Digital flexo and its development

In Drupa 95, CDI, the world’s first digital flexographic imaging device, was demonstrated. The introduction of the device immediately generated strong response and huge inciting effects on the market, and people have high expectations for this. After all, DuPont's flexo plate is in the leading position in the industry, and Barco's electronic products are also at the top level in the world. The joint attack of these two giants has played a decisive role. People attach great importance to it. The actual market reaction is also very strong. The voice is very high. More than 80 Barco systems have already been installed and put into production. Moreover, the fact has proved that the adoption of this digital imaging device can greatly improve the quality of prints, and the color consistency of prints also has a relatively large progress. Most of its users are packaging and printing companies, and some users have successfully successfully changed the folding carton printing from offset printing to flexographic printing. Even in the corrugated box market, the application of flexographic printing technology has become increasingly widespread. , and more and more people's interest. For a long time, flexo printing has always used the film-making method. This method of plate-making has many advantages, such as: relatively low cost, wide range of substrates suitable for printing, large range of ink selection, simple structure of printing press, and quality of printed matter. High and so on. In plastic flexible packaging printing, gravure printing is the biggest competitor of flexographic printing. However, flexo printing itself has a very large number of dots, forming breakpoints in high-light areas, and has poor stability during printing. The emergence of digital flexo completely changed this situation. The dot expansion of digital flexo printing is very stable, and dot gains are relatively small, which is almost the same as offset printing. Whether it is a small yang text (or line) or a scribbled text (or line), it can be clearly printed and not blunted after printing; 2% of the dots on the printing plate remain unchanged at 2% after image plate-making and printing. . Of course, this is also a certain condition - In fact, compared with the traditional analog plate-making method, the cost of production of the prepress plate is roughly the same, so the digital flexo printing version The price of wood may be slightly more expensive than ordinary flexographic plates. However, there is a big difference between this digital flexo and traditional flexo. The quality of the final prints obtained with digital flexo printing is higher, so flexo printing can take away the plastic film printing business from gravure and take away the carton printing business from offset printing. Moreover, the cost of digital flexo printing has also been greatly reduced, especially for short-lived printing because the commissioning and operation of flexographic printing presses is very simple and fast. A six-color job change takes less than half an hour. If sleeve technology is used, the time will be shorter. Although the price of the plate used for digital flexo printing is slightly higher, the overall production cost is also reduced because the printing cost is greatly reduced. There are currently two types of imaging systems: one is a system using an argon ion (Yag) laser imaging system (such as that of Barco and ohil/Scheepers) and the other is a system that uses laser diode imaging (such as Creo and Saturn's equipment). The latter is a typical offset CTP application in flexo printing. In fact, the optical properties and physical properties of laser diodes are not very suitable for flexographic plate making. Laser diodes cannot adapt to changes in thickness between commonly used flexographic plates, which may result in poor imaging and affect platemaking efficiency. In addition, in order to obtain a high-quality, perfect digital plate, the power (energy density) of each imaging laser beam must be compatible with the characteristics of the ablation layer. This requires that the laser head of the laser diode must be operated at a slow speed. This will inevitably affect the speed of plate making, which will lead to a decrease in production efficiency. The traditional dot gain compensation (DGC) and correction methods are not very accurate, and they all have different degrees of deviation. In the flexographic printing, they all cause unexpected highlights. Recently, Barco has introduced an all-digital approach that can both correct and complete DGC. This method has both high accuracy and color management capabilities that can be easily adapted to any workflow. The argon ion (Yag) laser imaging device can image directly on the sleeve, and this device is currently on the market, which makes the argon ion laser imaging technology has achieved glory. Imaging on the sleeve, there is no registration problem, and trapping processing is greatly reduced. In addition, due to the growing liveliness of the short live market, the use of sleeve technology also enables rapid changeovers on the press. In order to compensate for the variation in the thickness of the printing plate, it is necessary to adopt the sleeve technology according to the requirements of the performance of the optical imaging system. Due to the relatively short focal length of the laser diode imaging device, the laser diode imaging device seems unlikely to image on the sleeve. Barco and DuPont recently demonstrated a new type of media and imaging components. The QuadBearn (four lasers) is very fast imaging and has high plate-making efficiency and can meet the needs of users in the high-quality flexo and corrugated box market. With this CDI upgrade device, the productivity of digital platemaking is comparable to the productivity of film-making.