Documents disponibles écrits par cet auteur

Microstructure Variations in Paper Coating / Christina Dahlstrom in Industrial & engineering chemistry research, Vol. 51 N° 24 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8246–8252 Titre : Microstructure Variations in Paper Coating : Direct Observations Type de document : texte imprimé Auteurs : Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur Année de publication : 2012 Article en page(s) : pp. 8246–8252 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microstructure  Paper  coating Résumé : Nonuniformities in the coating layer, such as porosity variations and binder distributions, are known to affect print uniformity and barrier properties. However, in the literature the results are rather scarce or sometimes conflicting. We acquired high-quality images of coated paper cross sections using field emission scanning electron microscopy in combination with a new argon-ion-beam milling technique to directly observe and analyze the coating microstructures in relation to underlying base sheet structures. The results showed that coating porosity varied with mass density of the underlying base sheet for the relatively bulky clay/GCC coating, whereas for the more compact clay coating, the effect was small. Areas with more fibers in the base sheet were more compressed by calendering, resulting in a decreased coating porosity. A unique binder enriched layer of less than 500 nm thickness was found at the coating surface as well as at the coating/base sheet interface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202874z [article] Microstructure Variations in Paper Coating : Direct Observations [texte imprimé] / Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur . - 2012 . - pp. 8246–8252. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8246–8252 Mots-clés : Microstructure  Paper  coating Résumé : Nonuniformities in the coating layer, such as porosity variations and binder distributions, are known to affect print uniformity and barrier properties. However, in the literature the results are rather scarce or sometimes conflicting. We acquired high-quality images of coated paper cross sections using field emission scanning electron microscopy in combination with a new argon-ion-beam milling technique to directly observe and analyze the coating microstructures in relation to underlying base sheet structures. The results showed that coating porosity varied with mass density of the underlying base sheet for the relatively bulky clay/GCC coating, whereas for the more compact clay coating, the effect was small. Areas with more fibers in the base sheet were more compressed by calendering, resulting in a decreased coating porosity. A unique binder enriched layer of less than 500 nm thickness was found at the coating surface as well as at the coating/base sheet interface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202874z

New insights into coating uniformity and base sheet structures / Christina Dahlstrom in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10472–10478 Titre : New insights into coating uniformity and base sheet structures Type de document : texte imprimé Auteurs : Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur Année de publication : 2010 Article en page(s) : pp. 10472–10478 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : New  Insights--Coating--Uniformity--Base  Sheet--Structures Résumé : Base sheet structures, such as surface roughness and mass density distribution (formation), have been known to affect coating uniformity. However, the literature is not necessarily consistent in determining which structure controls coating uniformity. This study employed scanning electron microscopy (SEM) and image analysis, combined with autocorrelation and frequency analyses, to investigate the fundamental mechanisms of coating and to resolve some of the controversies in the literature regarding the base sheet effects. The results showed that coating thickness variation resembles a process of random deposition with leveling. At small length scales (in the size of fiber width), leveling causes a very strong dependence of coating thickness variations on the surface profile of the base sheet, whereas at larger length scales, coating thickness variation diminishes in its intensity by the same leveling effect, but still retains a significant correlation with base sheet structure, particularly formation. Frequency analyses clearly showed that the discrepancies in the results for the base sheet effects in the literature are due to the length scales used in the experiments, that is, the sampling area and the resolution of the measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900819c [article] New insights into coating uniformity and base sheet structures [texte imprimé] / Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur . - 2010 . - pp. 10472–10478. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10472–10478 Mots-clés : New  Insights--Coating--Uniformity--Base  Sheet--Structures Résumé : Base sheet structures, such as surface roughness and mass density distribution (formation), have been known to affect coating uniformity. However, the literature is not necessarily consistent in determining which structure controls coating uniformity. This study employed scanning electron microscopy (SEM) and image analysis, combined with autocorrelation and frequency analyses, to investigate the fundamental mechanisms of coating and to resolve some of the controversies in the literature regarding the base sheet effects. The results showed that coating thickness variation resembles a process of random deposition with leveling. At small length scales (in the size of fiber width), leveling causes a very strong dependence of coating thickness variations on the surface profile of the base sheet, whereas at larger length scales, coating thickness variation diminishes in its intensity by the same leveling effect, but still retains a significant correlation with base sheet structure, particularly formation. Frequency analyses clearly showed that the discrepancies in the results for the base sheet effects in the literature are due to the length scales used in the experiments, that is, the sampling area and the resolution of the measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900819c