Department of Anthropogenic Material Cycles, RWTH Aachen University, Wuellnerstr. 2, 52062 Aachen, Germany.
Department of Anthropogenic Material Cycles, RWTH Aachen University, Wuellnerstr. 2, 52062 Aachen, Germany.
Waste Manag. 2021 Mar 15;123:33-41. doi: 10.1016/j.wasman.2021.01.015. Epub 2021 Feb 5.
Flexible multilayer plastic packaging (MPP) has grown in popularity in the last years especially in food and medical sectors, and its share in the packaging industry is expected to increase further. Compared to traditional packaging with same functionalities, MPP is characterized by lower energy consumption in production and a reduced packaging weight. So far, the recycling of post-industrial MPP with specific material composition has been achieved by several companies. To our knowledge, all existing MPP recycling processes require a known material combination. In contrast to post-industrial MPP, post-consumer MPP still ends up in incinerators or as low-quality products, mainly because of the lacking ability to sort. This study investigates the detectability of post-consumer MPP with near-infrared spectroscopy, the state-of-the-art technology for sensor-based waste sorting. Firstly, MPP classification with near-infrared spectroscopy was analyzed with clean samples. Subsequently, the effect of waste collection and preprocessing in sorting plants on MPP classification was investigated. For this purpose, clean samples were covered with water and oil and mixed with lightweight packaging waste in a drum sieve. The results show it is possible to classify post-consumer MPP based on near-infrared spectra according to different sorting strategies. For the existing recycling processes which are suitable for post-consumer MPP, the corresponding object-based classification accuracy was found to exceed 96%.
近年来，柔性多层塑料包装（MPP）在食品和医疗领域越来越受欢迎，其在包装行业的份额预计将进一步增加。与具有相同功能的传统包装相比，MPP 的生产能耗更低，包装重量更轻。到目前为止，几家公司已经实现了具有特定材料组成的工业后 MPP 的回收。据我们所知，所有现有的 MPP 回收工艺都需要已知的材料组合。与工业后 MPP 相比，消费后 MPP 仍最终进入焚烧炉或成为低质量产品，主要是因为缺乏分类能力。本研究调查了近红外光谱对消费后 MPP 的可检测性，这是一种基于传感器的废物分类的最先进技术。首先，用清洁样品分析了近红外光谱对 MPP 的分类。随后，研究了在分拣厂的废物收集和预处理对 MPP 分类的影响。为此，将清洁样品用水和油覆盖，并在滚筒筛中与轻质包装废物混合。结果表明，根据不同的分类策略，基于近红外光谱可以对消费后 MPP 进行分类。对于适用于消费后 MPP 的现有回收工艺，发现相应的基于对象的分类准确率超过 96%。
