Manufacturing method of a preform for a turbomachine component made from composite material and corresponding component

A method for manufacturing a component made from composite material, the method comprising the following steps of:

• producing a preform with a fibrous reinforcement comprising a first fibrous portion and a second fibrous portion, the fibrous reinforcement being produced in one component, the first fibrous portion and the second fibrous portion being woven together in a first binding area and in a second binding area, the preform comprising an unbinding area delimited by first and second unbinding lines and in which the first and second portions are not locally connected to each other, the unbinding area being arranged between the first and second binding areas along a longitudinal direction L,
• injecting a matrix under pressure into an injection enclosure of an injection mold in which the preform is arranged,
• polymerizing the preform, and
• positioning a flexible bag which contains a fluid and which is arranged in the unbinding area between the first fibrous portion and the second fibrous portion before the step of injecting the matrix, the fluid applying an additional pressure to the preform during the step of polymerizing the preform,
• wherein the additional pressure in the flexible bag is monitored and controlled via a pressurizing device connected to the flexible bag.

A method for manufacturing a component made from composite material, the method comprising the following steps of:

• producing a preform with a fibrous reinforcement comprising a first fibrous portion and a second fibrous portion, the first fibrous portion comprising a first plurality of warp threads and weft threads woven together, the second fibrous portion comprising a second plurality of warp threads and weft threads woven together, the first and second plurality of warp threads and weft threads being woven together in a first binding area and in a second binding area, the fibrous reinforcement including an unbinding area located between the first and second binding areas, the first plurality of warp threads and weft threads being locally unconnected to the second plurality of warp threads and weft threads in the unbinding area,
• injecting a matrix under pressure into an injection enclosure of an injection mold in which the preform is arranged,
• polymerizing the preform, and
• positioning a flexible bag which contains a fluid and which, before the step of injecting the matrix, is arranged in the unbinding area between the first fibrous portion and the second fibrous portion, the fluid applying an additional pressure to the preform during the step of polymerizing the preform,
• wherein the additional pressure in the flexible bag is monitored and controlled during the polymerizing step via a pressurizing device connected to the flexible bag.