Search Results (33)

The cyclic process of the circular supply chain (CSC) involves many stakeholders, and how to synergistically promote the active participation of different entities in CSC practices in the complex context of interacting factors is an important condition for moving towards low-carbon sustainable development and realizing the economic benefits as well as the competitive advantages of enterprises. Therefore, based on the technology cycle perspective (recycling, remanufacturing, refurbishing, repairing, and reusing), this study combines text mining and bibliometrics to identify CSC drivers, establish a factor prioritization assessment model, and construct a comprehensive framework for a set of CSC implementation pathways covering multiple subjects and multidimensional factor interaction mechanisms. The results emphasize that the most critical drivers are policies and regulations, resource use efficiency, and consumer awareness and attitudes, with contribution rates of 5.1%, 4.5%, and 4.5%, respectively. On this basis, this paper explores the efficiency-enhancing path strategy for the synergistic implementation of CSC by multiple subjects from the perspectives of the four key subjects of CSC. It puts forward policy recommendations to promote the successful implementation of CSC at the level of mechanism construction and specific operation, to provide theoretical guidance for the cooperation of upstream and downstream subjects. Full article

This paper compares the performance of Deep Learning (DL) and multi-template matching (MTM) models for detecting small defects. DL models extract distinguishing features of objects but require a large dataset of images. In contrast, alternative computer vision techniques like MTM need a relatively small dataset. The lack of large datasets for small metal-surface defects has inhibited the adoption of automation in small-defect detection in remanufacturing settings. This motivated this preliminary study to compare template-based approaches, like MTM, with feature-based approaches, such as DL models, for small-defect detection on an initial laboratory and remanufacturing industry dataset. This study used You Only Look Once v5 (YOLOv5) as the DL model and compared its performance against the MTM model for small-crack detection. The findings of our preliminary investigation are as follows: (i) YOLOv5 demonstrated higher performance than MTM in detecting small cracks; (ii) an extra-large variant of YOLOv5 outperformed a small-size variant; (iii) the size and object variety of the data are crucial in achieving robust pre-trained weights for use in transfer learning; and (iv) enhanced image resolution contributes to precise object detection. Full article

In the context of green economy, Closed-Loop Supply Chain (CLSC) competition is intensifying. This study aims to help companies operating in green supply chains determine optimal remanufacturing strategies when competing with other firms. We examine the decision-making problem of CLSCs in competitive environments facing multiple remanufacturing mode options. The research constructs a Prisoner’s dilemma model for dual CLSCs, where each chain has three strategic choices: independent remanufacturing, outsourced remanufacturing, and authorized remanufacturing. Employing Stackelberg game models, Nash equilibrium analysis, and numerical simulations, this study explores how remanufactured product unit saving costs affect remanufacturing mode decisions concerning competitive intensity and discount policies. The study then draws the following conclusions: (1) CLSCs prefer outsourced and authorized remanufacturing in competitive scenarios; (2) Remanufactured product discounting significantly influences CLSC remanufacturing decisions; (3) Competitors typically adopt conservative strategies by aligning decisions with rivals. These results provide practical guidance for CLSCs selecting remanufacturing approaches when facing substitute competition, contributing to more sustainable and competitive supply chain operations. Full article

Additive manufacturing enables new design solutions across various engineering fields. This work presents a method to enhance the sustainability of adhesive joints by designing joints that can be disassembled and repaired multiple times. The approach involves the use of a Multi-Material Additive Manufacturing process to produce substrates with integrated circuits and electrical resistance, printed using a conductive filament. This resistance can be used to heat the thermoplastic adhesive layer up to 110 °C, allowing for reversibility in the assembly process and enabling joint re-use and repair without constraints on the component’s materials and thicknesses. The joints tested after successive assembly/disassembly operations reach maximum strength during the first iteration, which decreases by around 50% after five repair iterations. The focus of the work is on the feasibility of this process, but it is expected that performance can be improved after process optimization. This result could be highly valuable for enabling component in-service healing and the design for demanufacturing and remanufacturing. Full article

