White spots often occur in printing production, which is time-consuming and labor-intensive and affects production efficiency. When leakage occurs, many factories focus on how to solve the problem afterwards, but forget that the phenomenon of leakage can be completely avoided by making some minor adjustments before operation.

First, pre-press preparation

1. Check the viscosity of the ink before putting it on the machine to see if it is normal.

A common problem with printing blur is that the viscosity of the ink is too low, which is more likely to occur after repeated use. Because during the production process, printers often add water to the ink barrel, causing the viscosity of the ink to drop. This will cause printing to appear white, so the ink must be tested before going on the machine.

2. Check whether the printed version is in good condition

If the printing plate has been used for a long time or there is too much ink dirt on the printing plate, the ink transfer amount of the printing plate will be reduced. When the ink transfer amount is reduced, printing whitening will often occur.

3. Anilox roller

The cleaning of the anilox roller directly affects the printing situation. A large part of it is that the anilox roller is clogged and has not been cleaned. In this way, the ink carrying capacity of the anilox roller is small, resulting in printing whitening.

2. Learn how to eliminate white spots in printing

1. First check the thickness of the unprinted cardboard, and then check the thickness of the cardboard after it comes out of the paper feed sheet to see if the cardboard is crushed by the paper feed roller. If it is crushed, solve the problem of cardboard crushing first. The paper feeding gap is the thickness of the cardboard - 0.3mm.

2. Check whether the printing plate pressure is normal and whether there is enough ink on the printing plate. The hardness of the printing plate is suitable for the solid version at 34-36 degrees.

3. If the above is correct, then increase the printing pressure value. The pressure value should not be too high. If it is too high, it will easily produce printing paste, and the printing will slow down and wear out faster.

Of course, if the viscosity of the printing ink is correct and the printing plate and anilox roller are good, there will still be white spots in the printing. The main adjustment direction should be based on the ink process. Do not increase the printing pressure all the time. You can continue to increase the viscosity of the ink and the permeability of the ink. You can also adjust the printing machine to slip-feed mode for printing.