprises up to 19 weight percent kaolinite.
16. The method of claim 1 , further comprising at least one additional mineral comprising limestone, dolomite, or mixtures thereof.
17. The method of claim 16 , wherein the additional mineral comprises up to 55 weight percent dolomite.
18. The method of claim 16 , wherein the additional mineral comprises up to 17 weight percent limestone.
19. The method of claim 1 , wherein the glass fiber comprises:
53-64 weight percent SiO 2 ;
8-12 weight percent Al 2 O 3 ; and
a metal oxide (RO) component comprising MgO, CaO, SrO, BaO, or ZnO or mixtures thereof,
wherein the metal oxide component is present in an amount to provide a mass ratio of R 2 O/RO ranging from about 0.28 to about 1.5.