Analysis of the Effect of Air Pressure Variations on the Performance of Pneumatic-Based Automatic Can Waste Pressing Machine Reviewed from the Press Force

Abstract

This study analyzed the effect of air pressure and mold construction on the performance of an automatic pneumatic can press machine in reducing aluminum can volume. The research was motivated by the increasing amount of can waste that can affect environmental cleanliness. An experimental method was used with air pressures of 3.5, 4.0, 4.5, and 5.0 bar. Piston stroke distances were set at 0.008 m and 0.010 m. Three mold types were tested: flat, inward-hole (0.00050 m depth), and concave (0.00070 m depth). The experiments involved three beverage cans: Nescafe (diameter 0.05064 m), Lasegar (diameter 0.06124 m), and Kratingdaeng (diameter 0.06541 m). The observed parameters were final can height, piston movement time, and volume reduction. The results showed that higher air pressure generally increased the pressing force, resulting in greater can deformation and volume reduction. For Nescafe cans with a flat mold, the final height decreased from 0.01600 m at 3.5 bar to 0.00925 m at 5.0 bar. For Lasegar cans with the inward-hole mold, the final height ranged from 0.01000 m to 0.01050 m. For Kratingdaeng cans with the concave mold and a 0.010 m piston stroke, an anomaly occurred at 4.5 bar, where the final height reached 0.01900 m, higher than 0.01300 m at 4.0 bar. This result was likely caused by buckling during compression. The highest volume reduction, 93.4%, was achieved by Nescafe cans using a flat mold at 4.5 bar and a 0.010 m piston stroke.