Study for a method to assess the ease of disassembly of electrical and electronic equipment. Method development and application to a flat panel display case study

摘要

This report has been developed within the project “Technical support for Environmental Footprinting, material efficiency in product policy and the European Platform on LCA” (2013-2016) funded by Directorate General Environment, and focused on the development of a standardisable method with a verifiable metric to assess the reversible disassembly of electrical and electronic equipment (EEE). The main motivation of this study was the need for a robust method to evaluate the ability to access or remove certain components from products to facilitate their repair, reuse or recycling. Such a method is developed to serve different purposes, such as product design optimization, compliance to policies and end-of-life treatment improvement. Such a work is particularly relevant to the 2015 Circular Economy action plan that will “promote reparability, upgradability, durability and recyclability of products” through Ecodesign Directive and to the mandate addressed to European standardisation organisations in 2015 to develop standards on material efficiency of energy related products (ErP). The report provides a scientific background, with the review of current methods available in the literature, which were grouped into: 1) methods to categorise manual operations and disassembly actions and 2) methods to calculate the ease of disassembly of products. Based on the presented literature review, the proposed method focused on the identification of relevant product parameters and disassembly actions to be used for the calculation of a disassembly index. In particular, the authors have identified six basic and relevant disassembly actions of an average disassembly process: 1) Tool change, 2) Identifying connectors, 3) Manipulation of the product, 4) Positioning, 5) Disconnection and 6) Removing. For each of them, and for each type of fastener, a table of reference values was determined. Successively, an innovative disassembly index has been proposed and named as “ease of Disassembly Metric” (eDiM). Given a product and the sequence of actions to disassemble it, the eDiM calculation consists of associating a value of the reference table to each of these actions. The summation of these values finally results in the eDiM for the considered product and disassembly sequence. The eDiM index assesses the effort needed to completely or partially disassemble a product. The index is also representing an estimation of the time necessary for the disassembly and therefore it is expressed in standards unit of measurement for time (seconds). The eDiM index was tested on a 14” flat panel monitor (LCD), a small electronic device with a weight of 2.6 kg that can be disassembled on a workbench. The eDiM was calculated for the complete disassembly and also for the selective extraction of certain components, as the Printed Wiring Boards. The calculated values were also compared to the disassembly performed by a professional operator, in order to measure the possible deviations. Considering the complete disassembly, the comparison between calculated eDiM and measured values resulted in a limited difference (the calculated eDiM was 8.5% higher than the measured value), with the largest deviation observed for the disassembly action of “Identifying connectors”. Based on the results of the present analysis, the authors positively concluded on the feasibility to develop a robust and potentially standardisable method to assess the ease of disassembly of EEE. The method is based on information about the product composition and fastening that can be directly verified on the product. Authors also concluded that the proposed method is suitable to support product design for disassembly and policies for ecodesign.