First, color printing ink deployment This article from the perspective of the printing process of the plate, talk about the superficial understanding of the color printing ink deployment. The important point in ink dispensing is to master the principle of using the same type of ink and auxiliary materials of the same model. If the ink uses "05 type", auxiliary materials should also be matched to improve the printability of the ink. In addition, the number of primary color inks should be used as little as possible, that is, if the two primary color inks can be blended, the third type should not be used, so as not to reduce the brightness of the ink and affect the vividness of colors. There are two kinds of color ink deployment, one is dark ink deployment, that is, the use of three primary colors or the original color of the ink, without any bleaching agent deployment of the ink color; the other is a light color ink, that is, in the original ink to add dilute Formulated ink. (-) Dark ink dispensing method and color principle First of all, according to the original hue to determine the color of the ink to be used, and then take the appropriate amount of each color ink, on the ink station for a small amount of deployment. When deploying, one should master the principle of gradually adding dark ink in light-colored ink. Can not add dark ink and then add light color ink, because the light color ink color poor, if you use dark ink to add light-colored ink to the deployment, not easy to align the hue, often make the more the amount of ink adjustment, this It is not desirable. When the hue of the ink is adjusted to the hue of the original, the ink can be scraped with a printing paper and compared with the original. If there is any color shift, correct the color correction until it matches the printed sample. After adjusting the hue of the ink, the respective weights of the inks can be calculated so that batches can be prepared in proportion. If you use dark inks to mix dark inks, you should master their changing rules to improve the ink transfer effect. Such as: three primary colors ink mixing, the color obtained is approximately black; the two primary colors in the two primary colors equal or unequal temperature adjustment, can obtain a variety of inter-color, the hue is biased to the content ratio of the large fruit; Three primary colors of ink are mixed in various proportions to obtain a variety of complex colors; black ink is added to any color ink, and its brightness must be reduced to cause dark phase. If you add white ink, the brightness increases. The three-color inks can be used for the combination of color and complex colors. However, in terms of ease of deployment and minimization of the number of inks to be used, inter-color inks can be used. In the deployment of complex color inks, we should grasp the principle of color, must not take "this color plus points, the kind of color plus points" to test. Such as the blue lake in the green ink corresponding to the use of sky blue or peacock blue, avoid using dark blue to adjust, because the dark blue ribbon red taste, after joining the inevitable dark color instead of bright. By the same token, it is not possible to add reddish dark yellow ink, and the pale yellow ink should be used. For example, when red orange ink is used, red ink cannot be used because it has a blue taste, and the green color of blue and yellow is a complementary color of red, which makes the ink lack a bright sense. The color of some inks has its unique hue, just as the reddish hue of red is yellow, and for oranges it will increase the vividness of blacks. Indian orange color, if the effect of orange ink printing does not reach the bright, and the printing is less realistic, with red and lemon yellow mixed, printing color is much better. Another example is that the green scenery of the early spring should be printed with pale yellow ink to print the green and lovely leaves. If you use dark yellow ink tone, dark yellow ink contains red taste, red is green complementary color, the printed leaves must be dark, cloudy, not reflect the breath of early spring. In the deployment of complex ink, if you use the complementary color to correct the color cast, the color effect will be better. For example, if the color of some complex color ink is heavy, the yellow ink may be added to correct; if the red flavor is heavy, blue ink (such as peacock blue or sky blue ink) may be added to correct, and the effect of adding less amount and adjusting the hue effect can be achieved. . Another example is the black and yellow ink is not enough black, you can add a small amount of light blue as a color material, because the blue light is a blue ink with red light, but also the result of complementary color. (B) Preparation of pale ink Light-colored ink is ink added with diluting agent in the original ink, or mixed with other inks in white ink. The method of dispensing is based on the principle of diluting agent or white ink, supplemented by other color inks. Firstly, dilute the appropriate ratio of diluting agent or white ink, and then add the color inks in different times, so that the ink is uniformly mixed while observing the hue changes. When the degree of diluting is appropriate, use the printing paper to smear the ink color sample and the original document