| Titre : |
Numerical analysis for predicting the operability window of slot-die coating onto porous media |
| Type de document : |
texte imprimé |
| Auteurs : |
Tomomi Goda, Auteur ; Yuichi Sasaki, Auteur ; Mamoru Mizuno, Auteur ; Kazuhiko Morizawa, Auteur ; Hitoshi Hatakura, Auteur ; Shigetaka Tomiya, Auteur |
| Année de publication : |
2017 |
| Article en page(s) : |
p. 1053-1060 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Analyse numérique
Enduction par filière
Matériaux poreux
Pénétration (physique)
Revêtements
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
The ability to coat porous media is critical for forming composite functional thin films. A major technical concern for accurately predicting this process is that the flow of the coating bead and the penetration process must be considered. These phenomena strongly influence each other. Therefore, both the flow into porous media and the coating-bead flow should be simultaneously treated. In this study, the target is a high-productivity coating system based on a roll-to-roll process using a slot die. Slot-die coating is a premetered, precision coating method. We investigated the coating of porous media to estimate the practical operability window and the penetration depth using two-dimensional numerical analysis. For this purpose, both the coating-bead pressure and the capillary pressure were considered as driving forces of penetration. Moreover, the curvature of the backup roll opposite the slot die was also taken into account to achieve an accurate estimation. We demonstrate that the penetration depth and operability window for defect-free coatings can be well estimated and that the results are consistent with experimental results. |
| Note de contenu : |
Fig. 1. (a) Scheme of the experimental setup. (b) Scheme of the setup for slot-die coating onto porous media
Fig. 2. The calculated region and the boundary conditions
Fig. 3. Mesh information near the coating gap
Fig. 4. Effect of penetration and coating speed on the operability window and a plot of the coating gap vs. the coating-bead length ; (a), (b), and (c) show each state of the coating bead when the flow is steady
Fig. 5. Effect of penetration and coating speed on the operability window, plotted as the coating gap vs. the coating speed (a) on nonporous media and (b) on porous media. Defect-free cases are plotted as ‘‘s’’ and coating-defect cases are plotted as "3."
Fig. 6. Effect of the coating speed on the penetration depth. * Bead breakup occurred. ** When the coating speed was 5 m/min, the penetration depth reached the bottom of the porous medium
Fig. 7. Effect of coating speed on the coating-bead flow rate at different coating gaps
Fig. 8. Pressure distribution through the coating bead in a 31-lm gap. (a) Coating speed U = 20 m/min. (b) Coating speed U = 5 m/min
Fig. 9. Pressure distribution (a) through the coating bead and (b) of the penetration force in (1) 38-lm and (2) 31-lm gaps. (a-1) Coating gap H = 38 lm. (a-2) Coating gap H = 31 lm. (b-1) Coating gap H = 38 lm. (b-2) Coating gap H = 31 lm
Table 1 : Processing parameters and material properties for the coating experiments
Table 2 : Ranges of the dimensionless Reynolds, capillary, and Stokes numbers
Table 3 : Experimental conditions and results for the defect-free and bead breakup cases |
| DOI : |
10.1007/s11998-017-9985-7 |
| En ligne : |
https://link.springer.com/content/pdf/10.1007%2Fs11998-017-9985-7.pdf |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29140 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 14, N° 5 (09/2017) . - p. 1053-1060
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Numerical analysis for predicting the operability window of slot-die coating onto porous media in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 14, N° 5 (09/2017)
