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Larsson, Mikael
Publications (5 of 5) Show all publications
Larsson, M., Vidal, D., Zou, X. & Engström, G. (2007). Impact of calendering on coating structures. NORDIC PULP AND PAPER RESEARCH JOURNAL 22(2): 267-274
Open this publication in new window or tab >>Impact of calendering on coating structures
2007 (English)In: NORDIC PULP AND PAPER RESEARCH JOURNAL 22(2): 267-274Article in journal (Refereed)
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-20195 (URN)
Available from: 2013-01-21 Created: 2013-01-21 Last updated: 2013-01-21
Larsson, M., Vidal, D., Zou, X. & Engström, G. (2007). Paper coating properties as affected by pigment blendning and calendering study. TAPPI JOURNAL 6(8): 16-22
Open this publication in new window or tab >>Paper coating properties as affected by pigment blendning and calendering study
2007 (English)In: TAPPI JOURNAL 6(8): 16-22Article in journal (Refereed)
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-22232 (URN)
Available from: 2013-01-21 Created: 2013-01-21 Last updated: 2013-01-21
Larsson, M., Vidal, D., Engström, G., Lepoutre, P. & Zou, X. (2005). Paper Coating Properties as Affected by Pigment Blending and Calendering: An Experimental Study. Paper presented at 22nd PTS Coating Symposium, September 20-22, Baden-Baden, Germany (2005). Paper presented at 22nd PTS Coating Symposium, September 20-22, Baden-Baden, Germany (2005).
Open this publication in new window or tab >>Paper Coating Properties as Affected by Pigment Blending and Calendering: An Experimental Study
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2005 (English)Conference paper, Published paper (Other (popular science, discussion, etc.))
Abstract [en]

Many end-use properties of coated papers can be improved by optimizing coating formula-tions, more specifically by selecting and/or blending different types of pigments and binders. Although clay and GCC, with very different particle shapes, are known to create different coating structure, it is not well understood how and why blending these pigments affects the micro-structure. In addition, since most of the coated papers are subjected to calendering, it is also important to know to which extent the structures created by pigment blending are compressed by calendering. The aim of this work was, therefore, to gain insights into how and why pigment blending affects coating pore and surface structure, before and after cal-endering. Coating colours with different blending ratios of GCC and clay were prepared with a constant level of binder and co-binder. The coatings (30 g/m2) were then applied on plastic films and calendered using a paper sheet backing beneath to account for the part of com-pression absorbed by the base paper. Mercury porosimetry was used to characterize the pore structure of the coatings, while an AFM and an interference microscope were used to characterize the surface structure at a pigment size level. The results obtained from these techniques were also compared with and complemented by measurements of gloss and op-tical properties. The results showed that synergy occurs for various coating properties when blending GCC and clay. For example, the pore volume and pore size reached a maximum value around 70% clay and 30% GCC. This confirms the predictions obtained from particle packing simulation. Synergistic effect was also observed on light scattering which is con-trolled by the coating pore structure. However, no synergy was observed for smoothness and gloss. The gloss actually reached a minimum at low clay content and this was attributed to disordering of GCC structure by clay plates. It was found that calendering significantly compressed the coating layers (up to 45% decrease in pore volume), and some of the syn-ergies created by the blending were lost after calendering. Although the pure clay coating was twice more compressed by the calendering than the pure GCC coating, the blending of clay and GCC at a wide range of ratios showed a similar extent of compression. A mecha-nism is proposed to explain the observed synergies by blending and the compression caused by calendering

National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-22231 (URN)
Conference
22nd PTS Coating Symposium, September 20-22, Baden-Baden, Germany (2005)
Projects
Consolidation of Coating Layers
Available from: 2013-01-21 Created: 2013-01-21 Last updated: 2013-01-21
Larsson, M. & Engström, G. (2004). Interactions in coating colors based on GCC of broad and narrow particle size distribution and their effect on pore structure. Paper presented at 2004 TAPPI Coating and Graphic Arts Conference, May 16-19, Baltimore. Paper presented at 2004 TAPPI Coating and Graphic Arts Conference, May 16-19, Baltimore. Tappi
Open this publication in new window or tab >>Interactions in coating colors based on GCC of broad and narrow particle size distribution and their effect on pore structure
2004 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The objective of this work was to relate interactions in coating colors to shrinkage during consolidation and drying, and to the final coating pore structure. Formulations were based on ground calcium carbonate of broad and narrow particle size distributions, two water-soluble binders: carboxymethyl cellulose and soy protein, and styrene-butadiene latex. The interactions between water-soluble binder, latex and pigment were systematically studied with the help of rheological measurements. Shrinkage and pore structure data were derived from porosity measurements on the filtercake and the dry coating, and from light scattering data. The results indicate that the carboxymethyl cellulose interacted with both pigment and latex to form a network structure. The soy protein interacted only with the pigment on which it was adsorbed, leading to a steric stabilization, without significant network formation. The sterically stabilized pigment particles were found to exist in a more aggregated state in the colors than the electrostatically stabilized particles in colors containing carboxymethyl cellulose. The porosity of the filtercakes was found to be governed by the state of aggregation in terms of relative plastic viscosity and by the size of the aggregates. The pore structures of the final dry coating layers were governed, not only by the parameters that controlled the filtercake structure, but also by the shrinkage during consolidation.

Place, publisher, year, edition, pages
Tappi, 2004
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-20468 (URN)
Conference
2004 TAPPI Coating and Graphic Arts Conference, May 16-19, Baltimore
Projects
Konsolidering och reologiska egenskaper vid höga torrhalter
Available from: 2013-01-21 Created: 2013-01-21 Last updated: 2013-01-21
Larsson, M. & Engström, G. (2003). Rheological Characterization as a Tool for Evaluating Mineral Suspensions for Paper Coatings. Paper presented at ANNUAL TRANSACTIONS OF THE NORDIC RHEOLOGY SOCIETY, VOL. 11, 2003. Paper presented at ANNUAL TRANSACTIONS OF THE NORDIC RHEOLOGY SOCIETY, VOL. 11, 2003.
Open this publication in new window or tab >>Rheological Characterization as a Tool for Evaluating Mineral Suspensions for Paper Coatings
2003 (English)Conference paper, Published paper (Other (popular science, discussion, etc.))
Abstract [en]

Suspensions, used for paper coating, based on calcium carbonate pigments with different particle size distribution and different co-binders have been characterized, both using a rotational rheometer, and a capillary viscometer. The results indicated that the viscosity at high shear rates depended on hydrodynamics, whereas at low shear rates it depended mainly on interactions between the constituents

National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-23098 (URN)8798848623 (ISBN)
Conference
ANNUAL TRANSACTIONS OF THE NORDIC RHEOLOGY SOCIETY, VOL. 11, 2003
Available from: 2013-01-22 Created: 2013-01-22 Last updated: 2013-01-22
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