One of the applications of the silicone rubber coated fiberglass fabric is electrical insulation products. The silicone coatings can be used as electrical insulators, and they are the most successful materials for this usage. Electrical insulators are formed by a series of continuous ultrasonically welded seam. For example, a tubular insulator is formed by continuously moving the strip and a strip of dissimilar material. The strip is a cylindrical structure which has its own axis. The direction of elongation and the motion of the trips are the same. By this connection, they form a multiple layer sleeve with a seam being ultrasonically formed.