Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss...
description
Transcript of Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss...
![Page 1: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/1.jpg)
TroubleshootingPrint Head (Nozzle) ProblemsA step-by-step guide (version 1.0, summer 2011)
Troubleshooting common print head problems is not an easy task. It requires fundamental understanding of digital inkjet printing and a systematic, structured approach. This document will help you in identifying the cause of print head troubles and how to address them.
PRELIMINARY REMARKSModern digital inkjet printers and their print heads are sophisticated and, in a way, delicate. In order for them to operate in the best possible way, some criteria need to be taken into consideration. This starts with the installation of the printer: never install the machine in a location where it is tilted or where it may wobble or vibrate. Only when you printer is levelled, good operation of your printer and print head(s) is guaranteed. Also the conditions should be stable and within specifi cations regarding temperature and humidity. Furthermore, the use of good quality media is important too. Cheap media almost always has weak characteristics like uneven coating, bad calendering and a too high tolerance in thickness. This will result in poor looking prints that might even seduce you in thinking that your print head has issues. Finally, there is the ink used. Original inks are your best option, since they have been developed to match the print head used and the temperatures used. Third-party inks often do not take this into consideration enough and some of them are downright killing your print head(s).
HOW IT WORKSAlmost all modern digital inkjet printers work in the same way, pictured in the scheme below. There might be some additional parts in your printer like ink subtanks or fi lters, but in general, they all work alike.
The Ink Cartridge is holding the ink. A damper is a plastic structure with a mesh fi lter that acts as a one way valve. It has several functions. It can collect a small amount of air, it prevents ink particles from entering the head, it is a one way valve, it holds and dispenses ink. The structure is designed to keep the head performing well. It should be changed ideally once every six months (or when it is clogged by ink particles). The higher the speed of your printer, the bigger the damper should be. The damper then delivers the ink to the (piëzo-electric) print head. The print head is driven by the head board (or carriage board) which is controlled by the main board (which controls all electrical parts like the pump motor, ink board, servo board, junction board etc.)D
PSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m
INK CARTRIDGEINK BOARD
PRINT HEAD
CAP TOPWIPER
HEAD BOARD
MAIN BOARD
INK TUBE
DAMPER
PUMPPUMP MOTORELECTRICAL WIRE
![Page 2: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/2.jpg)
ABOUT INKS(Solvent) ink is made up of a few basic components: Pigment for color, Resin for gloss and adhesion, oil or water based co-solvents, and humectants similar to what is used in hair shampoo and some very proprietary elements. Inks must be fi ltered to about .2 microns to insure smooth fl owing through a modern print head.
Ink is not a solution. It is a colloidal suspension similar to milk. The pigment and resin make up the solids of ink. A resin is a liquid plastic. Imagine what happens to liquid plastic when it dries. Yes, it becomes a solid. When pigment ink binds with resin, it becomes a colored solid and is often diffi cult to loosen. This is why a head must be kept lubricated. Over time it will dry out even when at rest on a capping station. By keeping the capping station moist with a lubricant that loosens ink and lubricates the capping station it will keep the head properly moist and free fl owing.
PRINTING CONDITIONSHumidity should be at about 30 to 40 percent and temperature should be about 20 to 25 degrees Celsius. As temperature decreases, the ink becomes thicker which makes fl owability more diffi cult. When the temperature rises, the ink viscosity decreases, making the ink thinner. The changes in temperature can also affect the printing color. Low humidity can cause the heads and capping station to dry out causing ink drop out and impropper cleaning.
Make sure to put two drops of appropriate cleaning liquid on the capping station each evening and do not let the printer get below 18 degrees Celsius. Never use a cleaning liquid like Windex. Although it will clean, it does not keep the caps moist and they will turn hard, which is a hazard to the print heads. Of course this is also true for your wipers.
