Development of market economy, commodity trade greatly enriched, exports continued to increase. Folding as the most widely used form of transport packaging products, from a single line of text printing, the color quality copy of the sales package changes. As an important step after the box-channel technology, the printing, has become increasingly concerned about production processes.
1, box printing presentation
At present, China's box printing a variety of ways, traditional offset printing, flexographic printing, screen printing and the recent rise of the pre-printed flexographic, gravure prepress, digital printing have occupied their respective markets. Each method has advantages and disadvantages and printability range of actual companies and products to the right choice according to the characteristics of the production.
2, folding carton offset printing process
Offset is currently the most mature printing technology, occupies a prime position in the packaging and printing. Graphic portions and blank portions on the plate no ranking points, almost in the same plane,printing plate with water, and then to the printing ink supply, the use of the ink repulsion of principle to achieve printing. Its plate-making process is simple, low cost, high production efficiency, exquisite designs, quality and stability. But the way is not suitable for offset printing production line production and less efficient.
Folding offset printing there are two ways, one is the direct printing done on the cardboard, the other one is the first printing glossy paper, glossy paper again performed after laminating. Among them, the indirect printing because it is pre-printed on a single sheet of paper, its high print quality, print after polishing can also be surface decoration, film, etc., can greatly improve the box appearance, sales in high-end products Packaging has been a dominant position. But laminating lower processing efficiency. Direct printing mainly for micro-corrugated products, the way more applications in foreign markets, has been relatively mature, the improved production can offset press, such as MAN Roland 900 large-format printer can print directly qualified corrugated board . The printing cardboard strength at the expense of limited circumstances can effectively guarantee box moldability, but also to achieve the effect of fine print. But the equipment investment cost is still relatively high.
3, box flexographic printing process
Flexographic printing ink path is short direct printing. Its plates made of resin has a certain feel of elasticity, graphic part convex, concave blank portion, using a doctor blade, anilox ink supply means using environmentally friendly water-based ink production. The printing on the box directly to the pre-printed cardboard printing and tissue paper and then laminating two kinds. Printing can be linked directly to production, the box in the middle and low production of the most widely used.
Flexographic printing presses are mainly two unit-type models and satellite, its large format printing, multi-color, high quality and relatively low cost. Wide printable with flexo equipment 2.5 to 2.8 meters in width. Flexographic printing are light pressure printing for small loss of strength corrugated cardboard, water-based ink in line with environmental requirements. Flexographic printing plate easily vulnerable in its compressive deformation, dot gain is difficult to control. Image highlights some outlets are easily lost or severely increased in the darkened part of the network of about 85% will expand into the ground state merge, thus creating a tone reproduction range is not wide, only about 5% to 85% . For the rich layers of high-end print difficult to achieve the desired effect. In addition, subject to a variety of reasons the current printing inks and printing materials and surface treatment, the actual production rate is only about 100 meters to 300 meters. With advances in technology, flexo, water-based ink continuously improve the quality, adhesion, color strength growing, the use of closed squeegee system can also deliver better guarantee of ink, flexo printing speed and quality will It has been greatly improved.
4, pre-printing color box
There are pre-printed way the main pre-printed and pre-printed intaglio two flexographic, gravure prepress again as the main way. Process is the first to use gravure or flexographic printing Web, rewinding and then laminating the tile line to become corrugated, folding carton and finally die to get technical. Pre-printed tissue paper to be considered at the time of laminating pattern alignment problems, general installation of optical tracking control system in the cross-cutting, in order to achieve precise cutting of the pattern Department. Compared with the printed cardboard, pre-printed to provide more attractive products, and printing quality more stable and reliable, quality box after molding is relatively good. From the point of view of production efficiency, the use of web printing can be achieved non-stop for paper operation, for large quantities, relatively high print quality boxed product is particularly suitable.
To adapt to the high speed production of pre-printed, printing ink and paper materials also have higher requirements, such as smoothness of the paper better, its compression strength and burst performance to good. Practice has proved that coated white paper, although good color performance, but in the high-temperature drying process, the color will produce changes that affect the design effect; linked to pulp white paper, its surface smoothness is poor, the image quality of the printed dot on the poor, while the ink is consumed in large quantities, is not the best pre-printed paper. The white cardboard, its smooth and high, good print dot image quality, but also stand the test of corrugated high temperature bake bonding process, is the ideal pre-printed paper.
5, box of pre-printed intaglio process
Also short Ink gravure printing directly employed on its concave plate graphic part, show the image with the ink layer thickness of tone levels. Its products are solid ink, full, colorful, three-dimensional sense of strong, clarity, gloss characteristics of high-end products for the printing has a great advantage. Folding pre-printed intaglio device used mainly large units printer, and with a photoelectric detection computer cross and slitting machines to meet the requirements of the cross when precision laminating. In the paper preheating unit and humidifier installation of the production line can effectively regulate the moisture content of the paper, to ensure stable tension can reduce paper wrinkle during the impact sequence after the paper feed production and processing. Dust and explosion-proof ink devices using electrostatic attraction, PLC computer corrective devices, automatic print registration device, automatic image detection device for the production of high-quality printing products to provide a guarantee. But also can be printed once completed glazing, improved product quality.
Gravure-plate engraving technology currently used mainly for the production of electronic, cycle greatly reduced, but the cost is still high. Domestic equipment prices although more expensive imported equipment, but the equipment complexity, the cost of inputs is still large.
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