Analysis of many factors affecting the drying spee

2022-08-09
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Analysis of many influencing factors of ink drying speed

the speed of ink drying is affected by many factors, such as ink composition, ink additives, printing materials and external conditions, including the following aspects:

the influence of pigments

different pigments will have different effects on ink drying. Some pigments can promote drying, some delay drying, and others have no obvious effect on ink drying. Pigments that promote drying include iron blue and chrome yellow, while those that delay drying such as carbon black and lead oxide. Most organic pigments have no obvious effect on the drying of ink. Generally, in the same type of ink, the drying speed of red ink, black ink, blue ink and yellow ink is accelerated in turn

influence of ink additives

1. Influence of desiccant: the drying of the ink layer on the paper is mainly a process of physical and chemical changes, especially the process of oxidizing the conjunctiva of the connecting material. If the malignant disease is long, it cannot meet the production requirements, so desiccant can be added to the ink to accelerate the drying of the imprint. China is willing to strengthen cooperation with Malaysia in the fields of marine economy, maritime safety, marine scientific research, environmental protection, disaster prevention and control. Desiccant can accelerate the absorption of oxygen in the air by the binder in the ink to promote its molecular polymerization, and can accelerate the polymerization reaction, thus greatly accelerating the drying of imprinting

2. The influence of fountain solution abroad includes sage automotive interior parts company, BASF, Faurecia, Johnson Controls, Lear, Dow Chemical, DK leather company and DuPont: the stronger the acidity of fountain solution, the longer the drying time of ink. This is because in the offset printing process, the emulsification of oil and ink inevitably exists, the acid in fountain solution reacts with the desiccant, and the drying of ink is destroyed due to the failure of desiccant, Generally speaking, the pH value of fountain solution should be kept between 4.5 and 6, which has little effect on the drying of ink

3. Influence of additives: during the printing process, sometimes in order to make the ink have good printing adaptability, various additives need to be added to the ink, and these additives have a certain impact on the drying of the ink. For example, both Willy oil and white oil can inhibit the drying of ink. The main component of Willy oil is aluminum hydroxide, which will lose its function due to the adsorption of desiccant. At the same time, aluminum hydroxide will increase the emulsification of ink. White oil is also very easy to cause the emulsification of ink and affect the oxygenated conjunctiva of ink

influence of printing materials

paper has a great influence on ink drying, mainly manifested in:

1. PH of paper: the acidic substances on the paper surface can react with the metal salts in the desiccant, making the desiccant ineffective, preventing or destroying the oxidative polymerization reaction, slowing down the drying of imprints on the paper surface. The smaller the pH value of the paper, the slower the drying speed

2. paper structure: paper with rough surface, loose structure, high permeability and low sizing will promote drying, and vice versa, which is reflected in the way of osmotic drying. Ink accumulates thicker on paper with smooth and tough surface than on paper with rough and loose surface. In addition, it has less contact with air and slow oxidation of conjunctiva. Therefore, the drying of paper imprints with smooth and tough surface is very slow

3. water content of paper: the water content of paper has a certain impact on the penetration of ink and oxidized conjunctiva. The high water content of paper reduces the penetration of ink into paper, and the water can also block the oxidized conjunctiva of ink

external conditions - the influence of temperature and humidity

when the temperature rises, the movement speed of material molecules accelerates, the intramolecular energy increases, the reaction speed of oxidized conjunctiva also accelerates, and the drying accelerates. Generally, the drying speed is doubled for every 10 ℃ rise in temperature. The drying process is an exothermic reaction, and the heat released during printing sheet drying in turn promotes the drying of ink

the influence of humidity on drying is related to the pigments in the ink. When the humidity of some pigment inks is as high as 95%, the drying of the ink is still not affected. With the high relative humidity of the air, the oxidation conjunctiva speed will slow down correspondingly, and the drying speed will also slow down

influence of other factors

the smaller the area of the layout graphics and texts, the greater the emulsification of the ink, and the harder it is to dry the ink. At this time, it is necessary to control the moisture of the layout and appropriately increase the amount of desiccant to ensure the timely drying of the ink

if the ink layer is too thick, the contact area between the ink layer and the air will be reduced, and the contact between the ink and the paper will be reduced, and the oxidation conjunctiva and penetration will be affected

the stacking of prints also has a lot to do with drying. If the area of the paper is large, the paper surface is smooth, the stacking is high, the air is difficult to contact with the ink, and the oxygen is not supplemented in time, this will make the drying slow, especially in the middle of the print. In addition, the exposure of the printing sheet also affects the drying speed of the ink

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