How to allocate anilox roller to flexo printing machine
Most printed products have solid ground, lines, and continuous tone images. In order to meet the needs of various printed products, users must not adopt the method of installing several anilox rollers with several printing units on the flexo printing machine. Take the narrow-width unit type flexo printing machine as an example. At present, most of the domestic introductions are 6 + 1 type, that is, 6 color groups are designed for multi-color printing. The last unit can be used for printing and UV coating.
We recommend that for prints up to 150 lines, this 6 + 1 flexo printing machine should be equipped with 9 anilox rollers. Among them, four 700 lines, an ink layer thickness of 2.3BCM (1 billion cubic micrometers per inch), an anilox roller of 60 ° is used for gradation printing; three 360 ​​to 400 lines, BCM6.0, 60 ° The anilox roller is used for solid plate printing; 2 anilox rollers of 200 lines, around BCM15, 60 ° are used for gold printing and glazing. If you use water-based gloss oil, you should choose 360 ​​line anilox roller, so that the oil layer is slightly thinner, and will not affect the printing speed due to the problem of drying of the gloss oil. Water-based gloss oil does not have the special smell of UV gloss oil. The V setting of the anilox roller during printing can be determined by experiment and comparison. The thickness of the ink layer that the operator can observe during the test mainly depends on the line number and BCM value of the anilox roller.
What problems should be paid attention to during the use of anilox roller
The anilox roller we mentioned here refers to the laser engraved ceramic anilox roller. It is a high temperature and wear resistant coating material in aviation and aerospace. It is used according to a certain density, depth and a certain angle and shape. Laser engraved. The characteristics of this anilox roller are high cost and wear resistance. If used properly, its life can be up to several years; if used improperly, not only the life will be shortened, but also the anilox roller will be scrapped.
In the use process, the position of a certain anilox roller on the printing machine depends on the specific print. Different prints have different positions of the anilox roller, so the anilox roller is often replaced during printing. At present, most of the narrow-width machines are solid steel anilox rollers, which are very heavy. When installing the anilox roller, care should be taken to avoid touching the surface cover of the anilox roller with other metal objects. Because the ceramic coating is very thin, it is easy to cause permanent damage after collision. In the process of printing and cleaning the machine, the ink should be prevented from drying on the anilox roller. The special detergent recommended by the water-based ink manufacturer should be used. The brush should be cleaned with a stainless steel brush to ensure that the cleaning is clean and thorough. And develop the habit of frequently using high magnifying glass to observe the anilox roller net hole. Once the ink is found to deposit on the bottom of the net hole and there is a trend of increasing gradually, it should be cleaned in time. If the above method does not work, it can be treated by ultrasonic or sandblasting, but it must be carried out under the guidance of the anilox roll manufacturer.
Under normal conditions of use and maintenance, there is no need to worry about the wear of the anilox roller. The parts that are easy to wear in the ink transfer system are mainly squeegee blades. In contrast, the wear of the anilox roller ceramic coating can be said to be minimal. After the anilox roller is slightly worn, the ink layer will become thinner.
What's going on
As everyone knows, flexographic printing has a phenomenon of unidirectional elongation along the direction of printing paper. The proportion of elongation is related to two factors, one is the diameter of the plate cylinder (including double-sided tape), and the other is The thickness of the version itself. The larger the diameter of the plate cylinder, the smaller the plate thickness and the smaller the elongation. One concept that needs to be clarified here is that the elongation phenomenon is not caused by pressure during printing. In fact, the elongation deformation has occurred when the flexible printing plate is adhered to the plate cylinder through double-sided adhesive. Therefore, when designing the ink drawing, it is necessary to reduce the size, and the ratio is obtained by looking up the table according to the actual thickness of the plate and the actual printing length. If the computer is used for plate making, it is only necessary to give a one-way shrinking instruction before designing the ink image color separation. If you use hand-made film, you need to use a deformation machine, you can also get a scaled-down film.
What is the relationship between the number of printing screen lines and the number of screen lines of the anilox roller
In many articles introducing flexographic printing technology, the ratio of the number of printing screen threads to the number of screen rollers is set at 1: 3.5 or 1: 4. Based on practical experience and analysis of award-winning products evaluated by the American Flexographic Printing Technology Association (FTA) in recent years, the author believes that this value should be higher, about 1: 4.5 or 1: 5, for individual fine printing Products, this ratio may be even higher. The reason is that the most difficult problem to solve when printing a gradation plate with a flexographic printing machine is dot expansion. Selecting an anilox roller with a higher number of screen lines, the ink layer is thinner, and the dot expansion deformation is easier to control. If the ink color is not strong enough during printing, a water-based ink with higher color density can be selected to ensure the quality of the printed product.
How to design a flexographic ink map for easy overprinting
In the printing process, a key indicator that people often pay attention to is overprinting, because waste products caused by inaccurate overprinting often account for a large proportion of all waste products. Although the flexo printing machine manufacturers have provided a good basis for accurate overprinting in the design and processing process, and the automatic monitoring system has also provided a guarantee for accurate overprinting, but the operator's technical level and proficiency also have a great influence on the overprinting accuracy . If you can make some adjustments for the convenience of overprinting when designing ink drawings, you can greatly reduce the difficulty of printing and reduce the rate of waste.
The easiest way is to use reverse white characters when designing the original ink manuscript, or hollow out between the two colors to form a reverse white outline, or you can cover the third slightly thicker at the edges of the two colors overprint Dark contour lines, for the printing of finer prints, trapping technology can be used, the amount of trapping depends on the accuracy of the printing press, the quality of the paper used for printing and the level of the operator. Trap processing is easy to implement on a computer. If there is no computer, only ready-made dichroic film, you can use a special trapping processor (TrappingModifier), enter the amount of trapping amount, the machine will automatically generate a trapped processing Film. If there is no trapping processor, you can put a transparent spacer between the color separation film and the copy film and expose it with a single point light source copy machine, and you can also get a film with similar effects.
Pvc Binder,Eco Friendly Pvc Binder,Customized Pvc Binder,Colorful Pvc Binder
TAISHAN JINRI STATIONERY PLASTIC CO.,LTD , https://www.jinri-folder.com