Method of making a fibrous preform and a fibrous preform thus obtained

A method of making a fibrous preform in carbon and fibres of a carbon precursor, comprising:

• a step a) of superposing at least two layers of carbon fibres and fibres of a carbon precursor according to a predefined superposition axis (Z) so as to form a multilayer body;
• a step b) of needle-punching via least one first needle-punching device said multilayer body in a needle-punching direction substantially parallel to said superposition axis (Z) to arrange at least part of the fibres parallel to the superposition axis (Z), so as to obtain a needle-punched multilayer body,
• an optional step c) of superposing with each other according to said superposition axis (Z) two or more of said needle-punched multilayer bodies, obtained separately by applying said steps a) and b),
• wherein said fibrous preform consists of a single, multi-layer, needle-punched body or two or more needle-punched multilayer bodies, superposed with each along said superposition axis (Z),
• wherein in said superposition step a) the multilayer body is made by superposing one or more layers of fibre in a non-woven form on one or more layers of fibre in a woven form,
• and wherein in said needle-punching step b) the first portion of the multilayer body to encounter the needles of said first needle-punching device consists of at least one non-woven layer in order to prevent the needles from directly engaging the fibres of the woven layers underneath and in such a way that the fibres to be arranged parallel to said superposition axis (Z) belong to said first portion consisting of at least one layer of fibre in non-woven form.
• further comprising a step d) of shaping the fibrous preform conducted by cutting the aforesaid fibre layers out of the preform,
• wherein the fibrous preform has a thickness between 10 and 80 mm,
• wherein the fibrous preform has a circular cross-section according to a plane orthogonal to the superposition axis and has a diameter between 200 and 600 mm, and
• wherein the fibrous preform has a density of between 0.4 and 0.7 g/cm3.