Manuel Rodríguez-Martín, Pablo Rodríguez-Gonzálvez, Leticia Aguado, Susana Martinez-Pellitero
A low-cost method based on macro-photogrammetric reconstruction is presented to automatically detect wear and other defects in small gears created with additive manufacturing. This novel approach is oriented to preventive and predictive maintenance of gears in order to avoid faults in machines and devices. The experimentation has been conducted using three defective gears produced in Nylon PA-12. First, a robotic platform and a systematic macro-photogrammetric data acquisition procedure were used to accomplish the 3D reconstruction and generate the dense point clouds. Subsequently, a comparison between the dense point cloud and the ideal solid CAD model of the normalized gear has been carried out. For this aim, the models have been alignment in the same spatial system. The computation of the distances between solid models and point clouds allows the automatic visualization of different types of defects even for defects that are not visible to the naked eye. This conclusion has been checked from a statistical point of view considering the discrepancies obtained in the comparison and their distribution.
{"title":"Automatic Wear Detection on Normalized Gears Made by Additive Manufacturing from Dense 3D Point Clouds","authors":"Manuel Rodríguez-Martín, Pablo Rodríguez-Gonzálvez, Leticia Aguado, Susana Martinez-Pellitero","doi":"10.4028/p-w5k99c","DOIUrl":"https://doi.org/10.4028/p-w5k99c","url":null,"abstract":"A low-cost method based on macro-photogrammetric reconstruction is presented to automatically detect wear and other defects in small gears created with additive manufacturing. This novel approach is oriented to preventive and predictive maintenance of gears in order to avoid faults in machines and devices. The experimentation has been conducted using three defective gears produced in Nylon PA-12. First, a robotic platform and a systematic macro-photogrammetric data acquisition procedure were used to accomplish the 3D reconstruction and generate the dense point clouds. Subsequently, a comparison between the dense point cloud and the ideal solid CAD model of the normalized gear has been carried out. For this aim, the models have been alignment in the same spatial system. The computation of the distances between solid models and point clouds allows the automatic visualization of different types of defects even for defects that are not visible to the naked eye. This conclusion has been checked from a statistical point of view considering the discrepancies obtained in the comparison and their distribution.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135833370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francisco Javier Doblas-Charneco, Domingo Morales-Palma, Aida Estevez, Carpoforo Vallellano
An analytical model of the cold wire drawing process is used to implement an optimization procedure. The optimization aims to minimize the number of passes required to achieve a given reduction while maintaining a safe value of the drawing stress in each step. The number of passes and the sequence of intermediate diameters are the output of the optimization model. The sequence of diameters is optimal in the sense that minimizes a mathematical objective function, and their values must be considered a first attempt to determine appropriate values for a specific wire drawing operation. With respect to prior contributions, the work hardening of the material is exploited to reduce the number of passes. The reduction of the number of passes yields lower values of the aspect ratio, defined as the mean diameter divided by the contact length, which is an important factor to prevent the onset of internal defects. The optimization is performed numerically with mathematical programming and metaheuristic algorithms.
