Influence of particle size distribution of calcium carbonate pigments on coated paper whiteness
Tóm tắt
The optical properties of pigments used for paper coating are linked to their morphology. The light scattering through coated layers depends upon the size and the size distribution of the pigments and their packing behavior. In this report the effect of particle packing of various calcium carbonate pigments on the whiteness of the final coated paper is studied. Different grades of calcium carbonate pigments of different particle size distribution and optics were used for coating applications on base papers. Base papers of different optics were also selected. The entire study was carried out at different coat weights. It was observed that the overall scattering from the coated sheet depends upon the light scattering from the base paper as well as through the coated layer. Higher light scattering through the coated layer will lower the effect of the base paper, whether it is dark or bright. So high bright and white pigments are not only the criteria for an enhancement in the optical properties of coated paper; the particle size and size distribution should also be considered before introducing any pigment into a coating formulation. The base optics should also be chosen on the bases of the pigments’ optics and their morphology.
Tài liệu tham khảo
Osterhuber, EJ, McFadden, MG, Roman, N, “The Effect of Particle Size Distribution on the Structure and Optical Properties of Calcium Carbonate Containing Coatings.” International Paper and Coating Chemistry Symposium, Ottawa, Canada, June 1996
Santoa, NF, Velho, J, Gomes, C, “Influence of Calcium Carbonate Coatings Blends Upon Paper Properties.” Iberoamerican Congress on Pulp and Paper Research, 2000
Santoa, NF, Velho, J, “Calendering Influence on Structure Properties of Papers Coated with Different Calcium Carbonate Pigments.” Pulp and Paper International Congress, Sao Paulo-Brazil, October 2000
Mueller, K, Osterhuber, E, Donigian, D, “When Optimizing Paper Print Performance, Minerals Matter.” Pulp Pap. Int., 80 (4) 39–43 (2006)
Lepoutre, P, “Paper Coatings: Structure-Property Relationships.” Tappi J., 59 (12) 70–75 (1976)
Knappich, R, Burri, P, Lohmuller, G, Hugener, P, “Wet and Dry Coating Structure of Calcium Carbonate Pigments with Narrow Particle Size Distribution.” Tappi J., 83 (2) 91–98 (2000)
Ma, D, Douglas, R, Haefner, D, Dogariu, A, “The Influence of Fine Kaolin and Ground Calcium Carbonates on the Efficiency and Distribution of Fluorescence Whitening Agents (FWA) in Paper Coating.” Nord. Pulp Pap. Res. J., 23 (3) 327–332 (2008)
Dimmick, AC, “Influence of the Average Particle Size of Aroganite PCC on Coated Paper Properties.” 36th Pulp and Paper Annual Congress: ABTCP 2003, Sao Paulo, Brazil, October 2003
Krober, M, Dimmick, A, Aarni, E, Alderfer, G, “Structure Giving Calcium Carbonate and Influence of Coating Color Solids on Paper Performance.” 21st PTS Coating Symposium, Baden-Baden, Germany, September 2003
Hiorns, A, “Calendering Response of Calcium Carbonates in Double Coated Woodfree Paper.” 2001 Coating and Graphic Arts Conference and Trade Fair, San Diego, CA, USA, May 2001
Lehtinen, E, Pigment Coating and Surface Sizing of Paper. Book 11. Finish Pulp and Paper Engineers Association and Tappi Press, Finland, 2000