Abnormal behaviors in the capillary rheometry of plastisol formulations / Y. Demay in INTERNATIONAL POLYMER PROCESSING, Vol. XXXIII, N° 3 (07/2018)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXXIII, N° 3 (07/2018) . - p. 363-370 Titre : Abnormal behaviors in the capillary rheometry of plastisol formulations Type de document : texte imprimé Auteurs : Y. Demay, Auteur ; Y. Abdesselam, Auteur ; Jean-François Agassant Année de publication : 2018 Article en page(s) : p. 363-370 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse numérique Bagley, Correction de Chlorure de polyvinyle Ecoulement laminaire Formulation (Génie chimique) Modèles mathématiques Revêtements de sols Rhéologie Index. décimale : 668.4 Plastiques, vinyles Résumé : The rheology of plastisol formulations for flooring applications using knife-over-roll coating process is studied using both Couette and capillary rheometers. The behavior is similar in many aspects to the rheology of suspensions: Shear thinning behavior at low shear rate, then a Newtonian plateau at intermediate shear rates followed by a dilatancy peak. However several abnormal phenomena may be observed in capillary experiments. At very high shear rates, a second shear thinning behavior is observed which depends on the flow geometry. Due to the non-monotonous behavior of the plastisol viscosity, this is analysed using a dedicated numerical method. An apparent slip velocity has been determined. Otherwise capillary experiments point out the existence of important entrance pressure loss. These measures are interpreted using a modified Cogswell method as an important elongationnal viscosity, around hundred times the shear viscosity. Note de contenu : - CAPILLARY RHEOLOGY OF PLASTISOL FORMULATIONS : Rheology measurements protocol - Plastisol formulations - Bagley corrections - Influence of the capillary diameter - Numerical investigation of the flow curves - Poiseuille flow modelling for a non-monotonous viscous behaviour - RESULTS : Analysis as an apparent slip velocity for the small capillary diameter - Analysis of entrance pressure drop DOI : 10.3139/217.3554 En ligne : https://drive.google.com/file/d/1Rft14dDwixD5jh6JwdPzBYX6UY-uEsLz/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30805 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
20044	-	Périodique	Bibliothèque principale	Documentaires	Disponible

An overview of molten polymer drawing instabilities / Y. Demay in INTERNATIONAL POLYMER PROCESSING, Vol. XXIX, N° 1 (03/2014)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXIX, N° 1 (03/2014) . - p. 128-129 Titre : An overview of molten polymer drawing instabilities Type de document : texte imprimé Auteurs : Y. Demay, Auteur ; Jean-François Agassant, Auteur Année de publication : 2014 Article en page(s) : p. 128-129 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Défauts Fibres textiles synthétiques Filature Films plastiques Instabilités (physique) Matières plastiques -- Soufflage Polyéthylène basse densité Polyéthylène basse densité linéaire Index. décimale : 668.4 Plastiques, vinyles Résumé : Drawing instabilities and rupture are a serious limitation in polymer fibre and film processing. Draw resonance and fibre or film rupture depend on the processing conditions, heat transfer and on the rheology of the polymer and some of these defects may also be encountered for Newtonian fluids. This paper reviews the different instabilities observed in fibre spinning, cast-film and film blowing. The time dependent equations are presented for the simplified situation of constant width cast-film and two modelling strategies, linear stability analysis and direct simulation, are proposed and then applied to the different fibre and film processes. Note de contenu : - MODELLING STRATEGY : CONSTANT WITH CAST-FILM PROCESS - CAST-FILM PROCESS : Influence of cooling - Influence of the nieck-in phenomenon - Validity of the membrane model : 2D transverse simulation - FIBRE SPINNING DOI : 10.3139/217.2832 En ligne : https://drive.google.com/file/d/1k_l4Kx4EG4wtvZoULUHuq3lnuFR9ROAm/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=20584 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
16006	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Cast film extrusion / Jean-François Agassant in INTERNATIONAL POLYMER PROCESSING, Vol. XX, N° 2 (06/2005)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XX, N° 2 (06/2005) . - p. 136-148 Titre : Cast film extrusion : An overview of experimental and theoretical approaches Type de document : texte imprimé Auteurs : Jean-François Agassant, Auteur ; D. Silagy, Auteur ; Cyrille Sollogoub, Auteur ; Y. Demay, Auteur Année de publication : 2005 Article en page(s) : p. 136-148 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : Cast film extrusion is a widely used technique to produce polymer films for packaging or coating applications. The final width of the film may be smaller than the initial die width (necking phenomenon) and therefore is the final film thickness larger than what one could expect. Moreover it is heterogeneous (in terms of showing a larger thickness along the borders, also called dog bone defect). Above a critical draw ratio between the chill roll and the die both width and thickness fluctuations are observed (Draw Resonance Instability). All these phenomena limit the productivity of the process. This paper provides an overview of the processing and material parameters governing the development of these geometrical defects and instabilities. Numerical models capturing the main experimental features are proposed, allowing to investigate process modifications in order to limit the development of these defects. DOI : 10.3139/217.1874 En ligne : https://drive.google.com/file/d/18NFGRvtS8JN94uTvKOfK2Ep9NBeqzCNY/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3073 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001970	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Cast film problem : A non isothermal investigation / Cyrille Sollogoub in INTERNATIONAL POLYMER PROCESSING, Vol. XVIII, N° 1 (03/2003)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVIII, N° 1 (03/2003) . - p. 80-86 Titre : Cast film problem : A non isothermal investigation Type de document : texte imprimé Auteurs : Cyrille Sollogoub, Auteur ; Y. Demay, Auteur ; Jean-François Agassant, Auteur Année de publication : 2003 Article en page(s) : p. 80-86 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : An important problem arising in the cast film process is the so-called neck-in phenomenon, which may induce a drastic film width reduction as well as an inhomogeneous film thickness distribution (with the so called "dog-bone" defect on each side of the film). This neck-in phenomenon is highly influenced by the polymer rheology (increasing polymer elasticity leads to decrease markedly the neck-in), the stretching distance, the cooling conditions and the draw ratio. In this paper, we present a 2D Newtonian non-isothermal model based on a membrane approximation for the film. Stress balance, mass balance and temperature balance equations are solved iteratively using various finite element methods adapted to free surface problems and to transport equations. Coupling between mechanical and thermal equations is achieved introducing an Arrhenius temperature dependance for the viscosity. The influence of the heat transfer coefficient has been carefully investigated. DOI : 10.3139/217.1725 En ligne : https://drive.google.com/file/d/1BfTylWzfbG7YXlwFZAQZUUAob5qgUwoj/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15853 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001023	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Convective instabilities in the coextrusion process / Rudy Valette in INTERNATIONAL POLYMER PROCESSING, Vol. XVI, N° 2 (06/2001)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVI, N° 2 (06/2001) . - p. 192-197 Titre : Convective instabilities in the coextrusion process Type de document : texte imprimé Auteurs : Rudy Valette, Auteur ; P. Laure, Auteur ; Y. Demay, Auteur ; A. Fortin, Auteur Année de publication : 2001 Article en page(s) : p. 192-197 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : This paper is devoted to the numerical study of the stability of the plane flow for two immiscible fluids obeying Maxwell constitutive equation in a channel of aspect ratio 8. For fixed viscosity and flow rate ratios, the shape and non-linear behavior of interfacial waves induced by small perturbations of the input flow rate are studied using finite element simulations for various elasticity stratifications. The stationary flow, close to a Poiseuille flow and presenting a flat interface is first computed. Then the interfacial wave generated by a pulse-like disturbance on entry flow rates is computed by using time dependent computations. It takes the shape of a wave pocket which is amplified or damped while moving towards the die exit. In unstable cases, the maximum deviation increases with elasticity (the Weissenberg number). Interestingly, the elastic stratification between the two layers can counteract unstable waves due to viscous stratifications. Note de contenu : - Coextrusion instabilities - Governing equations - The numerical strategy - Viscoelastic resluts (Re=0) DOI : 10.3139/217.1635 En ligne : https://drive.google.com/file/d/1Alf8oq_luEtGEz_XYLVABvMMZ5wDUlnA/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15899 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001016	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Deux formulations éléments finis pour le calcul d'écoulements de fluides viscoélastiques : Streamline-Upwind et Lesaint-Raviart / C. Beraudo in LES CAHIERS DE RHEOLOGIE, Vol. XI, N° 3-4 (10/1993)

