Reasons and solutions for drawing on UV flatbed
The long-term work of the UV flatbed machine may cause the problem of drawing, which is a situation that many customers and models may encounter, especially some old machines, and often the customer is undergoing normal testing and the 100-gram test, wireframe The tests are all normal, but similar problems occur during normal printing. This is a very headache, but the cause of the drawing may be caused by improper operation and poor software settings. The following Zhengzhou Lecai for everyone to understand the reasons and solutions for the drawing of UV flatbed printers.
(1) clogging of nozzles: Digital printing is dot matrix printing, which consists of dots of a certain density (DPI). Therefore, any one of the nozzle holes is blocked. In the direction of the movement of the tile, a blank line is always produced, the so-called white drawing. This phenomenon is particularly likely to occur when unusual inks are encountered or when hoes that do not circulate are used. The main reasons for the internal plugging of the nozzle are: the design of the ink supply system is unreasonable, and the ink flow dead angle appears in the system and precipitates: the ink stability is poor, and the densification occurs during use; the dust, water vapor and other pollutants are polluted from the outside. The nozzle is blocked and can generally be solved by external cleaning.
(2) Spray hole oblique spray: the so-called oblique spray is the ink point can be pulled out. But it was not sprayed to the position where it should be sprayed. In this way, a white line appears in the place where it was sprayed, and a darker line appears next to it. The reasons for the skew are: the ink supply system or the ink itself, causing the nozzle hole to be in a semi-blocking state, causing the spray point to be biased; the nozzle parameters (voltage, waveform curve, etc.) are unreasonably set; the ink performance does not match the nozzle requirements.
(3) Overlap between the nozzles: The overlap between the nozzles is a common phenomenon of drawing. It is characterized by a wide brush width. Usually between 1~2mm, and sometimes there is no time. The main reason is that the sampling between the nozzles is not good. Make the position appear dark or light-colored lines all the time; the belt runs in the printing area. Even a few millimeters. There will also be lines that are noticeable or deep or light or white (exposed to the ground). The wire drawing that occurs in this case is sometimes absent or appears in a localized position of the brick. When this happens, only by improving the belt running accuracy. Or design to minimize the print distance between the colors to solve.
(4) Bubbles appear inside the nozzle: The drawing caused by air bubbles inside the nozzle is generally caused by a meteor-like blank in the printed artwork, and the width is 2~3mm or larger. The length ranges from a few millimeters to tens of millimeters, sometimes it is not. This phenomenon can only be solved by improving the ink supply system or adjusting parameters such as ink refilling and exhausting.
(5) Drawing due to deposition inside the nozzle: The drawing of the inside of the nozzle is characterized by sometimes dark, sometimes light, appearing in a certain area. And it is more serious when printing dark products. Generally, it is common in non-circulating nozzles, especially when the production time is long. The ink in the nozzle is sprayed out by the time of production. Can reduce the possibility of ink deposition in the nozzle, but if it appears. It can only be handled by a large amount of inkjet or by washing the nozzle with clean water.
Or take the UV flatbed printer nozzle calibration method as follows: Start the printing program in the computer, select the printer in the printing program, then click the right mouse button, select the protection, print the nozzle calibration, the machine will actively perform the proofreading operation, repeat the operation several times , you can use to improve the printing effect.
In summary, there are many reasons for drawing. In general, printing dark-colored artwork is easier to draw than lighter color; using a nozzle without a loop design is more likely to be drawn than having a loop; using an unstable ink is more likely to be drawn than using a stable-quality ink; Mature models have fewer draws than immature models. therefore. If you want to evaluate the quality of an inkjet machine, it is good or bad. We have to compare from a large number of sample production and long-term stability. It is not possible to draw conclusions in one sample at a time. At the same time, timely and intimate service is also an important guarantee to reduce drawing and improve the quality of products. Due to the continuous improvement of domestically produced equipment, the equipment using Ricoh nozzles in recent years has been better solved than other nozzle equipment in terms of wire drawing. Therefore, we have seen that the problem of drawing inkjet products in China is becoming less and less obvious, and the yield of inkjet products is getting higher and higher.
