Glass composition for improved refining and method
View Patent ↗A soda-lime-silica based glass composition for manufacturing on a float line that has a faster refining rate due to the introduction of alkali earth oxides such as BaO, ZnO and/or SrO in the amount of from about 1-4% in total. These oxides replace part or all of the MgO in the base glass composition thereby decreasing the overall MgO content in the glass composition to about 2% or less. The glass can realize a lower viscosity at high temperatures so that refining of the melt may occur faster.
1. A glass comprising:
a base glass portion of the glass comprising:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
Al 2 O 3
0-7%
K 2 O
0-7%
and wherein the glass is a float glass, and further comprises ZnO, BaO, and from 1 to 4% SrO and no more than about 2.0% MgO, and wherein the sum total of the SrO, ZnO and BaO in the glass is from about >1-4% and the glass contains no more than 1.25% BaO, so as to lower viscosity at high temperatures so that refining occurs faster.
2. The glass of claim 1 , wherein the glass comprises from about 2-4% SrO.
3. The glass of claim 1 , wherein the glass further comprises at least 0.5% ZnO and/or at least 0.5% BaO, and wherein the total sum of SrO, ZnO and BaO in the glass is no more than about 4.0% by weight.
4. A glass comprising:
a base glass portion of the glass comprising:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
Al 2 O 3
0-7%
K 2 O
0-7%
and wherein the glass is a float glass, and further comprises each of SrO, ZnO and BaO, wherein the sum total of the SrO, ZnO and BaO in the glass is from about 1-4% by weight and the glass contains no more than 1.25% BaO, and wherein the glass contains no more than about 2.0% MgO, so as to lower viscosity at high temperatures so that refining occurs faster.
5. The glass of claim 4 , wherein the glass comprises at least 1% SrO.
6. The glass of claim 4 , wherein the glass further comprises at least 0.5% ZnO, and/or at least 0.5% BaO.
7. A glass comprising:
a base glass portion of the glass comprising:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
Al 2 O 3
0-7%
K 2 O
0-7%
and wherein the glass is a float glass, and further comprises at least two of SrO, ZnO and BaO, wherein the sum total of the SrO, ZnO and BaO in the glass is from about 1-4% by weight and the glass contains no more than 1.25% BaO, and wherein the glass contains no more than about 2.0% MgO, so as to lower viscosity at high temperatures so that refining occurs faster.
8. The glass of claim 7 , wherein the glass comprises at least 0.5% SrO.