DEVELOPMENT AND ANALYSIS OF A PLASTIC SHREDDER
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Abstract
This study presents the design, modeling, and simulation of a dual-shaft plastic shredder for recycling polyethylene terephthalate (PET), high-density polyethylene (HDPE), and low-density polyethylene (LDPE) waste. The research addresses the challenge of plastic pollution in Nigeria through a simulation-driven engineering approach that eliminates costly physical prototyping.
Using SolidWorks 2025 for computer-aided design (CAD) modeling and finite-element analysis (FEA), a comprehensive digital prototype was developed and validated. The shredder features two counter-rotating 50 mm diameter EN8 steel shafts with 32 AISI D2 tool steel blades, driven by a 2.2 kW three-phase motor operating at 120 rpm. Design specifications target a hroughput
capacity of 40–60 kg/hr with output flake sizes of 10–15 mm.
Validation was performed through three complementary methods: mesh convergence analysis confirmed solution independence with less than 4.2% variation in maximum stress; analytical validation using classical beam bending and torsion theory yielded results within 11.7% of FEA predictions (analytical: 132.3 MPa; FEA: 148.2 MPa); and mesh quality assessment confirmed
computational reliability with Jacobian ratios between 1.0 and 4.982. Simulation results demonstrate structural integrity with a maximum Von Mises stress of 148.2 MPa (33% of EN8 steel yield strength), negligible shaft deflection of 0.003 mm, and a minimum factor of safety of 3.2, exceeding the design requirement of 2.0 by 60%. The study successfully demonstrates that computer-aided simulation can produce reliable, optimized recycling machinery designs suitable for local fabrication, contributing to sustainable waste management solutions in developing economies.
Using SolidWorks 2025 for computer-aided design (CAD) modeling and finite-element analysis (FEA), a comprehensive digital prototype was developed and validated. The shredder features two counter-rotating 50 mm diameter EN8 steel shafts with 32 AISI D2 tool steel blades, driven by a 2.2 kW three-phase motor operating at 120 rpm. Design specifications target a hroughput
capacity of 40–60 kg/hr with output flake sizes of 10–15 mm.
Validation was performed through three complementary methods: mesh convergence analysis confirmed solution independence with less than 4.2% variation in maximum stress; analytical validation using classical beam bending and torsion theory yielded results within 11.7% of FEA predictions (analytical: 132.3 MPa; FEA: 148.2 MPa); and mesh quality assessment confirmed
computational reliability with Jacobian ratios between 1.0 and 4.982. Simulation results demonstrate structural integrity with a maximum Von Mises stress of 148.2 MPa (33% of EN8 steel yield strength), negligible shaft deflection of 0.003 mm, and a minimum factor of safety of 3.2, exceeding the design requirement of 2.0 by 60%. The study successfully demonstrates that computer-aided simulation can produce reliable, optimized recycling machinery designs suitable for local fabrication, contributing to sustainable waste management solutions in developing economies.
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