TY - GEN

T1 - Classification of plastic waste packaging multilayer films using handheld near-infrared (NIR) spectrometer

AU - Stipanovic, Hana

AU - Arth, Patrick

AU - Koinig, Gerald

AU - Tischberger-Aldrian, Alexia

PY - 2023/10

Y1 - 2023/10

N2 - The amount of packaging waste in the EU is constantly increasing. To achieve the EU's plastic packaging targets from Directive (EU) 2018/851 of the European Parliament and of the Council of 30 May 2018 Amending Directive 2008/98/EC on Waste of a 55% recycling rate by 2030, the existing technologies of waste plastic classification require further development. Multilayer packaging films are imposed as one of the main challenges when separating waste plastic. They pose a challenge because of both material composition and their low material thickness. Demand for separating different multilayer films arises from the understanding that in the recycling process presence of different polymers lowers the purity of input material and, eventually, the quality of recycled material. Therefore, there is a need to develop a fast and robust on-site method for classifying multilayer plastic materials. Near-infrared (NIR) handheld spectrometers are imposed to fulfil the requirements. NIR handheld spectrometers are a cost-effective and non-destructive way to characterise waste plastic materials and have been proven to classify different monolayer plastic polymers successfully. However, their suitability for multilayer materials has not yet been determined. The tests were run to demonstrate the prospect of utilising a NIR handheld spectrometer to classify multilayer films. The used samples comprised the four most commonly found multilayer fractions in plastic packaging waste: PP-PE, PET-PE, PA-PE and PET-PP. Prepared samples were separated into two groups: one group used as a training set consisting of 70% of the samples, and another group used as a test set of 30%. Measurements were made in the NIR region of 1600-2400 nm. Spectra of the training set were used for creating a method tested using a test set. Spectra further went through pre-processing methods before performing chemometric and classification methods, PCA and KNN. The results of the test set classification show a high classification level, as well as KNN classification results. Overall results show promising outcomes for NIR handheld spectrometer to classify multilayer waste films.

AB - The amount of packaging waste in the EU is constantly increasing. To achieve the EU's plastic packaging targets from Directive (EU) 2018/851 of the European Parliament and of the Council of 30 May 2018 Amending Directive 2008/98/EC on Waste of a 55% recycling rate by 2030, the existing technologies of waste plastic classification require further development. Multilayer packaging films are imposed as one of the main challenges when separating waste plastic. They pose a challenge because of both material composition and their low material thickness. Demand for separating different multilayer films arises from the understanding that in the recycling process presence of different polymers lowers the purity of input material and, eventually, the quality of recycled material. Therefore, there is a need to develop a fast and robust on-site method for classifying multilayer plastic materials. Near-infrared (NIR) handheld spectrometers are imposed to fulfil the requirements. NIR handheld spectrometers are a cost-effective and non-destructive way to characterise waste plastic materials and have been proven to classify different monolayer plastic polymers successfully. However, their suitability for multilayer materials has not yet been determined. The tests were run to demonstrate the prospect of utilising a NIR handheld spectrometer to classify multilayer films. The used samples comprised the four most commonly found multilayer fractions in plastic packaging waste: PP-PE, PET-PE, PA-PE and PET-PP. Prepared samples were separated into two groups: one group used as a training set consisting of 70% of the samples, and another group used as a test set of 30%. Measurements were made in the NIR region of 1600-2400 nm. Spectra of the training set were used for creating a method tested using a test set. Spectra further went through pre-processing methods before performing chemometric and classification methods, PCA and KNN. The results of the test set classification show a high classification level, as well as KNN classification results. Overall results show promising outcomes for NIR handheld spectrometer to classify multilayer waste films.

KW - waste classification

KW - plastic waste

KW - multilayer films

KW - NIR handheld

KW - plastic recycling

M3 - Conference contribution

BT - Sardinia 2023 Proceedings

T2 - Sardinia 2023 - 19th International Symposium on Waste Management and Sustainable Landfilling

Y2 - 9 October 2023 through 13 October 2023

ER -