Abstract: A method for preparing a mixture of plastics that are incompatible in view of processing in a shaping process, such as by extrusion, characterized by providing an initial mixture of a first part which is essentially composed of uniform material in view of a group of chemical substances, and a second part, separating the first part from the second part, processing the second part to enlarge or modify the surfaces of the constituents of the second part, then recombining the first and second parts into a final mixture, with the second part being essentially uniformly distributed in the first part of the mixture so that an essentially uniform product will occur when processing the mixture in a shaping process. The invention is also directed to a mixture manufactured by this method.