Abstract: A method of manufacturing reinforcing fibers for a hydraulic binding material, to be used as an initial material for structural elements comprises the steps of providing a plurality of plant fibers and mineralizing the plant fibers. The mineralizing step includes opening the capilaries of the plant fibers, drying the same, impregnating the plant fibers with a lime water suspension, soaking the plant fibers with a formaldehyde-containing water glass solution, and intermediately drying the plant fibers between the impregnating and soaking steps. The plant fibers, after the drying, can be first impregnated with a lime water suspension, then dried, and after this soaked with a formaldehyde-containing water glass solution. It is also possible that the plant fibers, after drying, can be first soaked with a formaldehyde-containing water glass solution, then dried and after this impregnated with a lime water suspension.

Abstract: A method of manufacturing reinforcing fibers for a hydraulic binding material, to be used as an initial material for structural elements comprises the steps of providing a plurality of plant fibers and mineralizing the plant fibers. The mineralizing step includes opening the capilaries of the plant fibers, drying the same, impregnating the plant fibers with a lime water suspension, soaking the plant fibers with a formaldehyde-containing water glass solution, and intermediately drying the plant fibers between the impregnating and soaking steps. The plant fibers, after the drying, can be first impregnated with a lime water suspension, then dried, and after this soaked with a formaldehyde-containing water glass solution. It is also possible that the plant fibers, after drying, can be first soaked with a formaldehyde-containing water glass solution, then dried and after this impregnated with a lime water suspension.

Abstract: A succession of rectangular mats, consisting essentially of asbestos fibers or other filamentary material held together by a wet hydraulic binder such as cement, are conveyed by a series of trays through the gap between a pair of horizontal platens of a press. The upper platen carries a die for trimming the edges of a mat to be compacted, with the tray acting as an anvil. The trays are linked near their leading ends with two parallel, endless conveyor chains and have their trailing ends supported by rollers on rails which parallel the upper and lower runs of the chains and which form ramps for guiding these rollers onto the lower level downstream of the press and onto the upper level upstream of the press whereby each tray runs horizontally through the press between a loading and an unloading station.

Abstract: A mat of filamentary material is loaded onto a transport tray formed with an array of holes having a predetermined inside diameter. The transport tray is displaced between an upper and lower platen of a press. The upper press platen is provided with an array of downwardly extending pins having an outside diameter much smaller than the inside diameter of the holes in the transport tray, each pin being alignable with a respective transport-tray hole. The lower press platen is formed with an array of upstanding tubular nipples having an outside diameter smaller than the inside diameter of the transport-tray hole and an inside diameter corresponding to the diameter of the pin. Each nipple is arrayed beneath a respective hole in the transport tray and therefore beneath a respective pin so that as the upper platen descends the pin punches a hole in the mat using the nipple as a die. The upper end of each nipples lies in the plane of the upper surface of the transport tray.