How to ensure the stability of printing ink and im

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What can we do to ensure the stability of printing ink and improve printing quality

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core tips: during the printing process, we often encounter quality problems caused by too large ink color differences. So, is there any way to ensure the stability of printing ink and reduce losses for enterprises

first, roughly adjust the inking amount of ink bucket of each color group according to the area of proofing draft or printing plate. On machines equipped with ink remote control system, this work is easier to complete. More than 80% of this should be estimated. Do not adjust the ink on a large scale while printing to obtain the incremental manufacturing technology of titanium and other professional metals, so as not to cause a large color difference

secondly, according to the requirements of the production process sheet and the characteristics of the product, pre adjust the various links such as Feida, paper receiving, ink performance, pressure and so on to avoid being in a hurry during the official printing. Among them, it is the most important to ensure the reliable, continuous and stable paper feeding of Feida. Experienced operators adjust the air blowing, air suction, presser foot, compression spring, paper pressing wheel, side gauge, front gauge, etc. in advance according to the width and thickness of the paper, straighten out the movement coordination relationship between various parts, ensure that Feida can feed paper smoothly, and avoid ink color differences caused by Feida beating. Here, it is suggested that experienced workers and masters can adjust Feida in advance

in addition, the viscosity, fluidity and dryness of the ink should be properly adjusted in advance according to the quality of the paper used and the size of the image and text area, so as to improve the printability and ensure the normal printing. The blanket and the paper wool on the printing plate should not be cleaned due to frequent shutdown. 9 The choice of microcomputer interface and ink cover results in different shades of ink. If you add various adhesive removers and inking oils in the middle of printing, color deviation is certain

in a word, if we do a good job of pre adjustment before startup, we can greatly reduce the failure after the official printing, and the captain will have time and energy to focus on the ink color

correct adjustment of water and ink roller pressure

in the printing process, the image and text part of the printing plate must receive a continuous, uniform and appropriate amount of ink in order to obtain prints with consistent ink color. Therefore, proper contact and rolling relationship must be maintained between the ink roller and the ink roller, and between the ink roller and the printing plate, so as to achieve good ink transmission. If this work is not done carefully and correctly, the ink color will not be consistent

therefore, each time the water and ink rollers are installed, the pressure between them should be adjusted one by one by using the ink rolling bar, instead of the traditional method of testing the tension with a feeler gauge, because the latter has large actual errors caused by various human factors, and it should be prohibited on multicolor and high-speed machines. As for the width of the inking bar, mm is generally appropriate. First adjust the pressure between the ink transfer roller and the inking roller, then adjust the pressure between the ink transfer roller, the inking roller and the plate cylinder, and finally adjust the pressure between the water transfer roller, the plate water roller, the water transfer roller and the intermediate roller, as well as the pressure between the plate water roller and the plate cylinder. The ink bar between these waterways should be 6mm

after using the equipment for twoorthree months, it is necessary to readjust it, because after a period of high-speed friction, the diameter of the ink roller will become smaller, especially in the transmission. The pressure between the inking rollers becomes smaller, and the ink accumulated on the inking rollers will not be transmitted. When Feida stops printing or stops printing, due to the large amount of ink at this time, the ink color of the first dozens or even hundreds of inks is deep, and the ideal ink balance is difficult to achieve

this fault is generally difficult to find, and is only obvious when printing fine prints. In a word, the operation in this aspect should be meticulous and scientific, otherwise, the ink color of the mouth and trailing tip of the water, ink bar and printed matter will be different. When the moving seat is at its upper/lower limit position, it will cause faults and increase the operation difficulty

achieve ink balance

as we all know, ink balance is an important content in offset printing. If the water is large and the ink is large, the oil in water emulsification of the ink will occur, of course, the print quality will not be ideal. Through long-term practice, the author has found out some skills

first, ensure that the pressure relationship between water and ink rollers is properly adjusted, and the contents of fountain solution and isopropanol meet the general standards. On this basis, turn on the machine, close the water and ink rollers, and then stop the machine to check the printing plate. It is better to have a slight dirt of about 3mm at the mouth of the printing plate. Taking the water volume at this time as the initial water volume for printing can ensure the normal printing of general graphic products and basically realize the water ink balance

secondly, the water consumption should be flexibly adjusted according to other factors, such as the large graphic area of the printing plate, the rough surface of the paper, the need to add additives to the ink, and the change of printing speed, air temperature and humidity

in addition, the author also found that when the machine started printing, the body temperature was low. When the machine ran at high speed for oneortwo hours, the body temperature, especially the rubber roller temperature, would more than double or even higher. At this time, the water consumption would gradually increase until the ink reached a new equilibrium

it can be seen that it is not easy to achieve the balance of ink and wash, which requires operators to weigh and apply dialectically. Otherwise, the ink stability is difficult to control, and high-quality prints cannot be printed

proofing correction and color sequence arrangement

in production, we often encounter such situations: the sample provided by the customer is very non-standard, or only one color spray draft is provided without proofing. At this time, it is necessary to analyze the specific situation, and the effect of proofing cannot be pursued by increasing or decreasing the ink volume. Even if it is close to the proofing draft at the beginning, the stability of the ink color cannot be guaranteed, so the final quality of the printed product cannot be guaranteed. In this regard, the printing plant should actively exchange views with customers in a serious and responsible manner, point out the problems and modification suggestions in the sample, and make appropriate adjustments and reprints after obtaining consent

in production, the printing color sequence of the multi-color machine is usually determined by the ink viscosity. In multi-color printing, the ink is overprinted together in a wet press wet manner. Only when the optimal overprint rate is obtained, can the stable and consistent ink color be printed. The arrangement of the printing color sequence must be subject to the characteristics and quality requirements of the printed matter, not unchangeable

at the same time, the ink viscosity can also be adjusted. For example, the printing color sequence of a purple cover is different from that of a sky blue cover. The former is first green and then magenta, and the latter is first magenta and then green. Otherwise, the overprinted color will be spot like, neither plain nor stable. For example, for printing products mainly in black, black should be arranged in the last color group as far as possible. In this way, the printed products have a good gloss of black and avoid the occurrence of scratches and color mixing inside the machine

cultivate good operating habits

in any work, you must have a high degree of "hide and seek" and a strong sense of quality. You must standardize the process operation and adhere to the good traditional habits of "three evenings" and "three diligence"

for example, when comparing the signature on the template, the difference in distance, angle, light source, etc. will cause visual deviation, resulting in inconsistent ink color. At this time, the signature must be removed from the template and carefully compared; Long version live printing plate needs to be baked to reduce ink color deviation caused by version change; The blanket should be cleaned frequently. After each cleaning, more blotting paper should be placed to stabilize the ink color; After Feida finished printing, the ink color of fiveorsix newly printed sheets was too deep. The printing speed should not be too fast. The important thing is to keep the machine stable and normal; When adding ink to the ink bucket, because the new ink is hard and has poor fluidity, it should be stirred several times to avoid affecting the ink amount and causing ink color deviation

operators should keep learning, carefully observing and analyzing, find out the factors affecting ink color change from all aspects, and take corresponding measures to properly prevent and overcome them, strive to improve the stability and consistency of printing ink color, and effectively improve printing quality

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