Low viscosity E-glass composition enabling the use of platinum and rhodium free bushings
View Patent ↗A low viscosity E-glass composition including SiO 2 in an amount ranging from 52-54 weight percent, Al 2 O 3 in an amount ranging from 12-14 weight percent, F 2 in an amount ranging from 0-1.0 weight percent, Fe 2 O 3 in an amount ranging from 0 to 0.8 weight percent, Na 2 O in an amount ranging from 0-2.0 weight percent, K 2 O in an amount ranging from 0-2.0 weight percent, CaO in an amount ranging from 16-23 weight percent, MgO in an amount ranging from 0-3.0 weight percent, Li 2 O in an amount ranging from 0-3.0, TiO 2 in an amount ranging from 0-1.5 weight percent, ZnO in an amount ranging from 0-4.0 weight percent, and B 2 O 3 in an amount ranging from 8.0-10 weight percent is provided. The glass composition has a log 3 viscosity temperature between 1750 and 2150° F. and a ΔT temperature greater than 50° F.
1. A composition for preparing E-glass fibers comprising:
B 2 O 3 in an amount from 8-10% by weight of the total composition,
CaO in an amount from 16-23% by weight of the total composition,
Al 2 O 3 in an amount from 12-14% by weight of the total composition,
SiO 2 in an amount from 52-54% by weight of the total composition,
Fe 2 O 3 in an amount from 0-0.8% by weight of the total composition,
TiO 2 in an amount from 0-1.5% by weight of the total composition,
MgO in an amount from 0-3% by weight of the total composition,
F 2 in an amount from 0-1% by weight of the total composition,
Na 2 O in an amount from 0-2% by weight of the total composition,
K 2 O in an amount from 0-2% by weight of the total composition,
Li 2 O in an amount from 0-3% by weight of the total composition, and
ZnO in an amount from 0-4% by weight of the total composition
wherein said composition has a log 3 temperature less than or equal to 2100° F.
2. The composition of claim 1 , wherein said composition has a liquidus temperature less than about 2100° F.
3. The composition of claim 1 , wherein said composition has a ΔT greater than or equal to 50° F.
4. The composition of claim 1 , wherein said glass fibers formed from said composition are formed in a metal alloy bushing that is substantially free of platinum and rhodium.
5. The composition of claim 4 , wherein said metal alloy bushing is free of platinum and rhodium.
6. The composition of claim 4 , wherein said metal alloy bushing contains less than 5% of said bushing of at least one member selected from the group consisting of palladium-based alloys, ruthenium-based alloys, osmium-based alloys, iridium-based alloys, rhodium-based alloys, platinum-based alloys, nickel and chromium stainless steels and nickel-based alloys containing chromium and iron.
7. The composition of claim 1 , wherein
said B 2 O 3 is present in said composition in an amount from 8-10% by weight of the total composition,
said CaO is present in said composition in an amount from 18-23% by weight of the total composition,
said Al 2 O 3 is present in said composition in an amount from 12-14% by weight of the total composition,
said SiO 2 is present in said composition in an amount from 52-53% by weight of the total composition,
said Fe 2 O 3 is present in said composition in an amount from 0-0.5% by weight of the total composition,
said TiO 2 is present in said composition in an amount from 0-1% by weight of the total composition,
said MgO is present in said composition in an amount from 0-3% by weight of the total composition,
said F 2 is present in said composition in an amount from 0-1% by weight of the total composition,
said Na 2 O is present in said composition in an amount from 0-2% by weight of the total composition,
said K 2 O is present in said composition in an amount from 0-1% by weight of the total composition,
said Li 2 O is present in said composition in an amount from 0-2% by weight of the total composition, and
said ZnO is present in said composition in an amount from 0-2% by weight of the total composition.
8. The composition of claim 1 , wherein glass fibers formed from said composition are formed in a metal alloy bushing, said metal alloy bushing containing up to 50% of said bushing one or more precious metals selected from platinum, rhodium, palladium, ruthenium, osmium, iridium and combinations thereof.
9. The composition of claim 1 , wherein glass fibers formed from said composition are formed in a metal alloy bushing, said metal alloy bushing containing up to 25% of said bushing one or more precious metals selected from platinum, rhodium, palladium, ruthenium, osmium, iridium and combinations thereof.
10. The composition of claim 1 , wherein said composition has a log 3 temperature from about 1750° F. to about 2100° F.
11. The composition of claim 3 , wherein said composition has a ΔT from 50° F. to about 250° F.
12. The composition of claim 3 , wherein said composition has a ΔT greater than or equal to 100° F.