This paper discusses the design steps, working principle and structure of a small-scale thermo-plastic extrusion machine that will be used in a laboratory at the Sapientia University. The aim of the laboratory is to present the polymer processing technologies by student-built machines and to stress the importance of plastic recycling. In order to recycle plastic parts a grinding process is necessary, followed by extrusion. During the process the machine melts the polymer and extrudes a filament that can be converted into granulates or used as it is. The structure of the extrusion machine is rather similar to that of a commercial one, however it focuses on presenting the manufacturing principles and cost effectiveness.