Method for producing parts made of composite material having an organic matrix

A method for producing a part made of composite material having an organic matrix, comprising:

• arranging a fibrous preform of the part to be produced in a mold comprising an impregnation chamber by resting a first face of the fibrous preform on a support surface of the impregnation chamber, the impregnation chamber being closed by a flexible membrane placed facing a second face of the fibrous preform, said flexible membrane separating the impregnation chamber from a compaction chamber,
• injecting a compaction fluid into the compaction chamber so as to apply a compaction pressure to the flexible membrane,
• injecting a resin into the impregnation chamber from a lateral face to the first face of the fibrous preform in a direction parallel to the surface of the membrane so that the resin impregnates the fibrous preform and polymerizes to form an organic matrix within the fibrous preform, the compaction pressure being maintained on the flexible membrane before and during the injection, wherein the compaction pressure is further increased during the polymerization of the resin.