JUSTIFICATION OF THE CHOICE AND EXPERIMENTAL STUDY OF A SHREDDER FOR CRUSHING PETG PLASTIC WASTE FORMED DURING 3D PRINTING

Abstract

The article presents the results of a study of the shredding process of PETG plastic waste generated during FDM 3D printing with the aim of its further reuse as secondary raw material for 3D printers equipped with a screw extruder. The relevance of the research is driven by the need to reduce the volume of polymer waste, improve the efficiency of local recycling, and establish a closed-loop technological cycle in additive manufacturing. As the object of the study, PETG plastic waste of complex morphology was selected. Such waste is characterized by strip-like, contour, and elastic elements, which complicate its direct feeding into extrusion equipment and require preliminary mechanical preparation. For this purpose, a single-shaft mini-shredder was used, whose design ensures low-speed operation, high torque, and stable destruction of the polymer material without critical overheating or entanglement on the working components. The research consistently describes the loading of waste into the receiving hopper, shredding by the knife mechanism, and the accumulation of the processed material in the collection container. It was shown that the selected shredding scheme provides stable formation of fine- and medium-sized particles suitable for further processing. After shredding, sieve analysis was carried out, and as a result, the fraction meeting the requirements for feedstock for a screw extruder of a 3D printer was separated. Particles that did not meet the specified size criteria were returned for repeated shredding, which made it possible to implement a closed cycle for the preparation of secondary material. The obtained results confirm the feasibility of using a single-shaft shredder for preparing PETG waste for re-extrusion and demonstrate the practical potential of applying this approach in polymer recycling technologies for additive manufacturing.