{"title":"Mathematical Optimization of Cold Wire Drawing Operations","authors":"Francisco Javier Doblas-Charneco, Domingo Morales-Palma, Aida Estevez, Carpoforo Vallellano","doi":"10.4028/p-3lhbry","DOIUrl":"https://doi.org/10.4028/p-3lhbry","url":null,"abstract":"An analytical model of the cold wire drawing process is used to implement an optimization procedure. The optimization aims to minimize the number of passes required to achieve a given reduction while maintaining a safe value of the drawing stress in each step. The number of passes and the sequence of intermediate diameters are the output of the optimization model. The sequence of diameters is optimal in the sense that minimizes a mathematical objective function, and their values must be considered a first attempt to determine appropriate values for a specific wire drawing operation. With respect to prior contributions, the work hardening of the material is exploited to reduce the number of passes. The reduction of the number of passes yields lower values of the aspect ratio, defined as the mean diameter divided by the contact length, which is an important factor to prevent the onset of internal defects. The optimization is performed numerically with mathematical programming and metaheuristic algorithms.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135833557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reverse engineering, or the creation of models from physical objects, is increasingly being used in many industries including manufacturing, automotive design, and computer animation. The presented work focuses on the issue of data preparation for reverse engineering. The aim of the thesis is to map the issues of working with the Zeiss LineScan optical sensor on a 3D coordinate measuring machine in the metrology laboratory of the Regional Institute of Technology at the University of West Bohemia. The aim of the work was to map the software setting options supplied by the sensor manufacturer. The sensor can obtain clouds of three types of points: RSL (Raw Scan Lines - measured points, directly recorded by the scanner, without further adjustments), GSL (Gridded Scan Lines - points reduced and grouped into a grid of a given step), and QSP (Qualified Surface points - compressed and grouped points into a given grid). The evaluation of the experiment revealed the ideal setting for the specified measurement conditions. Reference objects with nominal lengths of 100 mm and 500 mm were chosen. The data required for evaluating each sensor setting were obtained through a series of measurements of these objects. The output of the experiment is a comparison of each option for setting up the scanning method. GSL points with a step setting of 0.1 mm were evaluated as the most suitable setting for measuring objects with similar shapes. They showed stable deviations within the selected tolerance of ± 0.03 mm for all measurement variations. RSL and QSP points, on the other hand, showed less stability of deviations across the measurements.
{"title":"Data Preparing for Reverse Engineering","authors":"Dana Kubátová, Ladislav Čížek, Vítězslav Netrval","doi":"10.4028/p-82p5tv","DOIUrl":"https://doi.org/10.4028/p-82p5tv","url":null,"abstract":"Reverse engineering, or the creation of models from physical objects, is increasingly being used in many industries including manufacturing, automotive design, and computer animation. The presented work focuses on the issue of data preparation for reverse engineering. The aim of the thesis is to map the issues of working with the Zeiss LineScan optical sensor on a 3D coordinate measuring machine in the metrology laboratory of the Regional Institute of Technology at the University of West Bohemia. The aim of the work was to map the software setting options supplied by the sensor manufacturer. The sensor can obtain clouds of three types of points: RSL (Raw Scan Lines - measured points, directly recorded by the scanner, without further adjustments), GSL (Gridded Scan Lines - points reduced and grouped into a grid of a given step), and QSP (Qualified Surface points - compressed and grouped points into a given grid). The evaluation of the experiment revealed the ideal setting for the specified measurement conditions. Reference objects with nominal lengths of 100 mm and 500 mm were chosen. The data required for evaluating each sensor setting were obtained through a series of measurements of these objects. The output of the experiment is a comparison of each option for setting up the scanning method. GSL points with a step setting of 0.1 mm were evaluated as the most suitable setting for measuring objects with similar shapes. They showed stable deviations within the selected tolerance of ± 0.03 mm for all measurement variations. RSL and QSP points, on the other hand, showed less stability of deviations across the measurements.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135833758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pedro J.P.D. Pereira, Raul D.S.G. Campilho, João P.G.T. Pereira, Luís C.F. Moreira, Chander Prakash
Soft robotics presents itself as a new path to adopt in several applications in the industry. The area of soft robotics aims to equip robots for unpredictable needs, providing them with capabilities that are based not on control systems, but on the properties of materials and the morphology of their bodies. This work aims the creation of a soft robotics application, more specifically a soft gripper. The development of an original concept of a soft material handler (soft gripper) is intended, capable of performing the stipulated handling functions, through certain actuation mechanisms, meeting the requirements and constraints presented in the next sub-section. The final solution is based on an improvement procedure supported on structural Finite Element (FE) analyses. Cost analysis and prototype construction/validation finalize the evaluation. The gripper was designed, a prototype was executed, and tests were carried out to prove correct operation. These tests were successful showing the project as suitable for a real production environment.
