Water-based inks do encounter a variety of problems in practical applications, which may involve the performance of the ink, the printing process, the adaptability of the substrate and environmental factors. Here are some specific questions:
 
1. Drying speed: The drying speed of water-based inks is usually slower than that of solvent-based inks, which may lead to problems of dragging, adhesion or reduced printing efficiency of printed matter.
2. Adhesion: On some substrates, the adhesion of water-based inks may not be as strong as that of solvent-based inks, which may cause the printed pattern to fall off or wear easily.
3. Water resistance and chemical resistance: the water resistance and chemical resistance of water-based ink may be insufficient, which may affect the durability and color stability of the print.
4. Color brightness and saturation: Water-based inks may not be as good as some solvent-based inks in terms of color brightness and saturation, which may limit their application in high-quality printed products.
5, printing accuracy: Water-based ink in the high-speed printing process may appear flying ink phenomenon, affecting the printing accuracy and clarity.
6. Storage stability: the storage stability of water-based ink may not be as good as solvent-based ink, and special attention needs to be paid to storage conditions to avoid ink deterioration.
7. Environmental adaptability: Water-based ink is more sensitive to environmental humidity and temperature, and inappropriate environmental conditions may affect the leveling of ink and printing effect.
8. Printing equipment compatibility: Switching to water-based inks may require adjustment or modification of existing printing equipment to adapt to the characteristics of water-based inks.
In order to solve these problems, researchers and engineers continue to improve the formulation of water-based ink, improve its performance, and also innovate in printing technology and equipment to better adapt to the characteristics of water-based ink. In addition, choosing the right substrate and pretreatment method is also the key to ensure the good printing effect of water-based ink.
 
 
The following is mainly to share 3 problems in the ink painting process:
 
1. What are the factors that affect the drying speed of water-based ink?
2. What is the reason for the phenomenon of water-based ink on paper?
3. Is water-based ink stable? How to prevent different shades of color?
 
 
What are the factors that affect the drying speed of water-based ink?
 
The drying speed of water-based ink refers to the time required for the ink to be transferred to the substrate after drying, if the ink dries too fast, it will dry and gradually accumulate on the printing plate and the roller, and may block the roller, resulting in the loss or destruction of half-tone dot, and the field part of the white leakage. The drying speed of the ink is too slow, and the back will be sticky and dirty in multi-color overprinting. It can be said that how the drying speed is an important standard to judge the printing quality of water-based ink, since the drying speed is so important, then what are the factors that affect the drying speed of water-based ink?
 
1. PH value, PH value refers to the alkaline resistance of water-based ink, which is an important factor in determining the suitability of water-based ink and printing, the PH value of water-based ink is too high, the alkaline is too strong will affect the drying speed of the ink, the back sticky dirty, poor water resistance; The PH value is too low, the alkalinity is too weak, the viscosity of the ink will increase, the drying speed will become faster, and it is easy to cause defects such as dirty plate, paste plate and foaming. Under normal circumstances, we should control the PH value of water-based ink between 8.0-9.5.
 
2.  the printing environment, in addition to the ink itself, how we print the external environment will also affect the drying speed of water-based ink, such as the temperature and humidity of the printing workshop affect the drying speed of water-based ink, relative humidity reached 95% compared with 65%, the drying time is almost more than 2 times. At the same time, the ventilation environment will also affect the drying speed of water-based ink. Good ventilation, fast drying speed, poor ventilation, slow drying speed.
 
3. the substrate, of course, in addition to the above two, due to the water-based ink printing to the substrate surface will be affected by the PH value of the substrate itself, when the paper acidity is high, the water-based ink as a drier coupling agent does not work, the alkali in the water-based ink is neutralized, so that the dryness is advanced; When the paper alkaline is high, the water-based ink dries slowly, and sometimes limits the water-based ink to achieve complete water resistance. Therefore, the PH value of the substrate material will also affect the drying speed of water-based ink. Of course, in addition to the above three main influencing factors, there are other factors that will also affect the drying speed of water-based ink, such as the stacking of substrates, etc., here we will not do a detailed introduction.
 
 
What is the reason for the phenomenon of water-based ink on paper?
 
What is the reason for the phenomenon of water-based ink on paper? The phenomenon of water-based ink is considered from the following three aspects:
 
1.  the problem of ink, the general original ink box instead of ink is very different
① If it is the original ink to consider whether it is expired or the inventory time is very long, these two situations will affect the precipitation of the ink pigment, the solution is to shake the ink cartridge at a room temperature of not less than 10 degrees to make the pigment fully mixed.
 
② If it is the replacement of ink caused by a lot of reasons, generally when the product is added to the water or diluent ratio of the problem, personally, there is no solution, first use the above treatment method to try, that is, hope that it is only the separation of the pigment.
 
2.  the paper problem is generally divided into coated cartons uncoated paper (must be the user's internal paper, outdoor paper water-based ink can not be fixed)
① There is nothing to say about uncoated paper, even if the large white paper that is the least interested in water-based ink is not more or less smearing if it is not a coating type, the solution is to use coated paper.
 
② Coated paper, the main consideration is whether the paper has been damp, there is no expiration, the use of the coating is too thin, no matter what kind of situation will make the paper coating mix can not make the surface protection, the middle color fixation, the bottom water seepage, and eventually cause halo. Only say that the solution of web paper preservation, the original corrugated packaging box and the plastic packaging inside do not let the unused paper then put back.
 
3. equipment problems consumables, print head with too long aging, resulting in uneven cloth ink formation of halo; Use different batches or brands of ink, so that different chemical ratios of ink mixed in the print head; Software, using the driver or RIP software printing, did not select the corresponding paper type, resulting in excessive ink jet exceeding the limit of paper can absorb water, resulting in smudge.
 
 
Is water-based ink stable? How to prevent different shades of color?
 
Water-based ink is also known as water-based (oil) ink, referred to as ink. Water-based inks are made from water-soluble or water-dispersed polymer resins, colorants, surfactants and other related additives through chemical processes and physical processing.
 
Water-based ink contains a small amount of alcohol water as solvent, ink stability. Therefore, it is especially suitable for food, medicine and other packaging industries. Water-based ink can be cleaned with water, non-flammable, non-explosive, no adverse effects on the atmospheric environment and the health of workers, and no fire hazards caused by static electricity and flammable solvents, with production safety.
 
Water-based ink is a new type of printing ink with high color concentration, non-soluble, good gloss, strong printability, good leveling and high solid content. Water-based ink is easy to operate. When printing, only need to add tap water in advance to adjust the ink according to the demand. In the printing process, directly add the appropriate amount of new ink, without the need to add additional water solvent, which can prevent the color of different shades. Water-based inks are generally no longer resoluble in water after drying. When printing, the plate must be immersed in the water-based ink to always keep rotating, otherwise the water-based ink on the plate will dry quickly, causing the plate roller to be blocked, resulting in no printing. In view of the rising price of organic solvents caused by the depletion of petroleum resources, the manufacturing cost and environmental use cost of solvent inks will increase day by day. The solvent of water-based ink mainly uses tap water, and because of the high concentration of water-based ink, the depth of gravure printing can be shallow.
 
Therefore, in terms of cost, although the price of water-based ink is high, its comprehensive use cost is estimated to save about 30% than solvent ink, and there are few concerns about solvent residual toxicity on the surface of printing materials, water-based ink has been successfully explored in the field of plastic gravure printing, which is undoubtedly a good news for color printing packaging factories.
 
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