In light of growing global supply chain instability and carbon neutrality initiatives, South Korea has highlighted the need for a circular economy to reduce its reliance on natural resources. As a critical strategy for promoting a circular economy, remanufacturing has become essential because of its ability to improve resource efficiency and reduce environmental impacts. The automotive sector, which accounts for 80% of the remanufacturing industry, plays a critical role in these efforts. Turbochargers, primarily made of cast iron, represent approximately 20% of sales in this sector and are significant contributors to greenhouse gas emissions, making them an important target for emission reduction. This study examined the greenhouse gas emissions associated with turbochargers across multiple remanufacturing cycles using the LCA method. The results indicated an approximate decrease of 50%, 48%, and 46%, based on a comparative analysis between brand-new products and those remanufactured one to three times. Comparing brand-new and remanufactured products does not fully capture the key advantage of remanufacturing. This advantage lies in its ability to extend a product’s life cycle by using core parts as primary raw materials and reducing the consumption of new resources. Therefore, it is important to consider the environmental impact of remanufacturing within an expanded process, where brand-new products are included in the entire life cycle. Using this approach, the accumulated annual greenhouse gas reduction effect for multiple remanufacturing indicated decreases of approximately 25%, 32%, and 35% for remanufacturing one, two, or three times, respectively, compared to using only brand-new products. This study shows that multiple remanufacturing reduces greenhouse gas emissions compared to the use of brand-new products. In particular, as remanufacturing is repeated, the product lifespan can be extended from 3 years to up to 12 years with a concomitant decrease in annual greenhouse gas emissions. These findings provide valuable data for modeling and encouraging the greenhouse gas reduction potential driven by remanufacturing across various industrial sectors. Full article

In depositing multiple layers on the surface of failed metal parts, the overlap rate is a critical factor in determining the surface smoothness and uniformity of the coating thickness. Therefore, special attention must be given to the spacing between adjacent melt tracks when planning laser paths on complex metal parts. A strategy for selecting the overlap rate for multi-track cladding is proposed, based on the key parameters of surface curvature, mass conservation, and the profile of single-track coatings. A multi-track overlap model is developed, expressing the relationship between coating morphology and the overlap rate. The optimal spacing value is determined to achieve the goal of high-quality coating remanufacturing. To verify the effectiveness of this method, nickel-based powder was used for laser forming on the surface of metal gears. The results showed that the surface of the cladding layer was smooth and flat, further demonstrating that this model helps improve the repair quality and overall performance of curved metal parts. Thus, it provides valuable guidance for the remanufacturing of failed metal parts. Full article

The rise of e-commerce has significantly impacted consumer shopping habits, resulting in profit loss for traditional supply chains. In response to intense competition, numerous companies have transitioned their business models to embrace dual-channel configurations, seeking to captivate customers and increase their market share. Nonetheless, research on decentralized dual-channel supply chain configurations is scarce and predominantly concentrates on single-period pricing. This paper addresses this gap by employing Stackelberg’s game theory to investigate the multi-periodic pricing and remanufacturing decisions within a decentralized dual-channel supply chain with reverse logistics, specialized in the manufacturing and sales of pharmaceutical products. Moreover, this work considers that the online channel pays a sales commission to the pharmacy in return for the provided after-sales services, aiming to incorporate the aspect of sharing revenues. A mathematical formulation is proposed in a multi-periodic environment allowing us to simultaneously maximize the total profits of the manufacturer, the pharmacy and the online channel, by optimizing the pricing and remanufacturing strategies. Numerical analyses examine the customer purchasing preference’s effect on the demand and pricing decisions of each channel, the impact of the collection cost on the optimal remanufacturing strategy, and assess the break-even point of the total profits generated in both channels according to the sales commission. This study’s novelty lies in employing Stackelberg’s game theory to develop a mathematical formulation for the multi-periodic pricing and remanufacturing problem within a decentralized dual-channel supply chain, incorporating a sales commission between both distributors. Full article

Several industries are facing many challenges in their production systems due to increasing customer demand. Customer demand is growing for products with innovative features that are flexible, good quality, and appealing. This paper presents a flexible production-inventory system that produces multiple parts of a product. Defective products may be produced during the production process. Those defective products are remanufactured immediately after inspection. Limited budget and space constraints are considered, along with product assembly. Based on different distribution functions, non-linear equations are calculated using the Kuhn–Tucker optimization technique. Numerical examples, a graphical representation, and sensitivity analysis are presented in this paper. The solution procedure evaluates the minimization of the total investment based on the ${\chi }^2$ distribution. This study examines electronic products those are more likely to be defective rather than perfect during production. Full article