{"title":"Design and Validation of Gripper Solution Using Soft Robotics Principles","authors":"Pedro J.P.D. Pereira, Raul D.S.G. Campilho, João P.G.T. Pereira, Luís C.F. Moreira, Chander Prakash","doi":"10.4028/p-gkwdy2","DOIUrl":"https://doi.org/10.4028/p-gkwdy2","url":null,"abstract":"Soft robotics presents itself as a new path to adopt in several applications in the industry. The area of soft robotics aims to equip robots for unpredictable needs, providing them with capabilities that are based not on control systems, but on the properties of materials and the morphology of their bodies. This work aims the creation of a soft robotics application, more specifically a soft gripper. The development of an original concept of a soft material handler (soft gripper) is intended, capable of performing the stipulated handling functions, through certain actuation mechanisms, meeting the requirements and constraints presented in the next sub-section. The final solution is based on an improvement procedure supported on structural Finite Element (FE) analyses. Cost analysis and prototype construction/validation finalize the evaluation. The gripper was designed, a prototype was executed, and tests were carried out to prove correct operation. These tests were successful showing the project as suitable for a real production environment.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alberto Gil-Cuadrado, Alberto Martínez-Gutiérrez, Javier Díez-González, Paula Verde, Rubén Ferrero-Guillén, Hilde Perez
The digitization of processes in the context of Smart Manufacturing enables the control and monitoring of production processes. Visual inspection of parts is a process where the surface finish of machined parts is evaluated. For this purpose, manual inspection units have been traditionally used to evaluate the validity of the parts. This manual inspection process requires the operator to position the lens to obtain the images, which supposes an inefficient and non-repeatable process producing a considerable waste of production time. In order to design a more competitive process in the context of Smart Manufacturing, we fully automate in this paper an industrial borescopy unit by implementing closed-loop stepper motors, sensors, and microcontrollers. In addition, a web server has been programmed where operators monitor and upload ISO codes depending on the inspected part. This web server is connected to the microcontroller and the borescope positioning camera for automatic imaging. Therefore, the visual part inspection unit has been digitized and provided with connectivity and intelligence as the cyber physical system of the Smart Manufacturing.
{"title":"Full Automation of a Manual Inspection Unit for Industrial Borescopy","authors":"Alberto Gil-Cuadrado, Alberto Martínez-Gutiérrez, Javier Díez-González, Paula Verde, Rubén Ferrero-Guillén, Hilde Perez","doi":"10.4028/p-a8vf4e","DOIUrl":"https://doi.org/10.4028/p-a8vf4e","url":null,"abstract":"The digitization of processes in the context of Smart Manufacturing enables the control and monitoring of production processes. Visual inspection of parts is a process where the surface finish of machined parts is evaluated. For this purpose, manual inspection units have been traditionally used to evaluate the validity of the parts. This manual inspection process requires the operator to position the lens to obtain the images, which supposes an inefficient and non-repeatable process producing a considerable waste of production time. In order to design a more competitive process in the context of Smart Manufacturing, we fully automate in this paper an industrial borescopy unit by implementing closed-loop stepper motors, sensors, and microcontrollers. In addition, a web server has been programmed where operators monitor and upload ISO codes depending on the inspected part. This web server is connected to the microcontroller and the borescope positioning camera for automatic imaging. Therefore, the visual part inspection unit has been digitized and provided with connectivity and intelligence as the cyber physical system of the Smart Manufacturing.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miguel Ángel Sebastián, Juan Claver, Lorenzo Sevilla Hurtado, Francisco Javier Trujillo Vilches, Marta Vera, Aurora Galán
Screw presses were machines widely used in various industrial sectors at the end of the 18th century and the beginning of the 19th century, among which the minting of coins stands out. In the Museum of the Royal Factories of Riópar (Albacete, Spain) there is a unique screw press, built in Paris at the beginning of the 19th century by the Delalande. Due to its structure and characteristics, it seems that its drive has been modified on at least two occasions, going from an initial design of a flywheel press with manual operation by several operators to the type of friction spindle with hydraulic wheel drive, for, to from 1940, be operated by an electric motor, as corresponds to its current configuration. Due to its age, characteristics and excellent state of conservation, this press is considered to have an important patrimonial and technological value. In the present work, we will proceed to the study of this screw press and the evolution of its typology throughout the two centuries of its existence. Its digital modeling is also considered, as well as the simulation of its operations. A comparative study of this press will be carried out with others of a similar structure, available at the Museum of the “Real Casa de la Moneda” of Segovia (Spain) and at the Museum “Casa de la Moneda” of the Fábrica Nacional de Moneda y Timbre (National Mint and Stamp Factory) in Madrid. Finally, it should be noted that this year marks the 250th anniversary of the creation of these Royal Factories, during the reign of Carlos III.
