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Fabrice Schmidt - One of the best experts on this subject based on the ideXlab platform.
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Infrared Heating stage simulation of semi-transparent media (PET) using ray tracing method
International Journal of Material Forming, 2011Co-Authors: Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, Maxime BordivalAbstract:Stretch blow molding or thermoforming processes includes an Infrared Heating stage of the thermoplastic preform by Infrared heaters. The knowledge of the temperature distribution on the surface and through the thickness of the preform is important to make good prediction of thickness and properties of the manufactured parts. Currently in industry, the fitting of the process parameters is given by experience and is expensive. Our objective is to provide tools that are able to simulate the heat transfers between Infrared heaters and preforms in order to reduce the fitting cost and to control the qualities of the end products. The optical method called “ray tracing” is used to simulate the radiative transfer. First, we compare the ray tracing method with the view factor method on a simple example: the Heating of a square sheet by one Infrared lamp. Then, we perform 3D Heating stage simulations and compare with experiments. The ray tracing method allows to compute a source term in the transient heat balance equation. Then commercial finite element method softwares can be used to solve the heat balance equation.
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Curing simulation of composites coupled with Infrared Heating
2010Co-Authors: Sawsane Nakouzi, Fabrice Schmidt, Yannick Le Maoult, J. Pancrace, Florentin BerthetAbstract:Because of higher specific strength and stiffness, low weight, and good resistance to corrosion, the use of composite materials in aerospace structures has increased. Aircraft industry has recently begun to investigate Liquid Composites Molding techniques (LCM) through research programs because of its ability to produce large parts at a low cost. In this paper, we have not addressed the filling step during which the resin flows through fibrous media, but we investigate the numerical simulation of curing reinforced RTM-6 by Infrared Heating. A ray tracing in-lab software called RAY-HEAT is used to compute the radiation energy due to the interaction between reinforced RTM-6 and lamps. Finite element based program COMSOL Multiphysics™ has been used to simulate the curing process. Thermochemical model has been implemented in order to compute reaction rate as a function of reaction temperature and degree of conversion using a cure kinetic model .
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A ray tracing method to simulate the Infrared Heating of semi-transparent thermoplastics
2010Co-Authors: Maxime Bordival, Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, B. PlantamuraAbstract:This paper focuses on describing RAYHEAT, a software based on the ray tracing method, developed in order to simulate the Infrared (IR) Heating of semi-transparent polymers. In this study, RAYHEAT is used to simulate the IR Heating step of a PET preform for the Injection Stretch-Blow Moulding (ISBM) process. The general principle of the method is to discretize, into a set of rays, the radiative heat flux emitted by halogen lamps, then to follow these rays inside the oven while they are not fully absorbed. The ray tracer computes the optical path of each ray-accounting for specular or diffuse reflections, refractions, etc…-from its emission point, and throughout the preform thickness. PET is assumed to behave like a non-scattering cold medium. Thus, the radiative heat flux absorption inside the preform is computed according to the Beer-Lambert law. Finally, the distribution of the radiative source term is calculated in the preform. In a second step, the radiative source term is applied as an input data in the commercial finite element software ABAQUS ® , in order to calculate the 3D temperature distribution in the preform. The source term is assumed to be time dependent in order to account for the preform movement throughout the IR oven. This method provides relatively small computation times, while keeping the memory requirements down to a minimum. Numerical results have been compared with temperature measurements performed on an in-lab IR oven. The model simulates suitably the Infrared Heating stage, and provides accurate predictions of the temperature distribution in the preform. The relative error between the temperature calculated by RAYHEAT, and the measured temperature, is less than 5%.
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Curing simulation of composites coupled with Infrared Heating
International Journal of Material Forming, 2010Co-Authors: Sawsane Nakouzi, Fabrice Schmidt, Yannick Le Maoult, J. Pancrace, Florentin BerthetAbstract:Because of higher specific strength and stiffness, low weight, and good resistance to corrosion, the use of composite materials in aerospace structures has increased. Aircraft industry has recently begun to investigate Liquid Composites Molding techniques (LCM) through research programs because of its ability to produce large parts at a low cost. In this paper, we have not addressed the filling step during which the resin flows through fibrous media, but we investigate the numerical simulation of curing reinforced RTM-6 by Infrared Heating. Finite element based program COMSOL Multiphysics T has been used to simulate the curing process. Thermochemical model has been implemented in order to compute reaction rate as a function of reaction temperature and degree of conversion using a cure kinetic model.
