Experience of the hottest label narrow flexographi

As one of the largest professional label manufacturers in Jiangsu Province, with the expansion of production scale and the improvement of label quality requirements, we deeply feel that the traditional printing equipment has become increasingly unable to meet the needs of production, so in 2002, the company decided to introduce new label printing equipment and chose the atlas 280 narrow width flexographic eight color printing machine, To cope with the growing label market demand

while introducing narrow width flexographic printing equipment, the special activity of this year's narrow width flexographic printing technology, focusing on children's books and teaching aids, was also applied to label production, which greatly promoted the development of the enterprise through two years of production. At present, our label products have been widely involved in medicine, daily chemicals, food and many other industries, and have been highly praised by nays group, white cat Co., Ltd., ony cosmetics and other well-known manufacturers. This article only summarizes our experience and experience in the production process, and shares and exchanges with our peers

technology experience

in recent years, the label market has become increasingly competitive, and users' requirements for label printing quality have been continuously improved; At the same time, the progress of label printing technology and the innovation of equipment that uses a series of reference voltage (like the code dispelling used in the weighing of the balance) to input the voltage to be converted (weighing objects) also provide the basis for the development of the leap in label printing quality

the use of narrow width flexographic printing technology has not only expanded the company's business scope and production capacity, and established a leading position in the technical competition, but also accumulated rich experience in prepress processing, plate material selection, line plate production and super capacitor brush technology with flexographic printing cycle times up to 1000

first of all, in terms of prepress processing, when we receive the design originals, we usually find that the orders designed by customers are mainly in the form of offset printing or gravure printing. If this kind of originals are completed by flexographic printing, the printed samples often have many quality problems, such as the color is not in place, the level is not obvious, hard edges appear, etc. Therefore, in order to better solve such problems, timely communication with customers is very necessary

secondly, in the selection of flexographic plates, we must also shop around. Printing enterprises need to fully discuss the use of plates, the production of line plates, the transition of levels, the increase compensation of points, the expansion rate of printing plates and other issues through cooperation with many well-known domestic plate making companies, summarize and sort out these data, and then formulate standards to provide reference for daily production. Such data management is not only conducive to production, but also can well control quality parameters, avoid the interference of human factors, and reduce the production failure

thirdly, due to the particularity of label printing, narrow width flexographic printing equipment has its outstanding characteristics compared with embossing and other types of flexographic printing equipment. From our experience, narrow width flexographic printing equipment is not only simple to operate, with high printing quality and operation efficiency, but also has strong combination, which means that it can make more kinds of products and have more competitive strength

experience exchange

good equipment also needs correct operation and reasonable maintenance to make it play its maximum role. In the use of narrow amplitude equipment, the biggest obstacle we encounter is not technical problems, but technological problems

1. the ink does not dry. Easy to fall off

for the problem of poor drying of ink, our solution is to use 9kw UV drying device, which is easier and faster to dry than 2kW lamp. When encountering the problem that the ink is easy to fall off, we usually analyze it with the ink supplier and raw material supplier. If it is found that the adhesion of the ink is poor, additives can be added. If the surface adsorption performance of the substrate is poor, corona treatment is required

2. Static electricity

static electricity is a common problem in production, especially when printing labels, it is necessary to install a complete set of electrostatic removal devices on the equipment, and strictly control the temperature and humidity of the workshop. Especially when printing in mold labels and film label products, the printing effect is better after removing static electricity and dust

3. Poor ink scraping effect

in the process of flexographic printing, when the scraper and the embossing roller are synchronously driven, it is easy to have knife threads, that is, there are traces of ink pulling out on the printed label, which on the ground shows that the color of some places is lighter than the surrounding color. At this time, the scraper should be adjusted to the best angle. In the selection of scraper, the blade of imported scraper is mostly carbon burned, and the scraping effect is better. The reason for the ink marks may also be that the ink itself is easy to produce bubbles and form marks on the roller. At this time, it is necessary to add some additives appropriately

4. ink bar

if there is an ink bar on the label, it is often that the gears and teeth on the printing plate cylinder and the embossing cylinder are not round, or there are indentations on the printing plate, so it is generally necessary to replace the plate cylinder gear. This kind of fault rarely occurs when the speed is fast, because the running in between gears is a kind of relatively fast instantaneous contact, which greatly reduces the resistance between gears

5. Number of lines added

from the point of view of the number of lines added in printing, the maximum number of lines in offset printing and gravure printing is higher than that in flexographic printing. The ideal number of lines added in flexographic printing is about 150 lines/inch. If it exceeds 175 lines/inch, it will increase the difficulty of flexographic plate making and printing, especially when the field and line are on the same plate, the ink volume in the field part is large, which is easy to cause ink blocking and other failures of the embossing roller, and it will also shorten the service life of the printing plate. In addition, in the processing of the online part, flexographic printing is completely different from offset printing and gravure printing. The points of offset printing and gravure printing can gradually change to zero, while flexographic printing can only achieve a minimum of 2%

today, with the development of UV technology, the enhancement of environmental protection awareness and the shortening of equipment maintenance time, users' acceptance of UV flexographic printing technology is also gradually improving. At the same time, users also pay more and more attention to the combination of various printing processes to meet the diversified needs of the label market, which leads to and promotes the emergence and development of narrow width rotary printing process We believe that the maturity of narrow width flexographic printing technology not only promotes the development and progress of flexographic printing technology, but also brings surprises to the development of label printing enterprises. Its rapid development is inevitable. (author: Qian Jun)