Permalink

Etude expérimentale du défaut hélicoïdal d’un polystyrène en écoulement / C. Combeaud in RHEOLOGIE, Vol. 4 (11/2003)  

Permalink

Etude expérimentale de l'instabilité oscillante des polyéthylènes linéaires / L. Robert in LES CAHIERS DE RHEOLOGIE, Vol. XVII, N° 1 (10/2000)

Permalink

Etude expérimentale du phénomène d'enrobage dans les écoulements de coextrusion / J. Mauffrey in LES CAHIERS DE RHEOLOGIE, Vol. XVI, N° 1 (10/1998)

Permalink

Etude de la stabilité d'écoulements de coextrusion / Rudy Valette in LES CAHIERS DE RHEOLOGIE, Vol. XVII, N° 1 (10/2000)

Permalink

Experimental investigation and modeling of a new high speed coating process / Achraf Kallel in INTERNATIONAL POLYMER PROCESSING, Vol. XXXI, N° 3 (07/2016)  

Permalink

Experimental investigation of the development of interfacial instabilities in two layer coextrusion dies / Rudy Valette in INTERNATIONAL POLYMER PROCESSING, Vol. XIX, N° 2 (06/2004)  

Permalink

Investigation of bubble instabilities in film blowing process / J. Laffargue in INTERNATIONAL POLYMER PROCESSING, Vol. XVII, N° 4 (12/2002)  

Permalink

Investigation of Polymer Stretching Instabilities : Application to Film Blowing / J. Laffargue in INTERNATIONAL POLYMER PROCESSING, Vol. XXV, N° 5 (11/2010)  

Permalink

Investigation of the interfacial instabilities in the coextrusion flow of PE and PS / Rudy Valette in INTERNATIONAL POLYMER PROCESSING, Vol. XVIII, N° 2 (06/2003)  

Permalink

Modelling of the plastisol knife over roll coating process / Y. Abdesselam in INTERNATIONAL POLYMER PROCESSING, Vol. XXXII, N° 5 (11/2017)  

Permalink

The polymer film casting process - An overview / Y. Demay in INTERNATIONAL POLYMER PROCESSING, Vol. 36, N° 3 (2021)  

Permalink

---

1 (1 - 17 / 17)