High-mesh line color flexo platemaking process

Due to the low toxicity of water-based inks, the wide coverage of the carrier, the high flex print resistance and the relatively low cost of the flexo press compared to offset presses, the future is full of hope for development.

The "Printing Magazine" presented to readers a monthly calendar sample full of tables at the West Point, fresh fruit and baskets, and comparable to world-class offset printing materials. It was October 20, 2000, Shanghai Ziguang Machinery Co., Ltd. YR-420 web. At the flexo printing press exhibition, the flexo printing products printed at a speed of 80 meters per minute under the concern of the flexographic printing industry and the leadership of one hundred delegates! Visitors couldn't help but took samples and carefully studied the taste...

This flexo is printed in China's Shanghai flexo printing industry with a domestic printer! It is under the jurisdiction of Shanghai Renshi Computer Graphics Co., Ltd. to undertake the production of flexographic plates, using AkzoNobel brand water-based inks and DuPont's Saili plates. One pays for the 150 line system and the other pays for the 175 line system. Anilox black version is 800 lines, magenta and blue are 700 lines, yellow is 600 lines, and all two printing conditions are the same.

Some people use DM-800 density meter to measure the product. When the blank paper is 0.00, the black field generally reaches 2.30 or more, and the highest point is 2.46, which is far more than the international and domestic general density contrast standards of the 1.80-2.00 offset printing products. Close to and achieve the visual effect of the best reversal film transparency of 0.03 to 2.40 (or 2.50). It's no wonder that the prints seem to have a strong contrast, with vivid colors and objects, delicate layers, and high definition.

The Renshi hardware equipment for making this flexo version: the color separation input is the S-3900 extension in Heidelberg, the output is the Barco 3800 and the Hercules photo output, and the first DuPont type 3 002 in Asia (maximum size 2 000 mm) ×1 200 mm) flexo platesetter flexo prints, rinses and ovens.

The research and development of Renshi's flexographic production software technology is based on the breakthrough of data and methods on offset printing plate image separation technology, and the establishment of a corresponding computer numerical control program system; then the transfer of this technology to the flexographic version Making research to explore. After a period of practice, important data has recently been obtained on key technologies and major breakthroughs have been achieved in practice! This flexo product is the result of using the newly researched data system.

As we all know, the expansion rate of flexo printing dots is far more than that of offset printing dots. The expansion rate of offset printing sites is consistent, and its specific expansion value is based on the difference in the number of lines of outlets, the percentage of network outlets, the shape of outlets, and the difference in the perimeter of the outlets. However, the expansion rate of flexographic printing dots we have measured for a long time is not the same as that of offset printing. The smaller the dots of flexo printing products, the higher the expansion ratio (not the expansion value) in printing is! This and the flexo product to pull open the requirements of the contrast between color and tone, showing the trend of running in reverse! What is the reason? How to calculate the compensation in computer numerical control? These issues have long puzzled us.

“Kung Fu pays attention to people.” In the recent exploration, we finally found the answer in the field of optics and chemistry of the flexo edition. The original curve CNC system was modified and new data characteristic curves were generated for output. Ziguang Machinery Co., Ltd. just commissioned this company to make a flexible test plate. The two products are the results of the first trial of the new data curve.

In general, there are many kinds of flexo printing machines such as narrow-width machine, wide-width machine, and slot machine. The carriers include self-adhesive, coated paper, cardboard, corrugated paper, plastic film, and various metal foils (such as aluminum tubes for beverages). Coverage is much larger than offset printing. The number of dot lines used in its graphics range from 30 lines (some are even thicker) to 175 lines. Due to the variety of circumference changes caused by the number of line dots, and the difference between the printer and the carrier, different types of curve data must be compiled so that the flexographic version can meet the pressure of a specific flexo press. Anilox roller printability. To this end, the company has compiled five characteristic curve data based on feedback from users' actual information. At present, they have been able to adapt to customer requirements under a wide variety of flexographic conditions. For these two products, a 150-line one is output with a 4th curve, and a 175-line one is output with a 5th curve. The effect of the product is basically the same. Facts have proved that the 21st century will be a digital century. Our arduous exploration has initially achieved the “image-number” conversion and computerized digital production management system in the production of flexible editions, which has ensured the stable quality of various products of the company.

Due to the extremely high expansion rate of flexo printing outlets, it is common sense to use the output of a circular dot plate with the most connotation and the shortest perimeter to slow down the dot gain rate during printing. However, behind this common sense, the high expansion rate of the flexo printing outlet itself and the change in the shape of the outlets will bring three problems: 1. The clarity of reproduction using the circular network will be reduced at a later level; 2. Flexo dot special The high expansion rate itself includes the change and decrease of the sharpness of the edge level in the printing process; 3. After the circular network is adopted, the percentage calculation of the circumference of the edge of the network point is completely different from that of traditional offset printing. Data mode. In this regard, we have completed the corresponding calculation method and its method of computer control at the time of output. With the mode of the management system, we have put into production and overcome and solve the above-mentioned three major problems.

In the flexo slot machine printing corrugated box, in addition to four-color machine or more color group machine, there are also three-color machine printing color graphics. At the same time, the color shift and ash content of three primary colors using different brands of water-based inks are also different. According to the actual situation provided by the customer, after the color separation is entered into the computer, the black version of the skeleton version is resolved to the C, M, and Y color versions to provide necessary correction and compensation for the data. Under the conditions of the non-black version of the three-color flexo printing, the printed product still seems to have a black color level and gray balance effect of four-color printing, and no color cast occurs. In addition, according to the different color deviations and gray ratios of the three-primary water-based inks used in the flexo printing plants, calculations are compensated in the computer so that the printed products can obtain the best color the customer needs under the conditions of the specific three-primary water-based inks. effect. Flexographic and offset printing, although each with different characteristics "interlaced as if separated by mountains", but after the conversion of the image-like, they can find the commonalities in mathematics, so it is "interlaced and unreasonable."

Therefore, it can be said that in the contemporary flexo platemaking technology, if you leave the calculation and control of the computer data, it is an unthinkable thing! Therefore, modern flexo platemaking belongs to the high-tech field. In the contemporary world printing industry, softness/development is the most favored one. Due to the low toxicity of water-based inks, the wide coverage of the carrier, the high flex print resistance and the relatively low cost of the flexo press compared to offset presses, the future is full of hope for development. The outstanding performance is now setting off a wave of "concave and soft, rubber to soft". However, the key to breaking through the quality of flexographic printing, approaching and achieving offset quality is not only the high-quality “technical talents” but also the scientific knowledge of equipment, materials, etc., and become “science and technology talents”. It is best to constantly develop and innovate technologies based on the needs of the market, and to compile and develop new software technologies through this innovative result, melt into quality control, and become a digital production management system. This is the key to the internalization of "science and technology industrialization." Therefore, whether or not we can create "innovative management talents for science and technology" is a decisive factor for the improvement and development of China's flexo printing industry.