{"title":"Technological and Heritage Analysis of a Singular Screw Press from the early 19th Century of the Museum of the Royal Factories of Riópar (Spain)","authors":"Miguel Ángel Sebastián, Juan Claver, Lorenzo Sevilla Hurtado, Francisco Javier Trujillo Vilches, Marta Vera, Aurora Galán","doi":"10.4028/p-gdmbr9","DOIUrl":"https://doi.org/10.4028/p-gdmbr9","url":null,"abstract":"Screw presses were machines widely used in various industrial sectors at the end of the 18th century and the beginning of the 19th century, among which the minting of coins stands out. In the Museum of the Royal Factories of Riópar (Albacete, Spain) there is a unique screw press, built in Paris at the beginning of the 19th century by the Delalande. Due to its structure and characteristics, it seems that its drive has been modified on at least two occasions, going from an initial design of a flywheel press with manual operation by several operators to the type of friction spindle with hydraulic wheel drive, for, to from 1940, be operated by an electric motor, as corresponds to its current configuration. Due to its age, characteristics and excellent state of conservation, this press is considered to have an important patrimonial and technological value. In the present work, we will proceed to the study of this screw press and the evolution of its typology throughout the two centuries of its existence. Its digital modeling is also considered, as well as the simulation of its operations. A comparative study of this press will be carried out with others of a similar structure, available at the Museum of the “Real Casa de la Moneda” of Segovia (Spain) and at the Museum “Casa de la Moneda” of the Fábrica Nacional de Moneda y Timbre (National Mint and Stamp Factory) in Madrid. Finally, it should be noted that this year marks the 250th anniversary of the creation of these Royal Factories, during the reign of Carlos III.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guzman Domínguez-Domínguez, Marcelo Romero, Domingo Morales-Palma, Manuel Oliva, Fernando Mas
In recent years, manufacturing companies have become more flexible and reconfigurable to adapt to new manufacturing paradigms and market demands. Simulation technology, which is one of the enablers of Industry 4.0, is usually used to evaluate the performance of manufacturing lines to predict their response against some manufacturing scenario. The concept of a digital twin has gained popularity in the last years. A digital twin is defined as a virtual system connected to the physical system that replicates its behavior. In this paper, a conceptual design of a digital twin-based manufacturing system is established. This includes the hierarchy of virtual elements, the relations between physical and virtual elements, and the definition of the data flow and type. A discrete event simulator has been developed to act as the digital twin of an anodizing treatment line. The simulator is connected to company systems through a neutral interface that feeds the simulator with the current manufacturing plan. The standalone digital twin has been validated using real data and allows one to perform what-if simulations in real time.
{"title":"A Prototype of the Digital Twin of an Aerospace Industrial Production Line","authors":"Guzman Domínguez-Domínguez, Marcelo Romero, Domingo Morales-Palma, Manuel Oliva, Fernando Mas","doi":"10.4028/p-tqrvn3","DOIUrl":"https://doi.org/10.4028/p-tqrvn3","url":null,"abstract":"In recent years, manufacturing companies have become more flexible and reconfigurable to adapt to new manufacturing paradigms and market demands. Simulation technology, which is one of the enablers of Industry 4.0, is usually used to evaluate the performance of manufacturing lines to predict their response against some manufacturing scenario. The concept of a digital twin has gained popularity in the last years. A digital twin is defined as a virtual system connected to the physical system that replicates its behavior. In this paper, a conceptual design of a digital twin-based manufacturing system is established. This includes the hierarchy of virtual elements, the relations between physical and virtual elements, and the definition of the data flow and type. A discrete event simulator has been developed to act as the digital twin of an anodizing treatment line. The simulator is connected to company systems through a neutral interface that feeds the simulator with the current manufacturing plan. The standalone digital twin has been validated using real data and allows one to perform what-if simulations in real time.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
María Pilar Lambán, Paula Morella, Juan Carlos Sanchez, Adrián Les, Jesús Royo, Fernando Quero
Nowadays, the energy consumption of machines is becoming increasingly important in production areas. This is mainly due to rising energy costs, but sustainability and energy savings also play an important role. This article aims to carry out a study on the energy efficiency of machine tools through the acquisition of energy data in real time. The proposed methodology is based on Patterson's definition of energy efficiency to analyse the energy consumption of the tools and evaluate its possible improvement through the development of productive, economic and environmental indicators. As a result of this study, the methodology developed is implemented in a machine tool for which the visualisation of these indicators is obtained in real time so that they can be used to help in decision-making to improve the energy efficiency of the tool. In short, this research seeks to provide a solution to one of the great challenges facing industry today due to the increase in energy costs, which is directly reflected in the cost of manufacturing.
