ComColor Ink passage Mechanism(Revised version)

RKC London Office13 April 2010

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)

Step1 Basic mechanism

Basic mechanism of ink circulation system

Difference of fluid levels

Cylinder pump

Negative tank

Pressure tankInk cartridge

Head

Circulation of ink

ComColor print head has 2 pipes witch are flesh ink pipe and drainpipe for ink circulation

Difference of fluid levels

Cylinder pump

Negative tank

Pressure tank

Print head

IN (flow in)

OUT (flow out)

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

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

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

Step2 Ink level and valve condition

Stayed ink

Flowing ink

Direction

Main SW is OFF/Sleep

Ink cartridge valve => ClosePressure tank valve => CloseNegative tank valve => OpenBellows => HPPump solenoid => Not work (close)

Stand by

Stayed ink

Flowing ink

Direction

Ink cartridge valve => ClosePressure tank valve => CloseNegative tank valve => CloseBellows => SuspensionPump solenoid => Not work (close)

Printing (Two tanks are full)

Stayed ink

Flowing ink

Direction

Ink cartridge valve => ClosePressure tank valve => OpenNegative tank valve => CloseBellows => SuspensionPump solenoid => Not work (close)

Printing (Pressure tank is low)

Stayed ink

Flowing ink

Direction

Ink cartridge valve => ClosePressure tank valve => OpenNegative tank valve => CloseBellows => SuspensionPump solenoid => Work (open)

Printing (Two tanks are low)

Stayed ink

Flowing ink

Direction

Ink cartridge valve => OpenPressure tank valve => OpenNegative tank valve => CloseBellows => SuspensionPump solenoid => Not work (close)

Prepare cleaning function (For Strong creaning)

Stayed ink

Flowing ink

Direction

Ink cartridge valve => ClosePressure tank valve => CloseNegative tank valve => OpenBellows => Suspension to lowerPump solenoid => Not work (close)

Normal cleaning

Ink cartridge valve => ClosePressure tank valve => CloseNegative tank valve => CloseBellows => HP to UpperPump solenoid => Not work (close)

Actually a few ink flow via pump and pressure tank, then pressure tank ink also come out from the heads

Stayed ink

Flowing ink

Direction

Strong cleaning

Ink cartridge valve => ClosePressure tank valve => CloseNegative tank valve => CloseBellows => Lower to UpperPump 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

Air valve mechanism

OFF

ON

Air flowSide pipe

Thick pipe

Thick pipe

Side pipe

Thin pipe

Thin pipe Thick pipe Side pipe

Pressure tank valve

Rubber cap To overflow tank

To common tank

Negative tank valve

To overflow tank

Rubber cap To common tank

Shaft

Shaft

Thin pipeThick pipe

Side pipe

Shaft

Step3 Swap the tank (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

Prepare to flow down ink-From Cyan tank-

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.

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 connectthe air filter tube.

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.

Replace Cyan tank-Before replacement-

Replace Cyan tank-During the test mode 2711-

1)Set the test mode 2711 to “1”2)Turn off the machine3)Turn on it then ink supply will start4)Ink level for negative tank will be full5)Ink level for pressure tank will be almost full5)Remove the three clamps6)Head cleaning will start6)Test mode 2711 will be “0” automatically

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

Fail condition 1

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.

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 itwill overflow