Designing of reverse vending machine to improve its sorting efficiency for recyclable materials for its application in convenience stores.

Plastics have multiple applications in disposable products, high-end technology parts, etc., owing to their functionality and manufacturing flexibility. However, their increased use has increased the global proportion of plastic wastes, which creates a serious environmental issue, thereby, creating a demand for plastic waste management techniques. Improving the efficiency of resource recovery by appropriate sorting and collection systems is necessary for successful plastic recycling. Therefore, this study proposed a three-step optimization process of a reverse vending machine (RVM), a small automatic recyclable waste sorter/collector system, for acquiring an optimal design and enhanced efficiency. The RVM system categorized recyclable wastes as plastics, glass, and cans using barcode, vision, and near infrared sensors. The average sorting efficiency of the designed RVM system was 94%, 95% for polyethylene terephthalate, and 98% for glass bottles. Therefore, the RVM system, with the average sorting efficiency of 95%, is suitable for application in on-site sorting in small-sized areas, such as convenience stores, which generate wastes on a small scale.