Development and Performance Evaluation of an Improved Waste Plastic Shredding Machine

Abstract

An energy-efficient plastic shredder was developed to recycle waste plastic, focusing on energy conservation and environmental sustainability, thereby reducing pollution and landfill space exhaustion. This paper presents a 60 kg plastic shredding machine designed and fabricated to address the environmental impact of plastic waste. The machine uses a combination of belt and gear drives, enhancing energy utilization. A 5.0 hp electric motor-powered machine was used to shred 10kg of polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), and polypropylene (PP) each at various sieve sizes of 10 mm, 7.5 mm, and 5.0 mm, determining its shredding time, specific mechanical energy, and recovery efficiency. The flakes of waste plastic were weighed and collected for testing. The percentage retention of PET, HDPE, PVP, and PP flakes was determined by analyzing the efficiency of shredding, recycling, machine efficiency, and fragments in reducing plastic waste of size 10 mm² x 10 mm². The shredder achieved an optimal performance of 53.6% in shredding PET and 52.3% in HDPE, with 95% and 83% recovery efficiency, and reduced specific mechanical energy by 1% within 2 minutes. PP, with 48% shredded, reduced PVC by 61% with a 10 mm sieve size, achieving 94% recovery efficiency and 100% increased throughput to 238.1 kJ/kg. The shredder demonstrated exceptional performance in shredding PET and HDPE, with an average particle size of 6.29 mm², achieving 95% recovery efficiency and reducing specific mechanical energy within 2 minutes. The low-cost, efficient, and user-friendly machine enhanced recycling activities, promoted technology transfer, and improved waste processing for local entrepreneurs.