Compositions: ceramic – Ceramic compositions – Refractory
Reexamination Certificate
2007-08-21
2007-08-21
Group, Karl (Department: 1755)
Compositions: ceramic
Ceramic compositions
Refractory
C065S374130, C065S195000
Reexamination Certificate
active
11294315
ABSTRACT:
Isopipes for use in making sheet glass by a fusion process are provided which exhibit reduced sag. The isopipes are composed of a zircon refractory which has a mean creep rate (MCR) at 1180° C. and 250 psi and a 95 percent confidence band (CB) for said mean creep rate such that the CB to MCR ratio is less than 0.5, the MCR and the CB both being determined using a power law model. The zircon refractory can contain titania (TiO2) at a concentration greater than 0.2 wt. % and less than 0.4 wt. %. A concentration of titania in this range causes the zircon refractory to exhibit a lower mean creep rate than zircon refractories previously used to make isopipes. In addition, the variation in mean creep rate is also reduced which reduces the chances that the zircon refractory of a particular isopipe will have an abnormally high creep rate and thus exhibit unacceptable sag prematurely.
REFERENCES:
patent: 2746874 (1956-05-01), Whittemore
patent: 2752259 (1956-06-01), Cook
patent: 3285757 (1966-11-01), Cornely
patent: 3338696 (1967-08-01), Dockerty
patent: 3347687 (1967-10-01), Henry
patent: 3359124 (1967-12-01), Henry
patent: 3437470 (1969-04-01), Overman
patent: 3682609 (1972-08-01), Dockerty
patent: 5023218 (1991-06-01), Zanoli et al.
patent: 5124287 (1992-06-01), Wehrenberg et al.
patent: 5407873 (1995-04-01), Goerenz et al.
patent: 5466643 (1995-11-01), Ishino et al.
patent: 6974786 (2005-12-01), Helfinstine et al.
patent: 2005/0130830 (2005-06-01), Ames et al.
patent: 11-246230 (1999-09-01), None
US 7,041,614, 05/2006, Ames et al. (withdrawn)
Corhart Refractories Corporation's product brochure entitled “ZS-1300 Dense Zircon Refractory,” 1993.
Corhart Refractories Corporation's product brochure entitled “ZS-835 Forehearth Zircon Refractory,” 1993.
Corhart Refractories Corporation's product brochure entitled “Zircon 20 Refractory,” 1993.
Corhart Refractories Corporation's product brochure entitled “ZS-835 HD: Low Blistering Dense Zircon Refractory,” 1995.
“Flat Glass,”Fundamentals of Inorganic Glasses, Academic Press, Inc., Boston, 1994, Chapter 20, Section 4.2, pp. 534-540.
Draper et al.,Applied Regression Analysis, “Two Predictor Variables,” Chapter 4, John Wiley & Sons, New York, 1981, pp. 193-212.
Kingery et al., “Plastic Deformation, Viscous Flow, and Creep,”Introduction to Ceramics, 2ndEdition, John Wiley & Sons, New York, 1976, pp. 704-767.
Helfinstine John D.
Liebner Daniel J.
Martin John L.
Neubauer Dean V.
Powell William R.
Corning Incorporated
Group Karl
Klee Maurice M.
Nicastri Christopher
LandOfFree
Sag control of isopipes used in making sheet glass by the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sag control of isopipes used in making sheet glass by the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sag control of isopipes used in making sheet glass by the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3895609