scholarly journals The Influence of Drying Conditions of Clay-Based Polymer Coatings on Coated Paper Properties

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Petronela Nechita
Keyword(s):  
Coating Layer ◽  
Polymer Coatings ◽  
Structure And Properties ◽  
Coated Paper ◽  
Paper Properties ◽  
Coated Papers ◽  
Polymer Binders ◽  
Surface Optical ◽  
Coating Color ◽  
Drying Conditions

Coatings based on pigment and polymer binders are applied on paper surfaces to improve their surface, optical, and printing properties. Besides the coating composition, the structure and properties of the coated papers are influenced by the coating layer consolidation upon drying. In this study, the influence of drying conditions on the structure and properties of coating layers based on natural pigments (clay) and polymer binders (butadiene acrylonitrile latex) has been analyzed. Using a laboratory rod Mayer device, the coatings were applied as thin layer (about 15–16 g/m2) on the paper surface and samples of coated paper were dried at 20 and 105 °C temperatures. The optical, structural, and water absorption properties of the coating layer were evaluated by the measurement of gloss, opacity, void fraction, light scattering, and contact angle. The obtained results highlighted that both the drying temperature and latex content in the coating color have a synergic effect on the coated paper quality.

scholarly journals The Effect of a Polymer-Stabilized Latex Cobinder on the Optical and Strength Properties of Pigment Coating Layers

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 568
Author(s):  
Zhenghui Shen ◽  
Araz Rajabi-Abhari ◽  
Kyudeok Oh ◽  
Sooyoung Lee ◽  
Jiachuan Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Coating Layer ◽  
Strength Properties ◽  
Porous Coating ◽  
Coated Paper ◽  
Pigment Coating ◽  
Surface Optical ◽  
Coating Layers ◽  
Coating Color ◽  
Polymer Stabilized

Coated paper with a porous coating layer may have enhanced light-scattering ability and thus favorable optical properties. However, the increased porosity of such a coating layer is likely to decrease the strength of the coated paper, thereby adversely affecting the quality of the paper in the printing and converting processes. In this research, polymer-stabilized (PS) latex was prepared and used as a cobinder for the pigment coating of the paper. The PS latex particles were colloidally stabilized by a 3:1 mixture of starch and polyvinyl alcohol. The influence of the PS latex cobinder on the viscosity, sedimentation, and consolidation of coating colors was investigated. In addition, the effect of the cobinder on the properties of coating layers, namely, their porosity and surface, optical, and tensile properties, was examined. The results revealed that the PS latex cobinder formed microstructures in the coating colors and affected their viscosity. The addition of PS latex also led to enhanced interactions between coating color components, which affected the consolidation of the coating color, resulting in the formation of dried coating layers with greater porosity and improved optical properties (i.e., higher brightness and opacity) relative to coatings without the PS latex cobinder. Furthermore, the addition of PS latex improved the tensile strength of the coating layers, which was attributable to the small size and the polymeric protective shell of the cobinder particles. Thus, these results show that this PS latex cobinder has the potential to be used for the production of high-quality coated paper products.

The influence of coating composition on the structural and functional properties of coated paper for packaging applications

2020 ◽  
Vol 35 (3) ◽  
pp. 408-418
Author(s):  
Petronela Nechita
Keyword(s):  
Functional Properties ◽  
Coating Layer ◽  
Binder Content ◽  
Structure And Properties ◽  
Coated Paper ◽  
Coated Papers ◽  
Structural And Functional Properties ◽  
Coating Composition ◽  
Pigment Type ◽  
Coated Surfaces

AbstractThe work presented in this paper is focussed on study of structure and properties of coating layers based on natural pigments (ground calcium carbonate and clay) and butadiene acrylonitrile latex as binder in correlation with functional properties of the final coated paper. It is quantified the influence of binder content and pigment type on the structural and liquids penetration properties of coating layer. The obtained results confirm that by increasing of binder content in the coating formulations a reduced efficiency of light-scattering and increased roughness for coated surfaces is obtained. At the high binder amounts (over 15 pph), the coating layer porosity is reduced and as result a lower liquids penetration in the coated papers is obtained.

