| Abstract [eng] |
The damage caused by plastic to nature is a very pressing problem, as various plastic waste accumulates in the wild and in the oceans, which harms animals and the ecosystem. In order to reduce plastic pollution, it needs to be recycled, but first it must be shredded. Shredding is done using shredders, and recycled plastic can be reused in various industries. Recycled plastic is widely used in the production of filaments for 3D printing. In this study, the mechanical properties of Markforged's thermoplastic "Onyx" and Kevlar-reinforced composite were first investigated, and they were described as a shreddable material during numerical modeling. Although there have been many studies on plastic shredding, improving shredding efficiency is the most important indicator of economic efficiency, and it is known that shredder efficiency is directly dependent on the geometry of the shredding blade. Therefore, in this study, the dependence of shredding efficiency on blade geometry was investigated using the Ansys 2023 R1 numerical modeling program. Efficiency was determined by calculating the work done during shredding, i.e., by calculating the area under the force-deformation curve. Lower values of work done indicate a more efficient blade geometry. During the study, numerical modeling was performed for milling and cutting cases. The results showed that the efficiency of milling depended directly on the value of the external (clearance) angle: the larger this angle (with respect to the shredded sample), the more efficient the shredding blade geometry. During numerical modeling of cutting operations, the opposite effect of the internal (rake) blade angle on the value of work done was determined. The smaller the grip angle (with respect to the shredded sample), the more efficient the blade geometry. |
