Heated Solvent to Clear Printhead

[jc1cell]

So, this 1604 valuejet head has pretty badly clogged black nozzles. I was able to work it to a certain amount of open nozzles but it's a back and forth kind of thing. Never getting even close to half the nozzles open.

I had read somewhere that heating up solvent and running it through the head (or letting the head sit on it) would help. This morning a local tech stated that they have tried heating up water and have seen solvent flow out of the head as if strings of ink were being pulled. I'm not so sure about using the water though.

My main question is how much to heat the solvent. Stove top or Micro. What is the flash point of the solvent? Don't want to blow my eyebrows off...then again...if you've seen them you may think it's a good idea :Big Laugh.

Even if it does work, I'm still concerned about what caused the issue to begin with. Don't think it's the maintenance station since it was placed new on the first head. I'm thinking it's the ink but plan on doing some lines and sub-tank flushing in reverse to get all ink and residue out of the way. Replacing the damper and o-rings and running ink again through the head.

The heads worked for about three months when placed new and then, both times, have had the black heads clog either half way or over 80%. The rest of the colors are fine.

So, any suggestions on the heating of the solvent?

jc

 

[Turtle]

I am no expert, but my common sense tells me heating solvent sounds like a bad idea. Even if you place the container in heated up water I would exercise extreme caution. The flashpoint for my mimaki jv3 cleaning solvent is 148˚f.....

 

[Rooster]

A word of warning. If you somehow fry the head and you stick it back into the printer, there's an excellent chance that you'll blow your main board or at least a fuze that's soldered into it.

 

[artbot]

i don't like that water idea at all. what he was describing was the water coagulating the ink inside the head. any time you heat up resin (which is what the ink is made of), you will lower the viscosity of that material. if you did heat it up, do a double boiler in the open air with nothing but a bowl of hot water and another container with solvent (use stainless so it will conduct the heat to the solvent). pour the solvent onto a paper towel in the center. as the solvent walks outward, place the head onto the paper towel lightly. it will create a mild vacuum at the surface of the head. you should see ink dispersing onto the towel. in fact you will see a pattern of where the ink is coming out and also refusing to flow. remember during this you can also use a loop to look directly at the tiny holes in the bottom of the print head. you can often see the ink sitting there clogging the head at the opening.

i was once told by a tech that if one must, you can take a swab, very wet, and lightly do a delicate pivoting motion on the head. no wiping, etc. i've done this before with no damage. but just be surgically delicate.

also, get some buytl carbitol. it has a very very light solvent property compared to butyl cellosolve which has none (both are components of your cleaning solution). but the carbitol takes foreeeeever to evaporate. you could jet 4:1 of that with some acetone and it would bite the ink, and also stay wet and continue to bite.

i have puddle of some white ink that i was modifying the other day and it's just as wet as it was the minute i poured it out. zero evaporation.

hope that helps.

 

[FatCat]

Fieldcenter sells a head washer which I believe heats the solvent and then pushes it through the head. $2500 and it's all yours...

http://www.youtube.com/watch?v=RTPUBTv-RRQ

 

[Jack Knight1979]

I've injected heated flush through my heads with pretty good success.

I had a head that was gone and as a final attempt ran acetone through it.
The tone didn't agree with the ink. Everything coagulated and the inside of the head went to gel.

I ended up buying a cheap stainless jewelry cleaner on amazon.com
An ultrasonic deal.

The vibrations heat up the solvent pretty well. Inject and clean.

 

[jc1cell]

Hey thanks guys for your replies.

I'm pretty much set on doing it and appreciate all the responses I have received. I agree with you artbot on the water bit. The tech said he has had success with it but I simply don't think printheads and water mesh well.

I did speak with flieldcenter, fat cat, and he stated that the dx4 and dx5 are the hardest to clean since they don't accept the vibrations too well and the heated flush has to be very, very slow.

I'm going to attempt artbots suggestion and follow up with yours Jack Knight. I'll keep you posted on the results.

jc

 

[FatCat]

I did speak with flieldcenter, fat cat, and he stated that the dx4 and dx5 are the hardest to clean since they don't accept the vibrations too well and the heated flush has to be very, very slow.
jc

Thank you, thats good to know.

*Curious, what ink were you using before the clogging problem occured?

 

[jc1cell]

*Curious, what ink were you using before the clogging problem occured?

We're on 3rd Party Ink. Our third set and all Graphics One ink (I imagine re-branded). OEM was good but we immediately changed. The first set of 3rd Party was causing issues with the capping station not sealing. The second set was good but required a lot of maintenance since it would clog the pump lines with dried ink fairly quickly. That was the XG brand.

This set is the XG2 (second power). We had great success when we switched. After a couple of months the black nozzles were showing only the bottom of each square on the test. Then the head fuse blew on the board. We changed heads and the fuse and all was good again until a couple of months after. This time 75% of the nozzles for the black were gone. It only showed random lines on each box.

I'm doing as much maintenance and troubleshooting as I can before blaming the ink since many factors can cause the head to dry. My next step is going through the process of heated solvent to try and clear the head. Once I can see a nice spray coming out I will clean the black ink lines and the black sub tank in an effort to remove any residue that may be clogging the lines and the damper. I will also change the dampers and the o-rings that seal the connection. I'm not sure it's either of those because I can pull ink quite easily from the dampers, it just doesn't flow through the head.

From there to new printhead and further troubleshooting if it continues.

jc

 

[FatCat]

This is one of the reasons I'm leery about switching to 3rd party inks. It seems so many are actually light-solvent and not eco-solvent, or the pigment particles are larger than OEM which leads to clogging.

You might want to give Francis a call (aka; Fieldcenter) as he offers a bulk ink solution. Seem to be several using it or the J-Star brand bulk system with little or no problems. I have been thinking about giving it a try, but I'm just too worried about the possibility of down-time, fixing parts, replacing expnsive heads, etc. where the OEM ink works flawlessly.

http://www.youtube.com/watch?v=prWX9jMdaUg&feature=related

 

[jc1cell]

That looks like the one we're using right now quite successfully as well. The second 3rd party was actually very good printing...the drain lines maintenance wasn't a major issue, just bothersome.

This most recent ink is great if I can pinpoint the problem to a physical issue rather than an ink issue. All the other colors are running smoothly.

What you say is true about third party inks but in my experience, after some time, the printer consumables (and not so consumables) start to show wear and can cause these symptoms regardless of the ink you have. So it's a matter of regular maintenance on the printer IMHO.

Not trying to start another OEM vs 3rd Party thread here though. Quite honestly, if OEM offered bulk systems (cartridge free) for these printers I would not have even thought twice about staying with them. There's just too much freedom with the bulk ink system.

jc

 

[jc1cell]

Do you guys think this part could be having problems?

http://www.cmykparts.com/DX5 MANIFOLD.html

Is this even something I should be messing with?

jc

 

[artbot]

when a head adapter is clogged, you will usually see a halo of missing ink near the middle of the test pattern. there is a circular screen (much higher mesh than found in the damper). if you have very sporadic printing drop out all over the length of the print head, it's most likely not a head adapter.