Maintenance of Solvent Printer & Printhead

1.Pay attention to the working environment

1) It has precision printhead in the internal structure of solvent printer .so that the machine should be placed steadily prevent from mechanical collision and vibration during daily use.

2) If working environment is not good, it may easily block the nozzle because nozzle may sucks the dust floating in the air, therefore better stay clean.

  • The working environment is not good to change too much ,the components may easily defects under the high temperature ,as well as the size of nozzle aperture change also will effect the printing quality .
  • The humidity betterto reach 40-60% relative humidity around the machine, it is recommended to use humidifier with 4-6L/hour water consumption or use a spray gun and a homemade humidi Also the humidity shouldn’t be too high, because printhead and the mechanical part of machine may be corroded.

2.Static electricitys influence on circuit board, printhead and inks

There are some problems may come out due to the static electricity is not eliminated in time , which will affect printhead’s status, cause ink flying or spatter, even destroy the nozzle or burn the electric circuit boards etc. Also it may affect the computer to be scrambled or crashed under high static electricity. Therefore, It is very important to take right and effective measures to eliminate static electricity for the machine.

  • A good way is to bury ground wire. It is advised to bury the ground wire for each printer separately ,Firstly connect the copper plate (more than 0.5 square meters) with the equipment through copper wire , then put and bury it into the wet space depth more than 1.5 meter , and can pour some salt water.
  • After bury groud wire successfully and running for more than 1 hour, measure the residual static valuesof printing machine (Method to measure: Adjust the multimeter to AC200, measuring probe the 220V stable power input zero line and ground line to read the values, the absolute vaule is residual static value of machine, should less than 1 ohm, if  value larger than 1ohm, should check the ground wire, to avoid burning printhead or the electric circuit board.
  • In addtion, another way to use electrostatic brush to resolved static electricity is also recommended.
  • The roughness of material surface will also affect the generation of static electricity. You’d better choose material with smooth surface and contains lower CaCO3 .

Choose ink with relatively high viscosity , also have better effect on anti-static electricity.

3.The Selecting of ink

1) The quality of the ink determine the quality of printed image, poor quality ink will not only cause print not smooth,blur,color not bright,fade fast,and will also has a bad effect on printhead using status and lifetime. So it is highly recommended to choose the qualified ink with appropriate density. Everytime after start printer , let it do self-checking first, confirm test-image good and make sure the ink can be better compatible by the printhead .

2) Precautions for replacing ink: 1 Discharge old ink ,clean the pipes with cleaning solution  2 Evacuate the air of pipe before fill new ink (can manually deal with the uncleaned places such as ink sac, wiper, waste ink plate etc) Otherwise may cause damage to printhead, decrease its lifetime, or cause ink break when printing.

4.The Maintenance of Whole Machine body.

1) Make sure inner parts of printer stay clean , wipe off the dust deposited on each parts regularly (turn off power before do cleaning)

2) Lubricating the linear rails, sliders, and bearings regularly.

3) Replace or clean the filter and ink system regularly, ensure that the ink cartridge can supply ink normally without leaking or air bubbles in the ink tube.

4) Check the condition of cable inside tank chain ,ensure that no circuit problem, or signal interference.

5) Can clean the encoder stripe and device surface with Alcohol , Do not use cleaning solution since it is corrosive, may  cause paint drop from device surface .

  • Timing beltshould in proper tension, too tight or too loose all not good.

7) Turn off power before install or detach printhead and boards.

8) Do not push the carriage by hand while the motor is working with power on, otherwise can cause displacement.

5.Reason of nozzle blocking and the maintenance methods :

  • Ink qualitynot good, have impurities. ink cartridge quality not

SOLUTION: Use filter devices to avoid the impurities , use better ink and ink cartridges.

  • The temperature and humidity change rapidly has a bad effect on ink and nozzle,which cause the blocked up.

The temperature and humidity of Storage and working environment has an effect on stability of ink, which lead to ink break or scattered or make ink dried on the surface of the nozzle etc. Temperature changes rapidly may easily break the balance of inner printhead and work abnormal , ink may also can’t use suddenly.

