Dimensional analysis of droplet size and ligament length during high-speed rotaryh bell atomization / Lutz Gödeke in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 1 (01/2021)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 18, N° 1 (01/2021) . - p. 75-81 Titre : Dimensional analysis of droplet size and ligament length during high-speed rotaryh bell atomization Type de document : texte imprimé Auteurs : Lutz Gödeke, Auteur ; Walter Oswald, Auteur ; Norbert Willenbacher, Auteur ; Peter Ehrhard, Auteur Année de publication : 2021 Article en page(s) : p. 75-81 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse dimensionnelle Atomisation Dépôt par pulvérisation Désintégration Epaississants Polyacryliques Taille des gouttelettes Index. décimale : 667.9 Revêtements et enduits Résumé : Modern spray-coating processes are based on high-volume, low-pressure, airless atomization or high-speed rotary bell atomization, often assisted by electrostatic charging to increase the transfer efficiency. The process from the liquid film flow beneath the bell, through ligament formation and consecutive disintegration to droplet deposition, has been constantly explored during the evolution of automotive spray coating. This work proposes a set of dimensionless groups that fully describe the process from film flow to ligament disintegration, including shear and elongational flow effects during atomization of particle laden, shear thinning, viscoelastic fluids. Note de contenu : - General process description and dimensional analysis - Table 1 : Liquid properties for the different mixtures S1-S5 of sterocoll SHT and SXT used in the experimental setup DOI : https://doi.org/10.1007/s11998-020-00389-2 En ligne : https://link.springer.com/content/pdf/10.1007/s11998-020-00389-2.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35352 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22605	-	Périodique	Bibliothèque principale	Documentaires	Disponible

How rheological properties affect fine-line screen printing of pastes : a combined rheological and high-speed video imaging study / Chenhui Xu in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 15, N° 6 (11/2018)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 15, N° 6 (11/2018) . - p. 1401-1412 Titre : How rheological properties affect fine-line screen printing of pastes : a combined rheological and high-speed video imaging study Type de document : texte imprimé Auteurs : Chenhui Xu, Auteur ; Norbert Willenbacher, Auteur Année de publication : 2018 Article en page(s) : p. 1401-1412 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Imagerie (technique) Rhéologie Sérigraphie Index. décimale : 667.9 Revêtements et enduits Résumé : Fine-line screen printing is still a great challenge due to the lack of overall understanding between the rheological properties and screen printing process. Here, we prepared ZnO pastes including ethyl cellulose or Thixatrol Max as an additive introducing different physical mechanisms of structure and flow control. Yield stress, viscosity, and its recovery after high shear were obtained using rotational rheometry. Filament breakup was determined in uniaxial elongational tests. Pastes were printed using a commercial screen designed for Si-solar cell front-side metallization, and the process was monitored with high temporal and spatial resolution using a transparent glass substrate and a high-speed imaging setup. Length of the pre-injection zone ahead of the squeegee scales inversely with yield stress and length of the cling zone behind the squeegee is proportional to filament rupture strain, irrespective of used additive. Paste spreading observable at the busbar and fine-line intersection takes place within 100 ms, irrespective of sample composition, demonstrating that fine-line electrode width is determined within the pre-injection zone where the paste is under pressure. A simple flow model is proposed relating electrode width to the reciprocal product of yield stress and high shear viscosity consistent with experimental data including both types of pastes. Note de contenu : - MATERIALS AND PREPARATION - EXPERIMENTS : Rheological measurements - High-speed video imaging of the screen printing process - RESULTS AND DISCUSSION : Rheological properties of pastes - Correlation of printing process features and rheological paste rheological properties - Printed electrode width DOI : 10.1007/s11998-018-0091-2 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-018-0091-2.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31357 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
20388	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Investigation of the flow field in thin polymer films due to inhomogeneous drying / Philip Cavadini in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 5 (09/2015)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 12, N° 5 (09/2015) . - p. 927-926 Titre : Investigation of the flow field in thin polymer films due to inhomogeneous drying Type de document : texte imprimé Auteurs : Philip Cavadini, Auteur ; Erz Joachim, Auteur ; Dirk Sachsenheimer, Auteur ; Anne Kowalczyk, Auteur ; Norbert Willenbacher, Auteur ; Philip Scharfer, Auteur ; Wilhelm Schabel, Auteur Année de publication : 2015 Article en page(s) : p. 927-926 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Couches minces -- Défauts Déformations (mécanique) Fluorescence Mesure -- Instruments Particules (matières) Polyacétate de vinyle Index. décimale : 667.9 Revêtements et enduits Résumé : In the field of organic and printed electronics (e.g., polymer solar cells, OLEDs, or Li-ion batteries), there is a growing demand for thin functional layers with highly homogeneous surface topology. If these layers are coated from the liquid phase, the coating and drying steps affect the surface quality. As a result of inhomogeneous drying rates, the solvent concentration can vary along the top surface and the thickness of a solidifying solution, leading to local differences in surface tension. In turn, Marangoni convection, as the balancing mechanism, can occur and cause surface inhomogeneity. The in situ reconstruction of the free surface during drying has been presented elsewhere. During this investigation phenomena occurred that could not be completely understood without knowledge of the respective flow field. In the present work, the visualization of the flow field in thin polymer films [methanol-poly(vinyl acetate) solution with 67 wt% methanol] due to inhomogeneous drying is presented. To resolve the flow field, we apply fluorescent particle tracking (µPTV). Since both measurement techniques cannot easily be applied at the same time, the boundary conditions were adapted to the way of observation of each experimental setup. In the case of the setup for surface reconstruction of the free surface, locally different evaporation rates were realized by drying on a structured substrate (varying material). To force similar variation of the drying conditions in the case of the µPTV setup, the drying film was partially covered. As expected, both boundary conditions result in a propagating wave front towards regions of high surface tension. Combining both experimental setups, we were able to visualize the free surface and the flow structures up- and downstream of the wave front and found different flow regimes. DOI : 10.1007/s11998-015-9725-9 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-015-9725-9.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24693 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
17467	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Waterborne automotive coatings : Application, particle interaction and microstructure / Norbert Willenbacher in EUROPEAN COATINGS JOURNAL (ECJ), N° 9/97 (09/1997)

[article]  inEUROPEAN COATINGS JOURNAL (ECJ) > N° 9/97 (09/1997) . - p. 810-817 Titre : Waterborne automotive coatings : Application, particle interaction and microstructure Type de document : texte imprimé Auteurs : Norbert Willenbacher, Auteur ; Thomas Frechen, Auteur ; Horst Schuch, Auteur ; Bernhard Lettmann, Auteur Année de publication : 1997 Article en page(s) : p. 810-817 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Industrie  automobile'  'Peinture  eau'  émulsion'  Liant  Latex  Interaction  Adjuvant  Epaississant  Microstructure  Formulation  'Acrylate  polymère'  'Propriété  rhéologique' Index. décimale : 667.9 Revêtements et enduits Résumé : The interactions between thickener and latex particles in waterborne automotive coatings and the corresponding microstructures have been investigated using dynamic mechanical spectroscopy, cryo-replication TEM and analytical ultracentrifuge techniques. Based on these results, tailormade strategies for an optimization of the rheological and hence the application properties have been deduced for coating formulations with different acrylate-type binders. Note de contenu : 2 Eperimental 2.1 Materials 2.1.1 Acrylate-type binders 2.1.2 Polyurethane dispersion 2.1.3 Rheology control agent 3 Methods 3.1 Rheological Measurements 3.2 Cryo-Replication-TEM 3.3 Analytical Ultracentrifuge (AUC) Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11426 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
002531	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 4 / 4)