In order to recycle glass fiber/fiber fabric production waste material, such as a material used in the manufacturing of rotor blades for wind turbines, and preferably where the material is bendable or flexible and reinforced in a plurality of layers in one or more directions in planes that are parallel with the surface of the material and stitch bonded together, the material is mechanically processed involving a size reduction of the material into shorter fiber length, in order to convert the material into one or more substantial pure glass fiber products. In this way it is possible inter alia to further process the material and create materials such as acoustic insulation wool, and chopped glass fiber strands.