In the gravure printing process of decorative texture, the design of the manuscript is very important. The design of the graphic and text is directly related to the anti-counterfeiting performance and the printing effect of the final printed product. The following 3 points should be noted when designing textures.
(1) Do not use a single texture. Gravure printing can achieve a good anti-counterfeiting effect, the main point is that it can print a variety of textures at the same time, and screen printing is very difficult to do a perfect match. If only one texture is used, this can be easily achieved using screen printing.
(2) For the same texture, it can be considered during the design that the plate-making factory uses a variety of different processes to produce more complex and varied texture effects.
(3) Because some special textures are generated through special software or some special practices, the printing plant should be more in contact with the platemaking factory in order to get effective support and reduce unnecessary losses.
Laser engraving gravure production
When using gravure printing UV decorative ink, in order to better show the effect of decorative texture, the ink layer thickness is much thicker than the normal color ink layer. Moreover, since the viscosity of the UV ink is much higher than that of other color inks, it is determined that a high amount of ink transfer must be used when gravure printing a decorative texture.
The gravure plate cylinder used for printing decorative textures is mainly produced by two processes of electronic engraving and laser engraving. Compared with the electronic engraving method, the laser engraving method has many advantages. First, the shape of the cell site is variegated. The laser engraving gravure can use a variety of cell shape, such as hexagon, square, line, circle, pincushion, etc. Shapes. If necessary, its cyberspace can also be freely combined and made according to needs. Secondly, the amount of ink transfer is large. At the same depth, the ink transfer volume of the laser-engraved network hole is 1 to 2 times higher than that of the electronic engraving network. At present, the depth of the electric-engraving version of the net hole can only reach 60 μm, which is far below the amount of ink needed for printing of UV decorative ink (except when using UV coating). Thirdly, the maximum number of screen lines that can be achieved by laser engraved gravure is much higher than that of electronic engraving. The maximum number of screen lines can be up to 200 lines/cm, and the angle can be freely selected without restriction. Fourth, the finest line of laser engraving can reach 0.02mm, which is impossible to achieve with electronic engraving.
When making UV printing decorative textures, we mix textures such as frosted, iced, and refraction, and the laser workstation can select different process parameters according to different textures to achieve the desired effect. For example, when making a frosted effect, in order to obtain a true grainy feeling, it is possible to select different dot shapes for engraving, and use the change of the process parameters to express different degrees of detail. In the performance of the ice flower effect, in order to reveal the detail of the ice flower texture, it is possible to engrave using a number of screen lines that are much higher than conventional. When engraving the refraction texture, different engraving methods are selected according to the line thickness required to express the refraction.
When a plurality of textures are mixed and engraved, the engraving process of the plate cylinder also becomes complicated. The complicated engraving process makes the rear end more variable and difficult to control. This is a difficulty in manufacturing such a concave printing plate cylinder.