Monobloc preform and blade for turbo machine

1. A fiber preform for a turbine engine blade or vane, the preform obtained by single-piece three-dimensional weaving, comprising:

a first longitudinal segment suitable for forming a root;

a second longitudinal segment extending the first longitudinal segment and suitable for forming an airfoil portion;

a first transverse segment extending transversely from a junction between the first and second longitudinal segments and suitable for forming a first platform; and

a second transverse segment extending transversely from the junction between the first and second longitudinal segments extending the first transverse segment and going away therefrom, suitable for forming a second platform;

wherein the first transverse segment is formed by at least a portion of a free tail, said free tail and said second longitudinal segment being woven jointly in non-interlinked manner, said non-interlinking beginning at the junction between the first and second longitudinal segments; and

wherein the second transverse segment and said first longitudinal segment are woven jointly in non-interlinked manner, said non-interlinking terminating at the junction between the first and second longitudinal segments.

2. The fiber preform according to claim 1 , wherein a number of layers of yarns, and thus the thickness, of the second longitudinal segment varies.

3. A blade or vane for a turbine engine, the blade or vane comprising:

a root;

an airfoil portion; and

a platform extending transversely from the airfoil at a junction between the root and the airfoil portion;

said blade or vane being made as a single piece of composite material by means of the fiber preform according to claim 1 , said preform being shaped in a mold and embedded in a matrix.

4. An intermediate casing for the turbine engine, the casing comprising a plurality of vanes according to claim 3 arranged angularly between an inner hub and an outer shroud.

5. The turbine engine, comprising at least one intermediate casing according to claim 4 .

6. A turbine engine fan, comprising a plurality of blades according to claim 3 .

7. A turbine engine, comprising at least one fan according to claim 6 .

8. The turbine engine, comprising at least one blade or vane according to claim 3 .

9. The blade or vane according to claim 3 , wherein said matrix comprises an organic material.

10. The fiber preform according to claim 1 , wherein the free tail and the second longitudinal segment are woven jointly in non-interlinked manner with a first non-interlinked plane therebetween, and

wherein the second transverse segment and the first longitudinal segment are woven jointly in non-interlinked manner with a second non-interlinked plane therebetween, the second non-interlinked plane is being closer to a free end of the first longitudinal segment than the first non-interlinked plane in a longitudinal direction of the fiber preform.