Reticulated ink roller strip test

Simply put, the purpose of the Inker Roller Strip test is to find the thinnest layer of ink so that our printing can meet the predetermined color density. The use of thin ink printing has several advantages: 1. It can reduce dot gain and increase the range of color adjustment; 2. Faster ink drying reduces ink sticking and speeds up printing; 3. Uses less ink; 4. Printing lines are clear--especially In the treatment of thin lines, anti-white characters, and footmarks. 5, reduce VOC consumption, help protect the environment. 6, printing preparation time is short, image processing speed. Before testing the roller slats, the purpose of the test and the requirements to be achieved should be clearly defined, and various test elements should be reasonably arranged so as to obtain satisfactory results. A typical test image should include: * Yin/Yang text; * Continuous vignetting color; * Yin/Yang lines * Long strips with white spots to measure ghosting; * Blur shadows; * Several grayscale gradients Transform lines. Mark the network cable and include all the gradients from dark to light; * A large block of 30% screen to observe the continuity and banding of the printing. Of course, the main result of the ink roller board test is to find a predetermined color density (slightly larger than it actually is). There are special designs in the test image just to better understand the printing conditions and their causes. They may not be related to the transfer roller. During the experiment, attention should be paid to the usual production time. Do not perform special environmental treatment, and do not transfer ink. Only the best, worst, and medium choices can be selected for printing materials. Monitor each experimental sample and record relevant data. Others may operate according to the common sense of printing test. Assessing the test results As previously stated, the color density is the main purpose of the test. When measuring the overall color printing, the color density of each color ink is adjusted to the maximum value so that it passes through all the ink roller test belts, and then according to the color separation meter or FIA's FIRST manual, it is determined that the gray balance needs to be achieved when printing. Color density, then add 0.07 points to its value, find the corresponding roller strip, which is the required ink roller parameters. For example, the value of magenta in printing is 1.25, then you should find a minimum of 1.32 slats, rather than the sliver is exactly 1.25, because some weak colors require higher ink flux when printing. Should establish a set of standards to represent the correspondence between the ink roller mesh, ink flux and various colors. In fact, one kind of printing color is weak and strong, and it is still stable in the strip test. Data error problems Regardless of what other people say, the value of field color density can sometimes go wrong. Ink may have pinholes or build-up, and the printed material will transmit a portion of the light, reflecting only 85% of the screen tone rather than the field value, all of which will affect the readings. Under this circumstance, we can read the values ​​of the outlets. It will be of great help. It is also possible to open the gray level and check the large area of ​​real ink that can be continuously inked. This can also provide us with useful reference. The density value of the ink roller test band should be the highest value, not the average. Line color printing For line color printing, as long as the detection of the most special color, the method is the same as the entire printing. However, it should be noted that its color will shift due to the thickness of the ink film. For this, refer to the relevant color standard data solution. Combination printing If the screen printing and the field must be printed at the same time, it is necessary to see which screen is the cleanest and fullest. The selection of the ink roller board should be lower than the standard of the whole printing, higher than the standard of the line printing, is the compromise between them. In the line color printing, the mesh roller has a high ink flow, and if the screen plate is rough, the image can be made clearer. Another problem with the ink roller speed is the solidification speed of the ink. Nearly every company can produce dense, slow-solidifying inks. However, sometimes the ink supplier does not know what kind of ink the thin ink film should require, so errors often occur. Thin ink film printing requires dense but slow drying inks. If the dry speed is too fast, it will cause dry edges on the edges, and the dots will be disintegrated and affect the printing effect. Therefore, slow-drying ink is preferable. Although the addition of slow additives in the ink can enhance the ink transfer effect and achieve the printing requirements of the thin ink film, it will affect other characteristics, and the ink dots of the printed product are also easy to fall off, which is inconvenient for production. Therefore, a simple test should be done one or two weeks before the formal experiment to allow the manufacturer time