Effect of resin infiltration on fumed silica-based thermal insulations

The thermal conductivities and the strengths of fumed silica-based thermal insulations prepared by the dry process and the resin infiltration method have been studied. Infiltration of the insulation samples prepared by dry processing of mixtures, consisting of fumed silica, ceramic fiber and a SiC opacifier, was performed to strengthen their binding structure. The high temperature thermal conductivities for the insulation samples obtained by the resin infiltration method were similar to those for the samples prepared by the dry process. On the other hand, the bending strengths for the former were superior to those for the latter. However, the resin-infiltrated samples were more brittle than the samples obtained by the dry process due to the occurrence of rigid bonding between the fibers and the infiltrated resin in the porous insulations. The thermosetting resin solution infiltration method appeared to be applicable to producing a dust-free fumed silica-based thermal insulation.