During the production of fibre-reinforced plastics in the injection moulding process, especially those with structure-bearing fibre composite inserts and inserts („overmoulding“), various faults and deviations can occur which impair the functionality and service life or lead to failure under load. For example, in addition to unintentional vacuoles, inhomogeneous distribution and alignment of the short fibres can occur or the connection of the inserted reinforcement structures to the injection moulding compound and their position can be faulty. Furthermore, geometrical deviations can occur due to mould wear or the insertion of too little plastic. In order to identify these quality deviations in the manufacturing process and to be able to carry out a non-destructive component inspection, the process and the component are monitored with the help of acoustic emissions.