Integrating labor awareness to energy-efficient production scheduling under real-time electricity pricing : an empirical study

With the penetration of smart grid into factories, energy-efficient production scheduling has emerged as a promising method for industrial demand response. It shifts flexible production loads to lower-priced periods to reduce energy cost for the same production task. However, the existing methods only focus on integrating energy awareness to conventional production scheduling models. They ignore the labor cost which is shift-based and follows an opposite trend of energy cost. For instance, the energy cost is lower during nights while the labor cost is higher. Therefore, this paper proposes a method for energy-efficient and labor-aware production scheduling at the unit process level. This integrated scheduling model is mathematically formulated. Besides the state-based energy model and genetic algorithm-based optimization, a continuous-time shift accumulation heuristic is proposed to synchronize power states and labor shifts. In a case study of a Belgian plastic bottle manufacturer, a set of empirical sensitivity analyses were performed to investigate the impact of energy and labor awareness, as well as the production-related factors that influence the economic performance of a schedule. Furthermore, the demonstration was performed in 9 large-scale test instances, which encompass the cases where energy cost is minor, moderate, and major compared to the joint energy and labor cost. The results have proven that the ignorance of labor in existing energy-efficient production scheduling studies increases the joint energy and labor cost, although the energy cost can be minimized. To achieve effective production cost reduction, energy and labor awareness are recommended to be jointly considered in production scheduling. (C) 2017 Elsevier Ltd. All rights reserved

Energy saving in tooling machines: a new unified approach to reduce energy consumption

Tooling machines are included in some EU directives, which set specific targets for the reduction of energy consumption in the near future. This paper aims to introduce a design approach that can be useful both for safety functional decomposition and for energy consumption evaluation of a generic tooling machines. This design approach tries to unify the existing divergent approach to energy efficient and safe tooling machines. A very simple application, already installed in some lathe machines currently produced in the EU, will give us all the necessary data (activity time counter) to perform a quantitative assessment in term of unified energy-efficient and safe machines. Moreover, the main results of an extensive survey made by a lathe manufacturer on real machines utilization and some measurement of wasted energy during standby mode of different machines will be presented. Those measurements show that it is not possible to define a proper LCA design method without considering that the wasted energy is a function of the size and type of processes and the specific operating conditions of the machine. Measurements, performed during stand-by of lathes with regenerative drives, are presented at the end of the paper

Eco-efficient process based on conventional machining as an alternative technology to chemical milling of aeronautical metal skin panels

