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Author Topic: Ink Clogging ?  (Read 13539 times)

davidh202

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Ink Clogging ?
« on: December 14, 2010, 09:20:46 pm »

While fairly experienced with photography, I am quite new to inkjet printing aside from the basic Inkjet office printer I use for forms.
There seems to be a lot of complaints about Epsons clogging problems, and since I now have a 7900 I keep my fingers crossed I won't have issues with my wonderful printer.
Are clogs due to a single issue such as  Ink drying on the head, poor consistancy of the manufactuerd ink,environmental dirt accumulating on the head over time(eg: paper residue),or a combination of all the preceeding issues?
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Ernst Dinkla

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Re: Ink Clogging ?
« Reply #1 on: December 15, 2010, 03:14:59 am »

In the 10 years I have worked with wide formats and followed the discussions there never was a moment that I thought we know what goes wrong in an inkjet head that causes clogging. Humidity, capping station neatness, air trapped, pigment settling, dampers blocked, dirty paper, etc etc. All solved and still clogging can happen.

That said the general experience is that Canons and HPs have less problems with clogging. My gut feeling is that we underestimated steam power as the driving force of ink droplets. I am curious about the pumping capacity of both technologies for comparable heads. Another reason must be the removal of droplet size variation per nozzle and substituting that by more nozzles per head while still keeping heads cheaper than possible with piëzo heads of the same capacity.


met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
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Peter McLennan

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Re: Ink Clogging ?
« Reply #2 on: December 15, 2010, 12:09:02 pm »

My gut feeling is that we underestimated steam power as the driving force of ink droplets.

Very interesting observation.   What I'm reading is that the Canon/HP bubblejet system uses heat to eject droplets, the piezo system that Epson uses doesn't.  The steam generated by this heating keeps the heads clean.  Correct, Enrst?
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deanwork

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Re: Ink Clogging ?
« Reply #3 on: December 15, 2010, 07:29:07 pm »

Ernst,

Didn't the 10K Epson's heat up the ink when the heads were charged in a related way to thermal printers? I know an Epson tech told me that years ago. I always wondered why in 8 years of use of that big printer I didn't and still don't have clogs in it and all my other Epsons did.

john
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Ernst Dinkla

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Re: Ink Clogging ?
« Reply #4 on: December 16, 2010, 03:46:56 am »

The steam generated by this heating keeps the heads clean.  Correct, Enrst?

That wasn't what I had in mind. There has been a time that thermal heads were not considered a pro solution for the wide formats we used for art prints and photography. For water based ink systems that has proven to be a wrong assumption. And yes steam power is a formidable force to squirt small ink droplets, not behind piëzo heads at similar frequencies and droplet sizes. It could take more energy to run than a piëzo head but at the total of energy consumption it probably isn't a significant difference.

Actually one of the problems with thermal heads can be the building up of ink on the thermal element in the nozzle construction. Chemistry of the ink has to counteract that. The main advantage of thermal heads is the simple construction of the thermal pump/nozzle and the lower price that goes with it. Where there have been versions that were more complicated to create variable droplet sizes that idea has been abandoned in the models we discuss here. Higher quantities of smaller, simpler nozzles/chambers creating fixed droplets of 3.5, 4 or 6 picoliter in a dense formation on the heads is the better solution. Keeping nozzles in reserve for the ones that fail isn't a cheap trick but a sound solution only possible when you can create high nozzle numbers on a relatively cheap head. The two heads that failed on my Z models didn't show a degradation period though, at least not in the prints and in the printer utility reports, they went belly up in an instant, one with a paper jam that I discovered too late.

In the sign industry it is not uncommon to heat the ink that has to be squirted by piëzo heads, the viscosity of the ink at room temperature not suitable enough to get pumped. There are advantages in the sense of faster "drying", less dotgain, better bond, lower quantities of solvents to use etc. "Drying" can be evaporation of solvents, UV curing, returning to a solid state (wax, resin) or a mix of that (Latex). The idea that piëzo heads run cool is a myth too, at the frequencies they have to run now and with smaller droplets than in the past the cooling effect of pumped ink isn't enough. Whether the Epson 10000 had any extra heating on the ink I don't know.

