Patent 7468337 was granted and assigned to Unifrax I on December, 2008 by the United States Patent and Trademark Office.
A temperature resistant vitreous inorganic fiber having a use temperature of up to at least 1000° C., or greater, having after service mechanical integrity, is non-durable (soluble) in physiological fluids, and is produced from a melt containing silica, magnesia, a lanthanide series element-containing compound, and optionally zirconia.