Using Handheld NIR Spectrometry in the Classification of Polyolefin Films

Plastic waste and its management are major environmental challenges. Near-infrared (NIR) spectroscopy has emerged over time as a cutting-edge technology for classifying and separating plastic waste, particularly polyolefins, which dominate the packaging industry. While NIR spectroscopy has proven effective for sorting polyolefin plastics, multilayer films present additional hurdles. One challenge is the difficulty of classifying thin films, which produce weaker spectra. The use of reflective backgrounds like copper or aluminum can enhance spectral quality, increasing the accuracy of identification. A recent study explored how different reflective materials—such as copper, aluminum, gold, silver, Teflon, and white tile—affect the classification of multilayer polyolefin films. By using a handheld NIR spectrometer, researchers aimed to optimize the classification process, making it possible to differentiate between polyolefin and non-polyolefin films with a single measurement, even for thin films. Their findings could contribute to better recycling processes, helping to address the growing plastic waste problem. Spectroscopy spoke to Hana Stipanovic, corresponding author of the paper resulting from this study, about this research.