This paper presents a number of novel active fasteners developed to significantly lower disassembly costs during reconditioning, remanufacturing, and recycling of products. In the initial stage of the fastener development process, the applicability of distinct trigger signals for active disassembly (AD) is evaluated. Based on this evaluation, the high robustness of using a pressure increase or decrease as a nondestructive trigger for AD is demonstrated. Since previously proposed pressure-sensitive fasteners face considerable drawbacks upon implementation in electronic products due to the ongoing trend of miniaturization, a second generation of pressure-based active fasteners is developed. Evaluation of these fasteners by means of axiomatic design techniques and prototyping demonstrates that the presented snap-fits, which make use of a closed-cell elastomer foam, are most robust. Subsequently, the contraction forces that closed-celled foams can exert as a function of an increase in ambient air pressure are experimentally determined. Furthermore, the implementation of pressure-sensitive foam-based snap-fits in both a modem and a payment terminal is described. Results of these experiments demonstrate that the contraction force of a cross-linked metallocene polyethylene closed-cell foams can reach up to 6 N/cm 2 at an overpressure of 2 bar and that the foam-based snap-fits can be released at a pressure increase of 2 bar.
Increasing resource prices, ever-higher complexity of products, recent developments in legislation and the importance of a green brand image have resulted in an increased interest of original equipment manufacturers to facilitate a disassembly based end-of-life treatment for their products. The main reason is that precious metals, rare earth elements and plastics can be recovered with the highest yield and purity in a disassembly based treatment. However, original equipment manufacturers currently face several issues for the implementation of design for disassembly. To overcome these issues, first of all an in-depth analysis of design-for-disassembly opportunities and challenges is presented. Taking into account the results of this analysis, innovative low-cost elastomer-based fasteners have been developed, which can be simultaneously released by applying a sufficiently high force over a period of time. In addition, an experimental validation method was developed and adopted to demonstrate that the developed fasteners allow reducing the disassembly time by 70%-90% for the housing of LCD TVs without compromising product robustness. The presented calculations indicate that the implementation of the developed fasteners is profitable from an overall perspective in regions with a labor cost higher than 7 (sic)/h. However, original equipment manufacturers currently lack incentives to adopt design for disassembly for products sold in a Business-to-Consumer market, which are jointly collected and treated at end-of-life. Therefore, a differentiation in recycling fees proportional to the reduction in disassembly time is proposed to provide economic stimuli for original equipment manufacturers to implement these fasteners. Such a differentiation scheme, combined with the presented insights on opportunities to facilitate disassembly processes and the required resistance of fasteners to forces in function of time, will stimulate and enable the development of products which can be disassembled in an economically viable manner, resulting in improved material recovery from end-of-life products in industrialized regions. (C) 2015 Elsevier Ltd. All rights reserved.
Cost efficient disassembly operations require the simultaneous release of multiple fasteners without the need to identify the location of every individual fastener. Despite the availability of a number of Active Disassembly concepts which offer significant potential to make systematic product disassembly economically viable, the stage of mass industrial implementation has not yet been reached. A novel fastener concept has been developed in an attempt to overcome some of the barriers that impede implementation of Active Disassembly in electronic consumer products. This fastener concept is based on the mechanical properties of elastomer materials and is triggered by an external force applied on the product housing.
Closing material loops for the housing of electronic equipment remains a particular technical challenge because of the common use of Flame Retardant (FR) plastics. Within an industrial collaboration, series of experiments were setup to demonstrate the technical and economic feasibility of closed loop recycling of back covers of End-of-Life Flat screen TVs (FTVs). The results of these experiments show that the used type of plastic and FR is strongly producer dependent. Therefore, this paper proposes to cluster FTVs based on product brand to facilitate closed loop recycling of PC-ABS and HIPS-PPO with phosphorous FRs.
