Lets talk about air

[printfan1138]

As I read through all the inkjet tutorials out there I often see people talking about the danger of getting air in the printer heads and that indeed is given as one good reason the OEM Cartridges are set up to quit working often wayyyyyyy before all that expensive ink is gone.
If a printer head has heat elements built in as in Canon products I suppose that is important but with a Piezo head ( or however it's spelled), like Epson products. that has no heating element and uses electric current I wonder if they are more forgiving of air? I try to avoid introducing air in my cis tubing but some always gets in when changing out the bottles of ink. Not a lot but some.
I use dampers and I think I read that they are set up to filter out air as long as it's not a lot of it. Anyway does anyone have any thoughts on this or hands on experiences good or bad? Just a thought as I enjoy printing my photographs. Printfan1138

 

[fotofreek]

Epson printers' Piezo-electric heads run into difficulty if a cartridge should run dry. An air-locked print head is, apparently, difficult to bleed the air out of so it can resume printing. If a Canon bubble-jet head runs dry, the heating element doesn't have the cooling effect of the ink and burns out. Both types of printers reserve a portion of the ink in the cartridge when it shows empty to prevent these problems from occurring.

 

[qwertydude]

Epson print heads won't burn out but once you get an air bubble in the print head it sure is annoying to get out. You have to usually run several successive cleaning cycles. This not only wastes a lot of ink from the good print heads but also fills up the waste ink pads. Not a problem if you've rerouted the waste ink tube but it still adds to the waste ink counter in the printer.

I get around this and clogs on my Artisan 50 easily by simply having a separate CIS cartridge filled with windex and the other end attached to a syringe filled with windex. The cartridge is from another CIS that didn't work cause ARC chips are incompatible with the Artisan 50. I simply set the printer to ink replacement which sends the print head to the middle and I can gently press the syringe to force windex out of the clogged print head onto the overspray pad area in the middle of the printer. This not only cleans out clogs but primes the print head too so when I reinsert my CIS cartridges it goes through its normal purge routine and everything works again. Afterward I use paper towels to sop up any windex and ink from the overspray pads, surprisingly it also serves to clean the overspray pads of ink too. I think this is the one advantage cartridges on top of the print heads have. With the hose to print head types like on the Artisan 710 you've got a lot of ink in the tubes to purge before windex can clear clogs and trying to get the printhead to the middle can be tricky, maybe unplugging the printer while printing something. It's important not to just pressurize the cartridge while it is on the park pad because it'll simply force air into the other print heads because the park pad is sealed and pressurizing one print head forces air into the others, it needs to be out in the open.

Also air might get into the final chamber in the cartridge so every now and then I pull all my cartridges and reprime them. I learned about all this hassle because I let too much air get into the final chamber and it finally worked its way into the print head and several cleanings couldn't fix it. It's easy just hold the cartridges leaned back, at a level below the tanks, pull the priming vent and it'll siphon ink slowly into the cartridge. When the final chamber it full then simply put the plug in, no excess pressure to spill ink and you got rid of air that could cause problems later on.

 

[Arfer Daley]

printfan1138

thats a good tip i will give that a go this weekend my printer has a few bars missing on the nozzle check and i have never cleaned the heads from new only just joining the forum not too long ago has really helped me
alot i thank you all

 

[Shankar]

I did not print while I was on vacation for two weeks and my Epson Workforce 845 connected to a CISS was idle the whole time.
After returning from vacation, the print nozzle check showed missing bars on all 3 colors and one black.
After several head cleanings, I still have a few bars missing from my magenta nozzle check.
Black, Cyan and Yellow bands show no missing bars.
Repeated head cleaning has not unclogged magenta.
I'd like to try to use 50-50 mix of Windex and DI water to clean the print head.
Questions:
1. Can I just clean the magenta nozzle and not the other 3 nozzles?
2. Which is better - squirting the cleaning fluid into clogged nozzle or running the print head carriage over a paper towel moistened with cleaning fluid?
3. If cleaning only the underside of print head should I remove the ink cartridges or leave them in.
I apologize if my questions have already been addressed - please help me locate the answers.
Thanks in advance,
Shankar

