The monograph considers the main technological and design aspects of computer-aided design of single- and double-screw machines for processing polymeric and other materials. Particular attention is paid to the modeling of mixing and dispersing processes in the working areas of double-screw machines. Engineering methods of optimal design for solving problems of minimization of technological power, mass and length of working bodies are given while ensuring the specified quality of products . The book is intended for engineering and technical workers involved in the design and operation of extrusion equipment for the processing of polymer materials . It can be useful for graduate students, undergraduates and senior students specializing in the processing of plastics and elastomers.