FLEXOGRAPHIC PRINTING Flexographic printing is the only letterpress process that is still showing growth, mainly in packaging, label, and newspaper printing. The main feature of flexographic printing is the use of flexible printing plates. Flexo printing is a typographic process that is growing in packaging, labeling and newspaper printing. A key feature of flexo printing is the use of relatively soft and flexible printing plates compared to printing plates used for book printing. It is possible to print on a wide range of absorbent and non-absorbent printing substrates. The principle on which a flexographic printing unit works is illustrated in figure 1.3-9. It can print on a wide range of absorbent and nonabsorbable printing paper by using a flexible (soft) printing plate suitable for printing paper and a suitable ink (low viscosity). The low-viscosity ink is transferred to the printing plate via a roller that is evenly screened with cells, the so-called screen roller / anilox roller (screen width 200-600 lines / cm, ceramic or hard chromed metal surface). The rubber or plastic plate is attached to the printing plate cylinder. Ink is transferred to the printing substrate by the impression cylinder. The use of a blade (together with the ink supply system) on the screen roller has a stabilizing effect on the printing process even from filling the cells on the screen roller. Low-viscosity inks are inked in very fine cell pockets on the so-called screen roller or anilox roller (screen 200-600 lines / cm, ceramic or hard chrome plated metal surface) The ink is transferred to the resin plate (printing plate). Rubber or elastic resin plate is attached to the plate cylinder. Ink is applied between the plate passing-through pressure cylinder and the ink pressure by the thickness of the paper, whereby the ink is transferred again to the paper. By using the doctor blade (ink supply) on the screen roller, the ink is uniformly supplied to the cells of the screen or the Anilox roller. With rubber plates in exclusive use, only a moderate printing quality of solid motifs and rough line drawings could be achieved. "Nyloflex" from BASF and "Cyrel" from DuPont. It is used for printing on packaging, photopolymer wash-off plates, etc. for today's higher-quality requirements. These allow screen resolutions up to about 60 lines / cm. With the rubber lathes that were used in the early days, it was impossible to reproduce only rough lines, not solid motifs or fine lines, not halftones. In today's high-quality packaging printing, DuPont's BASF uses photoplymer plate cleaning devices such as "Nyloflex" and "Cyrel". It reproduces screen resolutions up to 60 lines / cm.
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