The use of disinfection and cleaning chemicals in several municipal facilities, such as swimming pools and drinking water treatment plants, causes the degradation of various types of wood, which ...leads to failures in equipment and the corresponding need for maintenance. This degradation creates added costs for municipalities, as well as the closure of certain facilities due to curative or preventive maintenance and, in many cases, public health issues, due to the water being contaminated with deteriorating products. Through a thorough study of the degradation effect on the products, more resistant materials can be found which are able to withstand these adversities and increase the lifespan of wood in regular contact with chemical agents. This is achievable by the determination of the cost-effectiveness of the substitute material to replace these components with alternative ones, with properties that better resist the deterioration effects promoted by aggressive environments. No studies have been found so far strictly focused on this matter. The objective of this study is to evaluate the degradation presented by two types of wood, beech and oak, which are exposed to the action of chlorine in municipal facilities. This degradation varies according to the chlorine content and the materials' time of contact with the chemical agent, allowing the selection of new materials which will provide an extended lifetime of the components, reducing maintenance drastically, as well as costs for the facilities and the risk to public health. The performed experimental tests have shown that the oak wood has the best results regarding chlorine degradation resistance.
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Due to chlorine’s ability to kill bacteria and fungi through a chemical reaction, chlorine solutions are commonly used to clean and disinfect numerous public facilities, although these actions are ...also dependent to the equipment present in those facilities. Accordingly, the interest in studying its effect when in contact with different materials is obvious. This study was carried out through accelerated degradation tests and various analysis methods (optical microscope, scanning electron microscope, and tensile tests). The objective was to observe the wear presented by three polymeric materials, polyvinyl chloride (PVC), high-density polyethylene (HDPE), and polypropylene (PP), when exposed to chlorine’s action in swimming pools and drinking water treatment plants. The resulting effect depends on the chlorine content and the type of contact between the chemical agent and the material. The aim was to select the material less likely to be affected by chlorine through tests and analyses, allowing a longer component life. The use of certain more resistant polymeric materials can drastically reduce maintenance, reducing fundamental factors such as costs, the downtime of municipal facilities, and also the risk to public health. It was concluded that PVC has the most stable behaviour overall when in contact with chlorine solutions.
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Currently, there is a lack of affordable and simple tools for the estimation of these costs, especially for machining operations. This is particularly true for manufacturing SMEs, in which the cost ...estimation of machined parts is usually performed based only on required material for part production, or involves a time-consuming, non-standardized technical analysis. Therefore, a cost estimation tool was developed, based on the calculated machining times and amount of required material, based on the final drawing of the requested workpiece. The tool was developed primarily for milling machines, considering milling, drilling, and boring/threading operations. Regarding the considered materials, these were primarily aluminum alloys. However, some polymer materials were also considered. The tool first estimates the required time for total part production and then calculates the total cost. The total production time is estimated based on the required machining operations, as well as drawing, programming, and machine setup time. A part complexity level was also introduced, based on the number of details and operations required for each workpiece, which will inflate the estimated times. The estimation tool was tested in a company setting, comparing the estimated operation time values with the real ones, for a wide variety of parts of differing complexity. An average error of 14% for machining operation times was registered, which is quite satisfactory, as this time is the most impactful in terms of machining cost. However, there are still some problems regarding the accuracy in estimating finishing operation times.
One of the most critical factors in producing plastic injection molds is the cost estimation of machining services, which significantly affects the final mold price. These services’ costs are ...determined according to the machining time, which is usually a long and expensive operation. If it is considered that the injection mold parts are all different, it can be understood that the correct and quick estimation of machining times is of great importance for a company’s success. This article presents a proposal to apply artificial neural networks in machining time estimation for standard injection mold parts. For this purpose, a large set of parts was considered to shape the artificial intelligence model, and machining times were calculated to collect enough data for training the neural networks. The influences of the network architecture, input data, and the variables used in the network’s training were studied to find the neural network with greatest prediction accuracy. The application of neural networks in this work proved to be a quick and efficient way to predict cutting times with a percent error of 2.52% in the best case. The present work can strongly contribute to the research in this and similar sectors, as recent research does not usually focus on the direct prediction of machining times relating to overall production cost. This tool can be used in a quick and efficient manner to obtain information on the total machining cost of mold parts, with the possibility of being applied to other industry sectors.
The automotive industry demands high quality at very low prices. To this end, it is necessary to constantly innovate, making processes increasingly competitive, while continuing to ensure high levels ...of quality. Model diversification has forced the automotive industry to make its manufacturing processes more flexible, without losing competitiveness. This has been the case for car seats, where the quantities to be produced per batch are significantly lowering due to the diversity of existing models. The objective of this work was to increase the production rate of bent wires used in car seat cushions and increase the flexibility of changing wire types in production. After benchmarking the existing solutions so far, it was verified that none are capable of complying with the required production rate, while also offering the desired flexibility. Thus, it is necessary to start with a new concept of conformation of the wires used in these seat cushions. The new concept developed and integrated some of the previously known solutions, developing other systems capable of providing the desired response in terms of productivity and flexibility. To this end, new mechanical solutions and automated systems were developed, which, together with other existing ones, made it possible to design equipment that complies with all the necessary requirements. The developed concept is innovative and can be employed to other types of products in which it can be applied. The new concept developed yields a production rate of 950 parts/hour (initial goal: 800 parts/hour), features a setup time of around 30 min, ensuring the desired flexibility, and the tool costs about 90% less than traditional tools. The payback period is around 5 months, given that the equipment cost was EUR 122.000 in terms of construction and assembly, and generated a gain of EUR 280.000 in the first year of service.
