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Laser welding process in PP molding parts : evaluation of seam performance / N. Oliveira in INTERNATIONAL POLYMER PROCESSING, Vol. XXXI, N° 5 (11/2016)
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Titre : Laser welding process in PP molding parts : evaluation of seam performance Type de document : texte imprimé Auteurs : N. Oliveira, Auteur ; A. J. Pontes, Auteur Année de publication : 2016 Article en page(s) : p. 562- 569 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Lignes de soudure
Matières plastiques -- Moulage par injection
Matières plastiques -- Propriétés mécaniques
Matières plastiques -- Soudage
Microscopie
Polypropylène
Qualité -- Contrôle
Soudage laser
Soudures -- AnalyseIndex. décimale : 668.4 Plastiques, vinyles Résumé : New welding technologies have been implemented in the polymer processing industry in the past few years. Additionally, the most used polymer in complex products is polypropylene. This material can also be mixed with several additives, namely glass fiber, carbon nanotubes, etc. This compatibility with different additives allows products with characteristics that range from impact absorption to electrical conductivity. When it is necessary to join components in PP, they can be welded by hot plate, ultrasonic or laser welding. The present research aims at studying the influence of variables capable of influencing the final quality of the seam, namely those related to injection molding, such as mold temperature and cooling time, laser welding variables and materials, and how laser welding interacts with PP. The results showed that the most influential variables were mold temperature, laser velocity and laser diameter. The seams were analyzed using optical microscopy. They showed perfect contact between the components, despite the high standard variation present in the mechanical tests. Note de contenu : - EXPERIMENTAL METHODS : Transmittance analysis of the materials - Mechanical tests
- RESULTS AND DISCUSSION : Near-infrared spectroscopy - Mechanical properties - Optical Microscopy -DOI : 10.3139/217.3235 En ligne : https://drive.google.com/file/d/1XmFoCq0crwhcgbrtW9M0w2BURtK0EK9i/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27381
in INTERNATIONAL POLYMER PROCESSING > Vol. XXXI, N° 5 (11/2016) . - p. 562- 569[article]Réservation
Réserver ce documentModeling of plasticating injection molding - experimental assessment / C. Fernandes in INTERNATIONAL POLYMER PROCESSING, Vol. XXIX, N° 5 (11/2014)
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Titre : Modeling of plasticating injection molding - experimental assessment Type de document : texte imprimé Auteurs : C. Fernandes, Auteur ; A. J. Pontes, Auteur ; J. C. Viana, Auteur ; J. M. Nóbrega, Auteur ; A. Gaspar-Cunha, Auteur Année de publication : 2014 Article en page(s) : p. 558-569 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Matières plastiques -- Extrusion
Matières plastiques -- Moulage par injection
Modèles mathématiques
PlastificationIndex. décimale : 668.9 Polymères Résumé : A computational model for the description of polymer flow during the plasticating phase of the injection molding process is proposed. The polymer behavior is determined during the dynamic and static phases of the process. The model takes into account the backwards movement of the screw, the presence of a non-return valve and the conduction of heat during the idle times. Results for the dynamic and static phases of the plasticization are presented. The model is also used to study the influence of some important operative process parameters, such as, screw speed, backpressure, barrel temperatures and injection chamber length. The assessment of the computational results is made experimentally by comparing the average temperature calculated with measurements made in front of the screw nozzle using both, an IR camera and an IR thermometer. The differences between the computational and the IR camera measurements are below 5%. Note de contenu : - PLASTICATING IN INJECTION MOLDING : 1. Injection cycle - 2. System geometry - 3. Operating conditions - 4. Polymer properties
- MATHEMATICAL MODEL : 1. Global model - 2. Plasticating phase - 3. Stationary phase
- CASE STUDY
- RESULTS AND DISCUSSION : 1. Plasticating results - 2. Experimental assessmentDOI : 10.3139/217.2862 En ligne : https://drive.google.com/file/d/1PKnPdBFRT5VmulZYMftvN5VzzdUn6_eu/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22221
