Upgrading of the extruder screw design for secondary polymers processing

Some methods of polymeric materials waste recycling have been analyzed in this paper and the prospects of the theory development as well as extrusion technology and co-extruding processes have been shown. The purpose of this work was an analytical research of the backpressure in different sectors of the extruder when the pressed bulk moves through it and improvement of the working conditions of the device to fit the technology of plastics waste processing. The recommendations as to the calculation of the required design parameters of the screw, as the main structural element of the extruder, have been developed as a result of research, which makes it possible to achieve better processing of the pressed bulk under specified temperature and rate conditions due to the levelling of the backpressure and pumping effect in all sections of the device. The proposed upgrading provides productivity levelling in all sections of the extruder, which excludes intermittent work, breaks and thickness unevenness of the manufactured products. Through the analytical consideration of the extrusion process theory in various sectors of the extruder, which are characterized by different temperature conditions and the pumping effect, the equation for calculating of the auger screw inclination angle for each sector of the extruder has been obtained which makes it possible to improve the machine design. The example of the calculation of the screw design parameters for physical and chemical characteristics of low-pressure polyethylene under the conditions of its processing has been furnished