The Experts below are selected from a list of 4215 Experts worldwide ranked by ideXlab platform
Benoit Boulet - One of the best experts on this subject based on the ideXlab platform.
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A model predictive controller of plastic sheet temperature for a Thermoforming process
Proceedings of the 2011 American Control Conference, 2011Co-Authors: Benoit Boulet, Ahmad HaidarAbstract:This paper presents a method to control the surface temperature of a plastic sheet using model predictive control (MPC). Although control techniques have been developed for the heating phase of the Thermoforming process, oven heater temperatures in the Thermoforming industry are still largely adjusted by trial and error based on the experience of the operator. MPC is one of the advanced methods for process control that has been used in different plants since the 1980s. Even though the MPC controller can handle a multivariable process, the large number of computations makes it difficult to apply to large systems such as multi-zone temperature control in a Thermoforming machine. In this paper, the design of a model predictive controller is reported and implemented on a complex Thermoforming oven with a large number of inputs and outputs for precise control of sheet temperatures under hard constraints on heater temperature and their rates.
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terminal iterative learning control design with singular value decomposition decoupling for Thermoforming ovens
American Control Conference, 2009Co-Authors: Guy Gauthier, Benoit BouletAbstract:Terminal Iterative Learning Control (TILC) is a cycle-to-cycle control approach that can be used on Thermoforming oven. TILC automatically tune the heater temperature setpoints such that the temperature at the surface of the plastic sheet tracks a desired temperature profile. Industrial Thermoforming ovens can have a large number of temperature sensor (inputs) and heaters (outputs) which makes the design of TILC difficult. This paper presents the design of a TILC using the singular value decomposition decoupling technique. With this tool, the TILC design is facilitated for industrial Thermoforming oven.
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terminal iterative learning control applied to Thermoforming machine reheat phase
International Symposium on Industrial Electronics, 2006Co-Authors: Guy Gauthier, Benoit BouletAbstract:This paper shows the use of Terminal Iterative Learning Control (TILC) algorithm to control the plastic sheet reheat phase of Thermoforming machine. We use TILC as cycle to cycle control because we want to improve the adjustment of heater temperature setpoint that is actually done manually. We introduce the model of a Thermoforming machine and the TILC algorithm tested on a Thermoforming machine. Experimental results are included to show the effectiveness of the control.
M. M. Espinosa - One of the best experts on this subject based on the ideXlab platform.
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Rapid prototyping model for the manufacturing by Thermoforming of occlusal splints
Rapid Prototyping Journal, 2015Co-Authors: M Jimenez, L. Romero, Manuel Domínguez, M. M. EspinosaAbstract:Purpose - This paper aims to present an optimal prototyping technology for the manufacture of occlusal splints. Design/methodology/approach - To carry out this study, a comparative technique was used to analyze models obtained by different prototyping techniques. Subsequently, further tests were carried out with respect to the manufacturing of splints by means of Thermoforming in a vacuum. This involved an analysis of the most important variables such as prototype material, geometric accuracy, surface finish and costs. Findings - It was found that there is a group of prototyping technologies that are suitable for the manufacture of the models used in the Thermoforming of correction splints, the most appropriate technologies being based on ink jet printing (IJP-Objet), ultraviolet photo polymerization and fused deposition modelling due to the fact that they offer an optimal relationship between the cost and the quality of the model required for Thermoforming. Practical implications - The application of rapid prototyping techniques in medicine makes the production of physical models from three-dimensional medical image processing and their subsequent use in different specialties possible. It also makes preoperative planning processes, the production of prostheses and the preparation of surgical templates possible, thereby offering a higher quality of diagnosis, safer surgery and cost and time savings compared to conventional manufacturing technologies. Originality/value - This paper suggests that there exists a group of prototyping technologies for the manufacture of splints that offer advantages over existing technologies. The results also suggest that, in many cases, the most expensive technology is not the most appropriate: there are other options that provide an optimal model in terms of the cost and the quality needed for Thermoforming. © Emerald Group Publishing Limited.
Krishnan Jayaraman - One of the best experts on this subject based on the ideXlab platform.