{"title":"Development of Real-Time Indicators to Assess and Improve the Energy Efficiency of Machine Tools","authors":"María Pilar Lambán, Paula Morella, Juan Carlos Sanchez, Adrián Les, Jesús Royo, Fernando Quero","doi":"10.4028/p-t2yavi","DOIUrl":"https://doi.org/10.4028/p-t2yavi","url":null,"abstract":"Nowadays, the energy consumption of machines is becoming increasingly important in production areas. This is mainly due to rising energy costs, but sustainability and energy savings also play an important role. This article aims to carry out a study on the energy efficiency of machine tools through the acquisition of energy data in real time. The proposed methodology is based on Patterson's definition of energy efficiency to analyse the energy consumption of the tools and evaluate its possible improvement through the development of productive, economic and environmental indicators. As a result of this study, the methodology developed is implemented in a machine tool for which the visualisation of these indicators is obtained in real time so that they can be used to help in decision-making to improve the energy efficiency of the tool. In short, this research seeks to provide a solution to one of the great challenges facing industry today due to the increase in energy costs, which is directly reflected in the cost of manufacturing.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pelayo Fernández, Raúl Marqués, Natalia Beltrán, Blas Puerto, David Blanco
Additive Manufacturing (AM) production of plastic parts has experienced a continuous increase during the past decades. Simultaneously, advanced societies have become deeply concerned about the use of plastics and their impact on natural environments. As a result, there is a growing interest in recycled plastic as a feedstock material in additive manufacturing machines. However, the commercialization of recycled plastic filament introduces additional production and distribution steps. An alternative approach would avoid these steps by mixing recycled particles (obtained from local waste) with brand-new particles and using the resultant blend with Fused Particle Fabrication (FPF) machines, but some alimentary plastics, like Polyethylene Terephthalate (PET) have printability issues that hamper their direct use in AM. Present work analyses the feasibility of extruding blends composed of Polyethylene Terephthalate Glycol (PETG) spherical pellets and recycled Polyethylene Terephthalate (rPET) flakes so that local prosumers could give a second use to their own wasted water bottles. Additionally, tensile, and flexural specimens were analyzed for combinations of different rPET particle sizes and PETG/rPET blends (100%PETG, 30%rPET/70%PETG, 50%rPET/50%PETG, and 70%rPET/30%PETG). The experimental program included relaxation tests from which the relaxation modulus, E(t), was obtained. The results showed that the addition of PETG combined with a modification that insufflates pressurized air into the pellets inlet would permit to print blends up to a 70% rPET. It has also been found that an increase in the percentage of rPET causes a slight increase in the relaxation modulus of the test specimen. Finally, the viscoelasticity ratio remains nearly constant among the different blends whereas particle size has been found to have an influence on the results.
