Flexographic printing has its own characteristics and advantages. Flexographic printing uses water-based ink or alcoholic ink with environmental protection features, which is not harmful to human body, and is especially suitable for food. Most of the medical product packaging and liquid milk packaging are flexographic printing. Secondly, the narrow width flexographic printing machine can increase the screen printing unit to complete the processes of die cutting, embossing, and hot stamping online, which improves the production efficiency and reduces the production cost. Thirdly, customers now have strict requirements on the consistency of external packaging colors (especially solid colors), and flexographic printing can be almost the same as the first printing, ensuring the stability of the packaging.
Therefore, flexographic printing is gradually being recognized by customers. In just a few years, hundreds of flexographic printing production lines have been introduced in China; at the same time, the application of flexographic printing has also driven the development of the flexographic platemaking industry. However, the domestic flexographic platemaking started late because of various reasons. The difficulty and difficulty of pre-press flexographic printing are one of the main reasons. If the prepress processing of the flexographic plate is carried out according to the method of offset printing or gravure plate making, there will be many problems with the printed sample, such as darkening of the color, loss of gradation, loss of highlights or hard edges.
During pre-press processing, manuscripts can be divided into two types: line drafts and mesh adjustment drafts. Line drafts, also called outline drafts, contain text, lines, and field information. It is relatively easy to modify, but pay attention to the minimum text in the test print And the thinnest line size, do not exceed this size when processing. In addition, due to the effect of pressure during printing, the lines will become thicker, and certain compensation must be given to the production. The single thin wire will bend when the pressure is too large to ensure that its width is not less than 0.1mm. Mesh revision is a layered image or pattern, and there are many factors to be considered in the production. The screen adjustment process is the core part of pre-press processing, and the issue of the increase of printing dots should be fully considered when making a plate.
When using the traditional plate-making method, 1% of the dots are unstable during the production process and are easily lost. Therefore, the smallest dot formed on the printing plate is 2%, and 2% of the dots will increase to 10% after printing, so the printing The smallest dot on the proof is 10%, and dots below 10% cannot be printed. At this time, the following methods can be used to avoid and solve ingeniously.
(1) Ignore some levels without affecting the printing effect, even if the outlets below 2% are completely screened.
(2) Change all highlight points below 2% to 2% dots. Because the human eye's perception of color is relative, in some cases an illusion may arise, and 2% of the dots are regarded as highlights.
(3) Replace a certain color with another color, such as black is often used in food packaging instead of blue, black is used in leaf printing for red, or light color with the same hue is used for dark, etc., the methods are different.
The above methods actually lost less than 10% of the dots in printing. With the advancement of technology, Esko-Graphics Corporation has developed a new dot technology combining FM dots and AM dots to ease the problem. The use of FM dots in the highlight area of ​​the image (1% to 3% dots) just solves the problem that 1% dots on the flexographic version cannot be kept. In addition, many companies have introduced new computer-based plate-making equipment, which can produce 1% of the dots through different exposure methods, and can print less than 10% of the dots, but the printing plate is not durable, and the number of times the printing plant replaces the printing plate More. In short, because there are too many and variable factors in the printing environment, the staff should consider various factors before printing, so that the flexographic plate can meet the printing requirements to the maximum extent, and finally get the ideal printed matter.
Pvc Waterproof High Frequency Welding Machine,The machine have strong output power, reliable performance, using low-loss oscillation system, and special design oscillation tuner, so machine output power very strong and material can be welded in short time, automatic worktable help to improve production.
Using high sensitivity America-Imported anti-spark triode tube, which is useful for protect mould and products once machine over current. Adopting famous brand OMROM relay and CKC timer, greatly extend the life of the machine, reduce the machine failure.
PVC Waterproof High Frequency Welding Machine
Bag Sealing Machine,Pvc Waterproof High Frequency Welding Machine,Pvc Zipper Bag Welding Machine,Pvc Handbag Making Machine
Hangzhou Xiaoshan Wanfeng Mechanical & Electrical Equipment Factory , https://www.wanfengmachinery.com