The oil and gas (O&G) field is the most sought-after industry in the Gulf Cooperation Countries (GCCs) and holds significant importance in the region’s economy. Therefore, this sector requires various industrial electrical, and electronics equipment (EEE) products to perform multiple tasks throughout the upstream, downstream, and midstream segments. However, as these EEE products approach their end of life (EoL), the sector faces the challenge of managing failed units. As a result, replacing or recycling failed EEE products can contribute to the growing problem of electronic waste (e-waste), which can have severe environmental consequences. In addition, while some EEE products can be repaired or remanufactured with low reliability, many others cannot be fixed due to various technical reasons. This paper’s primary goal is to propose a circular economy strategy and sustainable practices that promote the longevity of industrial EoL electronic products in the O&G sector through remanufacturing. We introduced and implemented a new mathematical score, the Index Of Repairability (IOR), which aims to assess the ease of EEE repairability in the O&G sector and improve their lifespan and durability based on four criteria: design, spare parts availability, software access, and documentation. This novel mathematical metric leverages the analytic hierarchy process (AHP) and set theory. Additionally, original equipment manufacturers (OEMs) can adopt and benefit from this innovative IOR by incorporating eco-design principles and designing more easily repairable industrial products for technicians, thereby reducing the negative impact of e-waste, enhancing stakeholder satisfaction, and minimizing downtime. Furthermore, governmental organizations can implement regulations and incentives to advocate for and mandate the use of the IOR by OEMs, ensuring that the electronics industry prioritizes repairability, remanufacturing, and sustainability. Full article

Directed energy deposition is a typical laser remanufacturing technology, which can effectively repair failed parts and extend their service life, and has been widely used in aerospace, metallurgy, energy and other high-end equipment key parts remanufacturing. However, the repair quality and performance of the repaired parts have been limited by the morphological and quality control problems of the process because of the formation mechanism and process of the deposition. The main reason is that the coupling of multiple process parameters makes the deposited layer morphology and surface properties difficult to be accurately predicted, which makes it difficult to regulate the process. Thus, the deposited layer forming mechanism and morphological properties of directed energy deposition were systematically analyzed, the height and width of multilayer deposition layers were taken as prediction targets, and a PSO-BP-based model for predicting the morphology of directed energy deposited layers was settled. The weights and thresholds of Back Propagation (BP) neural networks were optimized using a Particle Swarm Optimization (PSO) algorithm, the predicted values of deposited layer morphology for different process parameters were obtained, and the problem of low accuracy of deposited layer morphology prediction due to slow convergence and poor uniformity of the solution set of traditional optimization models was addressed. Remanufacturing experiments were conducted, and the experimental results showed that the deposited layer morphology prediction model proposed in this paper has a high prediction accuracy, with an average prediction error of 1.329% for the layer height and 0.442% for the layer width. The research of the paper provided an effective way to control the morphology and properties of the directed energy deposition process. A valuable contribution is made to the field of laser remanufacturing technology, and significant implications are held for various industries such as aerospace, metallurgy, and energy. Full article

Along with economic development and technological innovation, rapid expansion of agricultural machinery has sparked widespread concern. In particular, the superiority of scrapped agricultural machinery recycling and remanufacturing in improving environmental sustainability, economic benefits, and carbon emission reduction has garnered public attention. Based on this reality, this study constructs models for five different agricultural machinery recycling channels according to different actors involved in recovery, dismantling, and remanufacturing. Each model’s equilibrium is determined by mathematical deduction. The applicable condition of each model and the influence of multiple factors are analyzed. The results indicate the following: (i) no single recycling channel is definitely superior to others, and different channels have their own applicable conditions that are influenced by transfer payments, supply chain cooperation, recycling prices, and supply and demand; (ii) cooperative scenarios are more conducive to attracting third-party enterprises to participate to increase supply chain revenue; (iii) rise in recovery and remanufacturing prices may lead to divergence among supply chain parties on channel selection; and (iv) oversupply requires government subsidies to maintain recycling and remanufacturing. Full article

Most frameworks for dealing with the complexity of designing for the circular economy have limitations in terms of correlating different domains of knowledge, correlating highly complex design strategies, and facilitating the process of design strategies’ discovery and development. This paper discusses how managers and designers can create products that can be circulated for several life cycles by considering five different circular objectives (i.e., maintenance/longevity, reuse, refurbishment, remanufacture and/or recycling). To achieve one or more of these objectives, multiple design strategies can be used at various phases of each product life cycle and throughout the product’s lifetime. A literature review is used in this article to evaluate how circular objectives and design strategies are classified in terms of relevance, product life cycle phases, and product life cycles. The three classifications are merged to create a novel conceptual framework, which is then tested through the use of four circular case studies to map out life cycles, circular objectives, and design strategies. The framework may help managers and designers better understand how their businesses and products interact along the supply chain, allowing them to establish more effective product lifetime plans. Full article

