The so-called special printing is the use of different from ordinary plate making, printing, finishing methods and materials for the production of special-purpose printing in general. Specifically, the main difference between the special printing and general printing not in format as the basis, but measured from plate making, printing, finishing methods and materials production and use five areas, all of which have different aspects and general printing That belongs to the range of specialty printing. With the commodity economy specialty printing and printing science technology continues to evolve and progress, showing strong vitality and broad prospects for development.
First, the flexographic printing process
Flexographic printing refers to the use of rubber or other flexible material resin letterpress, machine through the anilox roll to achieve transfer ink printing process method. The early flexographic printing due to the use flexographic printing inks, flexographic printing so there's commonly known. Since the flexographic process has letterpress, lithographic and gravure process commonality of substrate characteristics to adapt to a wider scope, simple structure, high precision. The machine is mainly composed pick roller, anilox rolls, the composition of the plate cylinder and the impression cylinder four parts.
Flexographic printing structure has three drum arrangement, stacked (ie, roll type), line type and satellites and so on. Three drum by multicolor single group, and each single group structure only three rollers, adjusting the amount of ink on the metal roller squeegee device, since the doctor blade in contact with the metal roller, easy to damage the texture roll, this is the kind of structural defects. Stacked flexographic printing press is the host on both sides of the respective units stacked monochrome printing, monochrome units each gear chain to drive through the host. When the aircraft roll paper by printing section, can be positive and negative printing, reverse printing is completed and before the ink dried. Another advantage is that when the machine and wash monochromatic color component adjustment or repair of the unit, other units are not affected, can continue without stopping production, capacity utilization is high. But the machine overlay accuracy than satellites almost, not printed stretch large, thin material substrates. Line type flexo presses single group constituted by a multi-colored paper between each color group operation is in the planar state, the tension can remain relatively balanced, it is suitable for printing thin and thick products. Satellite type flexographic printing machine structure, in the main frame has a impression cylinder, equipped with colored around the plate cylinder. The advantage of this machine is the overlay accuracy, scalability, more suitable for printing large substrates.