in INTERNATIONAL POLYMER PROCESSING > Vol. XXIX, N° 5 (11/2014) . - p. 558-569[article]Réservation
Réserver ce documentSolidification criterion on shrinkage predictions for semi-crystalline injection moulded samples / A. J. Pontes in INTERNATIONAL POLYMER PROCESSING, Vol. XV, N° 3 (09/2000)
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Titre : Solidification criterion on shrinkage predictions for semi-crystalline injection moulded samples Type de document : texte imprimé Auteurs : A. J. Pontes, Auteur ; R. Pantani, Auteur ; G. Titomanlio, Auteur ; A. S. Pouzada, Auteur Année de publication : 2000 Article en page(s) : p. 284-290 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : The phenomenon of shrinkage in injection moulding is particularly evident in semi-crystalline polymers. During cooling, these materials experience a transition from a completely amorphous to a partially crystalline status, which results in a severe change of all material characteristics, including volumetric parameters. In this study an iPP was injection moulded in a rectangular impression (120mm x 630mm x 62 mm) with a 1.5mm thick line gate. The influence of holding pressure and time, and geometry constraints on linear shrinkage was explored. In-mould shrinkage was measured by means of a recent method based on strain gauges. Experimental results are compared with predictions for shrinkage obtained by C-Mold and a code developed at the University of Salerno, which takes into account crystallisation kinetics. The solidification criterion resulted to be extremely relevant for shrinkage predictions. DOI : 10.3139/217.1594 En ligne : https://drive.google.com/file/d/1ODoaWDUb7LGE1p3TEFUrsf1VD0ZEYdf0/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15833
in INTERNATIONAL POLYMER PROCESSING > Vol. XV, N° 3 (09/2000) . - p. 284-290[article]Réservation
Réserver ce documentUsing multi-objective evolutionary algorithms for optimization of the cooling system in polymer injection molding / C. Fernandes in INTERNATIONAL POLYMER PROCESSING, Vol. XXVII, N° 2 (05/2012)
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Titre : Using multi-objective evolutionary algorithms for optimization of the cooling system in polymer injection molding Type de document : texte imprimé Auteurs : C. Fernandes, Auteur ; A. J. Pontes, Auteur ; J. C. Viana, Auteur ; A. Gaspar-Cunha, Auteur Année de publication : 2012 Article en page(s) : p. 213-223 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Algorithmes génétiques
Matières plastiques -- Moulage par injection
Systèmes de refroidissementIndex. décimale : 668.9 Polymères Résumé : The cooling process in polymer injection molding is of great importance as it has a direct impact on both productivity and product quality. In this paper a Multi-objective Optimization Genetic Algorithm, denoted as Reduced Pareto Set Genetic Algorithm with Elitism (RPSGAe), was applied to optimize both the position and the layout of the cooling channels in the injection molding process. The optimization model proposed in this paper is an integration of genetic algorithms and Computer-Aided Engineering, CAE, technology applied to polymer process simulations. The main goal is to implement an automatic optimization scheme capable of defining the best position and layout of the cooling channels and/or setting the processing conditions of injection moldings. In this work the methodology is applied to an L-shape molding with the aim of minimizing the part warpage quantified by two different conflicting measures. The results produced have physical meaning and correspond to a successful process optimization. Note de contenu : - Development of the optimization system
- Case study
- Results : Analysis of modelling results - Processing conditions optimization results - Cooling channels design optimization results - Optimization with cold runners - Simultaneous processing conditions and cooling channels design optimization resultsDOI : 10.3139/217.2511 En ligne : https://drive.google.com/file/d/1XWEoOP36g342emr4YzfxniQiKx5VVpUz/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=14689
in INTERNATIONAL POLYMER PROCESSING > Vol. XXVII, N° 2 (05/2012) . - p. 213-223[article]Réservation
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