Incombustible electromagnetic wave absorber made of nonwoven ceramic fibers

Incombustible electromagnetic wave absorbing material made of incombustible ceramic fibers are proposed in this paper. The hollow-type pyramids were experimentally fabricated by means of a nonwoven fabric production process and their flammability and electromagnetic wave absorption were investigated. By the tests using high-power microwaves and gas burner flames, it was confirmed that the material shows extremely good flame retardance. Also, it was confirmed that pyramids made of this material had good electromagnetic wave absorption characteristics. The pyramids made of this material are able to be used as absorbers for anechoic rooms instead of conventional plastic pyramids such as urethane foam or polystyrene pyramids, which are combustible.