What is the problem with printing white dots? How to solve the problem of printing white dots?

1. Powder of printing materials

Reason: The manifestation of this type of problem is that there are not many white dots and their positions are not fixed. Unlike paper wool and paper scraps, the powder droplets of printing materials lack their own surface strength, causing ink to adhere to small powder particles on the surface of the printing material, forming a white dot. When viewed with a magnifying glass, the white spot is almost devoid of ink.

Solution: Reduce ink viscosity. If the effect is not obvious, qualified enterprises can also print a layer of primer ink or desalination agent on the surface of the printed product to solve the problem of powder droplets. Due to the fact that the primer ink and desalination agent can cover the surface of the printing material, which is equivalent to scraping off a layer of putty on the surface of the printing material, the printed ink is actually printed on the primer ink or desalination agent coating, effectively reducing the printing white spots caused by powder droplets of the printing material.

2. Uneven materials

Reason: Sometimes the surface of the bearing material is uneven, which can also lead to printing white spots. For this reason, the main form of white spots in printing is the presence of many white spots and dense white spots.

Solution: For some large on-site pattern labels, the problem of white spots can be solved by printing twice. Generally speaking, printing primer ink can be used to increase the smoothness of the surface of printing materials to solve the problem of white spots.

3. Paper or dust

Printing white spots caused by dust in the printing environment are usually obvious and fixed in position. However, the white spots caused by paper hair are not very regular. Generally speaking, there are not many white dots at the beginning. After a period of printing, there will be more and more white paper wool and paper scraps on the drum of the machine.

Solution: If there is more dust in the printing environment, the workshop needs to be cleaned. The effective methods are watering and mopping the floor. If the printing white spots are caused by wool and paper scraps on the paper, a dust removal cloth can be added to the feeding section of the machine to reduce the generation of white spots.

4. Causes of static electricity

Cause: Some thin film adhesive materials will generate static electricity during the printing process, which will push the ink away and also cause the generation of white spots. The white spot caused by this phenomenon was observed under a magnifying glass, and an explosive effect was observed around the white spot. At the same time, it is obvious that during the printing process, there will be strong static electricity on the surface of the printing material, and frontline printing operators often get electrocuted.

Solution: Install an electrostatic precipitator on the printing machine. For printing enterprises without conditions, a humidifier can be installed next to the machine to increase the humidity of the local environment and also play a good role in removing static electricity.