Rotary offset presses have been increasingly favored by people for their extremely high production efficiency, but due to their own weaknesses, they are limited to publishing and printing. For packaging printing, due to the unfixed size of the packaging box, it is difficult for the web offset printing machine to display its advantages of high production efficiency in the field of packaging printing.
To solve this problem, many printer manufacturers have adopted plug-in technology. The so-called plug-in technology is to make the plate cylinder, the blanket cylinder and the impression cylinder on the printing machine into a separate component, which can be disassembled as needed. In this way, a number of inserts with different roller sizes can be made according to the need of the size of the print, but this technology is still unsatisfactory. First, the cost of making plug-ins is relatively high. If the size of the print is too large, the cost of the plug-in will be higher. Secondly, plug-ins are relatively heavy, and they are laborious and time-consuming to replace. Although they have been repeatedly improved, they are still very cumbersome. In addition, since the rotation of the drum needs to be driven by gears, the diameter size of the drum cannot be arbitrarily designed.
The emergence of sleeve technology has enabled greater flexibility in the printing of prints of different sizes, but when the sleeve is replaced, the transmission gear must be replaced, and the change in size cannot be steplessly changed.
The emergence and application of shaftless drive technology have greatly changed this situation. After the web offset press adopts the non-shaft drive technology, all the axes are driven by the servo motor. That is, the plate cylinder, the blanket cylinder, and the impression cylinder of the printing press are driven by independent servo motors, respectively. Due to the cancellation of the drive shaft and the transmission gear, the non-shaft drive offset press can realize the stepless change of the printing plate size and print the printing materials of different thicknesses.
It can be said that the perfect combination of Sleeveless technology and shaftless drive technology has changed the situation in which the length of repeated web offset presses is limited and a new revolution has been set in the offset printing market. Drandt-Gebbel is the first company to apply shaftless servo motor technology to web offset presses. Its proposed VSOP (variable sleeve size offset technology) concept enables printing plates and blankets to be installed According to the length of the prints and custom-made sleeve, with light weight, easy operation, quick replacement, high flexibility, wide range of substrates and other characteristics.
Currently, in the packaging and labeling market, the competition of various printing technologies is very fierce. In short-run printing, web offset printing is superior to gravure printing and flexo printing. First of all, offset printing plates can be made instant, and have excellent performance in screening, gradation, minimum dot size, and fine lines and text. Second, for different types of substrates, such as cardboard, labels, and films, the requirements for platemaking are different if gravure or flexo printing is used. However, if offset printing is used, the reproduction curve and print quality are the same for different printed materials. In addition, when printing on different substrates, offset printing has great advantages in color consistency. Therefore, with fewer and fewer prints and lower and lower prices today, there will be more markets and opportunities for web offset, and with new materials such as direct platemaking and seamless blankets. The successful development of rotary offset printing will usher in a broader space for development.