SOLUTION: Equip temperature adjustment device in the workshop, control temperature varies within 3-5 degrees.

  • Printhead voltage has an effect on printhead .

Too low voltage of printhead will make affect the saturation of images, however, the high voltage may cause damage to the piezoelectric crystal inner head nozzle,cause frequently leakage ink,decrease the lifetime of printhead. Therefore ,do not make head voltage too high if not affect image quality.

Different brand solvent printers require different head voltages, high voltage will also require high ink viscosity.

When the voltage of the printhead is high but the viscosity of ink is low, will cause burrs and floating too much ink and too fast speed ink jetting, and block up the printhead etc.

When the voltage of the printhead is low but the viscosity of ink is high ,will cause no ink-jetting, saturation not good, non-uniformity etc.

SOLUTION: Change to appropriate ink or adjust voltage.

  • Static electricity has an effect onSolvent printer and ink.

Must take right effective measures to eliminate the static electricity of the equipment to protect the printhead and circuit board.

  • The Cleaning way has an effecton printhead.

Recommend to wipe the nozzle with a quality soft non-dust cloth or a soft sponge or sponge swab .

  • Theworking habits has an effect on

Drying is most easily reason to block up the printhead, if printhead not use for a long time, should found a way to prevent the nozzle from drying out. In addition, be careful do not scratch nozzle while do cleaning.

  • Ink viscosity has an effect on printhead.

The ink viscosity is high, If heating circulation is not good, ink adhesion in ink tube, may result in insufficient inkjet volume and color breakage.

SOLUTION : Enhance the indoor temperature to reduce the viscosity of the ink.

 

The ink viscosity is low ,when sprayed ink on the lamp cloth will easily reflect back to nozzle and accumulate on the nozzle, which cause block up issue .

SOLUTION :Wipe the nozzle with swab cotton dipped in cleaning solution. Change high viscosity ink if want to resolve this problems completely.

Printhead Maintenance Methods:

Doing proper and effective maintenance everyday can greatly reduce the possibility of nozzle block.

  1. Installation complete and initially maintenance of printhead.
  • Before start printer andwork formally, please be sure to print pictures with C M Y K as many as possible for 1-2 days, and do test-print with C,M,Y,K four colors ensure that all nozzles keep ink-jetting condition.
  • Better take outthe sponge and cleaning bracket together from the machine during printing
  1. Daily maintenance of printheadbefore shutting down the machine
  • Clean theprinthead and make surenozzle in a good condition, turn off device power.
  • Clean the moisturizing sponge or non-woven fabric with special cleaning solution andsoak it.
  • Move back the carriage to cleaning side and tightly combined nozzle and the moisturizing sponge or non-woven fabric, or cover the nozzle surface with cleaning solution and tightly wrapped with cling film , to reduce the volatilize of cleaning solution.
  • Keep device in this status all night till tomorrow.
  1. The treatment method of nozzleblocked.
  • It is very important to clean it timely when the nozzle has slightly blocked.

Here are some tips: Clean the outside nozzle ink drop with a cotton swab dipped cleaning solution, suck out the residual ink from inner printhead by vacuum cleaner. Can also use Self-cleaning program of printer to clean.

  • The treatment method of frequently blocked nozzleduring printing.

Suspending work, keep the equipment power on, move the carriage to the cleaning position,pull off all the float switch datalines connected sub-inktank and printhead board, also unplug the ink supply tube (sub-tank end), then clean using the syringe extract the special cleaning solution to clean the nozzle, after cleaning re-connect with float switch cables and ink supply tube , then continue the work .

  • If the nozzle is seriously blocked, may need toclean it deeply manually

1st, Detach the printhead out from the install frame.

2nd, To put the printhead into a clean glass container (poured appropriate amount of special cleaning solution) and the head bottom soaked 2-3mm, seal the glass container by cling film and put to anti -ash place it for 1 day or more .

(Pay attention that do not let the signal interface on the top ofprinthead touch the cleaning solution)

3rd, After socked printhead, do microwave shaking with a speical ultrasonic cleaner, put the printhead into a clean glass container (poured appropriate amount of special cleaning solution) soaked bottom 2-3mm deep, then start the cleaner, not the time should be less than five minutes, to prevent from detroying the inner circuit.

This process shall not handle more than three times continuously.

4th, Use syringe to draw 40ML special cleaning solution, pull off the ink tubes, insert to ink inlet of printhead, make cleaning solution enter printhead till the nozzle inner ink is flushed out. Observe the status of water line spray out from printhead during the cleaning process, if all waterlines are straight ,it means the cleaning was effective, head can continue to be used ( on condition that both circuit and piezoelectric crystal are intact). If the waterlines are not straight, then try re-do serveral times of process 2nd and 3rd.

  • Recommed to send printhead back to manufacture to do repairing if it is blocked seriously.

6.Treatment if equipment not use for several days.

If printer will not be using for more than 2 days, should cleaned the ink inside printhead, otherwise it will volatilized and dry out, damaged the nozzle.

If the printer will not be used for more than 7 days, should clean the the pipe as well, method as follows:

1) Preparation: special cleaning solution, cotton swab, syringe, clean non-woven coton, alcohol, towel, cling film etc

2) Take out the ink tube from the main ink reservoir, select single color postive pressure on purge ink board to discharge the ink in ink tube and sub-ink cartridge (When Sub-ink cartridge is out of ink,device will have alarm, ignore it and let ink pump continue to absorb ink out from the pipe).

Can also use syringe to extract , or pour out the ink in sub-cartridge and clean it with special cleaning solution.

  • Put the ink tube of main ink reservoir to cleaning solution reservoir,let the device absorb ink automatically till device stop alarming then take out the ink tube. Once again discharge the cleaning solution under positive pressure, do it three times repeatedly (do not put the ink tube into ink reservoir or cleaning solution reservoir after last handle finished).
  • Shutdown the machine, open printhead ink tube connector, extract clean solution with syringe, insert to printhead ink tube connector to start spray and clean printhead. Do not Forcetoo much, absorb back the cleaning solution into syringe again after released, squeeze out from syringe and re-absorb clean solution to do again. Each printhead can do two times .
  • Use syringe suck air and insert to printhead ink tube connector to exhaust the rest cleaning solution inside printhead, till no solution in printhead.
  • Wrap the ink tube of main ink reservoir and ink inlet tube on printhead carriage with Cling film .
  • Use non-woven cloth or cotton swab to clean the carriage platebottom, printing platform, moisturizing plate, waste ink plate and flash fan.
  • The bottom ofhead plate sticks to the non-woven fabric (which slightly moistened with cleaning solution), wrap the entire bottom plate with cling film, and move it to the moisturizing tray to fix it .
  • Clean the debris on machine and unplug the power cable, cover the equipment with plastic cloth toprevent dust.
  • If machine will not be used for more than 10days, betterremove printhead out from device, inject special cleaning solution,wrap with cling film to avoid the volatilize of cleaning solution and dust intrusion. Put the printhead into a clean and anti-corrosion container and sealed to storage.

7.Other precautions for printhead maintenance.

  • The socket of the printheadshall not be touched by hand, ink or cleaning solution etc, to avoid The contaminated socket can be cleaned by alcohol.
  • The socket of printhead must be aligned and shall not be hard plugged during the installation, once the pinholes broken or not properly inserted, printhead can’t work normally.
  • Printhead must be kept in a good heat dissipation environment ,otherwise may causedamage of head circuit.
  • Static electricity is seriouslyharmful to printhead circuit, so must eliminate static electricity factors.
  • Use purge ink and test-print fuction of printerprogram, ensure that all colors will be inkjeting regularly during printing.
  • The surface of head nozzle film is made of polymide film, should be careful when installing and disassembling,cleaning and immersing. If it is injured by hard object, will cause the nozzle beam ray not straight and will affect image quality.

 

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