Resources are becoming more expensive and less accessible, for instance construction wood or semiconductors. In addition, climate change requires the conversion of the energy system to 100% renewable energy. Therefore, we need resources to prevent the climate crisis from worsening, but at the same time, we are suffering from a worsening resource crisis. State-of-the-art technologies, such as silicon-based photovoltaic or wind power plants, are harnessing renewable energy but causing problems and resource losses at the end of their useful life. This alarming situation must be addressed with renewable energy technologies that can be used longer, repaired and remanufactured, and properly recycled at the end of their useful life. An emerging technology that can complement the established systems is dye-sensitized solar cells (DSSCs). Their production is less energy intensive and they can be manufactured without toxic materials. In line with the concept of the circular economy, the service life of all products must be improved in order to reduce resource consumption. Therefore, we investigated the potential for remanufacturing DSSCs by taking apart old DSSCs, cleaning the components, and building new DSSCs from the remanufactured components. The remanufactured DSSCs have the same or higher efficiencies and can be remanufactured multiple times. Full article

Over the years, the innovation and development of electrical and electronic equipment have been on a steep rise. Millions of electronics are being sold or discarded every year in the form of waste. Sustainable IT (Green IT or Circular Computing) is one of the most environment-friendly methods of reusing discarded or waste user electronics. The remanufacturing of a computer refers to the disassembly, repair, and upgrade of the original computer to give it a new life, along with a warranty that is as good as a new product. The goal of this work includes studying and assessing the total environmental impact of refurbishing a computer using life cycle assessment (LCA) integrated with discrete event simulation (DES), to compare two business models: (1) a case of centralized remanufacturing where the plants are in the Middle East, which is the hub for receiving waste electronics and distributing remanufactured goods; (2) a case of decentralized remanufacturing where the plants are situated in each continent for over a range of computer models. The environmental assessment was conducted using the openLCA software in combination with the WITNESS Horizon software for the DES. The results show that decentralized remanufacturing is a much more environmentally friendly option for the remanufacturing of computers, and the decentralized remanufacturing operation has a better throughput as well as efficiency, as compared to the centralized remanufacturing operation. The centralized remanufacturing scenario has a climate change impact of 1035.19 kg of CO₂-Eq, as compared to the decentralized remanufacturing scenario with an impact of 816.12 kg of CO₂-Eq. In terms of the impact on the marine life, decentralized remanufacturing was found to have 0.28 kg of N-Eq impact, as compared to centralized remanufacturing (0.22 kg of N-Eq). However, this does not give us a complete picture, as the environmental impact of the computer in its previous life remains unknown. Multi life cycle assessment is the assessment process that can be used to get a clearer picture of the ecological footprint of the computer during its multiple life cycles. Full article

Plasma transfer arc cladding technology has been widely utilized in surface engineering, repairing and remanufacturing. In the present work, multiple cladded thick claddings were prepared on compacted graphite cast iron (CGI) substrates with iron-based powders through plasma transfer arc cladding technology using different plasma arc currents to improve the surface wear resistance. The coatings’ phase and microstructure were analysed through XRD, SEM and EDS. The coatings’ microhardness and wear resistance were characterized. There were pearlite, graphite, austenite and secondary carbides in the iron-based alloy coatings. Due to the heat influence during the multiple cladding process, a spheroidal graphite transition zone appeared between the substrate and the coating. The microhardness of the claddings varied from 363 to 402 HV as the plasma arc current was changed from 45 to 60 A. With the increase of plasma arc current, the cladding’s microhardness increased. The iron-based coating’s minimum friction coefficient and wear mass loss were about 0.48 and 4.2 mg, respectively, when the plasma arc current was 60 A, which are lower values than those of the compacted graphite iron substrate with the friction coefficient and wear mass loss of 0.55 and 8.2 mg. Compared with the substrate, the iron-based alloy claddings achieved the effect of reducing friction and wear resistance simultaneously, which resulted from the self-lubricating effect of graphite and high wear-resistance of carbides in the claddings. The iron-based coatings had a similar abrasive wear mechanism to the CGI, which should be helpful to repair or remanufacture CGI workpieces. Full article