US3881905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacture of metal oxide-containing colored glass
Assignee: PPG Industries Inc
•
Filing: 1974-02-21
•
Granted: 1975-05-06
•
Expires: 1994-02-21
Abstract
Abstract Colored flat glass is manufactured by forming a continuous sheet of glass while supporting the glass on a pool of molten metal in an enclosed forming chamber having a slightly oxidizing protective atmosphere within the forming chamber. As a result, glass of high quality is produced rather than a hazy-appearing glass that would be produced if such a glass were manufactured in a forming chamber having a conventional reducing atmosphere.
Inventors
- 👤 Deane G Cramer
- 👤 Paul W Kopp
- 👤 Manuel J Riolo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:50
CPC Classifications
C; C03; C03C; C03C1/00; C03C1/10; C03B; C03B18/00; C03B18/02; C03B18/12; C03C3/00; C03C3/04; C03C3/076; C03C3/078; C03C3/083; C03C3/085; C03C3/087
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
174 words
IN THE METHOD OF MAKING FLAT GLASS COMRPISING THE STEPS OF MELTING AND REFINING GLASS, DELIVERING MOLTEN GLASS ONTO A POOL OF MOLTEN TIN CONTAINING METAL IN AN ENCLOSED CHAMBER TO FORM A BODY OF GLASS ON THE POOL OF MOLTEN METAL AND COOLING THE BODY OF GLASS ON THE POOL OF MOLTEN METAL TO FORM A DIMENSIONALLY STABLE CONTINUOUS SHEET OF GLASS THEREFROM AND REMOVING THE CONTINUOUS SHEET OF GLASS FROM THE POOL OF MOLTEN METAL AND FROM THE ENCLOSED CHAMBER, THE IMPROVEMENT WHEREIN THE GLASS CONTAINS AT LEAST ABOUT 0.03 PERCENT BY WEIGHT (ANALYZED) OF A REDUCIBLE METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF NICKEL OXIDE, COBALT OXIDE, COPPER OXIDE, SILVER OXIDE AND MIXTURE THEREOF, AND COMPRISING THE STEPS OF FEEDING AN ATMOSPHERE GAS CONTAINING NITROGEN TO THE ENCLOSED CHAMBER CONTAINING THE POOL OF MOLTEN METAL AT A RATE AND NITROGEN CONTENT SUFFICIENT TO MAINTAIN AN ATMOSPHERE WITHIN THE ENCLOSED CHAMBER COMPRISING SUFFICIENT OXYGEN TO SUBSTANTIALLY PREVENT THE FORMATION OF A VISUALLY OBSERVABLE METALCONTAINING MATERIAL ON THE SURFACE OF THE GLASS.
Claim 2
Dependent Claim
174 words
IN THE METHOD OF MAKING FLAT GLASS COMRPISING THE STEPS OF MELTING AND REFINING GLASS, DELIVERING MOLTEN GLASS ONTO A POOL OF MOLTEN TIN CONTAINING METAL IN AN ENCLOSED CHAMBER TO FORM A BODY OF GLASS ON THE POOL OF MOLTEN METAL AND COOLING THE BODY OF GLASS ON THE POOL OF MOLTEN METAL TO FORM A DIMENSIONALLY STABLE CONTINUOUS SHEET OF GLASS THEREFROM AND REMOVING THE CONTINUOUS SHEET OF GLASS FROM THE POOL OF MOLTEN METAL AND FROM THE ENCLOSED CHAMBER, THE IMPROVEMENT WHEREIN THE GLASS CONTAINS AT LEAST ABOUT 0.03 PERCENT BY WEIGHT (ANALYZED) OF A REDUCIBLE METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF NICKEL OXIDE, COBALT OXIDE, COPPER OXIDE, SILVER OXIDE AND MIXTURE THEREOF, AND COMPRISING THE STEPS OF FEEDING AN ATMOSPHERE GAS CONTAINING NITROGEN TO THE ENCLOSED CHAMBER CONTAINING THE POOL OF MOLTEN METAL AT A RATE AND NITROGEN CONTENT SUFFICIENT TO MAINTAIN AN ATMOSPHERE WITHIN THE ENCLOSED CHAMBER COMPRISING SUFFICIENT OXYGEN TO SUBSTANTIALLY PREVENT THE FORMATION OF A VISUALLY OBSERVABLE METALCONTAINING MATERIAL ON THE SURFACE OF THE GLASS.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein the glass contains nickel oxide.
Claim 4
Dependent Claim
35 words
The method according to claim 2 wherein the glass contains from about 0.03 to about 0.2 percent by weight (analyzed) nickel oxide and the atmosphere in the enclosed chamber comprises nitrogen substantially free of hydrogen.
Claim 5
Dependent Claim
12 words
The method according to claim 3 wherein the glass consists essentially of:
Claim 6
Dependent Claim
29 words
The method according to claim 1 wherein the glass is a soda-lime-silica glass and the molten glass is delivered onto the molten metal at a temperature below about 2050*F.
Claim 7
Dependent Claim
46 words
The method according to claim 1 wherein the molten metal is substantially molten tin and the atmosphere within the enclosed chamber is maintained to contain sufficient oxygen to cause exposed coolers within the enclosed chamber to acquire a white-appearing coating thereon during the making of glass.
Claim 8
Dependent Claim
48 words
The method according to claim 1 wherein the atmosphere gas is fed to the enclosed chamber at a rate substantially in excess of that for feeding an atmosphere gas containing hydrogen to the enclosed chamber in the making of glass substantially free of readily reducible metal oxide colorants.
Claim 9
Dependent Claim
23 words
The method accordiNg to claim 1 wherein the atmosphere in the enclosed chamber is maintained to contain less than about 0.1 percent hydrogen.
Claim 10
Dependent Claim
68 words
The method according to claim 1 wherein a reducing gas is periodically injected into the atmosphere in the enclosed chamber for a sufficient time to substantially reduce the molten metal therein and thereafter the atmosphere is again maintained by the feeding of a nitrogen-containing atmosphere gas to comprise nitrogen and sufficient oxygen to prevent the formation of a visually observable metal-containing material on the surface of the glass.
Claim 11
Dependent Claim
20 words
The method according to claim 1 wherein the glass contains less than about 0.2 percent by weight (analyzed) iron oxide.
References Cited (Backward Citations)
US3674453A
Cited
US3723142A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |