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Simplified modeling of convection and radiation heat transfer during infrared heating of PET sheets and preforms / Y.-M. Luo in INTERNATIONAL POLYMER PROCESSING, Vol. XXX, N° 5 (11/2015)
[article]
Titre : Simplified modeling of convection and radiation heat transfer during infrared heating of PET sheets and preforms Type de document : texte imprimé Auteurs : Y.-M. Luo, Auteur ; L. Chevalier, Auteur ; F. Utheza, Auteur ; X. Nicolas, Auteur Année de publication : 2015 Article en page(s) : p. 554-565 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Calcul
Eléments finis, Méthode des
Matières plastiques -- Moulage par injection-étirage-soufflage
Polyéthylène téréphtalate
PréformesObjet constituant la majeur partie d’une pièce à fabriquer et qui nécessite un travail supplémentaire pour devenir une pièce finie. Ce terme s’utilise notamment pour le moulage, l’usinage, la taille d’outils en silex, la fabrication de fibre optique…
Rayonnement infrarouge
Simulation par ordinateur
ThermocinétiqueIndex. décimale : 668.4 Plastiques, vinyles Résumé : Initial heating conditions and temperature effects have an important influence during the injection stretch blow molding process of PET preforms. The paper provides a simplified modeling of the infrared (IR) flux provided by the IR lamps and the convection heat transfer with air, for the finite element simulation of the heating of PET samples. This modeling enables fast thermal simulations in industrial context. First, a complete 2D simulation of the air convection around a PET sheet sample is conducted using ANSYS/FLUENT to compute the local convection heat transfer coefficient. The distribution of this coefficient along the PET wall is then interpolated by a best linear fit function of the wall position to provide the boundary condition of the convection heat transfer thereafter. This boundary condition, coupled with the calculation of the infrared flux absorbed by the PET sheet sample, allows a 3D calculation of the time evolution of the sample temperature. This calculation is validated by comparing the experimental temperature distribution of the PET sheet obtained from an IR camera with the numerical results of the simulation. Second, we focus on the modeling of the heating of a cylindrical PET preforms by IR lamps. In our approach, the IR heating flux is calculated using the spectral and surface-to-surface radiation laws adapted to the sample geometry. The air convection effect around the preform is modeled using the heat transfer coefficient identified from the 2D plane sheet case. It is applied on the boundaries of a simpler model in Comsol where only the preform is meshed. The temperature distribution on the outer surface of the preform is compared to experimental measurements by thermal imaging. A good agreement is observed which validates the whole approach used. Note de contenu : - IDENTIFICATION OF THE THERMAL BOUNDARY CONDITIONS FOR THE INFRARED HEATING SIMULATION OF A PET SHEET : Complete 2D model of IR heating and natural air convection - Computation of convective heat transfer coefficient - Validation of a h for a 3D simulation of the PET sheet alone
- MODELLING OF THE INFRARED HEATING OF THE PET PREFORM : Computation of the incident radiation on the PET preform - 3D simulation of the IR heating of a PET preform and experimental comparaisonDOI : 10.3139/217.3092 En ligne : https://drive.google.com/file/d/1jNPbTXwC48CDbEjTkf9wyiMahsJcX2b5/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24818
in INTERNATIONAL POLYMER PROCESSING > Vol. XXX, N° 5 (11/2015) . - p. 554-565[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 17557 - Périodique Bibliothèque principale Documentaires Disponible Software-based control of IR ovens / Junsheng Luo in KUNSTSTOFFE INTERNATIONAL, Vol. 111, N° 1 (2021)
[article]
Titre : Software-based control of IR ovens : Efficient and precise heating up to thermoplastic composites Type de document : texte imprimé Auteurs : Junsheng Luo, Auteur ; Norbert Müller, Auteur Année de publication : 2021 Article en page(s) : p. 17-21 Langues : Anglais (eng) Catégories : Chauffage
Composites thermoplastiques -- Moulage par injection
Plaques (ingénierie)
Rayonnement infrarougeIndex. décimale : 668.4 Plastiques, vinyles Résumé : Infrared heating technology has become established as the standard in the processing of thermoplastic composite materials. It makes it possible to heat flat organo sheets of up to about 3 mm thickness within the cycle times characteristic for injection molding processing. The focus is on process control. On the one hand, it is important that the heating process is fast, on the other hand, the material must not be overheated. It is also important to achieve excellent temperature homogeneity. Simultaneous processing of blanks with different thicknesses is particular challenge. Note de contenu : - IR oven supports fast not handling
- Efficient heating of thick semi-finished products
