Department of Processing and Recycling, RWTH Aachen University, Aachen, Germany.
Waste Manag Res. 2021 Sep;39(9):1210-1213. doi: 10.1177/0734242X211003969. Epub 2021 Apr 9.
Bioplastics are developed to replace oil-derived plastics due to the high consumption of oil and related environmental impacts of oil-derived plastics. It was predicted that bioplastics can potentially replace 94% of conventional plastic production. With their increasing market share, more bioplastics will end in conventional post-consumer plastic waste streams. Although part of bioplastics is biodegradable and could be biologically decomposed, mechanical recycling achieves higher ecological benefits mainly because of its low pollution risk and the reduction in requirement for virgin feedstock. In this study, the classification of lightweight packaging waste with inflow of bioplastics, more specifically polylactic acid (PLA), was analysed with near-infrared spectroscopy to evaluate the influence of bioplastics on sorting processes of conventional plastics. Besides which, the sortability of PLA was determined through investigating the physical and the spectroscopic characteristics of both non-degraded and degraded PLA. The results show that the classification of all the materials was possible with a pixel-based accuracy of higher than 97.4% and PLA does not influence the sorting process of conventional plastics regarding detection and classification. Furthermore, the sorting of PLA from post-consumer waste is possible, which makes further recycling theoretically achievable.
由于石油消耗量大以及石油衍生塑料对环境的影响，生物塑料被开发出来以替代石油衍生塑料。据预测，生物塑料有可能替代 94%的传统塑料产量。随着生物塑料市场份额的增加，更多的生物塑料将最终进入传统的消费后塑料废物流中。虽然部分生物塑料是可生物降解的，可以被生物分解，但机械回收主要因为其污染风险低和对原生原料需求减少，而实现了更高的生态效益。在这项研究中，使用近红外光谱法对含有生物塑料（特别是聚乳酸（PLA））的轻质包装废物进行分类，以评估生物塑料对传统塑料分类过程的影响。此外，通过研究非降解和降解 PLA 的物理和光谱特性，确定了 PLA 的可分选性。结果表明，所有材料的分类都可以通过基于像素的准确率高于 97.4%来实现，并且 PLA 不会影响传统塑料的检测和分类过程。此外，从消费后废物中分拣 PLA 是可能的，这使得理论上进一步回收成为可能。
