The ink penetration problem of self-adhesive coated paper is usually due to the ink penetrating into the opposite side of the paper, resulting in obvious marks or oil stains on the opposite side of the paper. To solve this problem, it can be solved from the following aspects:
1. Ink adjustment
Reduce ink thinness: If the ink is too thin, containing too much connecting material, easy to penetrate the back of the paper. By adjusting the formula of the ink, reducing the proportion of the connecting material and increasing the concentration of the pigment, the ink penetration phenomenon can be effectively reduced.
Avoid using dry jointing material: too much dry jointing material will lead to the reduction of the high temperature oxidation conjunctiva of the paper, and the penetration and drying will be accelerated, thereby increasing the risk of ink penetration. Therefore, the use of non-dry bonding materials should be avoided or reduced as far as possible.
Adding ink mixing oil: Adding No. 0 ink mixing oil to the ink appropriately can improve the adhesion of the ink and help reduce ink penetration.
2. Printing process control
Control the printing thickness of the ink: printing the ink too thick will cause the drying speed to slow down, so that the connection material has more time to penetrate the back of the paper. Therefore, the printing thickness of the ink should be controlled to ensure that the ink layer is moderate.
Speed up ink drying speed: By adjusting the drying device of the printing press or increasing the drying time, speed up the drying speed of the ink, you can reduce the possibility of ink penetration.
Selection of appropriate printing materials: The selection of moderate ink absorption, appropriate thickness of coated paper as the substrate material, help to reduce ink penetration phenomenon.
3. Environmental condition control
Control temperature and humidity: keep the temperature and humidity of the printing shop within the appropriate range to avoid the impact of extreme environment on the ink drying speed and paper performance.
Good ventilation: Ensure that the printing workshop is well ventilated, which helps the rapid drying of ink and the discharge of harmful gases.
4. Maintain the device
Wash the roller regularly: Uneven or dry surface cracking of the roller can lead to thickening of the ink layer and flying ink phenomenon, which increases the risk of ink penetration. Therefore, the ink roller should be cleaned regularly to keep its surface smooth.
Check the printing pressure: ensure that the pressure of the printing press is moderate and uniform, to avoid excessive pressure resulting in ink penetration into the reverse side of the paper.
5. Other suggestions
Use transparent priming ink: Before formal printing, you can use transparent priming ink to pretreat the coated paper, improve the ink absorption and surface tension of the paper, and help reduce ink penetration.
Consult professional and technical personnel: If the above methods can not effectively solve the ink penetration problem, it is recommended to consult the self-adhesive label manufacturer or professional and technical personnel to obtain a more specific solution.
In summary, to solve the ink penetration problem of self-adhesive coated paper, it is necessary to comprehensively consider ink adjustment, printing process control, environmental condition control, maintain the deviceand other aspects. By taking the above measures, the occurrence of ink penetration can be effectively reduced and the quality of printed matter can be improved.