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Thermoforming woodfibre polypropylene composite sheets
Composites Science and Technology, 2003Co-Authors: Debes Bhattacharyya, Martyn Bowis, Krishnan JayaramanAbstract:Abstract Thermoforming of woodfibre–polypropylene composite sheets made without any modification of the fibres or the polymer is the focus of this paper, the emphasis being on their formability and the associated issues. Both the degree to which a material conforms to the desired part geometry after deformation and the extent to which a sheet material may be deformed before unacceptable defects occur are considered. Four Thermoforming processes such as V-bending, die-match forming, air pressure forming and deep drawing have been utilised to examine both single-curvature and double-curvature deformation conditions. The technique of Grid Strain Analysis (GSA) has been applied to quantify differences in strain distributions during sheet deformation. The effects of Thermoforming process parameters and sheet composition on sheet formability are also discussed. Notably, this study considers composite sheets reinforced with wood fibres rather than woodflour, enabling the study of fibre layup and fibre interlocking effects. While the tensile strengths of the composite sheets increase marginally the stiffnesses increase significantly compared to those of unreinforced polypropylene. The key deformation mechanism for layered woodfibre–polypropylene composite sheets is inter-ply shear while intra-ply shear dominates the deformation of homogeneous sheets. Forming temperature and blank size have the most pronounced effects on the formability of these composite sheets.
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Thermoforming woodfibre–polypropylene composite sheets
Composites Science and Technology, 2003Co-Authors: Debes Bhattacharyya, Martyn Bowis, Krishnan JayaramanAbstract:Abstract Thermoforming of woodfibre–polypropylene composite sheets made without any modification of the fibres or the polymer is the focus of this paper, the emphasis being on their formability and the associated issues. Both the degree to which a material conforms to the desired part geometry after deformation and the extent to which a sheet material may be deformed before unacceptable defects occur are considered. Four Thermoforming processes such as V-bending, die-match forming, air pressure forming and deep drawing have been utilised to examine both single-curvature and double-curvature deformation conditions. The technique of Grid Strain Analysis (GSA) has been applied to quantify differences in strain distributions during sheet deformation. The effects of Thermoforming process parameters and sheet composition on sheet formability are also discussed. Notably, this study considers composite sheets reinforced with wood fibres rather than woodflour, enabling the study of fibre layup and fibre interlocking effects. While the tensile strengths of the composite sheets increase marginally the stiffnesses increase significantly compared to those of unreinforced polypropylene. The key deformation mechanism for layered woodfibre–polypropylene composite sheets is inter-ply shear while intra-ply shear dominates the deformation of homogeneous sheets. Forming temperature and blank size have the most pronounced effects on the formability of these composite sheets.
Guy Gauthier - One of the best experts on this subject based on the ideXlab platform.
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terminal iterative learning control design with singular value decomposition decoupling for Thermoforming ovens
American Control Conference, 2009Co-Authors: Guy Gauthier, Benoit BouletAbstract:Terminal Iterative Learning Control (TILC) is a cycle-to-cycle control approach that can be used on Thermoforming oven. TILC automatically tune the heater temperature setpoints such that the temperature at the surface of the plastic sheet tracks a desired temperature profile. Industrial Thermoforming ovens can have a large number of temperature sensor (inputs) and heaters (outputs) which makes the design of TILC difficult. This paper presents the design of a TILC using the singular value decomposition decoupling technique. With this tool, the TILC design is facilitated for industrial Thermoforming oven.
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terminal iterative learning control applied to Thermoforming machine reheat phase
International Symposium on Industrial Electronics, 2006Co-Authors: Guy Gauthier, Benoit BouletAbstract:This paper shows the use of Terminal Iterative Learning Control (TILC) algorithm to control the plastic sheet reheat phase of Thermoforming machine. We use TILC as cycle to cycle control because we want to improve the adjustment of heater temperature setpoint that is actually done manually. We introduce the model of a Thermoforming machine and the TILC algorithm tested on a Thermoforming machine. Experimental results are included to show the effectiveness of the control.
Peng Wang - One of the best experts on this subject based on the ideXlab platform.
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Thermoforming simulation of multilayer composites with continuous fibres and thermoplastic matrix
Composites Part B-engineering, 2013Co-Authors: Nahiene Hamila, Peng Wang, Philippe BoisseAbstract:Abstract Continuous Fibre Reinforced Thermoplastics (CFRTPs) have made their way into the aerospace an automotive industries as structural components. Thermoplastic composites offer many advantages over thermoset composites such as low cycle time and recyclability. The development of a Thermoforming process is complex and expensive to achieve by trial/error. This can be favourably replaced by numerical analyses. A simulation approach for Thermoforming of multilayer thermoplastic is presented. Each prepreg layer is modelled by semi-discrete shell elements. These elements consider the tension, in-plane shear and bending behaviour of the ply at different temperatures around the fusion point. The contact/friction during the forming process is taken into account using forward increment Lagrange multipliers. A lubricated friction model is implemented between the layers and for ply/tool friction. Thermal and forming simulations are presented and compared to experimental results. The computed shear angles after forming and wrinkles are in good agreement with the Thermoforming experiment. It will be shown by the comparison of two simulations that the temperature field play an important role in the process success.