The treatment of the rapidly increasing number of End-of-Life (EoL) Flat screen Televisions (FTVs) presents major challenges and opportunities. Closing loops in plastic housing material flows remains a particular technical challenge because of the presence of additives, such as Flame Retardants (FR) in recovered housings. In the framework of a collaborative project PRIME with TP Vision the TV development site for Philips TVs and a Van Gansewinkel first level recycling plant, series of experiments are set up to recycle plastic housings of FTVs. In these series of experiments plastic back covers are manually disassembled from the current WEEE stream and sorted based on manufacturers information and polymer analysis. With these plastics, new back covers and testing bars are injection molded and evaluated. The results of these experiments and the presented cost-benefit analysis demonstrate the technical and economic feasibility of closed loop recycling of housing plastics and indicate further opportunities for design and process improvements.
Eco-design heuristics (defined as experience-based techniques for problem solving) can play a useful role in helping designers prioritize eco-design strategies. One of these eco-design heuristics (the 'use phase' heuristic) is: Frequently used electric and electronic products usually have, over their life span, a dominant impact in the use phase. Modern mobile devices like smart phones however have their dominant impact in the production phase and therefore challenge this heuristic. The paper asked whether this could be a trend and whether we might find more electric and electronic products that challenge the 'use phase' heuristic. We found that in general, the development of highly energy-efficient consumer electronics and the widespread shortening of product lifespans have indeed started to shift the focus to the materials and production phase of the life cycle. The case study of the Econova television showed that with a 'best in class' product like this TV, it is not possible to establish which life cycle phase is dominant. These findings led to several additions to the 'use phase' heuristic.
Energy consumption is responsible for a substantial part of the environmental impact generated by industrial production (Gutowski et al., 2006). Currently, minimising the energy consumption is hardly a priority for many machine designers, since they concentrate primarily on improving functionality, accuracy and safety. Nevertheless, alternative machine designs with improved energy consumption are emerging. This paper investigates the case of a laser cutting machine as common sheet metal processing machine tool. This paper verifies the potential for energy improvement by means of a case study. The analysis covers both the energy consumption during productive and non-productive time. Energy consumption improvement opportunities are identified. For this purpose a conventional CO2 laser-cutting machine was investigated and compared with a possible fibre laser based machine configuration. The analysis shows that the CO2 laser source and the chiller unit are the largest energy consumers during productive time. During non-productive time, 12% of the yearly energy consumption is required to keep the chiller and other components active. For the alternative machine configuration it is assumed that no energy is needed during off-mode. The same scenario saves 16.6 MWh during productive time because of the improved efficiency of a fibre laser source.
By repairing and reselling used products, reuse centres aim at creating low-skill jobs while offering low-cost and environmentally beneficial products. However, due to a combination of decreased efficiency of worn-out products and technological progress embodied in new products, lifetime extension of old products is not always the most beneficial scenario from an environmental nor an economic point of view. This paper investigates this trade-off for the case of washing machines in a Belgian context. For selected types of washing machines, critical reuse ages are determined above which reuse is environmentally or economically undesirable. A sensitivity analysis shows that these critical reuse ages are often sensitive to small changes of the input parameters.
Energy consumption is responsible for a substantial part of the environmental impact generated by industrial production [1]. Currently, minimising the energy consumption is hardly a priority for many machine designers, since they concentrate primarily on improving functionality, accuracy and safety. Nevertheless, alternative machine designs with improved energy consumption are emerging. This paper investigates the case of a laser cutting machine as common sheet metal processing machine tool. This paper verifies the potential for energy improvement by means of a case study. The analysis covers both the energy consumption during productive and non-productive time. Energy consumption improvement opportunities are identified. For this purpose a conventional CO2 laser-cutting machinewas investigated and compared with a possible fiber laser based machine configuration. The analysis shows that the CO2 laser source and the chiller unit are the largest energy consumers during productive time. During non-productive time, 12% of the yearly energy consumption is required to keep the chiller and other components active. For the alternative machine configuration it is assumedthat no energy is needed during off-mode. The same scenario saves 16,6MWh during productive time because of the improved efficiency of fiber laser source.
Industrial production inevitably results in an environmental impact. Energy consumption is responsible for a substantial part of this impact. Currently, machine designers spend little attention to minimising the energy consumption, since their primary focus is on the well-functioning of the machine.