Factors Affecting the Use of Ink(2)

Status of the ink supply system

The ink supply system is a prerequisite to ensure the smoothness and timeliness of the ink supply. Whether the ink supply system is normal or not greatly affects the use of ink, and then affects the quality and sustainability of print output. For example, ink pipe leakage will lead to ink discontinuity, insufficient ink supply to the print head, white line, wiredrawing, printing blank, and other phenomena, and some will lead to the imbalance of internal and external pressure on the print head, which will not be supplemented with ink for a long time, and even burn the print head.

For bubble print heads, It is relatively common (because the heating crystal of the bubble print head depends on ink to cool down, and the crystal is in a dry and high-temperature state for a long time, which is easy to age and scorch). Another example: the level of the ink cartridge is particularly critical for printers that use the siphon principle, because too high or too low a liquid level will destroy the siphon ink supply mode, resulting in head-pasting, white lines, lack of ink, and other phenomena. Of course, The ink with good quality (i.e. moderate viscosity, surface tension, etc.) is less affected by the liquid level than the ink with poor quality.

Working condition of the machine

Including print head, ink supply system, print head car, heating and drying system, media transmission system, etc. the printer is an organic combination of software and hardware. Only when all systems cooperate normally, can it have a good printing effect and better performance of ink.

For example, if the print head car is too high, it is easy to produce flying ink, because the running track of the ink drop is too long during the high-speed movement of the car, which is easy to make the ink drop deviate from its predetermined landing point, resulting in the blurred image and virtual edge. Therefore, the height of the carriage of most wide-width printers can be adjusted. Without affecting other factors, if you want to have a finer print output effect, try to lower the carriage of the print head as much as possible.

Another example: is the abnormal operation of the heating and drying system will affect the quick drying and adhesion of ink. Now many printers have pre-preheating (medium heating), post-heating (image heating), drying, and other devices, especially for solvent and weak solvent printers. The purpose of pre-preheating is to accelerate the movement of medium molecules, so that ink molecules can better penetrate and have better adhesion; Then heating is to accelerate the drying of the picture and improve the productivity of the printer (for printers with relatively fast output speed, the effect is obvious).

Moreover, for most printers with piezoelectric print heads, the print head has a working voltage. The voltage is too high, the ink output is large, and the output image is dark, but it will accelerate the aging of the print head; The voltage is too low, the ink output is small, prone to paste, and the image edge is weak, the image is blurred, and the color is relatively light.

Operation and maintenance conditions

The above factors are the objective conditions of the printout, and the operation process is the subjective factor of printout:

1. After shutdown and restart, before printing, check the working condition of the printer and print head, clean, and process the print head in time to make it in the best working condition. If it is shut down for a long time, it is best to shake the ink artificially, and even clean the pipeline (especially important for printers using solvent, weak solvent, and UV ink)

2. In the process of printing, we should deal with it in time according to the actual effect and situation of printing, such as adding ink, cleaning the print head, etc; No matter how high-quality ink is used, it is necessary to clean the print head and add ink to the ink bottle (barrel) in time at different intervals during the printing process. If the print head trolley wipes the paper during printing, it is necessary to stop the machine in time for inspection. The surface of the print head may be stained with ink or impurities of other colors due to paper wiping, resulting in hole plugging, hole deviation, and other phenomena, especially for water-based printers, because the nozzle of the print head of water-based printers is relatively small and easy to be blocked.

3. When replacing a new brand or batch of ink, the ink path should be cleaned When any two different brands of ink are mixed, the physical and chemical parameters of the ink will change greatly. When cleaning, it must be carried out in strict accordance with the specifications in the accompanying operation manual/user's Guide. Generally, the original ink in the ink path is pumped clean first, then the ink path is washed with cleaning fluid, and then the cleaning fluid is pumped clean, and then replaced with new ink. At this time, you can pump more new ink, wash the ink pipe with new ink, and remove the cleaning fluid as much as possible, because too much cleaning fluid is mixed in the ink, It will change the basic parameters of ink and affect the use effect of ink.