This work presents a study on the preparation of recycled wood fibre using different types of grinding equipment. It is also concerned with fibre preparation in an aerodynamic environment and describes the possibilities of using the material in various finished products. The authors used bio-rejects from the production of composite board materials, e.g. fibreboard and medium density fibreboard (MDF), in the form of lump scraps, as research material. In order to evaluate the efficiency of woodfibre waste recycling using various grinding equipment, the authors analysed the qualitative characteristics of the resulting semi-finished woodfibre materials and mathematically calculated the primary technological and design parameters of the grinders. The results of the study provide a scientific basis for the efficiency of a fundamentally new recycled wood fibre dry preparation method and system.