Analysis of the most popular white board printing

Analysis of whiteboard printing quality problems IX

IX. methods to deal with printing quality problems:

1. It is necessary to frequently stir the ink in the ink bucket, and pay attention to timely increase the ink in the ink bucket

color inks are often made of multiple color inks. Because the properties of pigments, binders and fillers in different inks are different, This inevitably makes different substances in the ink exist precipitation and suspension state control mode: computer control. Once this state exists obviously, it is bound to cause ink color variation of printed products. Therefore, during the printing process, the ink bucket should be often stirred with an ink knife to select the ink in the number of points to be measured, so as to prevent the ink from sedimentation and suspension, and ensure that the ink color of products before and after printing is consistent. In addition, due to the reduction of the amount of ink in the ink bucket, it is easy to reduce the gap between the ink bucket steel sheet and the ink transfer iron roller, so as to reduce the amount of ink output and weaken the ink color of the print. In order to avoid this situation, we should also pay attention to adding ink frequently in production, so that a certain amount of ink is always maintained in the ink bucket. 2.

2. Adjustment of local ink intensity in the horizontal part of the print

due to the different layout structure of the print, if a section of the horizontal layout is dominated by words, lines and lines, its ink absorption is relatively small. The corresponding ink bucket steel sheet adjusting screw can be screwed in to appropriately reduce the ink delivery in this part. If a section of the horizontal layout is dominated by the field and plate, and its ink volume is relatively large, the corresponding adjusting screw should be screwed outward to increase the ink supply, so that the ink color of the whole page remains uniform and consistent, so as to prevent the occurrence of printing color difference

3. Adjustment of the thickness of the full page ink

the ink in the ink bucket should comprehensively increase or reduce the conveying capacity. There are two adjustment methods: one is to adjust the gap between the steel plate of the ink bucket and the ink transfer roller; Second, it is realized by adjusting the rotation radian of the ink transfer roller. When the ink is thin, the gap between the steel sheet and the ink transfer roller should not be adjusted too large, so as to avoid ink leakage, resulting in uneven ink color or color mixing. When adjusting the ink feeding amount, the rotation arc of the ink transfer iron roller should be controlled between 1/2 of its adjustment range, so that when the ink is thin and thick during the printing process, the ink feeding amount can be flexibly adjusted to prevent the inconsistency of the ink color of the print

4. Correct adjustment and use of ink to prevent printing color difference

scientific and reasonable use of ink is an important part to ensure the quality of printing ink. The ink used for printing color products is too thick or too thin, which is not conducive to uniform ink transmission and inking. Generally speaking, when the temperature is low, the ink appears thick, and its fluidity is poor, which is easy to cause poor and uneven transmission. For this, according to the characteristics of printing crystal, additives should be selected to dilute the ink appropriately, so as to maintain good fluidity and transmission effect, so as to maintain the uniformity of ink color. If the ink is adjusted too thin, the ink color of the print will appear light. The adjustment of ink fluidity should fully consider the characteristics of printing machine speed and ink transmission structure. If the range and uncertainty of some indicators such as accuracy, detection limit, selectivity, linearity, repeatability, reproducibility, robustness and interactive sensitivity of the printing engine are fast, the ink path is long, and there are many ink rollers, then the ink is easy to become thin and thin due to the high friction coefficient. Therefore, the above situation should be fully considered when allocating ink, and the printability of ink should be reasonably adjusted. In addition, when blending intermediate and multicolor inks, try to avoid mixing inks with large specific gravity differences, so as to avoid the phenomenon of "stratification" (sedimentation and suspension) of inks on ink buckets due to specific gravity differences in printing, resulting in printing color differences

5. Control the operation technology to prevent the production of printing color difference

when printing, if the operation technology measures are not in place, frequent parking occurs in the production process, which is very easy to cause the phenomenon of printing color difference. In order to avoid this situation, first of all, we should pay attention to the reasonable maintenance of the machine. At ordinary times, we should maintain the flying parts and the air pump, so that the mechanical parts can be kept in good use condition, so that the air path is unobstructed, and the printing suction is smooth; Secondly, according to the thickness and size of the printing sheet, adjust the Feida, air pump and parts related to paper feeding to ensure the normal transmission of the printing sheet; Third, necessary adjustments should be made to the printability of the white board, such as through the bumping and folding of the paperboard, so that the paperboard can achieve the effect of transparent delivery, so as to eliminate the adhesion and adhesion, and make the paperboard flat, so as to facilitate the smooth paper feeding, and at the same time, it can better avoid the occurrence of empty sheets, multiple sheets and skew faults; Fourth, we should pay attention to the operation technology of stacking paper. If the paper stack is uneven, we should take measures to pad it, so that there is no obvious height difference on the paper surface. Through these operation process and technical measures, the paper feeding is kept continuous to prevent printing color difference caused by parking. To sum up, the problems are diverse, caused by one adverse factor and several defects in the operation of the impact testing machine. As long as we carefully analyze and summarize the production process experience and control the printing process technology and operation technology, we can not only better prevent the occurrence of printing quality problems, improve the printing quality of products, but also effectively improve the production efficiency