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A ray tracing method to simulate the Infrared Heating of semi-transparent thermoplastics
International Journal of Material Forming, 2010Co-Authors: Maxime Bordival, Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, B. PlantamuraAbstract:This paper focuses on RAYHEAT, a software based on the ray tracing method, developed in order to simulate the Infrared (IR) Heating of semi-transparent polymers. In this study, RAYHEAT is used to simulate the IR Heating step of a PET preform for the Stretch-Blow Moulding (SBM) process. The general principle of the method is to discretize, into a set of rays, the radiative heat flux emitted by halogen lamps, then to follow these rays inside the oven while they are not fully absorbed. The ray tracer computes the optical path of each ray - accounting for specular or diffuse reflections, refractions, etc. - from its emission point, and throughout the preform thickness. PET is assumed to behave like a non-scattering cold medium. Thus, the radiative heat flux absorption inside the preform is computed according to the Beer-Lambert law. Finally, the distribution of the radiative source term is calculated in the preform. In a second step, the radiative source term is applied as an input data in the commercial finite element software ABAQUS (R), in order to calculate the 3D temperature distribution in the preform. The source term is assumed to be time dependent in order to account for the preform movement throughout the IR oven. This method provides relatively small computation times, while keeping the memory requirements down to a minimum. Numerical results have been compared with temperature measurements performed on an in-lab IR oven. The model simulates suitably the Infrared Heating stage, and provides accurate predictions of the temperature distribution in the preform. The relative error between the temperature calculated by RAYHEAT, and the measured temperature, is less than 5%.
Yannick Le Maoult - One of the best experts on this subject based on the ideXlab platform.
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Infrared Heating stage simulation of semi-transparent media (PET) using ray tracing method
International Journal of Material Forming, 2011Co-Authors: Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, Maxime BordivalAbstract:Stretch blow molding or thermoforming processes includes an Infrared Heating stage of the thermoplastic preform by Infrared heaters. The knowledge of the temperature distribution on the surface and through the thickness of the preform is important to make good prediction of thickness and properties of the manufactured parts. Currently in industry, the fitting of the process parameters is given by experience and is expensive. Our objective is to provide tools that are able to simulate the heat transfers between Infrared heaters and preforms in order to reduce the fitting cost and to control the qualities of the end products. The optical method called “ray tracing” is used to simulate the radiative transfer. First, we compare the ray tracing method with the view factor method on a simple example: the Heating of a square sheet by one Infrared lamp. Then, we perform 3D Heating stage simulations and compare with experiments. The ray tracing method allows to compute a source term in the transient heat balance equation. Then commercial finite element method softwares can be used to solve the heat balance equation.
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Curing simulation of composites coupled with Infrared Heating
2010Co-Authors: Sawsane Nakouzi, Fabrice Schmidt, Yannick Le Maoult, J. Pancrace, Florentin BerthetAbstract:Because of higher specific strength and stiffness, low weight, and good resistance to corrosion, the use of composite materials in aerospace structures has increased. Aircraft industry has recently begun to investigate Liquid Composites Molding techniques (LCM) through research programs because of its ability to produce large parts at a low cost. In this paper, we have not addressed the filling step during which the resin flows through fibrous media, but we investigate the numerical simulation of curing reinforced RTM-6 by Infrared Heating. A ray tracing in-lab software called RAY-HEAT is used to compute the radiation energy due to the interaction between reinforced RTM-6 and lamps. Finite element based program COMSOL Multiphysics™ has been used to simulate the curing process. Thermochemical model has been implemented in order to compute reaction rate as a function of reaction temperature and degree of conversion using a cure kinetic model .
