Method of making hollow component of composite material using collapsable and reusable mandrel

A method of making a hollow product by curing a polymer matrix composite material and reinforcing fibers, comprising the following steps:

• providing a hollow mandrel of a thermosetting polymeric material having a glass transition temperature greater than or equal to 50° C., to be rigid at a room temperature with an original form, wherein the hollow mandrel further has a connector for pressurizing/depressurizing the hollow mandrel through a fluid;
• male mold laminating one or more layers of the polymer matrix composite material on the hollow mandrel;
• heating the hollow mandrel with a laminated layer to a curing temperature of the polymer matrix composite material, the curing temperature being higher than the glass transition temperature;
• pressurizing the hollow mandrel to maintain the original form during the heating;
• and
• depressurizing the hollow mandrel at a temperature higher than the glass transition temperature, wherein the hollow mandrel is more flexible than an ambient temperature, a depressurization causes a collapse or a contraction of a transversal dimension of the hollow mandrel to thus favor an extraction of the hollow mandrel from a product obtained with the curing of the polymer matrix composite material and a reuse of the hollow mandrel, and the hollow mandrel after the depressurization has a three-dimensional shape substantially equal to the original form.