At present, both producers and users pay more and more attention to the outer packaging of products, and the market has a growing demand for a variety of high-end packaging and personalized packaging. In this trend, the packaging and printing field is also constantly developing new processes and new materials to meet the needs of the packaging market. The smoke sign matte printing process is one of the best.
1. Sanding printing
Matte printing is to print a layer of transparent UV matte ink on a substrate with a glossy finish. After UV curing, a rough surface such as frosted glass is formed, and the screen printing method is often used. Since the pattern obtained by this printing is very much like the effect of metal etching and has a special rough feeling, it is also called imitation metal etching printing.
2. Smoke mark matte printing printing materials
Printing cigarettes generally use 250-300g/m2 gold, silver cardboard and vacuum aluminum-plated paper, and require a smooth surface with a high degree of smoothness, and can produce a mirror metal effect after printing.
It is also possible to use a method of printing color paste on white cardboard, that is, printing a gold or silver color paste on the cardboard using a coating device, but the color strength of the color paste is required to be high, the coating color is uniform, the clothing is flat, and the gloss is good. Compared with composite gold and silver cardboard, the effect of gold and silver coated paper is slightly worse.
3. Sanding ink
In the matte printing process, the matte effect is formed by the special properties of the UV matte ink. The smoke-printing matte ink is a colorless and transparent one-component UV-curable ink with a particle size of 15-30 μm. The printed product has a clear matte effect, and the ink film is full and the three-dimensional effect is strong, and the product can be improved. As a result, it is mostly used for packaging and printing of cigarette labels, wine labels, cosmetics, and health products.
UV matte ink has distinct advantages over traditional solvent inks: exquisite printing pattern, strong three-dimensional effect, no solvent, high solid content, low environmental pollution, fast curing, energy saving, high production efficiency; The film is resistant to friction, solvent and heat. The smoke label printing mainly uses medium sand ink, the appearance of which is a white translucent fluid, and the basic technical parameters are viscosity: 3.0±0.1Pa·s (25°C); specific gravity: 1.10g/cm3 (25°C); pH value: 6.5 ~ 7.5; non-volatile components accounted for more than 99%; curing speed is less than 5 seconds (40 m / min, 80 W / cm high pressure mercury lamp 3). This ink should be cured using a UV curing device. The mechanism is that the photosensitive resin in the ink binder absorbs the energy in the UV light and instantly forms a hardened film. If natural light curing is used, it takes about 2 to 3 days.
4. The printing process
(1) Printing machine
To ensure the accuracy of registration, matte printing is best used with automatic screen printing equipment with UV curing device. For example, Japanese Sakurai with a UV curing channel is facing a sheet-fed roller screen printing machine with a printing speed of 800-3,000 sheets/hour.
(2) Printing environment
Temperature: 25±5°C; Humidity: 45%±5%.
(3) Overprint standards
Plate and text should be consistent with the previous color printing to ensure that the overprint is accurate, and the overlay error should be ≤ 0.25mm.
(4) Printing color sequence
Tobacco label printing belongs to high-grade trademark printing, which requires not only rich colors but also certain anti-counterfeiting functions. Therefore, multi-color printing and multiple printing methods are often combined.
