Method and device for manufacturing a composite part with a complex shape

A method for making a three-dimensional composite part with a thermoplastic matrix and continuous reinforcement, comprising:

• obtaining a pre-impregnated fibrous preform of a polymer forming the thermoplastic matrix corresponding to a shape of the three-dimensional composite part by a three-dimensional knitting;
• placing the preform between a paired punch and die of a tooling, defining a sealed closed cavity between the paired punch and die;
• closing the tooling so as to apply a first pressure to the preform;
• bringing the sealed closed cavity to a melting temperature of the polymer impregnating the preform, referred to as an impregnation polymer, by maintaining the first pressure;
• cooling the sealed closed cavity comprising the preform to a temperature suitable for demolding while maintaining a second pressure;
• opening the sealed closed cavity and demolding the three-dimensional composite part.