On-line post consumer package identification by NIR spectroscopy combined with a FuzzyARTMAP classifier in an industrial environment

An optical setup consisting of a high-throughput near-IR (NIR) spectrograph with an InGaAs-array detector and specially designed collection optics is used to record spectra from post consumer packages located on an industrial conveyor belt. NIR spectra of packages of different polymers (PE, PET, PP, PS, and PVC) and of a cardboard/plastic compound are recorded between 900 and 1700 nm with 6.3-ms integration time, The visual distinction between the spectra is demonstrated by aid of principal component analysis (PCA) plots. The spectra are further classified by a FuzzyARTMAP neural network. The method is assessed to be suitable for on-line identification under industrial conditions.