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A ray tracing method to simulate the Infrared Heating of semi-transparent thermoplastics
2010Co-Authors: Maxime Bordival, Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, B. PlantamuraAbstract:This paper focuses on describing RAYHEAT, a software based on the ray tracing method, developed in order to simulate the Infrared (IR) Heating of semi-transparent polymers. In this study, RAYHEAT is used to simulate the IR Heating step of a PET preform for the Injection Stretch-Blow Moulding (ISBM) process. The general principle of the method is to discretize, into a set of rays, the radiative heat flux emitted by halogen lamps, then to follow these rays inside the oven while they are not fully absorbed. The ray tracer computes the optical path of each ray-accounting for specular or diffuse reflections, refractions, etc…-from its emission point, and throughout the preform thickness. PET is assumed to behave like a non-scattering cold medium. Thus, the radiative heat flux absorption inside the preform is computed according to the Beer-Lambert law. Finally, the distribution of the radiative source term is calculated in the preform. In a second step, the radiative source term is applied as an input data in the commercial finite element software ABAQUS ® , in order to calculate the 3D temperature distribution in the preform. The source term is assumed to be time dependent in order to account for the preform movement throughout the IR oven. This method provides relatively small computation times, while keeping the memory requirements down to a minimum. Numerical results have been compared with temperature measurements performed on an in-lab IR oven. The model simulates suitably the Infrared Heating stage, and provides accurate predictions of the temperature distribution in the preform. The relative error between the temperature calculated by RAYHEAT, and the measured temperature, is less than 5%.
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Curing simulation of composites coupled with Infrared Heating
International Journal of Material Forming, 2010Co-Authors: Sawsane Nakouzi, Fabrice Schmidt, Yannick Le Maoult, J. Pancrace, Florentin BerthetAbstract:Because of higher specific strength and stiffness, low weight, and good resistance to corrosion, the use of composite materials in aerospace structures has increased. Aircraft industry has recently begun to investigate Liquid Composites Molding techniques (LCM) through research programs because of its ability to produce large parts at a low cost. In this paper, we have not addressed the filling step during which the resin flows through fibrous media, but we investigate the numerical simulation of curing reinforced RTM-6 by Infrared Heating. Finite element based program COMSOL Multiphysics T has been used to simulate the curing process. Thermochemical model has been implemented in order to compute reaction rate as a function of reaction temperature and degree of conversion using a cure kinetic model.
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A ray tracing method to simulate the Infrared Heating of semi-transparent thermoplastics
International Journal of Material Forming, 2010Co-Authors: Maxime Bordival, Benoit Cosson, Fabrice Schmidt, Yannick Le Maoult, B. PlantamuraAbstract:This paper focuses on RAYHEAT, a software based on the ray tracing method, developed in order to simulate the Infrared (IR) Heating of semi-transparent polymers. In this study, RAYHEAT is used to simulate the IR Heating step of a PET preform for the Stretch-Blow Moulding (SBM) process. The general principle of the method is to discretize, into a set of rays, the radiative heat flux emitted by halogen lamps, then to follow these rays inside the oven while they are not fully absorbed. The ray tracer computes the optical path of each ray - accounting for specular or diffuse reflections, refractions, etc. - from its emission point, and throughout the preform thickness. PET is assumed to behave like a non-scattering cold medium. Thus, the radiative heat flux absorption inside the preform is computed according to the Beer-Lambert law. Finally, the distribution of the radiative source term is calculated in the preform. In a second step, the radiative source term is applied as an input data in the commercial finite element software ABAQUS (R), in order to calculate the 3D temperature distribution in the preform. The source term is assumed to be time dependent in order to account for the preform movement throughout the IR oven. This method provides relatively small computation times, while keeping the memory requirements down to a minimum. Numerical results have been compared with temperature measurements performed on an in-lab IR oven. The model simulates suitably the Infrared Heating stage, and provides accurate predictions of the temperature distribution in the preform. The relative error between the temperature calculated by RAYHEAT, and the measured temperature, is less than 5%.
S Monteix - One of the best experts on this subject based on the ideXlab platform.