I have seen some comments that the more complex and larger piëzo pumps tend to trap air more than the smaller simple thermal heads. The inks used in thermal heads are a bit more fluid too if compared to the piëzo types. At least that observation was made on HP Z monochrome inks that were used in Epson piëzo quad systems.


met vriendelijke groeten, Ernst Dinkla

New: Spectral plots of +180 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm

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VitOne

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Re: Ink Clogging ?
« Reply #5 on: December 16, 2010, 05:15:26 am »

I am not an expert but I had many printers and I will try to give you some suggestions.

Now I have an Epson R2400, an Epson 4880 and now also an Epson 7900 in one room. I had clogs with all my printers (except for the 7900, but it is a "new entry"), but now I have less to no problems. I never had clogging issues while printing. I could do a cleaning before the prints session (I always start with a nozzle check) but I never ruined a print because of clogging issues if the print was “clean and checked” before the beginning of the print session.

What I do to improve "anti-clogging" is this:

1) Use dust-covers (not necessarily the antistatic ones, also if they do a great job).
2) Check and control the humidity in the room. I had this possibility in the last moths and I can say that, since I started to have 50% humidity in the room, I got no more clogs in the R2400 and in the 4880, also after 2 weeks of not using the 4880 at all.
3) Try to print at least 2/3 prints each week and possibly, when you print, try to print as much as you can. I found that could be better to print twice a week 10 prints for session that 2 prints each day.

I would say that, if you are using OEM inks and good paper, in the 7900 there will be no clogging issues related to them. In the 4880 the paper cutter is slower and makes some "dust", but in the 7900 I could notice no small dots of dust or pieces of paper when I cut the sheets. I really don't know why the printer clogs but, in my experience, I think that the problem is 20% dust and 50% humidity and 30% not-working time between print sessions.
A close friend with an ipf5100 was happy about his printer clogging performance but he had to change print heads after 2 years of usage (he really used the printer for a few prints, 3 set of carts in more than 2 years). Here in Roma, Italy, I go sometimes around for print laboratories and what I could understand (probabily it is wrong, but is my experience) is that Canon are great printers, but if you think that they don't clog "for free" I could be not true. When the Epsons clog the Canons will start to partially kill the print head (usually for low humidity environments) and so what you waste in terms of Epson ink ($$$) is generally wasted for Canon print heads ($$$). Nobody seems to use other brands, so I have nothing to say about HPs or other printers.

You already have an Epson 7900, I think one of the best printers now, try to keep humidity high (if possibile) and to keep dust away from the printer.
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teddillard

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Re: Ink Clogging ?
« Reply #6 on: December 16, 2010, 09:51:58 am »

One of the most basic causes of clogging is turning the printers off, from my experience.  Leaving the printer on makes a significant difference in reducing clogging - I've seen it proven out on countless printers.  That, in spite of what Epson tech support told one of my clients - to do just the opposite, and turn the printer off when not in use.  :D  
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Ted Dillard

Doombrain

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Re: Ink Clogging ?
« Reply #7 on: December 16, 2010, 10:49:53 am »

Ernst,

Didn't the 10K Epson's heat up the ink when the heads were charged in a related way to thermal printers? I know an Epson tech told me that years ago. I always wondered why in 8 years of use of that big printer I didn't and still don't have clogs in it and all my other Epsons did.

john

no, all epson heads have a temp sensor to monitor the room/head temp so it can adjust droplet demand to compensate for humidity etc.
also there is a slight warming of the crystals which the ink cools.

it's a shame all the people, the thousands and thousands of people that don't have issues with their printers don't take the time to post on here.....
« Last Edit: December 16, 2010, 10:53:01 am by Doombrain »
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Randy Carone

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Re: Ink Clogging ?
« Reply #8 on: December 16, 2010, 10:54:47 am »

"it's a shame all the people, the thousands and thousands of people that don't have issues with their printers don't take the time to post on here..."

