Take you to understand the knowledge of water-based ink printing
Recently, water-based inks have attracted great attention in the industry.
Water-based inks use water as the dissolving carrier, which has significant environmental safety features that are incomparable to solvent-based inks. This unique feature is being more and more packaging printing companies look forward to. Water-based ink printing is not only applied to many organic food and agricultural products packaging above, children’s toy packaging bags category, more widely used to food packaging bags. In order to better use water-based ink, we should understand the requirements of water-based ink on the plate roller.
- water-based ink on the precision of the plate roller, finish, plating layer has high requirements, many times due to the slow drying of ink, transfer better, shallow depth of the plate roller cavity, this time the precision requirements of the plate is not high, the ink layer can not cover the defects of the plate body, such as some common “mold pattern”, “rubbing plate “and other problems are caused by this. Edition surface finish is not high, the ink is not easy to scrape clean, because the ink transferability is very good, scraper scraped after the ink attached to the surface of the gravure cylinder is very easy to transfer to the printing substrate, will lead to the print hanging dirty. For this reason have to often increase the pressure of the scraper, if the plate roller surface chrome layer hardness is not enough, the service life will be shortened.
- high, dark tone parts of the depth and gradient gradient and solvent ink printing plate has a large difference water-based ink transfer good, shallow network reproduction good performance is particularly prominent. Gravure ink in the cavity from the squeegee scraped to transfer between viscosity changes are not obvious, the network is very easy to reproduce intact. At this time, if the plate roller engraving parameters are still set according to the traditional solvent ink version, then it is easy to cause high, dark levels of contrast is greatly reduced, often missing the point. This requires the plate will be steeper gradient, darker parts slightly deeper, the middle to high tone parts shallower, only after taking into account this, high tone, dark tone gradient is perfectly reproduced.
- the degree of dot expansion than solvent ink to be larger in general, the printing viscosity of ink is lower, drying slower, coupled with various types of additives and alcohol co-solvents in the ink, so that the lines in the printed pattern, the word expansion is serious. Resulting in the print pattern lines become thicker, the sharp corners become blunt, the Yang word becomes larger, anti-negative word becomes smaller, the handwriting is blurred, the bar code scan through, resulting in scrap. So that we should take this into full consideration when making the plate, the lines will be properly reduced to some thin.
Advantages of water-based ink: 1, high color concentration, bright and vivid printing colors; 2, because it does not contain organic solvents, to ensure the safety and health of printing and packaging, non-toxic and harmless; 3, water-based ink production process almost no volatile organic gases (VOC) to the atmosphere, very environmentally friendly, which is incomparable to solvent-based ink.