- Highest temperature homogeneity with optimum material protection
- Controlling a large variety of operating states
- Reaching targets simultaneously with all control zones
- Heating up semi-finished products of different thicknesses together
- Figure : Three organo sheets of different thickness are heated in two IR ovens in the production of a door structural part
- Fig. 1 : The surface temperature is monitored using pyrometers during the entire heating process. A double-sided IR oven is equipped with six pyrometer as standard equipment. The picture shows an example of the temperature curve at one measuring position during the heating phase and the soaking phase
- Fig. 2 : A double-sided horizontal IR oven with 100 x 600 mm payload area : the radiators are combined into groups to allow for control on the basics of a specific temperature measurement
- Fig. 3 : In the experiment, thermal inhomogeneties were specifically induced (initiatial situation). The resulting heating curves were then optimized by automatic process control (CZ = control zone)
- Fig. 4 : Automatic optimization of the heating behavior leads to a more uniform, almost linear temperature rise
- Fig. 5 : Software-supported optimization of the control parameters ensures high control quality in the heating phase
- Fig. 6 : Thanks to automatic process optimization, the two organo sheets reach the temperature setpoint at the same time despite of their different thicknessesPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35099
in KUNSTSTOFFE INTERNATIONAL > Vol. 111, N° 1 (2021) . - p. 17-21[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22531 - Périodique Bibliothèque principale Documentaires Disponible
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Titre : Solar reflective coatings : A review Type de document : texte imprimé Auteurs : Yogita Gavhane, Auteur Année de publication : 2018 Article en page(s) : p. 55-61 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Matériaux hautes performances
Pigments inorganiques
Rayonnement infrarouge
Réflectivité thermique
Toiture -- Revêtements:Toiture -- PeintureIndex. décimale : 667.9 Revêtements et enduits Résumé : In the coatings world, the growing global demand for energy reduction presents opportunities and provides the movement for innovation; therefore, the potential for energy savings enabled by the coatings is becoming increasingly recognized. Sunlight at ground-level incorporates incident radiation in the ultraviolet, visible and infra-red regions with wavelengths spanning 300 to 2500 nm. Any part of the solar spectrum where a surface absorbs incoming sunlight will cause an increase in surface temperature above ambient temperatures. If heat cannot be re-radiated to the sky, it will conduct through roof spaces towards the ceiling and radiate downwards through insulation bans. This produc-es a heat load on buildings, resulting in loss of comfort or an increase in electricity bills and green house gas emissions for air-conditioning.
The 'cool roof and wall' technology for buildings is probably the best current illustration of how solar-reflective coatings can play an effective role in helping to combat the rise in energy consumption, but the time is arguably right for exploring other potential applications for these coatings. Marine, automotive and aerospace products are likely candidates to benefit from a new generation of solar-reflective coatings.Note de contenu : - Ultraviolet region (295-400 Nm)
- Visible region (400-700 Nm)
- Infrared region (700-2500 Nm)
- Reflection mechanism of infrared radiations
- Benefits of infrared reflective coatings
- Factors affecting infrared reflectivity
- Few attempts are listed as follows
- Applicatios of infrared reflective pigments : Buildings products - Cement, concrete and pavers
- Automotive application
- Infrared reflection from fire
- Current & future developmentsEn ligne : https://drive.google.com/file/d/1CCqUdOlcnyRiUDpcHDSF4o5qvCcj_Zg_/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31059
in PAINTINDIA > Vol. LXVIII, N° 8 (08/2018) . - p. 55-61[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20225 - Périodique Bibliothèque principale Documentaires Disponible Sustainable and invisible anti-counterfeiting inks based on waterborne polyurethane and upconversion nanoparticles for leather products / Jun Xiang in JOURNAL OF LEATHER SCIENCE AND ENGINEERING, Vol. 3 (Année 2021)
[article]
Titre : Sustainable and invisible anti-counterfeiting inks based on waterborne polyurethane and upconversion nanoparticles for leather products Type de document : texte imprimé Auteurs : Jun Xiang, Auteur ; Jianxun Lin, Auteur ; Zhonghui Wang, Auteur ; Shenglin Zhou, Auteur ; Zhenya Wang, Auteur ; Qiang Yan, Auteur ; Yidong Liu, Auteur ; Haojun Fan, Auteur Année de publication : 2021 Article en page(s) : 11 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Contrefaçon -- Lutte contre
Cuir
Encre en phase aqueuse
Mesures biophysiques
Nanoparticules
Polyuréthanes
