Hierarchical modelling for recycling-oriented classification of shredded spent flat monitor products based on HyperSpectral Imaging

Abstract

The number of flat monitors from televisions, notebooks and tablets has increased dramatically in recent years, thus resulting in a corresponding rise in Waste from Electrical and Electronic Equipment (WEEE). This fact is linked to the production of new high-performance electronic devices. Taking into account a future volume growth trend of WEEE, the implementation of adequate recycling architectures embedding recognition/classification logics to handle the collected WEEE physical-chemical attributes, is thus necessary. These integrated hardware and software architectures should be efficient, reliable, low cost, and capable of performing detection/control actions to assess: i) WEEE composition and ii) physical-chemical attributes of the resulting recovered flow streams. This information is fundamental in setting up and implementing appropriate recycling actions. In this study, a hierarchical classification modelling approach, based on Near InfraRed (NIR) - Hyperspectral Imaging (HSI), was carried out. More in detail, a 3-step hierarchical modelling procedure was designed, implemented and set up in order to recognize different materials present in a specific WEEE stream: End-of-Life (EoL) shredded monitors and flat screens. By adopting the proposed approach, different categories are correctly recognized. The results obtained showed how the proposed approach not only allows the set up of a “one shot” quality control system, but also contributes towards improving the sorting process.

Hyperspectral Imaging Applied to WEEE Plastic Recycling: A Methodological Approach

“…HSI is a cutting-edge approach to waste management that is rapidly gaining popularity as a quality control tool and as a core for sorting engines in several recycling processes [9]. Different HSI-based approaches have been proposed for plastic recycling [10][11][12], Construction and Demolition Waste (C&DW) recycling [13,14] and WEEE recycling [15,16].…”

Hyperspectral imaging-based approach for recycling space waste

“…NIR reflectance spectra indicate material composition due to the existence of certain chemical bonds (e.g., O-H, N-H, C-H, S-H,...) [7,8]. Several HSIbased strategies have been developed in recent years for the effective recycling of plastic [9,10], the handling of waste from electrical and electronic equipment [11,12], and the management of waste from construction and demolition [13,14]. The literature has shown that the utilization of HSI in the waste sector significantly impacts the efficacy of several stages of the circularity process, such as material selection, component identification, quality control at each stage of treatment, and so on.…”