 

[turbguy]

I did not print while I was on vacation for two weeks and my Epson Workforce 845 connected to a CISS was idle the whole time.
After returning from vacation, the print nozzle check showed missing bars on all 3 colors and one black.
After several head cleanings, I still have a few bars missing from my magenta nozzle check.
Black, Cyan and Yellow bands show no missing bars.
Repeated head cleaning has not unclogged magenta.
I'd like to try to use 50-50 mix of Windex and DI water to clean the print head.
Questions:
1. Can I just clean the magenta nozzle and not the other 3 nozzles?
2. Which is better - squirting the cleaning fluid into clogged nozzle or running the print head carriage over a paper towel moistened with cleaning fluid?
3. If cleaning only the underside of print head should I remove the ink cartridges or leave them in.
I apologize if my questions have already been addressed - please help me locate the answers.
Thanks in advance,
Shankar

There's a very good chance that you don't have "clogged" nozzles, but air-bound nozzles. You may get better results just letting the printer rest overnight (to let air dissolve into the ink) and trying a nozzle check again.

Not that clogs are not possible, just that air binding is possible, too. A very small amount of air in the piezo chamber with cause a nozzle "misfire", indistinguishable from a clog. Piezo nozzle chambers must be almost completely full of a non-compressible fluid to "spit" ink. That's not the case with thermal heads...any ink present in the minute nozzle chamber will vaporize and then "spit"...

(damn physics!)

 

[Shankar]

Thank you, turbguy, for your reply.
I followed your instructions and let the printer rest overnight. About an hour ago I ran a nozzle check and found nothing has changed - still magenta shows the SAME missing bars. I ran a head cleaning and ran another nozzle check after about 10 minutes. Still no change. I have attached a photo with hand written comments.
Another thing I have been noticing is that during nozzle check printout, (1) magenta strip appears to be slightly shifted to the right and (2) the bars in magenta band are not spaced like in other colors. See the second photo of a close up of magenta strip. I'm not sure if this is relevant to our discussion but decided to share with you.
I'm looking forward to suggestions.

 

[turbguy]

No super suggestions. The lack of a proper step-pattern (several neighboring nozzle lines are not "stepped" in several places, but are in line instead, or even step UPWARD going left to right) brings to mind electrical issues, such as a bad connection between the ribbon cable and the print head, or a build up of foreign matter on/in the nozzles themselves, or a timing strip issue, or a worn print head...but not sure...

If the pattern repeats after an overnight rest, it's probably NOT air-binding, IMO.

 

[Shankar]

Cross my fingers...
If it doesn't improve overnight, I may try nozzle cleaning over the weekend. I'm not good with electrical stuff.
Which brings me back to questions I raised in my first posting - any preferred way of cleaning?

 

[Shankar]

SUCCESS!!!
Finally last night I was able to get some time to really clean my WF845.
1. I thoroughly cleaned the parking pad and the rubber wiper with straight, Original Windex with Ammonia-D. It took me close to two dozen flushings to clean the sponges in parking pad to my satisfaction.
2. Overnight, I kept a Windex soaked paper towel under the print head. I moved the print head away from the parking pad for this step. Before retiring for the night, I grabbed the two ends of wet paper towel and gently moved it back and forth in the hope of removing any stuck on, dried ink from the bottom of print head. In the morning, I noticed that paper towel was saturated with ink. I had lowered my CISS ink tanks below the print head before retiring to avoid any possible siphoning of ink. Sure enough, I did see air in the ink tubes in the morning which I was able to remove by purging the carts.
3. I carefully wiped both sides of the mylar timing belt with a sponge tipped Q-tip.

In the morning, I removed the paper towel, turned the printer on and printed a nozzle check. No clogged nozzles in magenta, only a missing bar in black and cyan, which went away after a head cleaning.