Evaluation of the Spectral Variance within the same Plastic Classes
The majority of the plastic waste produced is thermally recycled, i.e. incinerated. The reason for this is that the plastics often cannot be properly identified. Multispectral imaging enables clear classification. So-called camera arrays are used for this purpose; filters in different wavelengths in the infrared range are fitted in front of the individual cameras. As plastics reflect and absorb long-wave light differently due to their different carbon chain structures, different materials appear in different colors. However, due to different fabrication methods their variances may differ.
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