The present invention relates to a process for producing composite profiles comprising at least two metal shells which are joined by struts comprising a thermoplastic material and a core comprising rigid polyurethane foam, which comprises introduction of the starting components of the rigid polyurethane foam into a hollow space formed by the metal shells, with the rigid polyurethane foam being formed, and subsequent application of a surface coating to the outer surface of the composite profile by means of a powder coating or baking enamel, where the rigid polyurethane foam is obtained by reaction of the following components: A) at least one polyisocyanate, B) at least one polyfunctional compound which is reactive toward isocyanates, C) one or more blowing agents comprising at least formic acid, D) optionally one or more flame retardants, E) optionally one or more catalysts and F) optionally further auxiliaries or additives, wherein the starting components of the rigid polyurethane foam do not comprise any inorganic fillers.