Analysis of Coating Pore Structure and its Effect on Printability of Low Gloss Coated Paper

2011 ◽  
Vol 236-238 ◽  
pp. 1178-1182
Author(s):  
Yan Xin Liu ◽  
Yu Long Wang ◽  
Shen Tao Qin ◽  
Fei Fei Liu
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Pore Volume ◽  
Coating Layer ◽  
Layer Structure ◽  
Capillary Absorption ◽  
Coated Paper ◽  
Base Paper ◽  
Small Pore ◽  
Coating Color

Coating pore structure of low gloss coated paper based on different pigment blends was analyzed using mercury intrusion method in this paper. The results show that pore size of coating layer structure of low gloss coated paper ranges from 20nm-500nm, and the range from 500nm-5000nm is mainly from base paper and interactions between coating color and base paper. Printability of coated paper can be well related with coating pore structure. Print gloss is strongly influenced by pore size and pore volume. Large pore diameters and small pore volume of coating layer structure can improve print gloss. Ink density increases with the increasing of pore diameter while the pore volume is kept constant. The increasing of pore volume of coat layer structure will improve capillary absorption and then improve ink absorption. The control of coating pore structure is very important for producing low gloss coated paper.

Research on the Coating Surface Microstructure of Coated Paper Related to Binder Migration

2014 ◽  
Vol 881-883 ◽  
pp. 1439-1442
Author(s):  
Ying Li ◽  
Wen Juan Gu ◽  
Bang Gui He
Keyword(s):  
Visual Analysis ◽  
Coating Layer ◽  
Mercury Porosimetry ◽  
Surface Microstructure ◽  
Coated Paper ◽  
Force Microscopy ◽  
Coating Surface ◽  
Atomic Force ◽  
Consolidation Phase ◽  
Coating Color

The surface topography and properties of coating layer have an important influence on penetration and distribution of the print ink. In this research, the main objective was to investigate the effect of binder migration on the coating surface microstructure. The surface microstructure was explored in the method of numerical and visual analysis using mercury porosimetry measurement, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The findings indicated that the binder migration on the coating surface affected the pore size, depth and distribution of the coated paper surface. The little binder migration in the consolidation phase of coating color made a contribution to the forming of the coating layer, which made the coating surface more smother to printing performance.

Evaluation of cut quality of woodfree coated papers

TAPPI Journal ◽  
2013 ◽  
Vol 12 (9) ◽  
pp. 9-15
Author(s):  
BENOÎT DUFOUR, ◽  
WOLFGANG BAUER ◽  
JEAN-FRANCIS BLOCH
Keyword(s):  
Coating Layer ◽  
The State ◽  
Point Of View ◽  
Test Method ◽  
Offset Printing ◽  
Paper Properties ◽  
Coated Papers ◽  
Cut Quality ◽  
Printing Papers

Dusting and blanket pollution are of particular interest in offset printing. Papers must be free of dust and loose particles to drastically reduce the wash interval of the blankets. Those particles are mainly generated during converting operations, such as sheeting. Considering the end-customer point of view, the visual aspect of the cut appears to be very important. To study in detail the influence of the sheeting parameters and paper properties on cut quality, a new test method to quantify the cut quality of woodfree coated papers has been developed. In particular, this method takes into consideration the state of the coating layer near the cutting edges.

Influence of Coating Binder Migration on Coated Paper Printing Properties

2013 ◽  
Vol 791-793 ◽  
pp. 286-289
Author(s):  
Zhao Hui Zhen ◽  
Zheng Shun Wang
Keyword(s):  
Cross Section ◽  
Coating Layer ◽  
Coated Paper ◽  
N Value ◽  
Coating Surface ◽  
Binder Concentration ◽  
Coating Color ◽  
Relationship Of ◽  
The Relationship

The coating binder migration and concentration in z-direction of coating layer especially in coating surface influence the coated paper printing properties. The results indicated that with the increase of coating surface binder migration, the coated paper opacity decreases, and the K&N value decreases. The relationship of K&N value and binder concentration in surface of coating layer was linear, which indicated that compared to binder dosage concentration in coating color, the K&N value and coating surface binder concentration has higher correlation. The more uniform the binder distribution in cross section of coating layer, the greater the IGT.

