In the printing of food aluminum foil bags, benzene exceeding the standard has always been a problem that plagues manufacturers. However, if a water-based gravure ink is used, this condition can be changed to reduce the contamination of the food contained in the residual solvent. In order to ensure the printing effect of custom aluminum foil bags
Adjust the viscosity of the ink with water, generally controlled at 15 to 25 seconds. Prevent the viscosity from being too high, resulting in dirty plates and pastes. When using an aqueous ink for aluminum foil bag printing, the pH should be controlled between 8.5 and 9. The drying temperature should be controlled between 50 and 60 degrees Celsius. When drying, the air volume should be large to ensure that the water-based ink transferred to the film can be quickly dried.
After the ink is poured into the ink tank, the plate cylinder is idling for 2 min to 3 minutes, and then printing is started to ensure that the plate cylinder is wet and the ink is effectively stirred. In the process of printing, if there is a temporary shutdown, it is necessary to ensure that the printing plate continues to rotate, to prevent the ink on the printing plate from drying up, and the grid is blocked. The depth of the cell of the plate cylinder is preferably shallower, which is advantageous for speeding up printing and saving ink. The mesh is too deep, which not only hinders the printing speed, consumes ink, but also tends to cause adhesion. The specific depth is maintained at 15 to 25 um. Before printing the customized food aluminum foil bag, adjust the viscosity of the ink according to the depth of the plate cylinder. Do not add water to the ink during the printing process. If necessary, add new ink to ensure the audio color is consistent. After printing, the plate cylinder should be washed immediately, the water should be poured into the early ink tank, and the plate cylinder should be rotated for cleaning, or 3% washing powder solution should be added for cleaning.
At present, the country has already made food aluminum foil bags into the mandatory 3C certification catalogue, which means that the water-soluble plastic bag printing will be more developed, because it has no benzene, no irritating smell, no pollution, very Suitable for printing plastic food bags. Under the general trend of environmental protection, this environmentally friendly ink-printed plastic bag product will usher in excellent development opportunities.