Programmable Logic Controllers Used in Collecting of Metal Packaging Waste Cristina Gabriela Sărăcin, Marin Sărăcin, Călin Ciobanu, Silviu Drăguş Politehnica University of Bucharest cristina.saracin@upb.ro, marin.saracin@upb.ro, ciobanu.calin@gmail.com, silviu.dragus@gmail.com Abstract - In today’s society, it is more and more emphasized the necessity to collect and recycle the waste products resulted from human daily activities. In the process of waste products collecting and transporting, one of the main impediments is the efficiently using of storage space, reason why, we have proposed a solution for compaction of small non ferrous metal cans. We developed a hardware structure composed from the individual selecting and positioning system, compacting lever both electrically driven, and the optical sensors system for the positioning of the tin can plus, inductive sensors for stroke limitation of the compacting lever. Then, we have programmed the PLC able to control (the execution elements) and ensure the succession of the process states. This application could be extended to an urban recyclable waste products collecting system that would involve execution elements and sensors able to ensure a reliable, robust and efficient functioning. At this solution, supplementary functions might be added, functions necessary to monitor the system and also useful for people’s attraction to waste products recycling (e.g. by providing valued coupons). I. INTRODUCTION Waste recycling is a very important matter in today’s trend of preserving the natural values of our planet. The waste recycling system is based on collecting usable waste materials (metals, plastic, paper and glass), transportation to a suitable recycling plant and the technological recycling process. The main issue in this system is the decreased awareness of the society towards recycling waste and the lack of a wide spread collecting infrastructure. Another problem, this time economical, it is the waste of space during transportation. This paper will focus on these issues and it will show a possible solution to decrease pollution with slow and non biodegradable waste. The society awareness versus recycling can be increased by implementing a wide spread waste selective collecting system capable of compaction and storage of reusable materials. Another way that can aid this purpose is a rewarding system capable of offering vouchers proportional to the quantity of usable material introduced into the system. In the following part of the paper we will present an aluminum can compacting system model that uses a Schneider Twido PLC, optical and hall sensors and an automotive electric window mechanism. We will also present the programming logic installed on the PLC. This part will cover the ways of reducing the waste of space on storage and transportation. In the last part of the paper we will detail the possibility of implementing of a global recycling system, based on compacting and storage units spread around neighborhoods and cities. These units can be integrated into a large scale control and monitoring system, allowing to increase the global efficiency by scheduling pick-up times and by setting truck routes depending on the status of each unit. II. DEMONSTRATIVE AUTOMATION SOLUTION A. Functional description To serve the purpose of efficient space usage, we developed a demo model of metal packaging compaction. The system is composed of 5 main elements: - the can stacking bin; - the one can feed mechanism; - the guiding slide with brush for can alignment; - the fixed part of the compacting mechanism; - the compactor lever. Fig.1. System components. B. Construction The For ease of construction we chose readily available materials (mdf board, 2/2” wood, screws). The system automation is realized by a Schneider Twido Micro-PLC (TWDLCAA16DRF) [1].