Whether plastic packaging waste is disposed of in different bins (source separation, S) or in a single bin (post source separation, P) is generally assumed to impact the waste stream’s quality. To elucidate this question, we evaluated the quality of LDPE, HDPE, and PP plastic waste from both separation systems (S and P) through a concise analytical strategy. The materials received similar treatment after collection (e.g., washing, NIR-sorting). A multivariate approach to ATR-FTIR spectroscopy was developed to assess their material composition and the effect of washing. Results were complemented by TGA, DSC, and py-GC/MS analysis. The material performance was investigated by a lab-scale extrusion and granulation, followed by an assessment of the mechanical properties and the melt volume rate. Our study reveals the HDPE materials to be of good quality, regardless of their source. For LDPE and PP, the P-materials are fractionally more contaminated after washing. Both PP-materials display poor material performance with highly fluctuating elongations-at-break (between 30% and 380%). S-LDPE was found to contain more polymeric impurities than P-LDPE. We conclude that the quality depends strongly on the material type and on the treatment after collection (washing, sorting). The multivariate approach to FTIR data evaluation we propose aims at simplifying the quality evaluation of polyolefin waste plastics and may serve as a basis for future work in this field.

中文翻译：

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不同分离系统的塑料包装废物的质量比较：通过 FTIR 光谱的非负矩阵分解增强结果

通常认为塑料包装废物是在不同的垃圾箱（源头分离，S）中还是在单个垃圾箱（源头后分离，P）中处理会影响废物流的质量。为了阐明这个问题，我们通过简明的分析策略评估了两个分离系统（S 和 P）中的 LDPE、HDPE 和 PP 塑料废物的质量。材料在收集后接受类似的处理（例如洗涤、近红外分选）。开发了 ATR-FTIR 光谱的多变量方法来评估其材料成分和洗涤效果。结果通过 TGA、DSC 和 py-GC/MS 分析进行补充。通过实验室规模的挤出和造粒研究材料性能，然后评估机械性能和熔体体积速率。我们的研究表明，无论来源如何，HDPE 材料的质量都很好。对于 LDPE 和 PP，P 材料在清洗后污染程度要高一些。两种 PP 材料的材料性能较差，断裂伸长率波动较大（30% 至 380% 之间）。发现 S-LDPE 比 P-LDPE 含有更多的聚合物杂质。我们得出的结论是，质量在很大程度上取决于材料类型和收集后的处理（清洗、分类）。我们提出的多变量 FTIR 数据评估方法旨在简化聚烯烃废塑料的质量评估，并可作为该领域未来工作的基础。