One of the problems that printers will encounter in the process of printing is the uneven ink color in the field printing. This is a common problem, so how to avoid and solve it? First of all, we need to know that the ink color unevenness of general printing products is manifested by two kinds of unevenness, i.e. water pattern unevenness and orange peel unevenness.
The reasons for these two phenomena are as follows: 1. The uneven color of the water pattern is mainly caused by the deep gravure carving and the low viscosity of the ink. 2. The main reasons for the unevenness of orange peel ink are the addition of excessive polar solvents such as butanone in the ink; the high viscosity of the ink leads to poor leveling; and the quality of the embossing cots, which results in uneven pressure on different parts of the printing cylinder.
The reason has been found, so what are the solutions?
(1) Contact with plate-making enterprises and find out the matching results of plate drum, ink and printing conditions by testing. On this basis, plate-making enterprises determine appropriate engraving process parameters. Gravure plate produced by this process has strong adaptability in solving uneven spot printing.
(2) When receiving new live parts, communicate with customers in time and try to avoid engraving the spot-color plate too deeply. If the Gravure Engraving is deeper, the working viscosity of the ink can be improved properly on the basis of guaranteeing the leveling of the ink.
(3) For spot orange peel irregularity, the first one is to reduce the ink viscosity properly, the second one is to reduce the pressure of the embossing roller properly, and the third one is to increase the printing speed as far as possible.
(4) Rational mixing of solvent and working viscosity of ink. When the printing speed is over 100 m/min, the ink viscosity is generally controlled at about 20-26 s, and the fast-drying solvent can be properly increased in the solvent ratio.
The above content is a small edition of Jinan Packaging and Printing. If you need more knowledge, please contact us in time or click on our official website for consultation: http://www.jnurs.com/