About the offset printing process of cosmetic tube:
The most common hose printing process is dust removal—surface pretreatment—printing (UV ink)—glazing—varnish UV curing (or thermal curing). A special hose printing machine can basically realize the above-mentioned process.
Introduction of cosmetic tube common printing process:
1. Offset printing
The ink is transferred to the printing plate through a set of ink rollers, and then the ink on the printing pattern is transferred to the blanket by the printing plate, and then the complete printing pattern is transferred to the substrate at one time by the blanket. The offset press for tube printing is different from what we usually call the offset press. Generally speaking, the offset printing plate is a lithographic plate. The ink is supplied to the printing plate by the principle of incompatible ink and water, and then transferred from the printing plate to the blanket. Although waterless offset printing has been developed, the printing plate is still a lithographic or flat intaglio plate. . The offset printing plate used for tube printing is letterpress, so it should be more accurately called letterpress offset.
The tube offset printing plate is usually made of light-curing resin plate material, which is produced through the main exposure, development, washing, drying, and post-exposure processes. The production time of a printing plate is about 30-40 minutes, and the printing endurance can reach more than 100,000. Since this printing plate is a resin plate, and the graphics and text parts are relatively high (about 0.5-0.6mm), when making the screen adjustment, the highlight part can only retain more than 5% of the dots, so the printing on the hose The pattern is not as fine as the flat offset printing. It is for this reason that the phenomenon of labeling on the tube packaging instead of the direct printing of iconic patterns such as trademarks on the tube has appeared.
2. Traditional screen printing
The domestically produced multi-color screen printing machine is usually composed of several single-color screen printing machines connected in series. It covers a large area, has a long hose conveying route, and the positioning accuracy between colors is worse than that of offset printing, and the printing speed It is also lower, making its cost higher. Due to the thicker ink layer of screen printing, it is currently mainly used for the printing of colored hoses or some non-varnish products.
In the hose printing method, the above two printing methods can also be combined. A fully automatic hose production line realizes the combined production of offset printing and screen printing, making the number of printing colors of the hose reach 12 colors.
3. Hot stamping
It has the advantages of fine and firm imprinting, good metal texture, strong covering power and high floating power. By heating and pressurizing, the gold foil is imprinted on the paper, which can show a strong metallic luster and lower cost. The printed patterns are clear, beautiful, colorful, wear-resistant, and weather-resistant.
4. UV printing
With the popularization and improvement of curing technology, UV curing inks are commonly used, whether it is hose offset printing or screen printing, which makes the control of the ink easier.