A study of the mechanical properties of coated papers using elastica stiffness and low-load indentation

TAPPI Journal ◽  
2011 ◽  
Vol 10 (10) ◽  
pp. 41-48 ◽  
Author(s):  
ROBERT RIOUX ◽  
DOUGLAS W. BOUSFIELD ◽  
NICK TRIANTAFILLOPOULOS
Keyword(s):  
Mechanical Properties ◽  
Shape Factor ◽  
Coating Layer ◽  
Processing Parameters ◽  
Dynamic Mechanical Properties ◽  
Coated Papers ◽  
Low Load ◽  
Pigment Type ◽  
Drying Conditions ◽  
Styrene Butadiene

Mechanical properties of coated papers, and specifically of a coating layer, are important during printing and converting operations. Those properties can be associated with several paper defects, such as coating pick, cracking at the fold, and dusting at the slitter. We introduced two dynamic tests for quantifying coating dynamic mechanical properties: (1) a closed loop elastica test and (2) a low-load indenter test. To evaluate these tests, several coatings on lightweight coated paper were produced with varying compositions and made under variable laboratory processing parameters. Pigment type, starch level, binder glass transition temperature, binder particle size, binder level, and drying method were varied. The moduli of a coating layer were extracted from elastica stiffness using a two-layer model. The shape factor of kaolin coating pigments had a significant effect; large shape factor led to increasing in-plane moduli but decreased elastic moduli measured in compression. The level of starch addition proportionally imparted stiffness. Laboratory drying conditions and styrene-butadiene latex type had a small effect.

scholarly journals Back-trap mottle: A review of mechanisms and possible solutions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6426-6447
Author(s):  
Hak Lae Lee ◽  
Hye Jung Youn ◽  
Ming He ◽  
Jiachuan Chen
Keyword(s):  
Coating Layer ◽  
Offset Printing ◽  
Coating Structure ◽  
Paper Substrate ◽  
Coated Paper ◽  
Printing Process ◽  
Coated Papers ◽  
Coating Uniformity ◽  
Color Density

Print mottle is a serious and common uneven printing defect that occurs when printing coated paper by the offset multicolor printing process. It is characterized by a non-uniform appearance in terms of brightness, gloss, or color density that appears mostly in solid printed areas. Back-trap print mottle and water-interference print mottle occur when the quality of the paper substrate, especially the coating layer quality, is not satisfactory. To cope with this quality problem of coated papers, the understanding of the offset printing process, the requirements of coated-paper quality, and the reasons for this problem should be addressed. In this review, the basic process of offset printing and the mechanisms of print mottles were explored, the importance of coating uniformity in both the coating structure and process was reviewed, and the approaches to cope with print mottle were introduced.

Analysis on Ink Layer Rub Resistance for Coated Paper Prints

2011 ◽  
Vol 380 ◽  
pp. 173-178
Author(s):  
Wen Hua Zhou ◽  
Bei Hai He ◽  
Chun Xiu Zhang ◽  
Yue Han
Keyword(s):  
Loss Rate ◽  
Fine Particles ◽  
Coating Layer ◽  
Color Difference ◽  
Coated Paper ◽  
Coated Papers ◽  
Color Density ◽  
Viscosity Reducer ◽  
The Impact ◽  
Print Color

Having been coated, the surface unevenness and pores on paper were covered by a coating layer composed of fine particles and binders, which can absorb ink well, thereby a good uniformity and smoothness of paper could be obtained, consequently, the reproducing capability for printing dot and good whiteness, gloss and opacity can be improved. In theory, the ink rub resistance for coated paper print is mainly affected by the ink absorbance property of paper, printing conditions, ink components, rub medium and so on. In this study, seven different kinds of coated papers, the viscosities of the inks were adjusted with a viscosity adjusting agent, and then the prints were prepared by proofing with the ink with different viscosities. After drying, the prints were used for rub testing. The impact of the basic properties of coated paper and the content of reducer in inks on rub resistance were discussed on the basis of a comparative analysis of the experimental data. Printing color density loss rate and print color difference were exploited in this paper to characterize the ink rub resistance for coated paper prints. In this study, it was found that ink rub resistance was mainly influenced by ink absorbency and smoothness of the paper. Under the similar conditions, the color density of coated paper print decreases with the rub strength increasing, color difference increased gradually, but not linearly. With the increase of ink viscosity reducer content, printing density loss rates as well as color difference changed, but not be linearly.

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