Metal inks for cigarette Packaging and printing
Metallic pigments in metallic inks have special metallic luster and are widely used in packaging printing, especially cigarette packaging printing. Since the composition and manufacturing process of metallic inks are very different from those of common inks, their performance is also quite different from that of ordinary inks. This mainly has the following performance:
1, metal ink particles are coarse. Compared with common inks, the particle diameter of the metal ink is generally 2-3 times that of ordinary ink pigment particles, and the larger the particle size of the metal pigment, the stronger the metal feel. Since the average particle size of the offset metal ink is small (generally, the average particle diameter of the offset metal ink is 5um, and the average particle diameters of the concave (soft) metal ink, screen printing metal ink, and gold metal ink are: 10 um, 20 um, and 30 um), so the metallic impression of the metal ink offset is inferior to that of the metal ink gravure and gold scan process.
2. In the manufacturing process of metallic inks, stearic acid added during grinding has a very important influence on the properties such as floatability and glossiness of metallic pigments. When printing, make sure that the stearic acid coating is not damaged.
3. The more regular the arrangement of the metal pigment particles on the surface of the printing ink layer, the better the metal texture.
4, due to the poor friction resistance of floating metal ink, so after the printing is generally also a layer of varnish to protect the metal ink film.
In the printing process of cigarette packaging metal inks, the following two points should be noted:
1, design and plate making. In the design, fine yin and yang characters, gradient mesh and other patterns should be avoided as much as possible using gold, silver ink printing. If the customer's design plan has been set, it is necessary to achieve the intended effect by adjusting the plate making process (such as the number of screens, gradients, etc.). Under normal circumstances, metal ink offset printing screen number of 133lpi, can be used 10% -90% of the gradient mesh (and metal ink gravure printing line number is 150lpi, can be 20% - 80% gradient mesh). In addition, the 45° screening angle is most conducive to the transfer of metallic inks, so gold and silver ink plates are best used with a 45° screen angle.
2, printing paper. Metal ink printing should use paper with high surface smoothness and gloss to facilitate the full realization of the metal effect.
Source: China Tobacco Packaging Ink Information Network
