| abstract |
A burn through resistant nonwoven mat and cover film composite for use in a thermal and/or acoustical insulation blanket system, are, preferably, made up of non-respirable and/or biosoluble base fibers and capable of retaining their integrity and dimensional stability during 4 minutes of exposure to a fluctuating high pressure flame front at a temperature of 1100° C. examples of non-respirable base fibers which make up the nonwoven mat are quartz fibers; aluminosilicate, aluminoborosilicate or alumina ceramic oxide fibers; partially oxidized pitch based fibers; and partially oxidized polyacrylonitrile fibers having mean diameters greater than 6 microns. Examples of biosoluble fibers are biosoluble glass fibers. Preferably, the nonwoven mats also include a lubricant sizing with a water repellent additive. |