RETRACTED: Automatic Sorting of Solid Black Polymer Wastes based on Visual and Acoustic Sensors (Retracted Article)

In solid waste treatment plants the waste gets crushed, classified and sorted. Among these processes the sorting is the determining step for recycling and reuse. Sensor based sorting technology has been developed and utilized for sorting of polymer ingredients in waste mixtures. One of the still remaining problem lies within the sorting of black polymer materials like plastics and rubbers which are very difficult to be sorted by conventional visual sensors. In this paper a new multi-sensor technology for black plastics sorting by using impact acoustic was introduced, since different plastics have different structures and acoustic emissions when an impact is given. A pilot multi-sensor sorting system which consists of a 3-dimensional visual sensor and an acoustic sensor was also built for this research and 3 kinds of plastics were tested. During the experiments the sizes of tested plastic pieces were measured by visual sensor and the acoustic emissions were captured by acoustic sensor. The signal processing and feature extraction of the visual and acoustic signals were realized by virtual instruments. The extracted features were used for classification of different plastic materials. Feature extraction by using power spectrum of each impact yield good result. This research provides a new approach for automatic sorting of black plastic polymers. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Organizers of 2011 International Conference on Energy and Environmental Science.