a fibrous web useful for compression molding stiff , board - like structural substrates for panels is formed of a thoroughly intermixed blend of wood fibers and synthetic plastic fibers with a dry , powdery , resinous molding material uniformly disbursed throughout the blend . the mass of intermixed fibers and resinous molding material is covered with a thin , randomly oriented , fibrous scrim material and the fibers are locked to each other and to the scrim mechanically by means of needling them together . the web is formed by drying wood fibers , spreading them into a mat , covering the mat with the synthetic fibers and thereafter , dispersing the fibers through a dispersion chamber and re - collecting and re - spreading them into a web by means of a picker roller , gravity dropping a powdery resinous molding material upon the web , redistributing and intermixing the fibers and the molding material with a second picker roller , applying the scrim and needling the combined scrim and fiber web for mechanically interlocking them .