The present invention relates to a process for producing a molding made from blowing agent-containing foam comprising at least one fiber (F), wherein the at least one fiber (F) is partially introduced into the blowing agent-containing foam. The two ends of the respective fiber (F) that are not surrounded by the blowing agent-containing foam thus project from one side of the corresponding molding. The present invention also provides the molding as such. The present invention further provides a panel comprising at least one such molding, produced by the process according to the invention, and at least one further layer (S1). The present invention also provides for the production of the panels of the invention and for the use thereof, for example as a rotor blade in wind turbines.