Classification of commercial plastics using hyperspectral long wave infrared emission imaging

Abstract: The long wave infrared regime of the electromagnetic spectrum has been used to identify and classify different types of plastics. This work presents an early-stage version of an industrial hyperspectral camera, which is based on a low-order scanning Fabry-Pérot interferometer and is sensitive to radiation with wavelengths from 8 µm to 15 µm. As a demonstration, the setup is used to record interferograms and distinguish between twelve types of common plastics heated to 60 °C. The plastic identification is based on a nine-component principal component analysis model combined with k-nearest neighbors. The resulting model shows a micro precision of 90 % and a macro specificity of 99 %, being able to classify all tested plastic types except ABS.