Produits commerciaux -- Contrefaçon
Rayonnement infrarougeIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Counterfeit leather products infringe the intellectual property rights of the business, cause enormous economic loss, and negatively influence the business enthusiasm for innovation. However, traditional anti-counterfeiting materials for leather products suffer from complicated fabrication procedures, photobleaching, and high volatile organic compound (VOC) emissions. Here, a sustainable and invisible anti-counterfeiting ink composed of waterborne polyurethane and water-dispersible lanthanide-doped upconversion nanoparticles (UCNPs) featuring ease of preparation, high photostability, non-toxicity, low VOC emissions, and strong adhesion strength for leather products is designed and synthesized. After decorating on the surface of leather products, the obtained patterns are invisible under normal light conditions. Upon irradiation at 808 nm, the invisible patterns can be observed by naked eyes due to the visible light emitted by 808 nm excited UCNPs. Our approach described here opens a new pathway to realize the long-term, stable anti-counterfeiting function of leather products. Note de contenu : - MATERIALS AND METHODS : Materials - Experimental methods - Measurements
- RESULTS AND DISCUSSION : OA-UCNPs nanoparticles - PVP-UCNPs nanoparticles - The WPU dispersion - The sustainable and invisible ACI - ApplicationDOI : https://doi.org/10.1186/s42825-021-00076-x En ligne : https://link.springer.com/content/pdf/10.1186/s42825-021-00076-x.pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37558
in JOURNAL OF LEATHER SCIENCE AND ENGINEERING > Vol. 3 (Année 2021) . - 11 p.[article]The efficient route to tailored organo sheets / Sebastian Baumgärtner in KUNSTSTOFFE INTERNATIONAL, Vol. 106, N° 10 (10/2016)
[article]
Titre : The efficient route to tailored organo sheets : Producing CFRP efficiently in a vacuum using infrared radiation Type de document : texte imprimé Auteurs : Sebastian Baumgärtner, Auteur ; Jennifer John, Auteur ; Frank Henning, Auteur ; Timo Huber, Auteur ; Benjamin Hangs, Auteur Année de publication : 2016 Article en page(s) : p. 123-127 Langues : Anglais (eng) Catégories : Bandes composites
Chauffage
Composites à fibres de carbone
Fibres à orientation unidirectionnelle
Fibres continues
Polyamide 6
Procédés de fabrication
Rayonnement infrarouge
Semi-produitsIndex. décimale : 668.4 Plastiques, vinyles Résumé : Continuous-fiber processing - Consolidation - A novel process enables the efficient consolidation of high-quality thermoplastic fiber-reinforced semifinished products. The material is heated with infrared radiation and consolidated quickly and efficiently under vacuum in the closed mold. Note de contenu : - Thermoplastic tape layup with defined property profile
- Consolidation as an essential step for achieving quality
- The operating principale in detail
- Study of semi-finished product quality
- FIGURES : 1. Thermoplastic tape layup combines the process steps of tape selection, tape layup, and consolidation as well as foring and back-molding or back-compression molding - 2. Scanning electron micrographs (SEMs) of consolidated layups (cross-laminate) with low and high pore content. The pores here are identifiable from the black and white areas - 3. Radiation-induced vacuum consolidation (RVC) protects the material against thermo-oxydative degradation - 4. An organosilicon coating on the old surface makes it possible to consolidate a tape layup without using any release agents at all - 5. Comparison of the bending stiffnes and bending strength achieved with RVC and a reference process reveals a far superior performance of the layup consolidated with RVC - 6. CT images of the carbon fiber-reinforced polyamide 6 layup consolidated with the RVC and reference processes. The top image show the representative sampes in plan view while the bottom images show the same samples in cross-section. Pores are identifiable as black spotsEn ligne : https://drive.google.com/file/d/1GqIWIjv2VrW5tfkuTKRPd-r195zIRrso/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28077
in KUNSTSTOFFE INTERNATIONAL > Vol. 106, N° 10 (10/2016) . - p. 123-127[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18402 - Périodique Bibliothèque principale Documentaires Disponible Ultra-violet and infra-red engineering / W. Summer / Londres [Royaume-Uni] : Sir Isaac Pitman & Sons (1962)
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PermalinkVisualization analysis of temperature distribution in the cavity of conventional PPS and high-thermal-conductivity PPS during the filling stage of injection molding / Akifumi Kurita in INTERNATIONAL POLYMER PROCESSING, Vol. 38, N° 1 (2023)
PermalinkWet chemical deposition of multifunctional conducting coatings made with a nanocomposite suspension / N. Al-Dahoudi in SURFACE COATINGS INTERNATIONAL. PART B : COATINGS TRANSACTIONS, Vol. 88, B4 (12/2005)
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