The automotive industry is a pioneer in solutions that meet market expectations. However, in the automotive industry, some less environmentally friendly technologies are still used, such as ...electroplating. Due to legislative restrictions in several countries, thin coatings made in a vacuum have been replacing coatings traditionally made by electroplating, mainly in decorative terms. This work is more focused on the use of these coatings made in vacuum for optical applications, namely on headlights and exterior backlit components. Although these components are protected during the period of use, there may be situations of contact during the assembly of the components or their repair, necessary to safeguard and to ensure that these coatings have the scratch and wear resistance needed to withstand any treatment deficiency during the operations referred to above. Therefore, this work is essentially focused on the study of the wear resistance of Cr coatings made by PVD (Physical Vapour Deposition) on polymeric substrates. To this end, the coatings previously studied have now been subjected to micro-abrasion tests, with a view to assessing their wear resistance. For this purpose, alumina abrasive has been used, and the wear mechanisms observed in the coatings were studied. The abrasion and scratch tests showed that the most stable film has the one provided with 10-layers, showing greater wear resistance as well, greater adhesion to the substrate and less cohesive failures in the performed tests. Given the nature of the substrate and the coating, the results obtained are very promising, showing that these 10-layer Cr thin coatings can overcome any careless operation during manufacturing, assembly and repair processes, when applied in lightning or backlit components in motor vehicles.
Automotive industries require constant technological development and the capacity to adapt to market needs. Hence, component suppliers must be able to adapt to persistent trend changes and technical ...improvements, acting in response to customers’ expectations and developing their manufacturing methods to be as flexible as possible. Concepts such as layout flexibility, management of industrial facilities, and building information modeling (BIM) are becoming ever more addressed within the automotive industry in order to envision and select the necessary information exchanges. Given this question and based on the gap in the literature regarding this subject, this work proposes a solution, developing a novel tool that allows the monitoring and assignment of newer/relocated equipment to the switchboards within a given industrial plant. The solution intends to increase the flexibility of production lines through the assessment, analysis, improvement, and reorganization of the electrical load distribution to develop projects accurately implying layout changes. The tool is validated with an automotive manufacturer. With the implementation of this open-source tool, a detailed electrical flow management system is accomplished, and it has proven successful and essential in raising levels of organizational flexibility. This has guaranteed the company’s competitiveness with effective integrated administration methods and tools, such as a much easier study upon inserting new/relocated equipment without production line breaks.
High pressure die casting is widely used in metalworking industry. Many of the components and devices directly linked to the hot parts are subjected to severe wear. However, some design updates can ...enlarge the lifespan of these components and devices. This paper proposes to show how a sustainable maintenance can be obtained by focusing resources on the analysis of the critical problem and its consequent mitigation, whereas they are originated on the human, machine/process or supplier level. Design science research (DSR) was the iterative research methodology chosen to integrate this work. The completion of the objective with the implementation of this new injection subset concept brought extremely beneficial results, such as reduction of its consumption, reduction of acquisition cost and waste generated, and reduction of the intervention time during maintenance operations, as well as increase in equipment availability time.
Due to the automotive industry’s strict demands, customers submit constant production pressure, leading to the adoption of new methodologies, techniques, and management ideas. The goal is always to ...minimise losses and waste. These demands also affect the maintenance department, which has to keep the balance between machines’ availability for production and ensuring that the machines’ proper running conditions translate into excellent-quality products. Thus, continuous improvement and correct management of maintenance activities are crucial for a company to maintain effective production, without defects, breakdowns, and accidents. Nevertheless, some maintenance activities should also prevent the degradation of equipment conditions in order to produce high-quality products. This paper presents an improvement of maintenance activities conducted on equipment that produces large tires. The main problems and technical difficulties of Machine Tolerance Check (MTC) activities are explored by analysing existing documents, internal knowledge, and changes to working methods. We discuss the implementation of the SMED (Single-Minute Exchange of Die) methodology in calibration procedures, as this method is commonly applied to machines’ setups to reduce downtime. At the end of the study, a 31% decrease in the duration of machine tolerance check activities was achieved, which led to a significant increase in the equipment’s availability.
Wire rope manufacturing is an old industry that maintains its place in the market due to the need for products with specific characteristics in different sectors. The necessity for modernization and ...performance improvement in this industry, where there is still a high amount of labor dedicated to internal logistics operations, led to the development of a new technology method, to overcome uncertainties related to human behaviour and fatigue. The removal of successive yarn coils from a twisting and winding machine, as well as cutting the yarn and connecting the other end to the shaft in order to proceed with the process, constitutes the main problem. As such, a mobile automatic system was created for this process, due to its automation potential, with a project considering the design of a 3D model. This novel robotic manipulator increased the useful production time and decreased the winding coil removal cycle time, resulting in a more competitive, fully automated product with the same quality. This system has led to better productivity and reliability of the manufacturing process, eliminating manual labor and its cost, as in previously developed works in other industries.
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