The invention relates to a method for producing composite components and comprises the steps: providing a moulded article core; and bringing at least a part of the moulded article core into contact with a polyurethane/polyisocyanurate reaction mixture, wherein a negative pressure p1 is applied during the contacting to at least the exterior of the moulded article core, at least temporarily. A positive pressure p2 is applied to at least the exterior of the moulded body core if a time t1 has elapsed since bringing the moulded article core into contact with the polyurethane/polyisocyanurate reaction mixture and/or a temperature T1 is achieved in the polyurethane/polyisocyanurate reaction mixture that contacts the moulded article core.