+1 for that comment. It's like root canal. Mine were painless and problem free, but we only hear about the 2-3% of root canals that were very painful.  ::)
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Randy Carone

Eric Myrvaagnes

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Re: Ink Clogging ?
« Reply #9 on: December 16, 2010, 11:35:38 am »

it's a shame all the people, the thousands and thousands of people that don't have issues with their printers don't take the time to post on here.....
I'm one of those, so I'll chime in here, although I don't do a vast amount of printing.

I got an Epson 2200 when they first came out and finally sold it about a year and a half ago when I bought a 3800. The only time I had a significant clog with the 2200 was after a six-week trip to Italy, with the printer off the entire time. It took a few cleaning cycles, with an overnight between a couple of them, before it started printing clean again. Other times I went almost a month between prints and only a couple of times did I need to do a cleaning cycle.

Since I got my 3800 I have not had a single clog, whether printing intermittently or regularly, summer or winter.

One thing that I am certain helps me is that I have whole-house hot air heating and air conditioning and humidification. In my printer room the humidity virtually never gets below 40% or above 50% and the temperature ranges from 65F to 72F (18 to 22 Celsius). The air is constantly filtered, too.

I have never covered either printer, but I am going to start doing that, too, after reading this thread.

So I suspect that most Epsons will behave nicely if given a good, steady environment, with controlled humidity and temperature.

Cheers,

Eric
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Peter McLennan

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Re: Ink Clogging ?
« Reply #10 on: December 16, 2010, 12:38:53 pm »

Perhaps it's the lowered humidity of winter, but my Epson 4800 clogging problems are driving me crazy recently.  A "Power Clean" a few days ago cleared things up nicely, but now, three prints later, I have problems again.

My (admittedly cheap and probably inaccurate) relative humidity meter indicates about 40% RH.  I've just rigged a towel and a bucket of water in the printer room to see if I can raise the RH and evaluate its effects.

What is incredibly annoying is the printer's response to an "auto" head cleaning.  On successive cleanings, whole channels can reappear or drop out completely, seemingly at random.  Can anyone explain what's happening here?  How can an ink channel disappear or get worse with a head cleaning?

 >:( >:( >:( >:(
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Sven W

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Re: Ink Clogging ?
« Reply #11 on: December 16, 2010, 12:43:05 pm »


What is incredibly annoying is the printer's response to an "auto" head cleaning.  On successive cleanings, whole channels can reappear or drop out completely, seemingly at random.  Can anyone explain what's happening here?  How can an ink channel disappear or get worse with a head cleaning?

 >:( >:( >:( >:(


Sounds like your capping station isn't air-tight enough.
/Sven
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teddillard

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Re: Ink Clogging ?
« Reply #12 on: December 16, 2010, 12:47:31 pm »

Humidity is definitely an issue, I've seen a number of installs where either the air conditioning in the summer or the heating in the winter required the addition of a humidifier to help with clogging issues.  Again, leave the printer on, too.  

A nozzle dropping out after a cleaning suggests there's something going on with the cartridges, which may also be what's causing what looks like clogging issues.  I've seen cartridges dry out, and air get introduced into the lines... in some cases when nothing else worked, we switched out new cartridges (yes, a pricey gamble) and it fixed the problem right away.  If your cartridges are fairly new and have not suffered abuse, the next thing I'd ask is about temperature.  Is it staying at a relatively normal room temperature throughout the day, or is the temp. varying a lot?  

I was trying to calibrate a display for a guy up here in Boston a while ago- got there first thing in the morning and the studio was down around 50º.  Had to essplain to him about LCDs (and fingers) warming up...  :D

...not sure what a "capping station" is.   ???
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Ted Dillard

Eric Myrvaagnes

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Re: Ink Clogging ?
« Reply #13 on: December 16, 2010, 03:08:28 pm »

I wonder if it could be a similar situation people have with plaque buildup in our arteries.?
I think rather than worrying about adding additional colors to the gamut, more emphasis should be spent by the manufacturers on addressing the more serious problem of clogging!!

