Wool, cellulosic, cellulose acetate, viscose, polypropylene, polyamide, such as polycaprolactam, polyhexamethylene adipamide and polyhexamethylcne sebacamide, polyacrylonitrile and/or polyethylene tercphthalate may for example be used. impregnation of the webs of fibrous material is preferably carried out in such a way that 50 to 500 parts by weight of monomers (including the high polymeric plasti