An apparatus for manufacturing an elongate composite element in undefined lengths, the composite element containing reinforcement fibers embedded in a matrix based on a composition containing a curable resin, including a vacuum chamber, rigid-walled inlet tubing, an impregnation chamber, rigid-walled transfer tubing between the vacuum chamber and the impregnation chamber, a sizing die and, downstream of the sizing die, irradiation tubes providing radiation in the ultraviolet-visible spectrum to prepolymerize the resin.