High alumina low soda glass compositions
A glass composition includes a base glass portion comprising: 65-75 wt % SiO 2 ; 5-15 wt % CaO; 0-5 wt % MgO; 0-5 wt % K 2 O; 10-14 wt % Na 2 O; and 1-5 wt % Al 2 O 3 ; wherein the glass composition has a ratio of Na 2 O to Al 2 O 3 is in the range of 9.5-12.5 wt %/wt %.
1 . A glass composition comprising:
a base glass portion comprising:
65-75 wt % SiO 2 ;
5-9.5 wt % CaO;
2.6-5 wt % MgO;
0-5 wt % K 2 O;
10-14 wt % Na 2 O; and
0.8-1.47 wt % Al 2 O 3 ; and
a colorant portion comprising:
30 to 120 ppm of CoO; and
no more than 7.5 ppm selenium,
wherein the glass composition has a ratio of Na 2 O to Al 2 O 3 in the range of 10.0-11.5 wt. %/wt.%, wherein the glass composition has a ratio of CaO to MgO in the range of 1.7 to 1.9 wt. %/wt.%, wherein the glass composition has an iron redox ratio in the range of 0.221-0.311, wherein the total iron in the glass composition is in the range of 0.01 to 0.30 wt. %, and wherein a glass sheet formed from the glass composition has an a* in the range of −3 to +1 and a b* in the range of −2 to −12.
2 . The glass composition of claim 1 , wherein the base glass portion comprises 0.1-0.5 wt % K 2 O.
3 . The glass composition of claim 1 , wherein the base glass portion comprises:
68-74 wt % SiO 2 ;
13-13.5 wt % Na 2 O;
1-1.4 wt % Al 2 O 3 ;
8.1-8.6 wt % CaO; and
4.5-5 wt % MgO.
4 . The glass composition of claim 1 , wherein the glass sheet has an a* in the range of −2.5 to 0 and a b* in the range of −4 to −9.
5 . The glass composition of claim 1 , wherein the glass sheet has a visible light transmittance of no greater than 80%.
6 . The glass composition of claim 1 , wherein the colorant portion comprises selenium in an amount from greater than 0 ppm to 3 ppm.
7 . The glass composition of claim 1 , wherein a colorant portion comprises at least one of the following oxides of manganese, tin, cerium, molybdenum, vanadium, copper, zinc, tungsten, and lanthanum, or any combination thereof.
8 . The glass composition of claim 1 , wherein the glass composition comprises 0.16-0.18 wt. % Fe 2 O 3 .
9 . A glass composition comprising:
a base glass portion comprising:
71.2-71.6 wt. % SiO 2 ;
8.3-8.6 wt. % CaO;
5.0-5.2 wt. % MgO;
0.24-0.25 wt. % K 2 O;
13.4-13.5 wt. % Na 2 O; and
1.1-1.2 wt. % Al 2 O 3 ; and
a colorant portion comprising:
30 to 120 ppm of CoO; and
no more than 7.5 ppm selenium,
wherein the glass composition has a ratio of Na 2 O to Al 2 O 3 in the range of 11.17-12.27 wt. %/wt.%, wherein the glass composition has an iron redox ratio in the range of 0.221-0.311, wherein the total iron in the glass composition is in the range of 0.01 to 0.30 wt. %, and wherein a glass sheet formed from the glass composition has an a* in the range of −2.5 to 0 and a b* in the range of −5 to −9.
10 . The glass composition of claim 9 , wherein the glass composition comprises 0.20-0.21 wt. % Fe 2 O 3 .
11 . The glass composition of claim 9 , wherein the ratio of CaO to MgO is 1.7 to 1.9 wt. %/wt.%.
12 . A method of producing a glass sheet comprising:
feeding raw batch materials into a container;
melting the raw batch materials in the container to form a molten glass composition;
passing the molten glass composition from the container into a pool of a molten metal such that the molten glass composition floats in the pool of molten metal;
forming the molten glass composition into a shape of a flat glass sheet on the pool of molten metal; and
cooling the molten glass composition to form the flat glass sheet, wherein the flat glass sheet comprises the glass composition of claim 1 .
13 . The glass composition of claim 1 , wherein the glass composition has a ratio of Na 2 O to Al 2 O 3 in the range of 10.5-11.0 wt. %/wt.%, and wherein the glass sheet formed from the glass composition has an a* in the range of −2.5 to 0 and a b* in the range of −4 to −9.
14 . The glass composition of claim 1 , wherein the glass composition has a ratio of Na 2 O to Al 2 O 3 in the range of 10.55-10.90 wt. %/wt.%, and wherein the glass sheet formed from the glass composition has an a* in the range of −1.8 to −0.5 and a b* in the range of −5 to −8.