Abstract: Provided is a composite for use as thermal insulation in high temperature environments. The composite comprises a layer of randomly laid and oriented, fine diameter, heat resistant fibers interlocked together into the form of a shape sustaining paper having a high fiber index and two lateral surfaces, said paper being compressed to produce a paper which has a thickness of from about 0.01 to 0.50 inch and a density of about 6 to about 30 lb/cu.ft. A high temperature resistant scrim is disposed upon each of the lateral surfaces of the paper, and a network of abrasion-resistant, high temperature-resistant threads is stitched through the scrim and the paper such that the scrim is mechanically locked to the paper by said threads. The network of threads and the scrim substantially retain the structural integrity of the said paper to maintain said paper in compression.

Abstract: A thermal insulation is formed by simultaneously spraying ceramic fibers and a binder at a surface to be covered. An aqueous binder is prepared prior to application to the fiber during the spraying operation. The binder includes an organic component which provides necessary wet and green adhesion to the substrate surface and wet and green cohesion to the newly formed lining prior to firing of the sprayed-on layer. The binder also includes an inorganic component which functions at and after exposure to a high temperature to secure the ceramic fibers to the substrate and to one another. Drying and firing of the layer develops strength in the inorganic binder. Known ceramic fibers such as alumina-silica amorphous fibers, alumina-silica-zirconia fibers, polycrystalline mullite fibers, alumina fibers, mineral fibers, or combinations thereof, and the like may be employed. The fiber may be precoated with the organic binder.

Abstract: A thermal insulation is formed by simultaneously spraying ceramic fibers and a binder at a surface to be covered. An aqueous binder is prepared prior to application to the fiber during the spraying operation. The binder includes an organic component which provides necessary wet and green adhesion to the substrate surface and wet and green cohesion to the newly formed lining prior to firing of the sprayed-on layer. The binder also includes an inorganic component which functions at and after exposure to a high temperature to secure the ceramic fibers to the substrate and to one another. Drying and firing of the layer develops strength in the inorganic binder. Known ceramic fibers such as alumina-silica amorphous fibers, alumina-silica-zirconia fibers, polycrystalline mullite fibers, alumina fibers, mineral fibers, or combinations thereof, and the like may be employed. The fiber may be precoated with the organic binder.