The Effect of Environmental Aging on Intumescent Mat Material Durability at Low Temperatures

Mat material durability data in the form of fragility curves were generated in a critical temperature region for three intumescent mat materials considered for low temperature converter applications. The mat materials were tested in a tourniquet wrap converter configuration employing a cylindrical ceramic substrate. Prior to developing durability data for these mat materials, the test items were subjected to various environmental thermal and/or vibration aging conditions. Mat material fragility data were generated in terms of the dynamic force required to impose prescribed differential motion between the can and substrate, thereby, subjecting the mat material to a dynamic shearing like that expected during resonant excitation. As expected, it was found that the mat material capacity to resist shearing deformation decreased when the test samples were subjected to 36 hours of low temperature thermal cyclic aging. However, when the samples were subjected to 36 hours of vibration aging, the mat material capacity to resist shearing deformation increased dramatically for two of the test materials. The environmental aging conditions imposed on the mat materials are discussed and corresponding durability data are presented.