How can Raman spectroscopy support optical detection systems for plastic identification in complex recycling streams?

Binary sorting between ABS and PS polymers is a challenge for the recycling industry, particularly when black pigments are present. We propose the sequential application of a hyperspectral sensor in the short-wave infrared (HSI-SWIR) and a Raman sensor unit (532 nm excitation). HSI-SWIR created maps which allowed for initial spectral and spatial assessment of the material stream and Raman point measurements enabled specific identification of ABS (white and black) and PS. The operationalisation of this sensor network requires advanced solutions for fast data acquisition, processing and classification.