Digital engraving gravure cylinder (bottom)

(Digital Engraving) 7. Faster engraving speed Since the introduction of electronic engraving technology 30 years ago, the engraving speed of these electronic engraving equipments has hardly changed much, but we know that engraving speed is also decisive for the production efficiency of engraving machines. One of the factors. At present, the engraving speed is generally 4000 cells per second. Only HelioTwin can place and sculpt two rollers in parallel on a machine tool, continuously increasing the productivity of engraving machines. The digital engraving method also makes it possible to automatically and quickly crossfeed. The automatic fast cross feed function checks the engraving data of the white area and skips the relevant lines automatically by means of fast cross feed. In practical production, it can save 20%~30% of the time. There are two types of engraving: polar engraving and spiral engraving. The quality of the plate cylinder obtained by the polar line engraving method is higher, and the spiral engraving speed is fast, which can save 20% to 30% of the time. In 1998, with the introduction of HelioSprint system, the performance of the engraving head itself has also been improved, which has doubled the engraving speed. Although most manufacturers now claim that engraving speeds have increased, it turns out that only HelioSprint systems are truly implemented in everyday applications. This new engraving head not only improves the engraving speed, but also greatly improves the engraving quality. VIII. Quality Improvement The quality of engraving is affected by the combined effects of various factors. First of all, the quality of the input data, previously used in the form of film storage data, but now are all digital data; Second, the calibration of the engraving machine, including the test cut (testcut); third, the physical properties of the engraving head, The carving head is responsible for transferring the data information to the drum; the fourth factor is the quality of the copper layer. However, the engraving drum itself is only an intermediate medium for the final print. What really matters is the final print. Therefore, the printing characteristics must also be taken into consideration during the engraving process. 1, the quality of the input data After discarding the film, the resulting drawbacks will disappear, the main problem is the pinhole (due to dust). Failures that may occur during a series of film processing are also eliminated. In other words, because the steps of outputting, copying, imposition, and developing and fixing are omitted, the disadvantages of these steps are eliminated. Therefore, it becomes more and more important how to better adapt digital data to gravure and provide the best service for gravure. The creation of engraving data requires specialized, high-quality, reliable processes. 2. Testcut In the previous section we already mentioned the testcut. In terms of engraving quality, it should be remembered that automatic test test systems (such as the CellGuard system) are not subject to subjective factors and therefore have higher accuracy and reliability. 3. Engraving head Even if the engraving head is as hard as a diamond (such as in an electronic engraving machine), as long as it continuously mechanically sculpts the copper layer, it may be worn or even damaged. Therefore, the operator must pay close attention to the condition of the engraving head. In this regard, the HelioSprint engraving head has the property of continuously improving the engraving quality, which is called “cell offset” and can make the edge contour of the printed product smoother, and can effectively eliminate the sawtooth effect of the gravure printing. Due to the improved geometry of the cell, the HelioSprint engraving machine has a deeper engraving depth than other engraving heads, so the density of printed matter is higher. 3. The quality of the copper layer is determined by electroplating technology and surface mechanical treatment. In this regard, quality standards for high-grade printing have been established. 4. Gradation Gradations Gravure images are affected by ink, substrate materials, and printing presses. In addition, the print quality depends on the number of screens and the angle of the screen. All of these factors affect the transfer performance of the drum. To overcome the effects of these factors, adjustments must be made through the engraving hierarchy. It is equally important to establish the gradation level for sculpting and the calibration curve from the roller to the substrate material. Although the methods and basic ideas for formulating tone levels are relatively simple, due to the gravure printing process involved, the process of setting tone levels is relatively time-consuming. As a result, many companies use their sculptural tone hierarchy as a trade secret. Nine, a new feature - continuous engraving Some engraving machines can continuously perform multiple engravings on one or two engraving rollers. This method of continuous engraving has the function of partial engraving, which means that the HelioKlischograph can realize longer unattended carving production. Continuous engraving on a roller, also to say that on the roller, it is possible to first engrave high-line fine text and bar codes, and then engrave lower-line images. The advantage of this method is that it skips over most of the area of ​​the drum to sculpt the fine parts individually without having to engrave fine high-net cables on the entire drum, which saves production time. Continuous engraving on two drums means that one drum can be automatically engraved after engraving one drum. This requires that the engraving machine must be able to install two rollers. Each roller is engraved first, and then the engraving machine can automatically move the engraving head onto the second roller, positioning and engraving. During unattended night shifts, this method is very good for time-consuming carving work. X. Digital carving - what is the outlook? In the past few years, the widespread application and popularity of filmless roller engraving technology has gradually occupied the dominant position in packaging and printing. At the same time, due to the development of a series of new functions, the production efficiency has been continuously improved, the production cost has been reduced, and the quality of engraving has been improved. At the same time, the operation of engraving machines has become easier and more convenient. In the future, there are two development trends worthy of everyone's attention. First, there will be more and more technologies for professional gravure printing. For example, the laser engraving technology of gravure cylinders has been developing very fast at that time, occupying the market for high-end goods (such as cigarettes, alcohol, etc.). There are significant differences between direct laser engraving and laser ablation imaging systems. Second, it has developed toward fully automated production, especially in countries with a relatively high level of industrialization. Because these countries have already prepared all kinds of corresponding conditions, and the timing has also matured, automatic electroplating production line and automatic engraving machine. The world's first fully automated engraving system, Hell Gravure Systemes, has reached the stage of installation and commissioning. These systems use different types of roller loading systems. Depending on the application, the roller is mounted on a HelioKlischograph by a crane or robotic arm (robot). Comparing with other printing processes, especially compared with the relatively low cost process (such as flexographic printing process), whether gravure printing has a competitive advantage depends largely on the production efficiency. Judging from the development of the past few years and the future development trend, the status of gravure printing in the high-end printing field is very favorable.