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modelling of Infrared Heating of thermoplastic sheet used in thermoforming process
Journal of Materials Processing Technology, 2003Co-Authors: Fabrice Schmidt, Le Y Maoult, S MonteixAbstract:Thermoforming consists of warming a plastic sheet and forming it into a cavity or over a tool using vacuum, air pressure and mechanical means. The process begins by Heating a thermoplastic sheet slightly above the glass transition temperature, for amorphous polymers, or slightly below the melting point, for semi-crystalline materials. As the final thickness distribution of the part is drastically controlled by the initial temperature distribution inside the sheet, it is very important to optimise the Heating stage. In most of the thermoforming machine, this step is performed using an Infrared oven constituted of long waves Infrared emitters. The goal of this study is to determine the efficiency of short waves Infrared emitters (halogen lamps) for the Heating step. The Infrared Heating of thermoplastic sheets will be modelled following two steps: an experimental set-up developed in our laboratory permits to measure the influence of parameters such as heaters temperature, incidence of the radiation, heat transfer coefficient, etc. An 880 LW AGEMA Infrared camera is used to evaluate the surface distribution of the transmitted heat flux by measuring the temperature distribution on the surface of the thermoplastic sheet. In addition, a numerical model using control volume method (software called PLASTIRAD) has been developed to simulate the Heating stage. In particular, it takes into account the spectral properties of both heaters and plastic sheet as well as the heaters directivity. Comparisons between experimental data and numerical simulations allow validating the numerical model using different types of emitters and polystyrene (PS).
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Modeling of Infrared Heating of Thermoplastic Sheet Used in Thermoforming Process
2001Co-Authors: Fabrice Schmidt, Yannick Le Maoult, S MonteixAbstract:Thermoforming consists of warming a plastic sheet and forming it into a cavity or over a tool using vacuum, air pressure and mechanical means. The process begins by Heating a thermoplastic sheet slightly above the glass transition temperature, for amorphous polymers, or slightly below the melting point, for semi-crystalline materials. As the final thickness distribution of the part is drastically controlled by the initial temperature distribution inside the sheet, it is very important to optimise the Heating stage. In most of the thermoforming machine, this step is performed using an Infrared oven constituted of long waves Infrared emitters. The goal of this study is to determine the efficiency of short waves Infrared emitters (halogen lamps) for the Heating step. The Infrared Heating of thermoplastic sheets will be modelled following two steps: an experimental setup developed in our laboratory permits to measure the influence of parameters such as heaters temperature, incidence of the radiation, heat transfer coefficient ,.. An 880 LW AGEMA Infrared camera is used to evaluate the surface distribution of the transmitted heat flux by measuring the temperature distribution on the surface of the thermoplastic sheet. In addition, a numerical model using control-volume method (software called PLASTIRAD) has been developed to simulate the Heating stage. In particular, it takes into account the spectral properties of both heaters and plastic sheet as well as the heaters directivity. Comparisons between experimental data and numerical simulations allow validating the numerical model using different types of emitters and polystyrene (PS).
Kathiravan Krishnamurthy - One of the best experts on this subject based on the ideXlab platform.
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microscopic and spectroscopic evaluation of inactivation of staphylococcus aureus by pulsed uv light and Infrared Heating
Food and Bioprocess Technology, 2010Co-Authors: Kathiravan Krishnamurthy, Joseph Irudayaraj, Jagdish Tewari, Ali DemirciAbstract:Pulsed UV light and Infrared heat-treated Staphylococcus aureus cells were analyzed using transmission electron microscopy to identify the cell damage due to the treatment process. A 5-s treatment with pulsed UV light resulted in complete inactivation of S. aureus even after enrichment. The temperature increase during the pulsed UV light treatment was insignificant, which suggested a nonthermal treatment. S. aureus was also Infrared heat treated using an Infrared Heating system with six Infrared lamps. Five milliliters of S. aureus cells in phosphate buffer was treated at 700°C lamp temperature for 20 min. The microscopic observation clearly indicated that there was cell wall damage, cytoplasmic membrane shrinkage, cellular content leakage, and mesosome disintegration after both pulsed UV light and Infrared treatments. Fourier transform Infrared microspectrometry was successfully used to classify the pulsed UV light and Infrared heat-treated S. aureus by discriminant analysis.
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Infrared Heating in food processing an overview
Comprehensive Reviews in Food Science and Food Safety, 2008Co-Authors: Kathiravan Krishnamurthy, Harpreet Kaur Khurana, Jun Soojin, Joseph Irudayaraj, Ali DemirciAbstract:ABSTRACT: Infrared (IR) Heating provides significant advantages over conventional Heating, including reduced Heating time, uniform Heating, reduced quality losses, absence of solute migration in food material, versatile, simple, and compact equipment, and significant energy saving. Infrared Heating can be applied to various food processing operations, namely, drying, baking, roasting, blanching, pasteurization, and sterilization. Combinations of IR Heating with microwave Heating and other common conductive and convective modes of Heating have been gaining momentum because of increased energy throughput. This article reviews aspects of IR Heating and presents a theoretical basis for IR heat processing of food materials and the interaction of IR radiation with food components. The effect of IR on food quality attributes is discussed in the context of samples and process parameters. Applications of IR Heating in food processing operations and future research potential are also reviewed.
