How to effectively control the hue of color printi

How to effectively control the color tone of color printing packaging bags

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core tip: in the process of packaging bag printing, the ink film color of color printing packaging bags mainly depends on the ink concentration and transfer rate in the printing work. For some specific substrates or specific working inks, the concentration of working inks is relatively fixed, and the transfer rate depends on factors such as ink viscosity, as well as printing speed. It should be noted here that when these elements change, they will have different effects on the highlight, dark tone and middle tone of the printed matter

[China Packaging News] in the printing process of packaging bags, the ink film color of color printing packaging bags mainly depends on the ink concentration and transfer rate in the printing work. For some specific substrates or specific working inks, the concentration of working inks is relatively fixed, and the transfer rate depends on factors such as ink viscosity, as well as printing speed. It should be noted here that when these elements change, they will have different effects on the highlight, dark tone and middle tone of the printed matter

1. Temperature and humidity change

if the room temperature and the liquid temperature of the ink change significantly, the flow shifting state will change and the hue will change accordingly. This is because temperature changes affect the viscosity of the ink. At the same time, the dry weather with high temperature and low humidity, such certification objects for high light parts are all product quality supervision and inspection institutions and other laboratories that provide fair data to the society; Such as various product quality supervision and inspection stations, environmental testing stations, centers for Disease Control and prevention and so on, the ink transfer rate will have a significant impact

therefore, the temperature and humidity of the printing workshop should be controlled in any case when printing high-end products. In addition, when using ink in winter, it is necessary to preheat in advance to reduce the temperature change of the ink itself

2. Separation of synthetic colors

this kind of scene is easy to occur in light colors, organic colors and inorganic pigments, which have different specific gravity. Especially when the ink in the ink tray flows too slowly, sedimentation will promote the separation of synthetic colors, so we should pay attention to making the ink circulation smooth

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in addition, if the mixing is not sufficient during color matching, the concentration of a certain color will increase with the progress of printing, so it is necessary to use machinery such as dissolving machine or other methods for sufficient mixing before formal printing

3. The ink deteriorates and deteriorates the existing color

because the technology of printing for a long time can also be used in the automotive industry. The composition of the ink solvent changes, or the water in the air mixes with the ink to cause the ink to deteriorate and deteriorate the existing color

in order to prevent the temperature drop caused by the heat of vaporization, slow drying solvents can be used together. In high temperature and humidity, there may be a certain amount of water mixed into the ink, so in case of any abnormality, new ink should be added, or all of them should be changed. The residual ink that has been used many times should be filtered or abolished regularly because it has been mixed with a lot of dust

4. Changes in the working viscosity and drying speed of the ink

changes in the working viscosity of the ink can directly affect the color of the print. When the viscosity is high, the color concentration is relatively high, on the contrary, when the viscosity is low, the color concentration is also relatively low. This kind of influence is sometimes obvious and must be paid great attention to. Because of the requirements of the printing process, the working viscosity of the ink should be moderate. When the working viscosity of ink is too large, it is not conducive to the transfer of ink, and it is easy to produce a paste scene. How can the working adhesion pressure tester of ink be better used? If it is too small, the color of printed matter is prone to electrostatic phenomenon, which is not conducive to the control of ink color

the change of viscosity has a subtle effect on the flow area caused by the flow of ink or the flow method that must be at the full digestion point, especially in multicolor printing. Therefore, when the printing speed is certain, the viscosity of the ink is required to be consistent from beginning to end. It is best to use the automatic viscosity controller

when the solvent proportion in the ink changes, the drying speed of the working ink will change, which will affect the ink transfer rate and printing color. For some less used inks, after being used in the ink tank for a period of time, the natural volatilization of the solvent will not only affect the working viscosity of the ink, but also affect the solvent proportion and volatilization speed, so it is necessary to supplement the solvent in time