High visible, low UV and low IR transmittance green glass composition
AssigneeGuardian Industries Corp.
InventorsSteven P. Beckwith, William M. Yankovich
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Abstract
A soda-lime-silica green glass favoring the yellow side, rather than the bluish side of the spectrum, is produced having high visible transmittance, low infrared energy transmittance, low ultraviolet radiation transmittance, and low total solar energy transmittance by manipulating the reduction of iron (as Fe.sub.2 O.sub.3) to FeO and the percent of these two oxides to achieve these characteristics without the use of CeO.sub.2 or other UV absorbing additives and by using conventional glass melting and refining apparatus.
Claims11
A green-colored infrared energy and ultraviolet radiation absorbing glass consisting essentially of SiO.sub.2, Na.sub.2 O, CaO, about 0.20-0.25% SO.sub.3, about 0.7-0.95% total iron expressed as Fe.sub.2 O.sub.3, about 0.19-0.24% ferrous iron expressed as FeO, and wherein said glass when between about 3.7 mm-4.8 mm thickness has a visible transmittance of greater than about 70%, an ultraviolet radiation transmittance of less than about 38% and a total solar transmittance of less than about 44.5%.
The method of forming a green glass which consists essentially of, on an oxide basis:
- ______________________________________ Material wt. % ______________________________________ Na.sub.2 O about 13.75 MgO about 3.90 Al.sub.2 O.sub.3 about 0.15 SO.sub.3 about 0.23 K.sub.2 O about 0.04 CaO about 8.72 (Total iron as) Fe.sub.2 O.sub.3 about 0.78 SiO.sub.2 about 72.41 FeO about 0.19 ______________________________________
- said green glass when between about 3.7 mm-4.8 mm thickness having a visible transmittance of greater than about 70%, an ultraviolet radiation transmittance of less than about 38% and a total solar transmittance of less than about 44.5%;
- the steps including forming said glass from a batch material consisting essentially of by weight:
- ______________________________________ Material wt. % ______________________________________ Sand about 59.66 Soda Ash about 18.68 Dolomite about 14.57 Limestone about 4.86 Salt Cake about 1.55 Iron Oxide about 0.62 Carbon about 0.06. ______________________________________
The method of forming a green glass which consists essentially of, on an oxide basis:
- ______________________________________ Material wt. % ______________________________________ Na.sub.2 O about 13.67 MgO about 3.91 Al.sub.2 O.sub.3 about 0.17 SO.sub.3 about 0.21 K.sub.2 O about 0.04 CaO about 8.70 (Total iron as) Fe.sub.2 O.sub.3 about 0.889 SiO.sub.2 about 72.41 FeO about 0.22 ______________________________________
- said green glass when between about 3.7 mm-4.8 mm thickness having the following characteristics:
- ______________________________________ Characteristic Range ______________________________________ Illuminant A (visible transmittance) >70% UV transmittance <38% Total Solar transmittance <44.5% IR transmittance 18%-21% Illuminant C about 495-510 nm dominant wavelength Illuminant D-65 L about 87%-91% a about -8 .+-. 3 b about 2 .+-. 2 Color purity about 2%-4% ______________________________________ the steps including forming said glass from a batch material consisting essentially of by weight:
- ______________________________________ Material wt. % ______________________________________ Sand about 59.60 Soda Ash about 18.66 Dolomite about 14.56 Limestone about 4.86 Salt Cake about 1.55 Iron Oxide about 0.71 Carbon about 0.06 ______________________________________
- and wherein during said forming of said glass the total iron expressed as Fe.sub.2 O.sub.3 is reduced about 27%.
Dependencies are inferred from the claim text.