Polyamide ink has good adhesion, dispersion, gloss, abrasion resistance, solvent release, softness for all kinds of material printing, and is mostly used for plastic film printing. When used in the printing of aluminum foil material, the excellent performance of this kind of ink can be shown, and its heat resistance can also meet the requirements of aluminum foil printing.
Vinyl chloride vinyl acetate copolymer synthetic resin/propionic acid resin is the main component of the ink for aluminum foil.
Its holding point is bright color, high concentration, particularly strong adhesion with aluminum foil, and good transparency, but due to its solvent volatility when used in gravure printing, it is easy to cause ink drying and deposition in the inking holes of gravure rollers, resulting in paste plate phenomenon when it is used in the surface printing of pharmaceutical PTP aluminum foil.
Therefore, it is necessary to carry out the necessary pretreatment for the deposition of frozen ink by stirring or increasing the temperature (water bath) of the deposited frozen ink. If the ink storage time is too long, the ink will be deposited, resulting in the ink on the upper layer of resin solution, the lower layer of pigment, the upper layer of light color, the lower layer of dark color, should also be stirred after use.