What are the problems with aluminum foil bags during the printing process?

1. The printing fastness of the aluminum foil bag is poor. For plastic substrates (such as plastic film), it may be due to insufficient corona treatment of the film, the ink and the printed material have poor affinity. The printing environment has a large temperature and humidity change; for the printing of aluminum foil bags, it is mainly due to the poor affinity of the ink and the surface coating of the printing material or the printing material, or the temperature and humidity of the printing environment vary greatly. The resulting printing fastness is poor.

2. The ink layer of the aluminum foil bag print has scratches. The scratch of the guide roller, the sand mixed with the ink, the unevenness of the blade, the improper angle of the blade and the plate are the causes of scratches on the printed product. According to the specific situation of the scratch phenomenon, the correct judgment should be made, and the specific reasons should be found, and corresponding measures should be taken to solve it.

3, aluminum foil bag color is thin. Ink color thinness and poor color light reflection performance can cause such a malfunction. When excluded, the performance of the ink should be adjusted. In addition, for the printing of plastic film, the surface is first covered with white ink, and then the color is sequentially ordered; when printing, the layer is first printed with three primary colors, and finally the ground color is laid. For the printing of aluminum foil, it is possible to print a white ink or a white paint first, and then print a color pattern.

4, aluminum foil bag bite color. In overprinting, the second color ink sticks off the first color ink, which is a bite color. The causes are: the ink layer is not completely dried after the first color printing, the second color pressure is large, or the machine speed is too fast, or the hot and cold air is bad, or the substrate printing is poor. Adding a proper amount of quick-drying agent, slowing down the speed, reducing the pressure of the impression cylinder, and increasing the amount of cold and hot air are the measures to be solved.

5, aluminum foil bag printed products are dull and dark, the ink layer is rough, there are many blank spots, and there are lines on the ground. The above problems may be caused by excessive ink solvent, coarse ink particles, excessive dilution of the ink, and excessive evaporation of the solvent. As long as the corresponding measures are taken to reduce their indicators, such ills can be eliminated.

6, aluminum foil bag blocking version. Because the cleaning is not clean, the ink is solidified in the cell of the printing plate, or the cell is blocked by paper wool, paper powder, etc., or when the printing is performed, the temperature is too high, and the solvent evaporates too quickly to cause blocking. The elimination methods include: reducing the temperature during printing, increasing the content of the ink solvent, taking care to prevent the dust from contaminating the ink in the environment, and reducing the drying speed of the ink.

Of course, the foil bag is imprinted, the ink color is uneven, the ink is sticky, and the back of the print is dirty. It is also a phenomenon often encountered in the gravure printing process. The key is to adjust the printing materials, inks, printing equipment, and operation. The relationship between the environment and the printing process ensures the quality of the gravure product to the greatest extent possible.