Mistakes in practical application of narrow-width flexographic printing presses

1, the product's suitability

At present, flexographic printing technology has made great progress. The quality of flexo printing products has been obviously improved, and good economic benefits have been achieved. It has basically been able to meet the needs of packaging and printing; in particular, the quality standard of UV flexo printing is precisely matching in color. Both the stability and the stability exceed that of offset printing. This is an optimal process choice for products that require stable, solid colors, such as stickers and folding cartons.

The world's flexographic printing technology is mainly adapted to the following areas: Medium and narrow flexo printing machines are mainly applied to trademark labels, clothing tags, boarding passes, luggage tags, folding cartons, stationery, small cartons, paper bags, and plastic portable devices. Bags, wrapping paper, paper cups, wallpapers, etc. The wide-format flexo machine is mainly used for the printing of corrugated box preprints, films, aluminized films, liquid packaging (such as milk Tetra Pak, juice recreation packs, etc.), food, instant food, cosmetics, and pharmaceutical packaging.

Domestic packaging and printing companies are often faced with the misunderstanding of the suitability of flexographic printing products: First, they do not fully understand the flexographic process, they do not fully understand the characteristics of flexo printing, and they habitually go with offset printing and gravure printing. Compare the clarity of the high cable and the gradient of the dot. Second, there is no perfect quality evaluation standard for flexo printing. There is no uniform standard for communication with customers, causing some misunderstandings and differences. Third, there is a lack of professional flexo designers, operators, and market development personnel, which can not give full play to the advantages of flexographic products, such as the ink layer thickness and color saturation, etc.; Fourth, it does not play a powerful role in flexo printing machine linkage. Advantages, combining a variety of printing methods and post-press processing technology, improve production efficiency and reduce product costs. The lack of understanding of print profitability and integration costs, and most domestic packaging and printing companies are still in the extensive stage of operation and management, and the system is still not systematic and normative in terms of profit assessment and cost integration.

2. Suitability of equipment and process

At present, the advantages of flexographic printing generally recognized in the field of packaging and printing are as follows: 1. The use of non-toxic water-based inks and UV inks is safe and environmentally friendly. It is called “green printing” and is widely used for the packaging and printing of medicines and foods. 2, the ink layer is relatively thick, color saturation is good, different batches of printing products can maintain the same ink, in line with the characteristics of packaging and printing requirements. 3. The printing materials of the flexo printer are extensive, besides all kinds of paper, it is also suitable for printing plastic film, corrugated paper, adhesive material, aluminum foil, metal foil and other materials. 4. The flexographic printing machine has a very strong comprehensive processing capability. It can be used to connect printing methods such as embossing, offset printing, screen printing, etc., to link glazing, laminating, die-cutting, discharging, cutting, cutting, folding, and even playing. Various complicated post-printing processes such as holes, marking, bronzing, and gluing are commonly referred to as "printing production lines." 5. Flexo printing production line has good linkage, fast printing speed, occupies few production sites, saves labor for subsequent processes, and avoids the waste of work flow between processes, resulting in low overall production costs and high economic benefits.

In recent years, with the continuous development and improvement of the world's flexo printing technology, China has held many international large-scale printing technology exhibitions, flexo-printing technical seminars and technical exchange meetings, and organized visits to and inspections abroad. In China's printing industry, People have witnessed the production process of high-quality color flexo products. They are convinced that the quality of flexographic products can already be comparable with gravure and offset printing, fully meeting the needs of current packaging prints, and having new technologies and technologies for flexographic printing. Recognition and requirements. In recent years, China has once again set off the culmination of the introduction of foreign flexographic printing technology and equipment. By the end of 2005, the country had introduced nearly 400 flexo production lines, mainly from the United States, Canada, Switzerland, Italy, the United Kingdom, and Germany. Japan, and Taiwan, China, are distributed in more than 20 provinces, cities, and autonomous regions across the country, and are mainly concentrated in such areas as Shanghai, Beijing, Guangdong, Yunnan, and Shaanxi.