and adjust it to the proper level. Dimmed color inks, distinguished from hue, also have primary colors, inter-colors, and complex colors. Any use of the three primary color inks to dilute, as long as the primary color ink can be added in batches. However, if it is between the color, complex color, lack of ink transfer experience, it is best to first mix the original ink into the dark ink of the ink color, and then add the dilute. The deployment of light-colored inks and mastering the degree of ink dilution are important technical aspects. If the dilute ratio is not enough, it will cause the lack of ink on the surface of the ink roller. The printed ink on the printing surface is prone to blooming. The ink layer will not dry and the color will not be bright. If the ink dilutes too much, only the thickness of the ink layer can be increased to achieve the desired hue for printing. In this way, the transfer of ink will make it easy for the layout of low-key areas to appear paste version, can not tell the depth level. At the same time, it is also easy to cause the bottom of the imprinting phenomenon. The deployment of light-colored inks should be based on the product quality requirements, as well as the paper characteristics, select the appropriate ink and diluting agent. Such as printing offset paper with 10 type ink printing general products, you can use "915" dilute agent (dimensional force oil) or "554" transparent oil. If the printed coated paper uses type 05 ink printed fine products, you should use 05-90 bright light or "8011, 8015" lighter. The deployment of light-colored inks should also pay attention to the original ink that is not resistant to light, is not resistant to oxidation, and is easily discolored, and should be avoided as much as possible for the deployment of light-colored inks, so as not to cause color instability. In addition, due to the fact that the white ink ratio is significant, in addition to the requirements for masking and color matching, a small amount is added for calling, and as far as possible, white ink is not used for diluting. In order to prevent the occurrence of poor color, color and other quality problems. When deploying inks, it is also necessary to pay attention to the proportion of different inks, such as the use of lead-chrome yellow ink and peacock blue green ink with a relatively large proportion. After a long time, the ink with a small proportion will float, and if not, it will sink. “Floatingâ€, if the yellow ink made of organic yellow pigments is used for deployment, this phenomenon will not occur. To sum up, only by learning to master color knowledge and understand the relevant conditions and use characteristics of inks and auxiliary materials can we scientifically deploy various color inks to meet the requirements of improving printing quality and production efficiency. $Page break $ Second, the effect of printing ink on the situation Plate printing is a widely used production process. How to improve the quality and production efficiency of color prints is worthy of analysis and discussion. The visual effect of printed ink is one of the important factors to measure the quality of printed matter. The following are the conditions that directly affect the ink color of printed products. (-) Effects of Printing Ink Layer Thickness and Viscosity on Printing Ink Color The moderate printing ink layer is an important measure to ensure the quality of the printed ink and to prevent the print from sticking. If the ink layer is thicker, its viscosity will inevitably increase, and it will easily lead to paper pull, which will affect the evenness of the printed ink. If the printing ink layer is thin and the ink viscosity is insufficient, the printed ink will be too light, and the visual effect of the printed product is also Just bad. As the printer's rotation time increases or the printing speed increases, the friction coefficient increases, and the ink temperature also gradually increases. Therefore, the ink becomes thin and its viscosity decreases accordingly. Therefore, these conditions must be taken into consideration when transferring ink to ensure that a batch of products can obtain a relatively balanced printing ink color. However, in the actual production process, the decrease of the ink viscosity is unavoidable, and the ink is often dark at the beginning of the printing process and fades afterwards. This can be achieved by appropriately adjusting the rotation angle of the ink transfer roller. The amount of ink keeps the shades of ink before and after. In addition, in order to prevent the ink viscosity variation from being too severe and affect the balance of ink color, the contact between each roller and the iron roller should not be too tight, and the glue should not be too hard to minimize frictional heat and keep the ink properly. concentration. (b) The effect of printing pressure on ink color of printed products Printing pressure is one of the important conditions for imprint transfer. Since the surface of the printing plate is not absolutely flat, the surface of the paper will inevitably contain slight irregularities and uneven thickness. If the printing pressure is insufficient or uneven, the printing on the plate will be printed. Ink will inevitably appear uneven. Therefore, the ideal printing process is