Apparatus for uniformly distributing a disintegrated fibrous material on a fiber layer forming surface in plants for the dry forming of paper

The formation head comprises a casing of substantially rectangular configuration in plan view provided with a perforated flat bottom-screen or sieve, and with a top wall having a number of openings communicating with the atmosphere. Opening into said casing is a conduit for feeding a flow of air-fluidized disintegrated fibers. A plurality of spaced parallel, horizontal rollers are rotatably mounted close to the perforated bottom of the said head structure. The said rollers are supported so as to be translated parallely to the bottom of the said structure. The said rollers are each provided with a plurality of peripheral radial needles. At a short distance from the bottom of the casing, parallely thereto, a moving web is mounted, cooperating with an underlying vacuum chamber onto which the screened fibers are deposited in a thin layer (S).