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Additive manufacturing (AM) refers to a group of manufacturing techniques that produce components in a layer-by-layer fashion. By virtue of its capability to produce parts with complex geometry and functionally graded materials, AM has been introduced and used in multiple industrial sectors and is leading the way into the “third industrial revolution”. One of the key considerations in Additively Manufactured Products (AMP) is the issue of sustainability which attracts increasing attention as modern society becomes more aware of environmental concerns. As a response to the growing requirement for sustainability, industries and customers are inclined to assess products and services through the perspective of life cycle sustainability. The integration of life cycle sustainability and AMP is still an open question and is the primary motivation for this study. Since the eventual goal of all advanced technologies is to serve and satisfy human society, social sustainability must be an essential part of all decisions regarding AMP. Limited studies that integrate social sustainability into AMP life cycle analysis is a current research gap in the body of the literature, and thus this paper will address it. The primary merit of this paper is developing a suitable full-dimension sustainability life cycle assessment framework to obtain a fundamental understanding of the performance of AMP life cycle sustainability. The proposed framework applies a more systemic AMP life span including AMP design, AM, usage, and end-of-life (EOL) handling. An AM produced gear is used as an example to illustrate the life cycle sustainability assessment framework. The results show that the AM stage has the highest influence on economic and environmental dimensions of sustainability and the EOL stage has the highest social impact. The results also indicate that AM mass production can significantly reduce the impact of sustainability. [ABSTRACT FROM AUTHOR]

Generation of goods and services are highly dependent on the use of natural resources. Until very recently, there was an implicit belief that the physical expansion of the economic system could be unlimited, as if the planet would have conditions and time enough to recover and continue to supply resources. This belief implies a confidence in an economic system that would provide whatever is necessary for a continuous growing production and consumption. Even believing that technology alone is not enough to solve the current environmental problems, it is certain that it can collaborate to mitigate climate change and to adaptation to changes in the environment. By bringing environmental aspects into discussions, eco-innovations can affect and transform the innovation system in order to create sustainable processes. However, the main challenge towards the transition to a more sustainable, cleaner and more equitable society is to set innovation in a new context, as until very recently it only considered the economic variables. This change means to value the social and environmental dimension of the innovation. In addition to eco-innovation, Life Cycle Assessment (LCA) is spreading in the industrial environment, offering promising perspectives. LCA is considered a valuable methodology in the environmental sustainability of industry. In this context, the present study addresses LCA and its relationship with the generation of eco-innovations. Drawing on contributions from literature on eco-innovation and LCA, the paper analyses available evidence on this relationship in a context of the transition towards sustainable development. To structure the debate, the paper offers a conceptual approach and an illustrative case on international researchers' and practitioners’ perceptions on the potentially positive relationship between eco-innovation and LCA. The study gathers data in the Web of Science (WoS) Core Collection and in Scopus, in order to provide a picture of the distribution of documents retrieved from these databases, dealing with both eco-innovation and LCA topics. The paper concludes that the convergence of the eco-innovation and LCA studies is quite plausible, but at least in its initial phase, the literature that unites both themes is scarcely found in publications in the area of innovation, being more frequent in the area of engineering and management that usually addresses LCA studies. [ABSTRACT FROM AUTHOR]

This paper reviews the published research pertaining to the use of superheated steam for carbon fibre reinforced polymer (CFRP) composite reclamation. Superheated steam has been used for this purpose for around a decade and was initially investigated to prevent the degradation of reclaimed fibres, which occurs during the oxidative char removal step of most pyrolysis-based reclamation techniques. The review evaluates the various methodologies employed with particular focus on the physical, mechanical, and chemical properties of the reclaimed fibres, and the environmental impact of using superheated steam for carbon fibre reclamation as determined by life cycle assessment. Superheated steam studies report recovering carbon fibres with retained tensile moduli of around 90%–100% and tensile strengths of 65%–100% when compared to virgin carbon fibres, however, when optimised it is shown that carbon fibres can be recovered with no loss in stiffness and strength. Most studies are still at laboratory- or pilot-scale, however, several companies are collaborating with researchers to investigate the potential of this reclamation method on a larger scale. Early analysis on the energy use of carbon fibre reclamation using superheated steam shows that energy savings of 25% could be made by recycling CFRP waste using superheated steam and using the recovered carbon fibres to displace virgin carbon fibres rather than landfilling and incinerating this waste. • Review of the developments pertaining to superheated steam use for carbon fibre reinforced polymer reclamation. • Superheated steam reclaimed carbon fibres retain tensile strengths of 65%–100% and tensile moduli of around 90%–100%. • Review of the life cycle assessment of superheated steam-based carbon fibre reinforced polymer reclamation. • Examples of superheated steam reclamation processes entering the pilot-plant/industrial phase. [ABSTRACT FROM AUTHOR]

