Low bio-persistent high temperature resistant inorganic fibers
A high temperature resistant inorganic fiber includes 72 to 77.3 weight percent silica; 10.2 to 15 weight percent magnesia; 12.4 to 17 weight percent calcia; 0 to 1.5 weight percent alumina; and 0 to 0.6 weight percent total alkali oxides; the fiber has a use temperature of at least 1260° C.; the fiber may exhibit a shrinkage of greater than 5% after exposure to a temperature of 1400° C. for 24 hours; and the fiber may have a melt temperature of less than 1400° C.
1 . A high temperature resistant inorganic fiber comprising:
72 to 77.3 weight percent silica;
10.5 to 15 weight percent magnesia;
12.5 to 17 weight percent calcia;
0 to 1.5 weight percent alumina; and
0.1 to 0.6 weight percent total alkali oxides;
wherein the fiber has a use temperature of at least 1260° C. and exhibits a shrinkage of less than 3% after exposure to a temperature of 1260° C. for 24 hours;
wherein the fiber exhibits a shrinkage of greater than 5% after exposure to a temperature of 1400° C. for 24 hours; and
wherein the fiber does not comprise strontia.
2 . The fiber of claim 1 , wherein the fiber comprises 11 to 15 weight percent magnesia and 13 to 17 weight percent calcia.
3 . The fiber of claim 1 , wherein the fiber exhibits a dissolution rate of greater than 100 ng/cm 2 -hr after 6 hours in simulated lung fluid.
4 . The fiber of claim 1 , wherein the fiber comprises greater than 0 to 0.5 weight percent lithium oxide.
5 . The fiber of claim 1 , wherein the fiber comprises greater than 0 to 0.5 weight percent potassium oxide.
6 . The fiber of claim 1 , wherein the fiber comprises 0.5 to 1.1 weight percent alumina.
7 . The fiber of claim 1 , wherein the fiber comprises:
73 to 75.8 weight percent silica;
11 to 15 weight percent magnesia;
13 to 17 weight percent calcia;
0.2 to 1.5 weight percent alumina; and
0.1 to 0.6 weight percent total alkali oxides.
8 . The fiber of claim 1 , wherein the fiber comprises potassium oxide and lithium oxide and wherein a weight ratio of potassium oxide to lithium oxide is less than 7.
9 . The fiber of claim 1 , wherein the fiber comprises potassium oxide and lithium oxide and wherein a sum of the potassium oxide and lithium oxide is from greater than 0.2 weight percent to less than 0.5 weight percent.