Deterioration of the ink system causes treatment of biting

When our company Chaoli Fu 313A ink appeared color reverse transfer phenomenon (biting color), our company immediately sent technical personnel to the scene test analysis. At the time of the scene: 313A ink printing black and white PE film production of industrial protective film, red, blue paint, speed 30 meters / min, the workshop is very hot, when the coating oil red ink, blue ink recurrence, reversed India phenomenon. After detailed investigation and analysis, the technicians obtained the following results: The workshop temperature was high (the workshop had a self-adhesive coating machine at the same time, and the amount of heat was extremely high), reached 38°C or above, and the ventilation was poor, and the humidity also reached 90%; The solvent ratio used by customers is isopropanol:ethyl ester=7:3. According to the workshop and environment, the solvent ratio is obviously faster; all of the customer's diluted solvents are placed in long-term openings with a 50 kg barrel. Due to the combined effects of the above three factors, a large amount of water in the air enters the ink in the printing tank, causing the ink system to deteriorate in a relatively short period of time, causing a water pattern during ink printing, and the adhesion fastness is not sufficient. Biting phenomenon.

Our company's technicians did on-site test without any adjustment of printing, and found that the phenomenon of reverse printing was not obvious within two hours of printing, and the fastness of printing patterns was also good, but as time went by, the printing pattern began to appear. Flowers, reduced gloss, insufficient attachment fastness, etc., and bite-coloring are also increasing. After the machine was shut down, it was found that a large amount of water droplets accumulated on the back of the blade, the viscosity of the ink in the ink tank increased, the fluidity was poor, and the phenomenon of swelling was accompanied. The solvent was re-exchanged and isopropanol: ethyl ester: butyl ester = 5:2:3, and arranged for printing at night, avoiding the time of operation of the self-adhesive coater and the high temperature during the day. From 9:00 pm to 6:00 the next day, there was no reverse shift in printing.

Experience summary: The external environment has a great influence on printing. Experienced printers know that when people feel comfortable with the environment, printing is relatively smooth. When people themselves feel bad, printing is prone to failure. The authors ask the users to do some proper control of the environment before the operation, such as temperature, humidity, ventilation, etc., to avoid similar situations. (Case Study / Yan Yongyue)