Abstract: A method for impregnating a fibrous preform by injection or infusion, comprising steps of: —providing a mold having at least two portions, said mold presenting an inlet orifice and a vent orifice placed on opposite sides of the mold; —placing a fibrous preform in a portion of the mold; —placing a thermo-expandable seal in a passage formed between an inside wall of the mold and the fibrous preform, said passage extending substantially along the direction (X) extending between the opposite sides of the mold; —closing the mold; —heating the mold so that the thermo-expandable seal expands and shuts off said passage; and—impregnating the fibrous preform with an impregnation material.

Abstract: A method for impregnating a fibrous preform by injection or infusion, comprising steps of: —providing a mold having at least two portions, said mold presenting an inlet orifice and a vent orifice placed on opposite sides of the mold; —placing a fibrous preform in a portion of the mold; —placing a thermo-expandable seal in a passage formed between an inside wall of the mold and the fibrous preform, said passage extending substantially along the direction (X) extending between the opposite sides of the mold; —closing the mold; —heating the mold so that the thermo-expandable seal expands and shuts off said passage; and —impregnating the fibrous preform with an impregnation material.