based on the "three levels" (ie, the plate surface and the ink roller and the lining body are relatively flat to obtain good contact conditions), and the thinner ink layer is used to achieve a balanced printing pressure. , to get a more uniform ink on the print. If the printing pressure is insufficient or uneven, there is a poor contact between the lining body and the printing plate surface. By increasing the amount of ink to be fed, the visual effect of the ink on the printing surface can be satisfied, but this not only increases the consumption of ink, but also occurs easily. Dirty printed products are undesirable. (3) The effect of the quality of the rubber roller on the print and ink As far as the embossing and peaceful printing process is concerned, whether the printed product can obtain the ideal ink color has a close relationship with the quality of the rubber roller. The equipment for printing color prints is equipped with an ink transfer roller, an ink roller and an ink roller. There are five or six or even more than ten ink meter rollers, of which the ink roller and the ink roller are the most influential factors in the ink shade. The quality of the rubber roller is mainly manifested in the aspects of elasticity, stickiness, roundness, and surface finish, while the main influence on ink density is stickiness. In the printing process, only a certain degree of stickiness of the rubber roller is ensured, so as to ensure that the amount of ink applied to the plate surface is uniform during each printing cycle. However, in the actual production process, the cohesiveness of the rubber roller is not stable. First, due to the increase of paper dust in the ink, the viscosity of the colloid is affected; secondly, the viscosity agent (ie, glycerin) on the surface of the colloid increases with the temperature and the use time. Prolonged and lost, the adhesive surface of the roller gradually reduces the viscosity, the corresponding decline in the ink absorption performance, thus affecting the balance of ink ink. Therefore, the printing plate product should use a more stable quality polyurethane roller. If printing bulk products, clean the rollers at a proper time. (4) The influence of the difference in paper quality on the ink color of printed products In fact, the relationship between paper and ink is complicated. If only considering the shade of ink in a book, it should be noted that the smoothness of the paper surface has a certain relationship with ink. If the pressure of each plate is the same, the smoothness of the surface of the paper is inversely proportional to the consumption of ink, and the amount of ink sucked by the sleek lover is small, and vice versa. Therefore, if there is a difference in the smoothness of the positive and negative sides of the paper, the method of increasing the amount of ink and the pressure should be taken as appropriate and appropriate adjustments can be made. The printing is used to print glossy first, and when the rough surface is printed later, the pressure and the ink supply are appropriately increased, so that both the positive and negative ink colors have an ideal visual effect. Practice has shown that the effect of the above method is much better than simply increasing the amount of ink delivered, and the printing quality is better. (5) Effect of light changes on the ink color of printed products The light source that normally identifies printed ink is three types of sunlight, fluorescent light and electric light. The light emission of these three light sources is different, and the color of the emitted light is different. The eyes are pure white light, the fluorescent light is white with green, and the electric light is reddish and slightly yellowish. Although sunlight and fluorescent light sources are somewhat similar, the differences between the two should be taken into account when identifying higher quality products. The effect of light on the identification of ink is not only the light source, but also the light intensity and the irradiation angle. Under the same light source, the intensity of the reflected light on the sample sheet is mainly determined by the distance between the proof sheet and the light source, and the strong and weak ones are weak. The correct angle of illumination should be the angle of incidence equal to the angle of reflection. Irradiation on the proofs will inevitably result in partial refraction, but it does not have much influence on the identification of ink. In the identification of ink color, whether it is day or night should be carried out in the same light intensity and irradiation angle, in order to prevent ink mis-correction caused by color cast or before and after the ink variation. (6) The impact of overprinting on ink color is not allowed The fineness of products produced by the outlets, and whether the overprint of various printing plates are accurate, will have a great influence on the printing hue. The accurate hue effect of the overprinting is also good, and the overprint of the overprinted print will be deviated. This is due to the difference in position of overprinting of each color dot
The hue, brightness, and printability of the color printing ink are directly related to the quality of the color print, so it is necessary to properly grasp the ink preparation method.