Paper dyeing process, the object of the dye’s role is paper fiber. Dye and different mechanisms of action of different pulp, such as alkaline dyes have a great affinity for lignin, suitable for high content of pulp with pulp; Pulp with a strong negative surface, the direct dye is almost no adsorption of negative ions , With the real surface charge decreases, the dye near the fiber surface was fixed. This adsorption is caused by non-electrostatic forces, aluminum vanadium is commonly used in papermaking dye retention agent, because most papermaking dye is anionic, cationic aluminum compounds and anionic dye cationic precipitation and adsorption in the fiber surface was retained , This mechanism occurs in the pH value of 4.0-5.2, when the charge density of aluminum ions, charge strong role.
Water-soluble direct dyes have been widely used in the paper industry, and pigments are commonly used in colored coated paper. Dyes and paper fibers are covalently bonded, ionized, coordinated, hydrogen bonded And the intermolecular force binding, the color fastness depends on the binding strength, whether to combine the main, depending on the structure of the dye molecules.
Paper dyeing dyes are mainly alkaline yellow O (paper-specific yellow, fire paper dyeing, kraft paper dyeing), direct scarlet 4BE (firecracker paper coloring), alkaline rose (cultural paper dyeing, brushing paper coloring), acid red GR Paper-linked red), direct yellow-brown MD (yellow paperboard coloring), direct dark brown MM (teaboard dyeing), basic goods blue (newsprint dyeing, brushing paper staining), alkaline goods green , Brushing paper coloring), basic magenta, direct fast black, direct lake blue 5B (cardboard dyeing), alkaline violet 5BN (cultural paper, brushing paper special), fluorescent whitening agent VBL (toilet paper whitening) Frozen yellow G (toilet paper coloring, whiteboard coloring), alkaline orange block (kraft paper staining).
