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:
Apr. 14, 2015
Filed:
Nov. 20, 2009
Katsuhiko Kemmochi, Camas, WA (US);
Thomas Kayser, Leipzig, DE;
Robert Joseph Coolich, North Bonneville, WA (US);
Walter Lehmann, Leipzig, DE;
Katsuhiko Kemmochi, Camas, WA (US);
Thomas Kayser, Leipzig, DE;
Robert Joseph Coolich, North Bonneville, WA (US);
Walter Lehmann, Leipzig, DE;
Heraeus Shin-Etsu America, Inc., Camas, WA (US);
Abstract
A silica crucible is made in a mold cavity of the type in which ambient atmosphere can be drawn through silica grain in the cavity. In one embodiment, a silica grain layer is formed in the mold cavity and gas, which may comprise helium, nitrogen, hydrogen, or a mixture thereof, is introduced into the mold cavity. The silica grain layer is heated while substantially no ambient atmosphere is drawn through the silica grain. Thereafter, at least a portion of the silica grain layer is fused while drawing ambient atmosphere through the silica grain. The gas displaces air in the mold cavity thereby reducing nitrogen oxides and ozone.