The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 2007
Filed:
Dec. 05, 2005
John D. Helfinstine, Big Flats, NY (US);
Daniel J. Liebner, Corning, NY (US);
John L. Martin, Weston, WV (US);
Dean V. Neubauer, Horseheads, NY (US);
William R. Powell, Horseheads, NY (US);
John D. Helfinstine, Big Flats, NY (US);
Daniel J. Liebner, Corning, NY (US);
John L. Martin, Weston, WV (US);
Dean V. Neubauer, Horseheads, NY (US);
William R. Powell, Horseheads, NY (US);
Corning Incorporated, Corning, NY (US);
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 (TiO) 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.