CLOGGED PRINT HEAD NOZZLESClogged nozzles are extremely common with printers that have not been cleaned on a continual basis . Think a moment. Do you not change the oil in your car about 10.000 km to keep the engine running smoothly? Most of us do.There are multiple areas that cause problems with nozzles fi ring well:
The Capping Station Pads The Pump(s) The Wiper(s) The Dampers The Print Head
The Capping Station is where the head rests and where the head gets cleaned. The capping station has a foam pad touching the head and a tube leading from the capping pad to a pump. Ink gets sucked from the head through the foam pad. When the printer is not used for a while the ink on the pad starts to dry which causes the nozzles in the head to dry as well. Most inks are made of a group of chemicals which include resin. Liquid resin becomes solid plastic when it dries which it is hard to disolve and break up. The capping station pump can wear out which will result in insufi cient suction. This will prevent proper cleaning.The dampers are the fi rst line of protection. The tubing from the cartridge goes to the damper which sits directly on the print head. The damper has a fi lter inside it to capture any particles that could clog the nozzles. After a good deal of ink travels through the damper, you may have particle build up which will prevent the fl ow of ink causing nozzles to drop out. Dampers should be replaced every six months.The print head contains extremely small nozzles that refi ned ink fl ows through. The surface of the head must be kept lubricated in order to prevent the head from drying out the ink. If ink inside the head forms solid particles it will block ink from fl owing. It is imperative for the capping station pad to be kept moist to prevent the head from drying.
DPSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m
![Page 3: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/3.jpg)
NOZZLE DROP OUT SCENARIOSWhen the output of your printers indicates missing nozzles (or nozzle drop out), a nozzle test pattern can tell you what is causing it. Please refer to the different nozzle test pattern below to determine the problem you have. 1 - UNSTABLE NOZZLE OUT
The missing nozzles change their position after cleaning.POSSIBLE CAUSES • Air bubbles in the ink line or print head nozzle area, and it does not come out. • The wiper rubber blade is rounded and not sharp enough anymore • The wiper rubber blade has gelled ink or dried ink on it.ACTIONS • Check the print head for bubbles on the nozzle plate • Check the damper and ink lines for air bubbles • Check the cartridge valve for good functioning • Check, clean and/or replace the wiper blades
2 - STABLE NOZZLE OUT
The missing nozzles do not change its position all the time.POSSIBLE CAUSES • Some kind of dusts are inside or on the surface of print head nozzles. The print head nozzle surface, cap rubber, and wiper rubber has to be cleaned every day. • The print head surface might be damaged by head crash with the media. • The print head has been used for a long time with a high head gap which is larger than 3.0 mmACTIONS • Clean the caps, wiper blade and nozzle surface • Replace the print head
3 - MULTIPLE ADJACENT MISSING NOZZLES
Many adjacent nozzles out at the same time.POSSIBLE CAUSES • Poor air seal somewhere inside the ink line. • Air bubbles on the cap rubber or broken cap rubber.ACTIONS • Check and replace the cap tops • Check the damper and ink lines for air bubbles • Check the cartridge valve for good functioning • Check the pumps for good functioning
DPSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m
![Page 4: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/4.jpg)
4 - MIXED COLOR 1Base color has another color on the nozzle test.Like if Cyan nozzle test has Magenta color on it, and the Magenta color has the normal densityPOSSIBLE CAUSES • Ink mist might be attached on the print head nozzle surface. • The wiper rubber blade is rounded and not sharp enough.ACTIONS • Clean the print head nozzle surface • Check, clean and/or replace the wiper blades
5 - MIXED COLOR 2If the color is completely mixed.POSSIBLE CAUSES • There is a possibility of both ink lines are mixed on the same cap rubber, and it may fl ow back into the ink line a little bit. • The wiper rubber blade and cap rubber may be dirty.ACTIONS • Check the cap tops and replace if necessary. • Clean and/or replace the wipper blade. • Clean and/or replace the cap tops.
