| 摘要 |
PURPOSE:To obtain the subject material improved in flexibility and causing no smoking due to fires or use at elevated temperatures, by gathering rock wool fibers of specific,composition into a sheetlike mat which is then subjected to needling into a felt sheet form. CONSTITUTION:Rock wool fibers 4-7mum in average fiber length composed of 40-42wt.% of silicon oxide, 15-17wt.% of aluminum oxide, 4-6wt.% of iron oxide, 16-19wt.% of calcium oxide, 10-12wt.% of magnesium oxide, and a total of 4-5wt.% of potassium oxide and sodium oxide, also containing <=24wt.% of nonfibrous matter >=100mum in fiber diameter are gathered into a sheetlike mat, which is then needled into a felt form 80-150kg/m<3> in density. According to its use, one side of the sheet is provided with an aluminum thermal insulation layer, or the sheet is bent into a cylindrical form whose outer periphery is provided with an aluminum layer. |
