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, 2012
Filed:
Jun. 04, 2010
Stefan Ochs, Bad Camberg, DE;
Steffen Zwarg, Wolfen, DE;
Mirko Wittrin, Sandersdorf, DE;
Martin Trommer, Bitterfeld, DE;
Stefan Ochs, Bad Camberg, DE;
Steffen Zwarg, Wolfen, DE;
Mirko Wittrin, Sandersdorf, DE;
Martin Trommer, Bitterfeld, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
A known method for producing synthetic quartz glass comprises the method steps: (a) forming a cylindrical SiOsoot body having an inner portion and at least one free cylinder jacket surface surrounding the inner portion; (b) thermally drying the porous soot body; and (c) vitrifying the dried soot body with formation of the cylinder from synthetic quartz glass. Starting therefrom, to indicate a method which permits a particularly flat radial distribution in the inner portion of the cylinder, it is suggested according to the invention that the dried SiOsoot body that is present after method step b) should be subjected to a homogenizing method prior to vitrification, the homogenizing method comprising the following steps: (I) heating the soot body to a consolidation temperature to form a sealing layer in the area of the at least one cylinder jacket, the sealing layer sealing the inner portion to the outside; (II) cooling the soot body from the consolidation temperature; and (III) annealing the soot body in the range of a homogenization temperature during a period of at least 5 hours so that the radial profile of the hydroxyl group concentration flattens in the inner portion.