Abstract: A burn through and flame propagation resistant system, includes a sheet of burn through and flame propagation resistant paper made of aramid fibers, mica flakes, and aramid fibrid binder; and one or more sheets of polymeric film, preferably, flame propagation resistant polymeric film, bonded to at least one major surface of the sheet of burn through and flame propagation resistant paper to form a laminated sheet. Preferably, for many applications, the system is also water vapor transmission resistant with the sheet or sheets of polymeric film or a coating providing the water vapor transmission resistance. The burn through and flame propagation resistant paper and/or polymeric film(s) may have major surface(s) coated with a heat sealable adhesive, e.g. for securing the laminated sheet to itself or another laminated sheet to form a bag or envelope for encapsulating insulation.

Abstract: A burn through and flame propagation resistant system, includes a sheet of burn through and flame propagation resistant paper made of aramid fibers, mica flakes, and aramid fibrid binder; and one or more sheets of polymeric film, preferably, flame propagation resistant polymeric film, bonded to at least one major surface of the sheet of burn through and flame propagation resistant paper to form a laminated sheet. Preferably, for many applications, the system is also water vapor transmission resistant with the sheet or sheets of polymeric film or a coating providing the water vapor transmission resistance. The burn through and flame propagation resistant paper and/or polymeric film(s) may have major surface(s) coated with a heat sealable adhesive, e.g. for securing the laminated sheet to itself or another laminated sheet to form a bag or envelope for encapsulating insulation.

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.