1. ComColor Ink passage Mechanism (Revised version)
RKC London Office
13 April 2010

2. Advantage of ink circulation system
Removal of air bubble and some dust in ink
Decrease cleaning time
Decrease cleaning ink consumption
Cool down heads by ink
This system is effective for cool down heads such as car radiator. Then long time and
high density printing is available continuously
Improve the white line
This system is able to keep fresh ink at head nozzle. (When ink viscosity will be high,
white line occur easily. If old ink stay at the nozzle for long time, ink viscosity will be
high)

3. Step1 Basic mechanism

4. Basic mechanism of ink circulation system
Cylinder pump
Negative tank
Pressure tank
Ink cartridge
Head
Difference of fluid levels

5. Circulation of ink
ComColor print head has 2 pipes witch are flesh ink pipe and drainpipe for ink circulation
Cylinder pump
Negative tank
Pressure tank
Print head
IN (flow in)
OUT (flow out)
Difference of fluid levels

6. Difference in fluid levels
Negative tank
Pressure tank
Piezo nozzle ＜
Gravity
Negative pressure for making meniscus
Positive pressure for flowing down ink
On the above condition, it unable to make meniscus

7. How to make meniscus on ComColor
Pressure tank
Piezo nozzle ＜
Gravity
Positive pressure for flowing down ink
Bellows
Negative tank
Negative pressure for making meniscus

8. How to make meniscus on HC
HC series
Reservoir
ID unit
Head
Negative pressure for making meniscus
Positive pressure for flowing down ink ＜
As for HC, don’t need any additional unit such as bellows

9. Step2 Ink level and valve condition

10. Main SW is OFF/Sleep Ink cartridge valve => Close
Pressure tank valve => Close
Negative tank valve => Open
Bellows => HP
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction

11. Stand by Ink cartridge valve => Close
Pressure tank valve => Close
Negative tank valve => Close
Bellows => Suspension
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction

12. Printing (Two tanks are full)
Ink cartridge valve => Close
Pressure tank valve => Open
Negative tank valve => Close
Bellows => Suspension
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction

13. Printing (Pressure tank is low)
Ink cartridge valve => Close
Pressure tank valve => Open
Negative tank valve => Close
Bellows => Suspension
Pump solenoid => Work (open)
Stayed ink
Flowing ink
Direction

14. Printing (Two tanks are low)
Ink cartridge valve => Open
Pressure tank valve => Open
Negative tank valve => Close
Bellows => Suspension
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction

15. Prepare cleaning function (For Strong creaning)
Ink cartridge valve => Close
Pressure tank valve => Close
Negative tank valve => Open
Bellows => Suspension to lower
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction

16. Normal cleaning Ink cartridge valve => Close
Pressure tank valve => Close
Negative tank valve => Close
Bellows => HP to Upper
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction
Actually a few ink flow via pump and pressure tank, then pressure tank ink also come out from the heads

17. Strong cleaning Ink cartridge valve => Close
Pressure tank valve => Close
Negative tank valve => Close
Bellows => Lower to Upper
Pump solenoid => Not work (close)
Stayed ink
Flowing ink
Direction
Actually a few ink flow via pump and pressure tank, then pressure tank ink also come out from the heads

18. Air valve mechanism Air flow OFF ON Side pipe Side pipe Shaft
Thick pipe
Shaft
Thin pipe
Thick pipe
Thin pipe
Thick pipe
Side pipe
Pressure tank valve
Rubber cap
To overflow tank
To common tank
Negative tank valve
Side pipe ON
Shaft
Thin pipe
Thick pipe

19. Step3 Swap the tank (cyan tank)

20. Prepare to flow down ink -From Cyan tank-
Clamp the pressure tubes without Cyan.
Disconnect the negative tubes and insert to overflow tank.
Clamp the Cyan drain tube and insert to the overflow tank.
Place some paper on the BP unit

21. Prepare to flow down ink -From Cyan tank-
Remove the clamp at the drain tube.
Ink in the Cyan negative tank will flow down slowly.
When the Cyan negative tank become to empty, air bubble will come up to the pressure tank.
Exchange ink in the pressure tank and coming up air.

22. Prepare to flow down ink -From Cyan tank-
Clamp the pressure common tube.
Remove the rubber black cap.
Air filter tube switch from overflow tank to pressure valve (thin pipe side)
When remove the clamp, ink will flow down quickly.
Prevent to enter some dust through pressure tube, you should connect
the air filter tube.

23. Replace Cyan tank -Before replacement-
When two tanks for cyan become to empty, you should clamp between ink cartridge and negative tank, and also pressure air valve connection return to normal condition, disconnect the ink cartridge, and then re-connect the drain tube.
After that you can remove the cyan tanks.

24. Replace Cyan tank -During the test mode 2711-
1)Set the test mode 2711 to “1”
2)Turn off the machine
3)Turn on it then ink supply will start
4)Ink level for negative tank will be full
5)Ink level for pressure tank will be
almost full
5)Remove the three clamps
6)Head cleaning will start
6)Test mode 2711 will be “0”
automatically

25. Fail condition 1
If the clamp for another color’s drain tube is not enough, another color ink also will flow down from the negative tank slowly.

26. Fail condition 2
If you forget to clamp for another color’s pressure tube, after remove the common tube, another color ink also will flow down from the pressure tank quickly.
And then the negative tank will overflow, ink will come out from negative tank to overflow tank.

27. Fail condition 3
During the test mode 2711, if you remove the clamps before cyan pressure tank become to full condition, some air through to another pressure tank.
As a result, another color tank will flow down to negative tank, and then it
will overflow