Method and system for the manufacture of annular fibrous preforms

A method of manufacturing an annular fiber preform, the method being characterized in that free fibers are deposited on a rotary support turntable by means of a hollow deposition cone having a conical outer wall surrounding a chamber and pierced by multiple perforations, the cone being disposed above the turntable and having a generator line extending in the vicinity of the top surface of the turntable and substantially parallel thereto in a zone for depositing fibers on the turntable, the fibers being deposited on the turntable by a process comprising the steps which consist in:

• bringing fibers to the outer surface of the perforated wall of the cone in a cone feed zone that is remote from the deposition zone on the turntable;
• holding the fibers against the outer surface of the perforated wall of the cone by establishing suction inside the chamber, thereby producing suction through the perforations in the wall of the cone;
• transporting the fibers from the cone feed zone to the zone for deposition on the turntable by rotating the cone about its axis;
• and
• ceasing to hold the fibers on the cone in the deposition zone by localized interruption of the suction through the perforations in the wall of the cone, at least in said zone, so that the transported fibers are deposited on the turntable which is driven in rotation about its own axis simultaneously with the cone rotating.