Due to the rapid development of flexographic technology in China, it has led to the development and production of domestic flexo printing machines, anilox rollers, plate materials, inks, and equipment and equipment for plate making and flexo printing. China's flexo production supply chain It has been formed and has made great progress in recent years. In addition to the production of more than 10 flexo presses by the China Flexographic Association, the production of key components for flexo presses has gradually grown up. The manufacturers who can mass produce ceramic anilox rolls include: Shanghai Laser Under the group's sculpture branch company, Shanghai Aokeli Printing Machinery Co., Ltd., etc.; Manufacturers who can produce cutting cylinders indispensable for flexo printing machines include: Shanghai Bernell Yahua Printing and Packaging Machinery Co., Ltd., Kunshan Xiazao knife Mould Production Co., Ltd., etc.; Shaanxi New Century Printing Materials Research Institute, Tianjin Ink Co., Ltd. and Shanghai Printing Technology Research Institute and other units developed water-based inks, water-based gloss oils, water-based additives, UV light oils, and UV inks. In the aspect of platemaking, Xinhua Precision Plate (Shanghai) Co., Ltd., Dalian Fule Flexo Plate Co., Ltd., and Toyo Laser Color Separation Flexible Co., Ltd. (Shanghai) Co., Ltd. have all introduced foreign full-platemaking equipment and technologies, making the domestic flexographic version. Platemaking technology is at the same level as the international one.

Shanghai Xinyi Sun Machinery Co., Ltd. is a wholly-owned subsidiary of Japan Sun Machinery Co., Ltd. and is a high-tech enterprise specializing in R&D and manufacturing of rotary printing machinery. With the support of Japan’s headquarters’ strong technology reserves, it has been in Shanghai since 1995. After the establishment of the plant, the scale has been continuously expanding. It has been the top spot in the field of business forms and receipt printing machinery manufacturing in China for many years. In recent years, it has also become a major player in the manufacturing of label rotary presses and flexographic printing presses. The TLC-type satellite rotary press has not only filled the gaps in the domestic printing press manufacturing industry, but also ranked top in the industry with an annual sales and manufacturing of more than 40 sets; at the end of 2006, it also has a new machine to fill the domestic gap. Type-TCF type medium format flexographic printing machine has been put into production in March 2007 and has attracted great attention from the industry. It will surely bring more international competitiveness to the domestic packaging and printing companies.

The selection of medium-narrow flexographic printing presses and the potential errors in the applicability of equipment and processes for domestic packaging and printing companies are as follows: First, the choice of flexo printing machines should be suitable for the characteristics of the printed products; second, the flexographic printing machine The selection of configuration and auxiliary equipment should be reasonable; in addition, the flexo printing process must be properly adjusted.

From the structure of the flexo press, there are three basic types: laminated, crew and satellite. Laminated flexographic printing press has simple and compact structure, small floor space, low manufacturing cost, and easy printing on the front and back; its disadvantages are complex transmission, many gear gap points, difficulty in combination of color groups, poor overprinting accuracy, and difficulty in online connection; Simple prints and prints that require positive and negative printing. The printing unit of the unit type flexo press has the same structure, simple and reliable transmission, simple operation and maintenance, wide adaptation, convenient combination of color groups, easy post-press processing procedures, and high overprint accuracy; its disadvantage is that it covers an area of ​​up to Paper lines are long, waste of printed materials is large, and tension control of materials is demanding. The satellite type flexographic printing press completes the color printing registration on the common printing cylinder. Since the printing material is tightly attached to the pressing cylinder, the tension of the material changes little, the material deformation during drying is small, the machine structure is compact, and the paper feeding line is short; Therefore, it is especially suitable for the printing of thin materials with wide width and difficult tension control. Overprint accuracy is higher than the former two types. The disadvantage is that the machine cost is higher, the number of color groups is limited by the size of the central cylinder, and the color groups are arranged at different angles. , It is difficult to increase the color group, and the post-printing process is difficult to connect online.

When choosing a medium-width flexo press, the printing company must reasonably determine the configuration. Can not ignore the characteristics of printing products and the rationality of the process, but blindly online too many processing procedures; too many processes, with unreasonable will reduce the speed of the whole machine, waste of materials; before ordering equipment, it is best to ask the manufacturer's Professionals formulate design plans based on their own company's products, and fully consider the user's applicability, product quality requirements, and the use of cost and other factors. In addition, after setting the host's plan, we must also consider the selection of auxiliary equipment and components, such as flexographic plate-making equipment, anilox roller cleaning equipment and anilox roller number and the number of lines and so on.