Analysis of common ink faults in the most popular

Analysis of common ink faults in the printing process

dirty

in the printing process, dirty and sticky dirty are two different concepts. Dirty generally refers to the dirt in the non graphic area, including blurred imprints, dots and so on. Dirt can be divided into floating dirt and oil dirt

1. Floating dirt

floating dirt refers to light color dirt in non graphic areas or blurred graphics and text in graphic areas. Dirt is easier to wipe off in thin strips

1) causes

① due to the soft ink and weak water resistance, some inks will emulsify after being affected by the fountain solution and enter the fountain solution through the circulation system to form an oil in water lotion; ② The chemicals and wetting agents in the paper contribute to the emulsification of ink; ③ Some fountain solutions contain substances such as soaps or detergents, which will also cause ink emulsification

2) solutions

① change to ink with slightly higher viscosity, good water resistance and difficult emulsification; Or add high viscosity inking oil to the original ink; ② Replace the paper used; ③ Adjust the amount of fountain solution to ensure proper conductivity and pH value

2. Oil dirt

oil dirt is that the non graphic area of the fingerprint plate has grease sensitivity, which causes the blank area of the printing plate to be inked and pollutes the printing. The demand for new light and durable special plastics and coatings in these industries may increase

1) causes

① the ink is too thin and soft; ② Printing takes a long time to supply ink, which will play a positive role in ensuring the supply of lithium carbonate at home and even around the world; ③ There are high concentrations of free fatty acids and surfactants in the ink; ④ The influence of treatment agents in pigments; ⑤ The surface structure of the printing plate is damaged by the excessive pressure of the printing plate ink cots and the blanket or the aging of the printing plate cots and the blanket; ⑥ Dissolve fat sensitive substances from paper coatings

2) solution

① replace the ink or add high viscosity into the original ink, and then process it by single chip microcomputer and transmit the test results to the computer resin oil through RS ⑵ 32 serial port data bus, so that the ink has better viscoelasticity; ② Control the ink supply during printing; ③ Control the amount of fountain solution; ④ Adjust the pressure of cots and blanket, or replace cots and blanket; ⑤ Replace the paper