{"title":"Using PETG/rPET Blends in Fused Particle Fabrication: Analysis of Feasibility and Mechanical Behaviour","authors":"Pelayo Fernández, Raúl Marqués, Natalia Beltrán, Blas Puerto, David Blanco","doi":"10.4028/p-5m4uqt","DOIUrl":"https://doi.org/10.4028/p-5m4uqt","url":null,"abstract":"Additive Manufacturing (AM) production of plastic parts has experienced a continuous increase during the past decades. Simultaneously, advanced societies have become deeply concerned about the use of plastics and their impact on natural environments. As a result, there is a growing interest in recycled plastic as a feedstock material in additive manufacturing machines. However, the commercialization of recycled plastic filament introduces additional production and distribution steps. An alternative approach would avoid these steps by mixing recycled particles (obtained from local waste) with brand-new particles and using the resultant blend with Fused Particle Fabrication (FPF) machines, but some alimentary plastics, like Polyethylene Terephthalate (PET) have printability issues that hamper their direct use in AM. Present work analyses the feasibility of extruding blends composed of Polyethylene Terephthalate Glycol (PETG) spherical pellets and recycled Polyethylene Terephthalate (rPET) flakes so that local prosumers could give a second use to their own wasted water bottles. Additionally, tensile, and flexural specimens were analyzed for combinations of different rPET particle sizes and PETG/rPET blends (100%PETG, 30%rPET/70%PETG, 50%rPET/50%PETG, and 70%rPET/30%PETG). The experimental program included relaxation tests from which the relaxation modulus, E(t), was obtained. The results showed that the addition of PETG combined with a modification that insufflates pressurized air into the pellets inlet would permit to print blends up to a 70% rPET. It has also been found that an increase in the percentage of rPET causes a slight increase in the relaxation modulus of the test specimen. Finally, the viscoelasticity ratio remains nearly constant among the different blends whereas particle size has been found to have an influence on the results.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135834475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magdalena Ramirez-Peña, Manuel Otero-Mateo, Andrés Pastor-Fernandez, Moises Batista, Alberto Cerezo-Narvaez
A large vessel, such as a container ship or an oil tanker, requires painting processes that include not only application, but also cleaning, substrate preparation and corrosion treatment. Moreover, these processes take place during construction (both in the construction of blocks in the workshop and in the assembly at the dock) and also during the operation phase of its life cycle, as part of its maintenance. This research analyzes the advantages of the implementation of key enabling technologies in painting processes versus the proposal of preventive measures, collective and individual protection, and training of workers in traditional manual processes. Using the Fine-Kinney method, which assesses potential hazards and associated risks, the degree of danger of the different tasks present in the current painting processes of large vessels is measured. These risk scores is compared with those of the new activities resulting from the simulation and automation of the associated processes, analyzing their justification by confronting their level of correctness (risk mitigation) with the cost factors of their implementation. The results show that, from a health and safety point of view, the proposal of these measures is fully justified. Therefore, it can be concluded that the inclusion of key enabling technologies in the painting processes of a ship throughout its life cycle drastically reduces risk levels, improving the safety and health conditions of the workers involved, without prejudice to an increase in the cost of services or in the delivery deadlines to the client, which confirms their reliability.
{"title":"Impact of Key Enabling Technologies on Safety Risks in Shipbuilding. Application to Painting Activities on Large Vessels","authors":"Magdalena Ramirez-Peña, Manuel Otero-Mateo, Andrés Pastor-Fernandez, Moises Batista, Alberto Cerezo-Narvaez","doi":"10.4028/p-rg62m6","DOIUrl":"https://doi.org/10.4028/p-rg62m6","url":null,"abstract":"A large vessel, such as a container ship or an oil tanker, requires painting processes that include not only application, but also cleaning, substrate preparation and corrosion treatment. Moreover, these processes take place during construction (both in the construction of blocks in the workshop and in the assembly at the dock) and also during the operation phase of its life cycle, as part of its maintenance. This research analyzes the advantages of the implementation of key enabling technologies in painting processes versus the proposal of preventive measures, collective and individual protection, and training of workers in traditional manual processes. Using the Fine-Kinney method, which assesses potential hazards and associated risks, the degree of danger of the different tasks present in the current painting processes of large vessels is measured. These risk scores is compared with those of the new activities resulting from the simulation and automation of the associated processes, analyzing their justification by confronting their level of correctness (risk mitigation) with the cost factors of their implementation. The results show that, from a health and safety point of view, the proposal of these measures is fully justified. Therefore, it can be concluded that the inclusion of key enabling technologies in the painting processes of a ship throughout its life cycle drastically reduces risk levels, improving the safety and health conditions of the workers involved, without prejudice to an increase in the cost of services or in the delivery deadlines to the client, which confirms their reliability.","PeriodicalId":46357,"journal":{"name":"Advances in Science and Technology-Research Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135833357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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