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DECONTAMINATION OF MILK AND WATER BY PULSED UV-LIGHT AND Infrared Heating
2006Co-Authors: Kathiravan KrishnamurthyAbstract:Efficacy of pulsed UV-light and Infrared Heating for inactivation of pathogens was investigated. Pulsed UV-light was very effective in inactivating S. aureus on agar seeded cells and in phosphate buffer. Complete inactivation of S. aureus was achieved within 5-s treatments. Raw milk inoculated with S. aureus was treated with pulsed UV-light by varying distance of milk sample from the quartz window, volume of milk, and treatment time. The log10 reduction obtained varied from 0.16 to 8.55 log10 CFU/ml. Complete inactivation of S. aureus was obtained at two conditions with corresponding reductions of 8.55 log10 CFU/ml. Continuous treatment of milk was tested in order to determine the feasibility of industrial application of pulsed UV-light treatment. Reductions of S. aurues in milk varied from 0.55 to 7.26 log10 CFU/ml. Complete inactivation was achieved at two conditions. Sensory evaluation of pulsed UV-light treated pasteurized skim milk and 1% milk suggests that there was some perceivable change in the quality. B. subtilis spores in water were treated with pulsed UV-light in an annular flow chamber. Flow rates up to 14 L/min resulted in complete inactivation of B. subtilis spores. No growth was observed during incubation under light and no-light conditions. The efficacy of Infrared Heating on inactivation of S. aureus in milk was tested. The effect of depth of milk, Infrared lamp temperature, and treatment time were investigated. Reductions of 0.10 to 8.41 log10 CFU/ml were obtained for treatments up to 4 min.
Ali Demirci - One of the best experts on this subject based on the ideXlab platform.
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microscopic and spectroscopic evaluation of inactivation of staphylococcus aureus by pulsed uv light and Infrared Heating
Food and Bioprocess Technology, 2010Co-Authors: Kathiravan Krishnamurthy, Joseph Irudayaraj, Jagdish Tewari, Ali DemirciAbstract:Pulsed UV light and Infrared heat-treated Staphylococcus aureus cells were analyzed using transmission electron microscopy to identify the cell damage due to the treatment process. A 5-s treatment with pulsed UV light resulted in complete inactivation of S. aureus even after enrichment. The temperature increase during the pulsed UV light treatment was insignificant, which suggested a nonthermal treatment. S. aureus was also Infrared heat treated using an Infrared Heating system with six Infrared lamps. Five milliliters of S. aureus cells in phosphate buffer was treated at 700°C lamp temperature for 20 min. The microscopic observation clearly indicated that there was cell wall damage, cytoplasmic membrane shrinkage, cellular content leakage, and mesosome disintegration after both pulsed UV light and Infrared treatments. Fourier transform Infrared microspectrometry was successfully used to classify the pulsed UV light and Infrared heat-treated S. aureus by discriminant analysis.
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Infrared Heating in food processing an overview
Comprehensive Reviews in Food Science and Food Safety, 2008Co-Authors: Kathiravan Krishnamurthy, Harpreet Kaur Khurana, Jun Soojin, Joseph Irudayaraj, Ali DemirciAbstract:ABSTRACT: Infrared (IR) Heating provides significant advantages over conventional Heating, including reduced Heating time, uniform Heating, reduced quality losses, absence of solute migration in food material, versatile, simple, and compact equipment, and significant energy saving. Infrared Heating can be applied to various food processing operations, namely, drying, baking, roasting, blanching, pasteurization, and sterilization. Combinations of IR Heating with microwave Heating and other common conductive and convective modes of Heating have been gaining momentum because of increased energy throughput. This article reviews aspects of IR Heating and presents a theoretical basis for IR heat processing of food materials and the interaction of IR radiation with food components. The effect of IR on food quality attributes is discussed in the context of samples and process parameters. Applications of IR Heating in food processing operations and future research potential are also reviewed.