Characteristics of water-based ink and attention problems - water-based inks, flexo, ink - printing special printing industry
Flexo is a flexible, high resolution, can warp the relief. In recent years, flexo printing in the field in rapid development, and its prospects are generally good. Flexo printing is a unique roller through the right amount of ink transferred to the substrate. The proper use of ink is directly related to print production operations and printing quality, general use flexible printing ink is thin, is Liquid ink, from the rheological point of view is close to Newtonian fluid ink, with very good fluidity, viscosity is only 0.1-1Pa / s. Currently the main use flexible printing ink of three types: organic Solvent Of ink, Water-based ink , And UV curable inks. One water-based ink in its environmental protection, economic advantages have been flexible printing holds great weight. In this paper, the water-based flexo ink printability and its study in a simple to use.
1, the composition and characteristics of water-based ink With the general composition of printing ink, as water-based ink is usually a coloring agent, binders, auxiliary agent composition. Stain is water-based ink coloring material, to a specific color ink. For so imprinted in the flexo color is gorgeous, the coloring agent is generally used in chemical stability, high tinting strength pigments; link to material from the water, resin, amine compounds and other organic solvents. Resin as the most important water-based ink composition, usually water-soluble acrylic resin, binders for ink adhesion components directly affect the function of drying rate, anti-sticking properties and so dirty, but also affect the ink gloss and ink transfer, amines mainly to maintain an alkaline PH value of water-based ink, makes acrylic resin to provide a better printing results, water or other organic solvent soluble resin mainly to regulate the ink's viscosity and drying rate; auxiliary agents mainly include: defoamer blockers, stabilizing agent, diluting agent of several. As the water-based ink is a soap composition, the use of easy to produce bubbles, so to join the silicone oil as antifoaming agent, to suppress and eliminate air bubbles, while improving the ink transfer performance. Blocker used to suppress water-based ink drying speed, to prevent ink drying on the anilox roller to reduce the paste version. Stabilizer can adjust the PH value of ink can also be made thinner to reduce the ink viscosity. Diluent is used to reduce the appearance of water-based ink colors, but also as a light agent, to improve the brightness of water-based ink. Another water-based ink also add some wax to increase its wear resistance.
Second, the PH value of water-based ink PH value of water-based ink water-based ink is directly related to the viscosity, drying and so on printability. Experimental results show that the viscosity of water-based ink with PH value decreases linearly increased with the drying of PH value gradually rises linearly. The PH value of water-based ink amines rely mainly on the maintenance of the printing process of the volatile amines, PH value to decline, causing increased ink viscosity, metastatic poor, dry faster, plug the roller, paste version failure occurs. Therefore, to maintain stable water-based ink PH value, on the one hand to avoid leakage of amines, for example, cover the ink tank cover. On the other hand to add time quantitative stabilizer. Usually water-based ink PH value should be maintained at between 8.0-9.5, PH value is too high impact print quality are too low, PH value is too low, the impact of the printing properties of acrylic resin to play; PH value is too high, the ink is slow drying , printed materials prone dirty and water resistance of adhesive on the back of the problem of poor.
Three issues in the use of water-based ink In dry water-based ink can be mixed with water before, once the ink dries, then no longer soluble in water and ink. Therefore, before using water-based ink to be sufficient mixing to maintain uniform ink composition. The ink, the ink tank contains impurities such as remaining ink should be first filtered, which together with the new ink to use. Do not let the time of printing ink to dry on the roller, so as not to dwell hole to plug. Obstruction caused by the printing ink quantitative transmission instability. Flexible in the printing process is to always keep a wet ink to prevent ink drying on the plate after the text block design. We also found that when water-based ink viscosity slightly, not casual water, so as not to affect the stability of ink can be added to adjust the amount of stabilizing agent.
I am an expert from China Quality Digital, usually analyzes all kind of industries situation, such as crystal table clock , multi alarm clocks.