Inorganic fiber
An inorganic fiber containing silica and magnesia as the major fiber components and which further includes an intended iron oxide additive to improve the dimensional stability of the fiber. The inorganic fiber exhibits good thermal insulation performance at 1400° C. and greater, retains mechanical integrity after exposure to the use temperature, and which remains non-durable in physiological fluids. Also provided are thermal insulation product forms comprising a plurality of the inorganic fibers, methods of preparing the inorganic fiber and of thermally insulating articles using thermal insulation prepared from a plurality of the inorganic fibers.
1. An inorganic fiber comprising a fiberization product of greater than 75 weight percent silica, magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 4 weight percent alumina, wherein said inorganic fiber exhibits a shrinkage of 10% or less at 1400° C.
2. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 78 weight percent silica, about 17 to about 20 weight percent magnesia, from about 5 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, 1 weight percent or less calcia, and substantially no alkali metal oxide.
3. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 86 weight percent silica, about 12.5 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.
4. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 86 weight percent silica, about 12.5 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina and 1 percent or less of calcia.
5. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 86 weight percent silica, about 12.5 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, 1 percent or less of calcia, and substantially no alkali metal oxide.
6. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 79 weight percent silica, about 15 to about 20 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.
7. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 79 weight percent silica, about 15 to about 20 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and 1 weight percent or less calcia.
8. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 79 weight percent silica, about 15 to about 20 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and substantially no alkali metal oxide.
9. The inorganic fiber of claim 1 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 79 weight percent silica, about 15 to about 20 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, 1 weight percent or less calcia, and substantially no alkali metal oxide.
10. The inorganic fiber of claim 1 , wherein said fiberization product further includes a viscosity modifier.
11. The inorganic fiber of claim 10 , wherein said viscosity modifier is selected from the group consisting of alkali metal oxides, boria, and mixtures thereof.
12. The inorganic fiber of claim 11 , wherein said viscosity modifier comprises boria.
13. A method of insulating an article, including disposing on, in, near or around the article, a thermal insulation material, said insulation material comprising the inorganic fiber of claim 1 .
14. An inorganic fiber containing article comprising at least one of bulk fiber, blankets, needled blankets, papers, felts, cast shapes, vacuum cast forms, or compositions, said fiber containing article comprising the inorganic fiber of claim 1 .
15. The inorganic fiber of claim 1 , wherein said inorganic fiber has an average diameter of greater than 4 microns.
16. The inorganic fiber of claim 15 , wherein said inorganic fiber exhibits a shrinkage of 5% or less at 1400° C.
17. The inorganic fiber of claim 16 , wherein said inorganic fiber exhibits a shrinkage of 4% or less at 1400° C.
18. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 15 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.
19. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 15 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and 1 weight percent or less calcia.
20. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 15 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and substantially no alkali metal oxide.
21. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 15 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, 1 weight percent or less calcia, and substantially no alkali metal oxide.
22. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 17 to about 22 weight percent magnesia, 1 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.
23. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 17 to less than 24 weight percent magnesia, 1 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and 1 weight percent or less calcia.
24. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 17 to less than 24 weight percent magnesia, 1 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and substantially no alkali metal oxide.
25. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 80 weight percent silica, about 17 to less than 24 weight percent magnesia, 1 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, 1 weight percent or less calcia, and substantially no alkali metal oxide.
26. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 78 weight percent silica, about 17 to about 20 weight percent magnesia, from about 5 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 2 weight percent alumina.
27. The inorganic fiber of claim 16 , wherein said inorganic fiber comprises the fiberization product of greater than 75 to about 78 weight percent silica, about 17 to about 20 weight percent magnesia, from about 5 to about 8 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 2 weight percent alumina, and 1 weight percent or less calcia.
28. An inorganic fiber comprising the fiberization product of 70 or greater weight percent silica, magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , about 1 weight percent or less calcia, substantially no alkali metal oxide, and greater than 0 to about 4 weight percent alumina, wherein said inorganic fiber exhibits a shrinkage of 10% or less at 1400° C.
29. The inorganic fiber of claim 28 , wherein said inorganic fiber exhibits a shrinkage of 5% or less at 1400° C.
30. The inorganic fiber of claim 28 , wherein said inorganic fiber comprises the fiberization product of about 72 to about 80 weight percent silica, about 17 to about 22 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , greater than 0 to about 3 weight percent alumina, and a viscosity modifier.
31. The inorganic fiber of claim 30 , wherein said viscosity modifier comprises boria.
32. The inorganic fiber of claim 28 , wherein said present inorganic fiber comprises the fiberization product of about 72 to about 78 weight percent silica, about 17 to about 23 weight percent magnesia, from about 5 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 2 weight percent alumina.
33. The inorganic fiber of claim 28 , wherein said inorganic fiber comprises the fiberization product of about 72 to about 86 weight percent silica, about 12.5 to about 26.5 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and 0 to about 3 weight percent alumina.
34. The inorganic fiber of claim 28 , wherein said inorganic fiber comprises the fiberization product of about 75 to about 79 weight percent silica, about 15 to about 20 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.
35. A method for preparing the inorganic fiber exhibiting a shrinkage of 10% or less at 1400° C. comprising:
forming a melt with ingredients comprising greater than 75 weight percent silica, magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 4 weight percent alumina; and
producing fibers from the melt.
36. The method of claim 35 , wherein said melt of ingredients comprises greater than 75 to about 86 weight percent silica, about 12.5 to less than 24 weight percent magnesia, 1 to about 10 weight percent iron oxide, measured as Fe 2 O 3 , and greater than 0 to about 3 weight percent alumina.