International Journal of Sustainable Manufacturing (5 papers in press)
Sustainability analysis of Ti-6Al-4V machining using statistical design methods: effects of cooling techniques and machining strategies
by Hussien Hegab, Ali Hosseini, Ibrahim Deiab, Hossam Kishawy
Abstract: Minimising energy consumption and making machining processes more environmentally friendly are the two essential requirements of sustainable machining. As a result, development of technologically advanced yet efficient machining processes with minimum energy consumption and least toxic waste is an evolving field of research and study. In this paper, the effects of several lubrication techniques as well as different machining strategies (classic and hybrid), when machining Ti-6Al-4V, have been studied. Three different factors, namely energy consumption, surface quality, and flank wear, have been measured to evaluate the effectiveness of different lubrication techniques and machining strategies. Analysis of variance (ANOVA) has also been employed to analyse the influence of process parameters on the above-mentioned factors to determine the optimum levels of machining parameters and verify the experimental results. the accuracy of the model has finally been verified using the ANOVA results.
Keywords: sustainability; Ti-6Al-4V; minimum quantity lubrication; hybrid machining.
Disassembly system design and analysis with environmental and economic parts selection using life cycle inventory database by input-output tables
by Tetsuo Yamada, Yusuke Suzuki, Yuki Kinoshita, Tadayuki Masui, Norihiro Itsubo, Masato Inoue
Abstract: To prevent material starvation and global warming caused by manufacturing, disassembly systems for End-of-Life (EOL) products should be environmentally and economically designed to promote a closed-loop supply chain for assembly products. With parts selection in the disassembly systems, parts/materials with higher CO2 volumes should be recycled for environmental reasons. On the other hand, parts/materials with higher profit, which is the difference between the revenue of recovered materials and disassembly costs, should be disassembled for economic reasons. A disassembly system design considering not only the environmental loads but also the recovered parts/materials are proposed by using a Product Lifecycle Management (PLM) tool. However, from a technical and financial standpoint, it is not easy for the disassembly factory sites to create the 3D-CAD models and obtain the environmental information using the PLM tool. This paper proposes a disassembly system design with the environmental and economic parts selection using a life cycle inventory database by input-output tables.
Keywords: CO2 emissions; reuse and recycling; product recovery values; environmentally conscious manufacturing; sustainable manufacturing; closed-loop supply chains.
Techno-eco-efficiency performance of 3D printed impellers: an application of life cycle assessment
by Heshan Jayawardane, Ian Davies, Garry Leadbeater, Michele John, Wahidul Biswas
Abstract: Rapid industrialisation had led to a scarcity of resources. The concept of sustainable manufacturing has emerged to address this scarcity and to minimise environmental degradation. 3D printing, also known as additive manufacturing, could potentially reduce material wastage, energy consumption, and resulting emissions. A techno-eco-efficiency framework was developed to produce technically, economically, and environmentally feasible centrifugal pump impellers 3D printed using the fused filament fabrication process. Firstly, surface properties, geometric properties, build material properties, static structural and dynamic properties, and the hydraulic performance of impellers were assessed in order to investigate how process parameters, such as infill pattern, infill rate and reinforcement material affect the technical performance. Secondly, the eco-efficiency performance of technically suitable impellers was assessed using environmental life cycle assessment, life cycle costing tools, and portfolio analysis. Thus, this techno-eco-efficiency framework was used to achieve sustainable manufacturing and could act as a decision support tool for selecting cost-competitive, environmentally benign, and technically feasible products. Alternatively, it would assist product designers and manufacturers to minimise a trade-off between technical and resulting eco-efficiency performance.
Keywords: additive manufacturing; eco-efficiency; life cycle assessment; 3D printing; sustainable manufacturing; sustainability assessment; fused filament fabrication; composite additive manufacturing.
Environmental sustainability benchmarking of roof type using life cycle assessment
by Asela K. Kulatunga, Raitha Peiris
Abstract: At present, alongside the gradual growth of the building construction industry, a massive number of materials have come to be used. Hence, there is a diversity in the impacts caused to the environment by these materials. Consequently, when the product life cycle of a building component (which is constructed by assembling these materials) is considered, its environmental performance is difficult to determine. Likewise, the environmental performance of the entire building component can be evaluated by categorising it into classified scenarios. Considering this need, a scenario-based life cycle assessment (LCA) is generally conducted on roofs, which are one of the main components of a building. One of the major differences between roofs that can be seen is the roof cladding material, and by changing the cladding material, the LCA was conducted repeatedly. The clay cladding roof is compared with commonly available alternatives, such as the PVC roof and the asbestos roof. Clay roof tiles, as a material, could be eco-friendly, but the results of this research study have proven that this is not always the case. The factors that affect this deviation from expectations are further analysed in this research. In addition, a guide is provided on how to recover the depleted eco-sustainability that existed previously in the clay roof tile.
Keywords: life cycle assessment; environmental sustainability; sustainable manufacturing; roofing materials.
Comparison of energy consumption and environmental emissions of diesel engine after-treatment devices based on life cycle assessment
by XiaoLei Mei, Tao Li, ShiTong Peng, HongChao Zhang
Abstract: Now, after-treatment devices have been proven to affect reducing emissions. However, manufacturing after-treatment devices also produce pollution emissions. This study used a life cycle assessment (LCA) method to evaluate three diesel after-treatment devices: diesel oxidation catalyst (DOC) converter, diesel particulate filter (DPF) and selective catalytic reduction (SCR) converter. The data results show that after-treatment devices have different impacts on the environment, and SCR has more environmental impact. The ozone depletion potential (ODP) pollution is the largest and cannot be ignored. The use of after-treatment devices has great emission reduction benefits, and the quantified reduction rate of environmental indicators exceeds 96%, except for global warming potential (GWP, about 15.26%). An engine equipped with after-treatment devices has some environmental benefits, which are reflected in the five indicators of GWP, AP, EP, POCP and RI, but the use of urea in SCR devices will increase the impact of ODP.
Keywords: engine after-treatment devices; life cycle assessment; catalytic converter; environmental impact.