There are prepared cement plates with an incorporated reinforcement of fibrillated polymeric film in the form of an open net, by means of the continuous process accomplished on Hatscheck machines and comprising, in the order, the following operative steps:
a) unwinding one or more nets, each consisting of a plurality of fibrillated polymeric film layers, in an open form, from continuous reels, b) cutting such net into pieces having a length approximately equal to the circumference of the forming roll, or a length equal to the one of the entire net wound up by the roll for each plate, c) causing the net pieces to be impregnated by a cement mix optionally containing one or more wetting agents, d) depositing the net pieces onto a conveyor belt on which a cement mix layer containing from 15 to 100 parts by weight of water referred to 100 parts by weight of solids, and having a thickness at least equal to that of such net, e) subjecting the net, after its coming into contact with the cement layer, to percussion and vertical vibration actions, f) applicating vacuum in order to remove the water in excess and to raise the compactness degree between net and cement, g) winding the net-cement panel on a roll having a circumference equal to the length of the plate to be obtained, and simultaneous application of pressure, h) cutting the plate at the notch around which the ends of the net pieces are arranged, i) compressing the plate so cut.