The overall current status of flexo printing in the soft package market is that printing quality is difficult to match with gravure, but after hard work, it is not impossible to approach the quality level of gravure printing. Shanghai Violet Machinery's flexographic printing machine uses the Australian Acrylic ceramic anilox roller (black 800 lines/(ten), red, blue 700 lines/(ten), yellow 600 lines/(ten)), and the prints are measured by a Japanese DM 800 densitometer. When the white version is 0.00, the black field is as high as 2.4, which exceeds the density contrast standard of offset printing 1.8~2.0 and is close to the visual effect of the best reversal film 0.03~2.45. It seems that the contrast is strong, the colors are bright and thick, the layers are delicate, and the resolution is very high.
The advantages of both gravure printing and flexo printing are obvious: Flexographic printing can print a wide range of materials. For extremely thin plastic films and rough-surfaced substrates, such as some non-calendered thick paper, concave India is difficult to print. Flexo printing with light printing pressure (about 2kg/cm), with alcoholic or water-based ink, thin ink layer, easy high-speed printing, from the perspective of printing speed is currently the fastest in all printing processes, is gravure 1 .5~2 times (usually 200~400m/mln, printing up to 680m/mln).
Of course, because the printing plate is easily deformed, it is difficult to control, although it is lightly pressed, the graphic line point of the flexographic printing tends to expand, and the outlets generally increase (%-30% increase, intermediate tone up to 50%), it is inevitable that people have Abrupt sense. Gravure's high-level transition is quite stable, and it is easy to make 175 lines/(ten) of “net-free†effects.
The flexo plate making fee is about 30% of the gravure printing, and the cost is much lower, but its printing rate is 10% of that of the gravure printing. For products with a short version and low printing quality, of course, the flexo should be used. In particular, the flexible type of satellites is easy to operate, with fast registration, and the loss is significantly lower than that of gravure printing. The running cost is also much lower. However, when the plate is flexo-printed, the small dots below 3% are easily lost. No such worry. Therefore, for fine products, especially long-length or high value-added products, gravure should be used.
Gravure printing is dominant in the packaging of European branded goods. About 80% of the products of well-known brands use gravure printing. For fine products with particularly high demands, in the case of large-area field and fine meshes, they may sometimes adopt the same way as flexo printing. For flexo printing, it is more convenient to operate and maintain. It is equipped with a set of printing plate cylinders that can adapt to different printing lengths to adapt to the change of specifications. However, at present, the traditional flexographic plate is still mainly made of flat sheet. When affixed to the curved roller, due to the thickness of the plate material and the thickness error of the adhesive tape, the bending deformation of the plate material compensates the dimensional error, and human factors. It is difficult to control the problem of overprint errors caused by this, but there is no problem with this gravure.
The multi-colored satellite-based flexographic printing press has a large diameter and high height of the center impression cylinder, and it is inconvenient for the plate loading operation. The more the number of colors, the larger the cylinder, the greater the self-weight of the steel cylinder, and the greater the power for operation. The consumption is much greater than that of the unit-type gravure printing machine, and the trolley-type loading system of the unit-type gravure printing machine is flexible and convenient. Flexographic printing uses alcoholic or water-based inks, with a thin ink layer and low consumption, which is consistent with the concept of environmental protection and green packaging. Some people use it as a reason to eliminate gravure. First of all, gravure printing is currently dominated by benzene-based inks, especially domestically. This is an indisputable fact. However, alcohol-based gravure inks have been found in the early days, but their performance, mainly print fastness, is not very satisfactory. In developed countries in Europe and America, The inks they use are often flexo and gravure.