Common faults in special paper printing


2022-08-23 10:10

Common faults in printing

1. The transparent ink has agglomeration phenomenon

The main reason and the solution: This phenomenon generally occurs when the temperature is low. In this case, the ink should be heated at room temperature of 35℃.

In a word, the solvent ratio imbalance, improper drilling control or process operation error are likely to lead to many failure phenomena, so every link should not be sloppy. When printing with transparent ink, in order to obtain the ideal effect, all links must be strictly checked, and the appropriate ink should be selected according to the actual situation of printing.

2. The gloss after printing is not very high

The main reasons and solutions for this phenomenon are:

(1) The transparency of the ink itself is poor, and the ink with good transparency should be replaced.

(2) During printing, the solvent volatilizes too fast and the drilling degree is too low. The appropriate slow-drying solvent should be selected according to the needs, and the ink drilling should be checked and improved.

(3) The uniformity of the aluminized layer is poor, resulting in poor reflective gloss. The aluminized film should be replaced, and the surface should be uniform and free of pinholes.

(4) The angle of the squeegee is too large, the shallow mesh of the printing plate should be adjusted, and the angle of the squeegee should be controlled well. Generally, the angle should be controlled at about 35 degrees.

3. The annoying "pocket" phenomenon

Careful observation of its flashing effect will reveal that there are pinholes on its surface, as if it was not printed. The main reasons and solutions for this failure are:

(1) The surface of the embossing rubber roller is not delicate enough, or there are foreign objects such as dust, which cause the ink here is not thick enough. Check whether the imprinting rubber roller is dirty, wipe its surface clean, check the quality of the rubber roller; replace the qualified rubber roller.

(2) The plasticizers, lubricants, etc. contained in the film float to the surface, preventing the normal transfer and lubrication of the ink. Before printing, the plastic film should be preheated and other pre-press treatments, and the film should be heated and printed. If it still does not work, the appropriate plastic film should be replaced.

(3) The ink drilling degree is too high, drying too fast or lack of drilling agent causes ink transfer and poor wet adaptability. The degree of ink drilling should be appropriately reduced and slow-drying solvents should be used.

(4) The printing pressure is too small. The printing pressure can be appropriately increased, and attention should be paid to controlling the printing pressure (usually around 4kg).

(5) The problem of the printing plate or the imprinting rubber roller (shows that the pitting is more regular). The printing plate and the imprinting rubber roller should be carefully checked for defects. If so, the plate should be remade or the rubber roller should be replaced.

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