El fresado químico es un proceso diseñado para la reducción de peso de pieles metálicas que, a pesar de los problemas medioambientales asociados, se utiliza en la industria aeronáutica desde los años 50. Entre sus ventajas figuran el cumplimiento de las estrictas tolerancias de diseño de piezas aeroespaciales y que pese a ser un proceso de mecanizado, no induce tensiones residuales. Sin embargo, el fresado químico es una tecnología contaminante y costosa que tiende a ser sustituida. Gracias a los avances realizados en el mecanizado, la tecnología de fresado convencional permite alcanzar las tolerancias requeridas siempre y cuando se consigan evitar las vibraciones y la flexión de la pieza, ambas relacionadas con los parámetros del proceso y con los sistemas de utillaje empleados. Esta tesis analiza las causas de la inestabilidad del corte y la deformación de las piezas a través de una revisión bibliográfica que cubre los modelos analíticos, las técnicas computacionales y las soluciones industriales en estudio actualmente. En ella, se aprecia cómo los modelos analíticos y las soluciones computacionales y de simulación se centran principalmente en la predicción off-line de vibraciones y de posibles flexiones de la pieza. Sin embargo, un enfoque más industrial ha llevado al diseño de sistemas de fijación, utillajes, amortiguadores basados en actuadores, sistemas de rigidez y controles adaptativos apoyados en simulaciones o en la selección estadística de parámetros. Además se han desarrollado distintas soluciones CAM basadas en la aplicación de gemelos virtuales. En la revisión bibliográfica se han encontrado pocos documentos relativos a pieles y suelos delgados por lo que se ha estudiado experimentalmente el efecto de los parámetros de corte en su mecanizado. Este conjunto de experimentos ha demostrado que, pese a usar un sistema que aseguraba la rigidez de la pieza, las pieles se comportaban de forma diferente a un sólido rígido en términos de fuerzas de mecanizado cuando se utilizaban velocidades de corte cercanas a la alta velocidad. También se ha verificado que todas las muestras mecanizadas entraban dentro de tolerancia en cuanto a la rugosidad de la pieza. Paralelamente, se ha comprobado que la correcta selección de parámetros de mecanizado puede reducir las fuerzas de corte y las tolerancias del proceso hasta un 20% y un 40%, respectivamente. Estos datos pueden tener aplicación industrial en la simplificación de los sistemas de amarre o en el incremento de la eficiencia del proceso. Este proceso también puede mejorarse incrementando la vida de la herramienta al utilizar fluidos de corte. Una correcta lubricación puede reducir la temperatura del proceso y las tensiones residuales inducidas a la pieza. Con este objetivo, se han desarrollado diferentes lubricantes, basados en el uso de líquidos iónicos (IL) y se han comparado con el comportamiento tribológico del par de contacto en seco y con una taladrina comercial. Los resultados obtenidos utilizando 1 wt% de los líquidos iónicos en un tribómetro tipo pin-on-disk demuestran que el IL no halogenado reduce significativamente el desgaste y la fricción entre el aluminio, material a mecanizar, y el carburo de tungsteno, material de la herramienta, eliminando casi toda la adhesión del aluminio sobre el pin, lo que puede incrementar considerablemente la vida de la herramienta.Chemical milling is a process designed to reduce the weight of metals skin panels. This process has been used since 1950s in the aerospace industry despite its environmental concern. Among its advantages, chemical milling does not induce residual stress and parts meet the required tolerances. However, this process is a pollutant and costly technology. Thanks to the last advances in conventional milling, machining processes can achieve similar quality results meanwhile vibration and part deflection are avoided. Both problems are usually related to the cutting parameters and the workholding. This thesis analyses the causes of the cutting instability and part deformation through a literature review that covers analytical models, computational techniques and industrial solutions. Analytics and computational solutions are mainly focused on chatter and deflection prediction and industrial approaches are focused on the design of workholdings, fixtures, damping actuators, stiffening devices, adaptive control systems based on simulations and the statistical parameters selection, and CAM solutions combined with the use of virtual twins applications. In this literature review, few research works about thin-plates and thin-floors is found so the effect of the cutting parameters is also studied experimentally. These experiments confirm that even using rigid workholdings, the behavior of the part is different to a rigid body at high speed machining. On the one hand, roughness values meet the required tolerances under every set of the tested parameters. On the other hand, a proper parameter selection reduces the cutting forces and process tolerances by up to 20% and 40%, respectively. This fact can be industrially used to simplify workholding and increase the machine efficiency. Another way to improve the process efficiency is to increase tool life by using cutting fluids. Their use can also decrease the temperature of the process and the induced stresses. For this purpose, different water-based lubricants containing three types of Ionic Liquids (IL) are compared to dry and commercial cutting fluid conditions by studying their tribological behavior. Pin on disk tests prove that just 1wt% of one of the halogen-free ILs significantly reduces wear and friction between both materials, aluminum and tungsten carbide. In fact, no wear scar is noticed on the ball when one of the ILs is used, which, therefore, could considerably increase tool life

A framework for energy monitoring of machining workshops based on IoT

Machining workshop is a widely distributed manufacturing system that consumes massive energy in low efficiency. Due to the complicated and dynamic energy flow of the machining workshop, machinery manufacturers still lack an effective method to monitor and manage the energy efficiency. Hence, this paper proposes an energy efficiency monitoring system for machining workshop with the support of the newly emerging Internet of Things (IoT) technology. With the application of the proposed system, potential opportunities for energy efficiency improvement can be identified. Machinery manufacturers can easily reduce energy consumption and energy cost by managing the machining process

Latest Developments in Industrial Hybrid Machine Tools that Combine Additive and Subtractive Operations

