Design of Used PET Bottles Crushing Machine for Small Scale Industrial Applications

Abstract

In this study, PET bottles crushing machine was designed to convert used PET bottles into shreds readily available for recycling. Preliminary tests and mechanical factors were extensively evaluated on the conceptual designs to ensure that the concept with optimal performance and efficiency is selected. Experimental test was conducted to determine the power required to overcome the shear stress of the PET bottles and it was found out that 10hp was the power required. With a set of crushing forces ranging from 1000-3000N, Finite Element Analysis (FEA) was performed for five different scenarios on the 201 Annealed Stainless Steel cutting blade to inspect the material response to stresses and corresponding deformations. The maximum von Mises stress was 2.089e+006N/m^2. The material yield strength was found to be 2.92e+008 N/m^2, and applying a force of 3000N on the cutting blade produced a maximum displacement of 2.220e-003 mm. This therefore imply that the material will not deform or fail under a force equal to or below the material yield strength value. Tests carried out on the final machine design indicated efficiency of 82.2% which is only 6% less than the efficiency of existing ones.