Study On The Environmental Friendly Coated Paper Made From Midium-brightness Base Paper

Regarding the tightened environmental policy and the pressure from wood resource scarcity in China,economical and environmentally friendly raw materials are desired by pulp and paper manufacturers to maximize the profitability in increasing competition.This tendency has been followed in the production of art coated paper,which features good color reproduction ability among printing papers.In this thesis,a coated paper was proposed to be produced with medium-brightness base paper and eco-friendly adhesive(bio-latex).The feasibility of this concept was experimentally investigated using the coated paper made from high-brightness base paper as a control.The effect of pigments blending ratio on the optical,mechanical properties and printability of coated paper,which produced with medium-and high-brightness base paper respectively,was firstly studied.The results showed that the brightness of coated paper produced with medium-brightness base paper was essentially affected by both the brightness and opacity of pigment,while that produced with high-brightness base paper was dominated by the brightness of pigment alone;as pigment composition changing,the properties of coated papers produced with two different brightness base paper developed in similar trends,however,the brightness of coated paper produced with higher-brightness base paper varied more than that from lower-brightness base paper;the pigment blending ratio in pre-coating had greater effect on the roughness of coated paper than that in top-coating,while the brightness was more affected by the later;there is no negative correlation between gloss and PPS roughness of coated paper;the brightness of base paper positively affected the brightness,gloss,and print gloss of coated paper,and negatively affected the roughness,but the influence on the print gloss is low;the increase of GCC content in coating contributed to the improvement of the surface strength of coated paper;the mechanical properties of coated paper,such as tensile strength and tear strength,were basically dependent on those of base paper.The coat weight of coated paper was found to be positively related to the coated paper brightness and roughness,but negative to the gloss and print gloss.The properties of coated paper produced with medium-brightness base paper were stabilized when the coat weight exceeded 32 g/m2.The study on the performance of biological latex in coated paper production showed that,when fixed amount of latex was used in top-coating,and 6pph of carboxyl SBR latex were equivalently substituted by bio-latex in pre-coating,the coated paper brightness could be significantly improved,and other properties were similar with the use of starch in a same dossage;as the viscosity of latex increased,the gloss and print gloss of coated paper decreased,while the other properties were little changed;when 3pph of carboxyl SBR latex were substituted by bio-latex in both pre-coating and top-coating,the coated paper possessed a slightly decreased brightness and gloss,slightly increased roughness,significantly increased surface strength,which could satisfy the surface strength requirements for superior product in China national standard of coated paper.