Hybrid machine tools combining additive and subtractive processes have arisen as a solution to increasing manufacture requirements, boosting the potentials of both technologies, while compensating and minimizing their limitations. Nevertheless, the idea of hybrid machines is relatively new and there is a notable lack of knowledge about the implications arisen from their in-practice use. Therefore, the main goal of the present paper is to fill the existing gap, giving an insight into the current advancements and pending tasks of hybrid machines both from an academic and industrial perspective. To that end, the technical-economical potentials and challenges emerging from their use are identified and critically discussed. In addition, the current situation and future perspectives of hybrid machines from the point of view of process planning, monitoring, and inspection are analyzed. On the one hand, it is found that hybrid machines enable a more efficient use of the resources available, as well as the production of previously unattainable complex parts. On the other hand, it is concluded that there are still some technological challenges derived from the interaction of additive and subtractive processes to be overcome (e.g., process planning, decision planning, use of cutting fluids, and need for a post-processing) before a full implantation of hybrid machines is fulfilledSpecial thanks are addressed to the Industry and Competitiveness Spanish Ministry for the support on the DPI2016-79889-R INTEGRADDI project and to the PARADDISE project H2020-IND-CE-2016-17/H2020-FOF-2016 of the European Union's Horizon 2020 research and innovation program

The potential of additive manufacturing in the smart factory industrial 4.0: A review

Additive manufacturing (AM) or three-dimensional (3D) printing has introduced a novel production method in design, manufacturing, and distribution to end-users. This technology has provided great freedom in design for creating complex components, highly customizable products, and efficient waste minimization. The last industrial revolution, namely industry 4.0, employs the integration of smart manufacturing systems and developed information technologies. Accordingly, AM plays a principal role in industry 4.0 thanks to numerous benefits, such as time and material saving, rapid prototyping, high efficiency, and decentralized production methods. This review paper is to organize a comprehensive study on AM technology and present the latest achievements and industrial applications. Besides that, this paper investigates the sustainability dimensions of the AM process and the added values in economic, social, and environment sections. Finally, the paper concludes by pointing out the future trend of AM in technology, applications, and materials aspects that have the potential to come up with new ideas for the future of AM explorations

Energy performance certification in mechanical manufacturing industry: a review and analysis

The energy performance certification has been recognized as an effective assessment methodology and tool to systematically manage energy consumption and improve energy performance. In the process manufacturing industry and building industry, a large number of energy performance certifications have been applied worldwide with remarkable results achieved in energy saving and emissions mitigation. Mechanical manufacturing industry, which is characterised as a typical discrete manufacturing having a wide distribution in operations with large consumption of energy and low efficiency, has a considerable potential of benefiting from energy saving and emissions mitigation. The objective of this paper is to perform a review and analysis of energy performance certification in the mechanical manufacturing industry for evaluating its potentials and applicability for performance enhancement. We begin with analyzing energy performance certification and research gaps to develop an operational definition of energy performance certification. The scope of energy performance certification and the method for data acquisition are reviewed. Next, we establish the classification of energy performance certification from perspectives of the energy benchmarking, rating and labelling to lay a foundation for its implementation framework and evaluating its practicability. Through the systemic review and analysis, the current state of researching energy performance certification is provided with the methods for developing energy performance certification summarized and analyzed. These findings are useful references for managers to strengthen energy management and monitoring and improve energy performance in the mechanical manufacturing industry.- This work was supported by Fundamental Research Funds for the Central Universities (SWU118068), the National Natural Science Foundation of China (Grant No. 51875480 and 51805479) and Humanities and Social Science Research of Ministry of Education (No. 17YJC630082)

Life Cycle Energy Assesment of Advanced Fiber Reinforced Composite Design and Manufacturing Methodologies

