The difference between CI flexo printing machine and Unit type flexo printing machine
Difference in machine structure：
The printing unit of the CI flexo printing machine is arranged around the center cylinder, and the printing is performed under the same tension. The tension is stable, the feeding path is short, and stable register printing.
The printing units of the unit type flexo printing are arranged in sequence and sequentially heated by the oven after and after printed, which will cause changes in the printing materials, Especially inaccuracy register printing caused by the tension fluctuate during the process of raising and lowering speed. Factors such as printing perimeter control and printing plate roll accuracy differences can cause printing instability.
Difference in register printing type：
The register printing of CI flexo machine is printing under the same tension. The principle of register printing is according to phase difference of each motor to perform register printing control , there is no effect on start-up, shutdown, acceleration, deceleration, and quality of printed labels.
The register printing of unit type is based on the detection of printed marks for register printing after printed and there is a lag adjustment. For start, stop, acceleration, deceleration, quality of the printed target, etc., there will be detection of printed marks to adjust and lag, causing waste.
Waste from printing clutch pressure：
The register printing of CI flexo printing dose not need to be adjusted under combined pressure and separation pressure, and the register printing accuracy is not affected.
But In the unit type, after the pressure is removed, there is no printing detection mark. the reading and detection of the mark after printing is wasteful.
Different finished product rates：
It is no need to operate the CI flexo printing machine after restarting, accelerating, and changing rolls. The waste of changing rolls is generally about 10 meters. But for the unit-type flexo printing machine, the printing marks will change after printing and changing rolls. After marking, there is waste in adjusting again, and the waste of changing rolls is generally more than 100 meters. The finished product rates of CI flexo printing machine is around 99.5%, while finished product rates of unit printing is around 97%.
Different production efficiency:
The printing unit of CI flex printing machine is heavy, generally about 25 tons, and ensure the stable high-speed printing. The printing process is that after the color ink is dried, it is finally entered into a large oven, and drying is more energy-saving. Printing speed is generally 260-320 m / min. The colors of unit type are arranged separately, and after each color is thoroughly dried, it enters the next color. The printing speed is generally 100-150 meters / minute.
The operation of CI flexo printing machine is easier. Register printing, pressure, roll changing are all automatic. The unit type flexo priting machine separate arrangement of each color makes the operation more difficult. Generally, operating CI flexo printing machine only needs two people, while the unit type flexo printing machine needs 3-4 people, and the operator needs “eyes and hands fast”, which has higher requirements.
Printing pressure stability
The central cylinder of the CI flexo printing machine adopts constant temperature control, and the printing pressure is relatively stable. For unit type flexo printing machine, the change of each printing bottom roller is different, and compared with CI flexo printing presses, the printing pressure constant is poor.
The inks of CI flexo printing machine are centralized, which is beneficial to ink management and reducing waste. The unit-type flexo printing machine inks are arranged in rows on the transmission side, which increases the difficulty of managing ink and wastes cleaning ink.
Order change time is different:
CI flexo printing machine are concentrated in the single station. The same personnel and the same number of printing groups, and order changing time is generally 20 minutes, while unit type flexo printing machine require 40 minutes. For non sleeve type flexo printing machine takes longer than 80 minutes. The CI flexo printing machine saves more than 50% on order change time.
Flexographic printing is a method of using rubber printing plates mounted on a cylinder of various repeat lengths which is inked by a roll carrying fluid ink. For every revolution of the printing plate cylinder an image is roduced.
Rotogravure printing is a newer technology that relies on engraved individual cylinders to produce the printed image.
Each option has certain advantages, (Flexographic is great for smaller quantity runs and generally is cheaper where Rotogravure produces better quality images) but recent advances in pre-press cylinder engraving technology has allowed us to deliver “gravure”quality at “flexo”prices.