subject: Popular Knowledge: Toward Water [print this page] With the rapid economic development, people's living standard has gradually improved, China entered the environmental era of printing, which requires Packaging Printing Material improvement, while packaging and printing ink is an important part of the material. As the water-based ink does not use solvents, environmentally friendly, so its research and application of more and more attention.
1. Water-based ink composition Water-based inks are water-based polymer by a specific resin, pigment, water, and add the additive process by the combination of physical and chemical ink, referred to as ink.
1) water-based resin Water-based ink water-based polymer resin is the most important part of it from the link in the main ink material effect on the ink viscosity, adhesion, gloss, printability drying, and has a significant impact. At home, often with rosin modified maleic acid resin as binders to produce ink, but only for the printing of such inks generally Carton Can not satisfy, the high-end packaging and printing the required gloss and water resistance requirements. Urethane resin, the stability of the good, but some of the printing adaptability and soluble slightly worse. Others include modified with styrene maleic acid resin, water-based amino resin and polyvinyl alcohol and carboxymethyl cellulose, the polymer resin generally contains carboxyl, hydroxyl and amino groups such as hydrophilic, after dealing with a specific process became completely soluble in water, resins, water-based ink as the connection material.
2) pigment Pigment ink color characteristics given to meet the requirements of color printing. Common organic pigments and inorganic pigments can be used for water-based ink. Since most water-based ink for the alkali soluble resin, the pigment used, the basic ability to use the paint. Distribution of pigment ink solvent ink density than much larger, and the water's surface tension and polarity big difference with the solvent, making pigment dispersion more difficult to ink directly affect the stability, viscosity and pH value. Increase with added surfactant affinity resins, and water soluble binders, and pigments with affinity to solve the stability problem ink. Pigments used in the printing process, they should choose color pigment made Yan Leung, low viscosity, high stability system to produce water-based pigment ink.
3) Additives To improve the performance of water-based inks need to add various additives, and water-based ink used in printing ink additives is more important than the solvent. Through scientific use of these additives to improve the water-based ink weaknesses, can improve the stability of water-based ink. Commonly used water-based ink additives are the following:
Defoamer: used to suppress and eliminate air bubbles produced, the amount is generally 1% to 2%. In general, when the viscosity of water-based ink is too high, pH value is too low, or when the printing press running speed compared soon they may easily produce bubbles, if bubbles will appear larger leakage than white, the black color uniform, is bound to affect the print quality.
pH value stabilizing agent: mainly used to regulate and control the pH value of water-based ink, it stabilized at 8.0 to 9.5 range. At the same time, it can adjust the viscosity water-based ink, and ink dilution. In general, the printing process at regular intervals on the pH value should be added to an appropriate amount of stabilizer to maintain good water-based ink printing status. Commonly used additives such as ammonia or ethanolamine.
slow drying agent: can inhibit and slow down the drying rate of water-based ink, to prevent the ink in the printed version or Anilox roller Drying occurs, reduce the blocking version and paste version of the incidence of failure such as printing. General should be controlled in 1% of the total ink volume to 2%, and if adding excessive ink drying is not complete, print will stick dirty or odors.