Aha! Epson should mix a little Lipitor into each ink cartridge (and cut down on the trans fats).  ;D
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Ernst Dinkla

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Re: Ink Clogging ?
« Reply #14 on: December 16, 2010, 04:22:24 pm »


it's a shame all the people, the thousands and thousands of people that don't have issues with their printers don't take the time to post on here.....


Yes, though they probably can't help either in analysing what keeps their printers squirting without issues. It usually are drivers that get an accident with a car that causes a recall on thousands of the same model, not the thousands that get home safely driving the same car.


met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/


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Sven W

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Re: Ink Clogging ?
« Reply #15 on: December 16, 2010, 04:47:21 pm »



...not sure what a "capping station" is.   ???

The capping station is where the printhead rests when not in action. And it must be 100% airtight, otherwise you can
get air in the ink chambers and a common result from that is suddenly dropped channels/colors. Here in EU there was
a programme under warranty that replaced the capping station on 4800.

/Sven
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Farmer

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Re: Ink Clogging ?
« Reply #16 on: December 16, 2010, 05:02:58 pm »

It could be the cap assembly, but I'd consider the wiper blade first.  It may just be getting very dirty and so it's not cleaning the head correctly.

Like any sort of industrial or professional equipment, having it serviced/cleaned periodically is a good idea.
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Phil Brown

John Hollenberg

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Re: Ink Clogging ?
« Reply #17 on: December 16, 2010, 10:59:35 pm »

Quote
it's a shame all the people, the thousands and thousands of people that don't have issues with their printers don't take the time to post on here.....

While that may be true, every Epson printer I have owned (2200, 2400, 9600) had varying degrees of clogging problems.  The 9600 was totally unusable, in spite of multiple service calls by Epson.  A friend who has a 2400 has periodic clogging as well.  In contrast, my Canon printers have never produced a flawed print due to clogging, since any clogged nozzles are remapped to good nozzles in the printhead.  I don't even bother doing a nozzle check on the Canon printers.
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bill t.

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Re: Ink Clogging ?
« Reply #18 on: December 16, 2010, 11:26:21 pm »

What is incredibly annoying is the printer's response to an "auto" head cleaning.  On successive cleanings, whole channels can reappear or drop out completely, seemingly at random.  Can anyone explain what's happening here?  How can an ink channel disappear or get worse with a head cleaning?

On my 9880 the effect where clogs seem to walk around from nozzle to nozzle means you've got some sort of contamination like dirt, or one of Fluffy's hairs, or cloth fibers, canvas fibers, or media dust, or something like that fouling the heads and the cleaning mechanism.  It's not actually clogged nozzles which I think are relatively rare.  The nozzles are blocked by something sitting on top of them.

Subsequent cleaning cycles just move the crud around to a different position, without being able to remove it.  When I see that happen on two subsequent auto cleaning cycles I give the heads the lintless-paper-towel soaked with water or Windex treatment, and I also very gently wipe the squeegee and the two docking station landing zones with my immaculately clean fingers.

Usually two more cleaning cycles brings everything is back to glowing health, and I'm good to go for 2 or 3 more rolls of canvas.  Usually.  If the new 8300 ever does that, I'm going to shoot it.
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Peter McLennan

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Re: Ink Clogging ?
« Reply #19 on: December 17, 2010, 02:21:26 pm »

Thanks, Bill.  I'll try the Windex and paper towel procedure.  But first:

The relative humidity in my printer room is 40%.  In an effort to raise the RH, I've installed a small plastic tray containing a water-soaked cloth inside the Epson 4800, raised the lid slightly to prevent inadvertent printing and enclosed the whole assembly with a plastic sheet to contain whatever moisture evaporates. I'll report results.
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