The gravure printing machine is printed by circular pressing and direct printing. The printing plate is directly formed on the plate cylinder, and is inked by ink or ink jet. There is no ink distribution mechanism. Due to the thick ink layer, the gravure printing machine uses a fast-drying ink which is volatile and requires a drying device.
It can be seen from the above that in the printing of the gravure printing machine, in the whole process of printing, the ink plays a role throughout the entire printing process; which is very important, then from which aspects to select the ink that meets the requirements, what conditions must be guaranteed, this is The primary problem solved by each printing house.
The main principle of gravure printing machine: Since the gravure ink layer is thicker than the offset printing, after one color printing; the drying system must be used to quickly evaporate and dry the ink solvent on the printed matter to fix the ink on the substrate. Each color is dried and the ink drying speed is matched to the printing speed.
The drying method of the gravure printing machine is generally hot air drying. The drying device is composed of a heat generating device, a ventilating device and an exhaust port; and the hot air drying chamber is formed, and the printing sheet is dried from the hot air drying chamber. The drying speed is controlled by adjusting the amount of air flow.
With this drying device, the deformation of the printed sheet is small, which is beneficial to ensure the quality of the printed product. After the sheet is dried by hot air, it should generally be cooled by a cooling roll.
There are some concave shades on the printing plate of the gravure printing machine, which change with the color of the original. Therefore, gravure printing is a printing method in which only the thickness of the available ink layer in the conventional printing indicates the color is dark, which can rely on the cavity structure and the ink layer.
The thickness is different to reflect the shade of the ink. The thickness of the ink layer of the printed product can reach 1 – 50μm; so the density change range is large, the layer is rich, and the color is thick, which is suitable for continuous adjustment and beautifully produced high-grade album. In addition, the quality of the printed product is stable, and the ink of the batch is not uniform.
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