to prepare the corresponding ink for formal experiments. In addition to determining the color density and ink solidification speed, the other features of the test picture are just to further determine the printing performance. In general, the lower the ink flow of the ink roller, the finer the ink line of the ink roller. There are several different grayscale gradient lines on the test picture, which are the contrast lines of different screens. When the ink roller's ink flux decreases, some grayscale lines will appear bridging or dirty. In general, a 150 line screen can be matched with a 900 cpi (350 line) low ink flow ink roller, but when the ink roller screen line becomes larger or the ink flux increases, this screen will also appear bridging and dirty. When printing, it is imperative to make the highlights and halftone areas of the screen printing the clearest to achieve good printing results. Both the highlights and the midtones are clear, and the printing plate network plays an important role. The lower the general ink volume, the clearer the cable. The ink roller of the highest network line can match the finest printing plate cable, but the color density will become insufficient. Therefore, after determining the color density, the problem of the printing plate network line should be confirmed again. The problem of the highlight area is blurred. The highlight area is blurred. Mainly due to the invasion of the network. If the halftone dot is smaller than the mesh aperture of the ink roller, the dot will infiltrate the ink roller mesh to absorb excessive ink particles, causing the highlight area to be dirty, so the screen plate should be replaced. Intermediate toning If the ink film is too thick, bridging will occur at the dots and the intermediate toning will be unclear. At this time, according to a vignetting screen or a gradient screen, a screen net that can make the middle toning the most clear can be selected. The dot expansion can be based on the results of the ink roller test board, find the relevant number of network lines, and solve the problem of network expansion. General film printing machine 120 lines / inch, corrugated printing 85 lines / English. You can also read the value of the key tone area or use the densitometer to understand the general trend of dot gain, and draw the line of change by plotting. Contrast Contrast is an indicator of the difference between 100% screen tone and solids. This standard does not make much sense in the ink roller test. Blurring of dots When using an ink roller with a small amount of ink, you can reduce the negative effects of dot blurring and do not cause dot gains. The 30% screen patch can understand the vignetting and banding of the vignetting image by observing the printed patch. If there is a banding phenomenon in the vignetting image, it can be concluded that there is a problem with the printing press, regardless of the ink roller. However, the use of a small flow rate ink roller can also reduce banding. Dirty and full text: When the ink film becomes thin, text and lines can also be thinned. At this time, we must carefully select the printing plate to ensure a clear reproduction of text and thin lines. Pinhole screen pinholes prevent the ink from coloring. Is to increase the pressure, change the ink composition or simply no matter, it depends on the specific circumstances. Image Fidelity and Tone Range Measurement of the dot color range with densitometers reveals that thin ink film printing has features of reduced dot gain, increased contrast, and increased tonal range. Unexpected problems The thicker ink roller on the screen is more ink-jet, and the ink flow on the cable is less. Therefore, we select the appropriate ink roller. But sometimes there are unexpected results. The truth is that after all, it is a fact. Such things also help us. Ghost ghosting refers to the phenomenon in which a previously printed pattern continues to remain in the subsequent printing process. In general, its effect will increase as the ink roller flow decreases. Under what circumstances will you ignore it? It depends on the circumstances. Other dust, paper fibers, LDPE, paper hair will affect the thin ink film printing. Sometimes it is very serious, it will ruin the entire image, and such issues should also be noted. Looking at the full text, we should be able to draw the following conclusions: * Do not choose the ink roller board that just satisfies the color density requirements; * Coordinate between the printing screen mesh and the ink roller mesh, find a balance point, can make the printing tone the most clear; *The scheme of combination printing is the color density, the number of screens, and the clear compromise of the screen. * The ink roller strip test is to find the appropriate parameters so that the ink roller meets the color density requirements with the lowest ink flow rate; * If ink Fast drying, or color does not meet the requirements, should contact the ink supplier in advance. In short, the ink roller strip test can eliminate the influence of human guessing, providing an objective basis for us to select the appropriate anilox ink roller.