Gravure Printing Digital Platemaking Technology and Surface Treatment

Gravure printing is mainly used in a wide range of fields such as food packaging, human leather, cigarette packaging, building home decoration materials, flooring materials, and fabrics. Intaglio printing ink has high gloss, strong coloring power, vivid color, good transfer printing and overprinting performance, high printing density, large contrast, enlarged balance of halftone dots, high printing plate resistance, and high printing speed.

Many gravure printing factories in China use a lot of plate making methods, but with the rapid improvement of printing plate making technology in recent years, digital plate making gradually occupied the mainstream of the market. Digital platemaking is when the manuscript is copied onto the plate. The color information is transmitted in the form of digital signals. Its main advantages are:

1 Simplify the plate making process. A well-designed graphic file can be printed by computer control. 2 It reduces the direct cost of platemaking and eliminates the use fee of the film.

3 Reduces the loss of signal in the process of color restoration, and is more conducive to color management;

4Solve the continuous seamless splicing of graphics on the drum, which greatly enhances the practicality of the fields such as decoration and textiles;

5 The format change is more free. At present, it is possible to make a 2800mm×2000mm format printing plate at home. It is completely free from the limitation of the output film of the photofinisher; 6 It can provide precise positioning for multiple processes on the same roller, and can be different on the same plate. Lines, outlets with different network line angles.

According to the actual situation in China, gravure digital platemaking has three methods:

1 electronic engraving machine mode;

2 laser engraving and post-corrosion treatment;

3 electroplating alloy laser direct ablation plate making method.

Electronic engraving machine

The electronic engraving machine is a modernized technology using integrated automation control, and has a highly-quality and stable precision machine. Taking the German Hell machine as an example, engraving frequency 4000Hz-8000Hz network cable range: 40-140 lines / cm, after the manuscript is produced by color separation, through the RIP after 1-BitTiff graphics format or bill unit to the electric engraving machine workstation, through the digital The signal-driven diamond engraving needle vibrates on the surface of the copper plate cylinder to sculpt the pit. The diamond carving head has a quadrangular pyramid shape. The v-shaped pits produced by the electric head not only changed in depth, but also changed in size, thus completing the halftone reproduction of the graphic and text.

All electric production data are collected in digital form and can be used in subsequent jobs with high reliability. The manuscript becomes a digital signal from being scanned and sent to the software for color separation and then transmitted to an electric engraving machine or a color proofing machine. This is very favorable for the standardization and standardization of the production process, and thus the quality of the printed matter is more assured. Moreover, the electric carving workstation uses TIFF graphic data for transmission, after HelioLight version workstation for convenient integration and setting the working parameter configuration, the engraving software generates electric carving curves, records the electric carving parameters and shows the engraving status until the disc is saved. (Convenient for multiple use and revision).

The electric carving process is relatively mature, simple in control and realistic in level reduction. The disadvantage is that the amount of ink on the ground is limited, and the ink layer does not have enough hiding power for some rough substrates; due to the mesh wall partition between the mechanically engraved network points and the net points, the occurrence of sawtooth edges on the edge of the lines formed by the net holes is inevitable. , Small text is not clear when printing and it is easy to break or paste. However, Germany's Haier recently introduced the Xtreme engraving technology. It can reproduce the finest parts with extremely fine lines of up to 400 lines/cm. Fine text can be independently selected for recording resolution without depending on the number of engraving lines. The flow of ink smooths the outline and creates the outline. Both conventional sites and FM screening can be implemented.