6 - NOZZLE DEFLECTION 1Nozzles are defl ected from their correct position to Right-Left-up-Down (but each nozzle is straight).POSSIBLE CAUSES • Some kind of dust attached on the print head nozzle surface. • The head gap might be too high to print on the media surface, and the fi red ink can not be straight. • The print head data cable has non constant malfunctioning contactsACTIONS • Clean the print head nozzle surface and plate • Replace the print head data cable
7 - NOZZLE DEFLECTION 2Nozzles are defl ected very badly when compared to nozzle defl ection 1 (Curled, Dotted line, Fired half size, Crooked).POSSIBLE CAUSES • Some kinds of dusts are inside or on the surface of print head nozzles. • The print head surface might be damaged by head crash with the media. • It had been used for long time with high head gap which is larger than 3.0 mm.ACTIONS • Clean the nozzle surface or replace the print headD
PSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m
![Page 5: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/5.jpg)
8 - EATEN NOZZLE TESTWhen your nozzle test pattern looks like this, the nozzle shows that their is a problem in the electrical system. POSSIBLE CAUSES • The head data cable might be malfunctioning • There might be a problem with the head board • There might be a problem with the main boardACTIONSVerify the head cables, the fuses on the main board and the head board. Switch head cables with a good working nozzle row (color) and see if the problem moves along with the head cable. If it doesn’t: replace the print head. If it does: replace the head cable and check again.
9 - COMPLETELY MISSINGWhen a complete color is missing on the nozzle test patternPOSSIBLE CAUSES • There is a problem in the electrical system • There is a problem in the ink delivery system.ACTIONS • Check the damper and ink lines for air bubbles • Check the tubes and pumps for a blockage • Check the cartridge valve for good functioning • Check the head data cables • Check the head (carriage) and main board and their fuses
IN CASE OF AIR IN THE INK DELIVERY SYSTEM Check the Ink Cartridge Perform cleaning more than once do a new nozzle test Check leak at the cap - perform a cleaning and watch the head surface before wiping. If there are ink drops on the surface of the head, the cap is not leaking. If the head surface is clean, the ink is not absorbed Check the pump for broken tube, tube clogging etc Check the print head for air bubbles - the way to remove air bubbles in the print head is to either perform a number of cleanings or open the valves of the ink cartridges, switch the cap off and then squeeze the round surface of the damper (of the nozzle row where missing is found). Do this until all nozzles in the row have dropped at least 10 drops of inks. Close the valves and switch the cap on and perform a cleaning Check the ink tubes visually for air bubbles - open the valves of the ink cartridge and switch the cap off. Disconnect the ink tube at the damper and pull ink with a syringe until the air bubbles are gone Check the condition of the dampers and replace when worn or damaged Check the valve and the joint of the ink cartridge - for checking the valve of an ink cartridge, close all valves, disconnect the joint of the cartridge to be checked, connect a syringe, open the valve for the cartridge to be tested and draw the syringe slowly. If you feel you have to pull hard to get ink out of the cartridge, the valve is likely to malfunction and needs to be replaced.
DPSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m
![Page 6: Https Digiprintsupplies.zendesk.com Attachments Token 9zadretbiapxzss Name=Troubleshooting+Print+Head+(Nozzles)+Problems](https://reader036.fdocuments.in/reader036/viewer/2022082218/55cf9954550346d0339cd082/html5/thumbnails/6.jpg)
JAMMED NOZZLESNozzles can become completely jammed or blocked when ink has dried in them. This happens when the printer was not in use for a longer period of time or when the head and caps were not moist when the printer was idle. In this case, resin has dried and blocked the nozzles. Sometimes several cleanings in a row help to correct this problem, but usually you need a stronger solution for this problem. We advise strongly against wiping or swabbing the print heads with cleaning liquid. The nozzles are to fragile to whitstand the relative roughness of most wipes and swabs and very often too much pressure is used when doing so.Using an ultrasonic cleaning device (such as DIGIPRINT SUPPLIES Cleansonic ultrasonic cleaner Pro) is a better option here. The ultrasonic waves while mildly vibrate the resin chunks out of the nozzles without damaging the print head.
NEW PRINT HEAD INSTALLATIONPlease be aware of these guidelines when installing a new print head. Before working on a machine like your printer, always conduct the following steps fi rst.
Switch the power OFF. Remove the electrical cable from the socket. Otherwise, you may suffer electric shock or the machine’s electric circuits may be damaged. Press the power button again to release all the rest tension in the capacitors. Disconnect all cables from the machine. Not doing so could cause damage to the print head and/or boards
DPSn
otes
ww
w.d
igip
rint
-sup
plie
s.co
m