An application of capacitance proximity sensor for identification of recyclable materials

Capacitive proximity sensor is often used in various industrial applications for contactless measurement of an object or target displacement and position. In this research, the capacitive proximity sensor is used for new alternatives in detecting recyclable materials specifically plastic and paper for aiding in the separation process. The detection of the sensor for this study is based on the permittivity values of each material where the sensor is adjusted according to the tested material permittivity. Several experiments have been conducted using different types of papers, plastics, and a combination of both materials for this study. At the end of the experiment, the sensor is able to detect a different type of paper and plastic. The sensor also able to detect the combination of both paper and plastic based on their difference in permittivity values. However, there are some limitations to this system such as the size, density, permittivity values, as well as the distance between both sensor and target are affecting the accuracy of the detection system causing the sensor to fail in identifying the samples