Automotive industry at large is focused on vehicle light-weighting since a 6%-8% increase in fuel efficiency can be achieved with a 10% reduction in vehicle weight [1]. With the growing demand for cost-effective and sustainable light weighting of automobile structures, interest has increased in the application of fiber reinforced plastic (FRP) composites for use in the Body-in-White (BiW), which can account for up to 40% of the total vehicle weight. Traditional FRP composite manufacturing processes like vacuum assisted resin transfer molding, autoclave consolidation or use of automated fiber placement have been successfully used for marine and aerospace applications. However, these processes are not suitable for the automotive industry due to the low production rate, need for highly skilled labor for manufacturing and quality control, and poor joining with traditional structural materials like steel. This necessitates the use of higher throughput outof-autoclave (OOA) processes like high pressure resin transfer molding (HP-RTM), wet compression molding (WCM) or even fiber reinforced thermoplastics (FR-TP) forming. The transition to these OOA processes face two major challenges: a) the time-consuming iterative design and thermal profiling process required for metal tools which increases cost; and b) the lack of a low-cost, scalable, and sustainable multi-material joining pathways that can enable integration of FRP composite parts with traditional metal structures. This is because existing composite joining methods necessitate significant redesign of existing OEM infrastructure, incur high capital costs, and produce weak joints between metal and composite components. iii To address the first challenge, a new paradigm where additive manufacturing of thermoplastic filament reinforced with continuous fiber is used to develop a low-cost and sustainable composite tool, is investigated. Furthermore, additive manufacturing can enable faster tool design turn-around times and allows for designing of complex tool geometries with embedded sensors and conformal cooling channels. This opens greater avenues for process and design optimization and will enable manufacturers to gain a better understanding of the process based on sensor data gathered in real time from the embedded sensors. To address the later challenge, a highly integrated multi-material, FRP-intensive BiW design was developed using unique multi-material transition joints which retain existing OEM joining infrastructure [2]. It incorporates multi-material transition joints where continuous dry fibers are laid through machined looped channels in a metal substrate and additional metal layers are additively manufactured on top of the looped fiber and metal substrate to embed the fibers within the metal and create a strong metal – fiber mechanical interlocking bond. The fibers are then infused with a thermoset matrix that fills out the loops as well, forming a string FRP-metal transition [3]. Thus, the resulting CFRP component with metal tabs can be spot welded to other metal components without piercing, drilling, or punching holes - significantly increasing the mechanical performance of the multi-material joints. To ascertain the advantages of these multi-material designs and the use of state-of-the-art additively manufactured smart tools, their life cycle impact must be investigated and compared with existing technology. The results from the LCA can provide vital understanding of the energy requirements of the new processes methodologies and can help iv quantify the benefits offered by transitioning to this new proposed paradigm of composite design and manufacturing from a sustainability and emission reduction standpoint. To best of the authors knowledge there have been no studies that address the LCA for each of the proposed solutions. Thus, this work, conducts two comparative life cycle analyses on the proposed additively manufactured smart composite tool for OOA processes and for the multi-material designs for automotive structural components. Different scenarios are studied for both the LCAs to consider the existing FRP production processes as well as the production process of traditional materials

Improving energy efficiency of machine tools

Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 125–130.Manufacturing is responsible for about one half of global consumption of primary energy, a great deal of which is consumed by machine tools producing discrete parts. The topic of energy efficiency is driven forward by machine tool users who demand low operational costs, as well as social and legislative forces requiring environmentally friendlier manufacturing. This paper aims to provide examples and good practices for improving machine tool energy efficiency with a focus on metal cutting machine tools. During the design stage, there are various opportunities to minimize inherent energy losses by selecting and dimensioning drives and peripherals. On the other hand, users have a large impact on productivity by using the machine effectively and knowledgeably. The paper also presents techniques for measurement and analysis of the energy profile of machines which help to better target energy saving measures on already existing machines

Best Environmental Management Practice in the Fabricated Metal Product manufacturing sector

This report encloses technical information pertinent to the development of Best Environmental Management Practices (BEMPs) for the Sectoral Reference Document on the Fabricated Metal Products manufacturing sector, to be produced by the European Commission according to Article 46 of Regulation (EC) No 1221/2009 (EMAS Regulation). The BEMPs, both of technological and management nature (identified in close cooperation with a technical working group) address all the relevant environmental aspects of the Fabricated Metal Products manufacturing facilities. The BEMPs described in this report provide guidance on the cross-cutting issues and optimisation of utilities of the manufacturing facilities. Moreover, the BEMPs cover also the most relevant manufacturing processes, looking at energy and material efficiency, protecting and enhancing biodiversity, using of renewable energy and using rationally and effectively chemicals e.g. for cooling of various machining processes. Each BEMP gives a wide range of information and outlines the achieved environmental benefits, appropriate environmental performance indicators to measure environmental performance against the proposed benchmarks of excellence, economics etc. aiming at giving inspiration and guidance to any company of the sector who wishes to improve its environmental performance.JRC.B.5-Circular Economy and Industrial Leadershi