In machining processes, there are contradictions between high efficiency and environmentally-friendly machining. This indicated that there is a major potential for sustainable machining to both increase efficiency and protect ecological balance. For this, the employment of effective methods has become imperative to reduce resource use. In this way, the use of analysis and optimization tools to select the tool material, cutting parameters, cooling/lubrication conditions, etc., will be a benefit for minimizing waste without sacrificing efficiency. In the literature, researchers have used various methods to reveal the requirements of sustainability. However, reaching the concept of sustainable machining by using one more than technique confuses the readers. Therefore, it was deemed necessary to present and discuss the current methods, models and analyzes in a comprehensive review paper. In this context, this paper reviewed the previously published works, especially focusing on sustainability and energy consumption modeling methods in machining operations. At the end of the study, it was seen that LCA provides a systematic and quantitative view of the system and thus can act as a decision support tool. Moreover, it can give an idea to the manufacturers about the improvement of the process and the areas of innovation. However, the method has several disadvantages such as relatively expensive and specific software, obtaining inventory data, impractical to use, time-consuming and requires large amounts of data. Various mathematical models and algorithms have been developed to deal with the complex situations and offer a more practical use compared to LCA. However, it is difficult to state that clear results have been achieved thanks to these models. It was seen that in complex machining processes, only approximate results can be found with models, which leads to questioning the reliability of the models. [ABSTRACT FROM AUTHOR]

The reduction in the use of raw materials and the spread of energy efficient processes and components are necessary from both the economic and the environmental viewpoints. This paper presents the design of an innovative multi-functional agricultural machinery able to integrate three separate traditional implements used for hay raking, hay baling and bale wrapping, i.e. hay rake, round baler and bale wrapper machines, with the aim of speeding up the harvesting operations and reducing both the energy consumption and the global environmental impact. A comparative analysis about the adoption of the traditional implements and the new multi-functional machinery is reported. Particularly, the reduction in both the fuel consumption (−32%), the human labor (−66.7%) is discussed together with a differential environmental analysis of the proposed system and the traditional implements. To meet such a last purpose, the study adopts the life cycle assessment methodology carefully quantifying the impact indicators for three different categories, i.e. human health, ecosystem quality and resource depletion. The results highlight a global environmental impact reduction of about 35%. The proposed system represents an effective and competitive improvement to ease and speed the haymaking process and to reduce the environmental impact of such a key farmer activity. [ABSTRACT FROM AUTHOR]

Despite the substantial effort on almost all levels during the last decades, the buildings' renovation rate needs to be at least doubled from the current 1% to meet ambitious energy efficiency goals. In the same way, the energy-intensive material replacement did not reach yet the desired grade in terms of sustainability measures and outlined goals heading to a low-carbon economy. This paper summarizes principles of sustainable development together with the current methodological framework relevant to the civil engineering and construction industry. The main part is devoted to the identification and understanding of principal factors preventing faster adoption of energy efficiency measures. High initial financial costs, investment risk over a long-term period, poor acceptance of sustainable measures, lack of information, and limited methodological framework for a reliable evaluation of environmental projects with the intergeneration context or understanding of externalities of human activities are identified as the main barriers to the sustainable building retrofits. These barriers are closely related each other and can be merged into several groups according to the stakeholders or scientific disciplines to amplify their primary impact. Notwithstanding, solution strategies based on narrow boundary conditions and limited multidisciplinary approach prevent substantial advances towards the sustainable building sector. In this regard, the major obstacles preventing the achievement of energy efficiency goals can be remedied by interdisciplinary cooperation. • Lacking multidisciplinary approach hinders sustainable measures adoption. • Limited public acceptance prevents a stronger political commitment. • Methods of social measures need to be studied for decision support. • Sustainable building industry transition is not a technical issue only. [ABSTRACT FROM AUTHOR]