Automatic high-speed smartphone disassembly system

Abstract

Given the increased amount of waste and the high concentration of valuable metals in smartphones, the need for the material recycling of smartphones is increasing. However, developing an automatic high-speed disassembly system faces three difficulties: detaching the batteries secured with adhesive, the differences in the internal structures of smartphones with respect to manufacturers and types, and the need for preferential breakage that disables the screws without damaging the battery. In the present study using experiments and simulations, these difficulties were overcome by freezing the smartphones to disable the battery adhesive, performing internal structure analysis using X-ray scanning and deep learning, and ensuring preferential breakage by disabling the screws by press cutting and then simultaneously striking the top and bottom of the smartphone. In the end, a fully automatic high-speed disassembly system was developed. Currently, the system's throughput is approximately 600 units per hour, with a disassembly success rate of 88.3 % on average, as experimentally validated using 1213 smartphones of various types and manufacturers. The disassembly success rate varied widely with the smartphone manufacturer. Thus, in combination with the current sensing technology that enables automatic determination of the manufacturer, recycling plant operational strategies can be designed. For example, when the smartphones of 15 designated manufacturers were processed, 97 % of them were processed, and roughly 90 % of the processed smartphones were successfully disassembled.