Abstract: This process consists in making separately a set of individual plies consisting of rods impregnated with thermoplastic resin, in assembling several individual plies in order to form a rod bundle, in encasing at least the rods in at least one elastomer and in curing the injected elastomer. The ends of the rods have a rectangular shape, the rods having central parts joined to the ends by transition zones such that the surface area of the cross-section of the rods is constant and the length of the transition zone is very small. Cut pieces consisting of fibers, arranged on each side of the ends of the rods comprise fibers oriented at more or less 45 degrees to the longitudinal fibers of the rods.