Fading Ink (VJ 1204)

[Biker Scout]

Test squares are printing pretty light, then go down to almost nothing.

Looking for possible causes, fixes, workarounds.

Printer has brand new print head. Printed on it for about 20 - 25 days after installed. Then a project that wasn't printer related kept us occupied for a little less than a week. (Maybe 4 days) Went back to printing, and we basically got nothing.

Cleanings and power flushes only get us to about 65% solid coverage with banding still. Then they eventually go back to fading out.

What am I over looking? The dampers are a year old, but aren't leaking. I've got some new ones on the way. Would they actually be the cause of the lack of flow?

(The blob in the picture is from me massaging the dampers)

 

[Compilla]

What does the nozzle check look like ?

 

[Biker Scout]

Practically non-existent at this point.

However, if I do a vacuum draw directly off the head, I can get a pretty decent nozzle check. But then it goes back to printing lighter and lighter.

 

[MachServTech]

What does the nozzle check look like ?

its kinda pretty like clowns at the circus....little tiny blocks of color....yay!

 

[MachServTech]

Check to see if the ink lines have air in them. If it is depriming from the damper backward check the dampers.

 

[SE SignSupply]

I say clogged damper filters (unlikely if OEM Epson ink has been in use) or bad damper o-rings.

 

[Biker Scout]

Here's my set-up I came up with for unclogging the print head. This doesn't put extra strain on the printer's pump, as well as reducing ink amounts on the chips. Every time you run a cleaning cycle, it ticks off "X" Amount of ml's of ink that should have passed during cleaning cycle... even if the actual ink amount is less than that because of a clog.

Plus, the peristatic pump can't draw as nearly as hard as my 2 stage. I created the little capping station on the CNC Router, and then with the print head off, I cast a mold and poured silicone around the head to create a perfect fit and tight seal everytime. And it's real silicone, not kitchen and bath stuff. You have to mix it from 2 parts, and it's a platinum cure so it's solvent resistant.

 

[Biker Scout]

What's a damper filter? How can I check a damper? Ink seems to flow out of them when I squeeze or use a syringe.

 

[SE SignSupply]

What's a damper filter? How can I check a damper? Ink seems to flow out of them when I squeeze or use a syringe.

In each damper there is a micro filter, if you look closely it will be round and about a 1/4" in diameter.

I have always been told never to squeeze a damper, not sure why?

Personally, I think you have an ink delivery problem. We have not seen ANY bad printheads on the VJ series of printers.

 

[Biker Scout]

The printer was printing fabulously just a few days ago. Took a short break, and now nothing! This obviously isn't normal, so something is a miss.

How could all the 8 dampers have gone bad?

Is there any recommended way of temporarily flushing the damper, until my new ones arrive?

 

[luggnut]

don't squeeze the dampers .. that membrane helps to keep the lines primed to only flow one way. sounds like you don't have a seal and vacum created... could be the orings are not sealing to kept the vacum or could be the lines have air. i had a similar problem and had to disconnect the lines from the dampers and pull ink with the syringe thru the supply lines one at a time then reconnect and pull ink through the capping station to finally get ink fully in the lines with no air. by the time i did all this the heads had clooged and i had to soak them... all in all a few day nightmare learning experience!!!

 

[Biker Scout]

OK, thank you. I'll try that.

 

[randya]

Another thing to check is to make the nozzles drop out (by printing) and then stop the printer (lift cover, do not let the head go back to the cap station) and look at the bottom of the head.

Make sure the bottom of the head is clean and clear.

There are various methods that nozzles drop out.
One is lack of ink, i.e. clogged dampers, air in line, air leaks
Another is ink pooling on the bottom of the head and preventing ink from dropping.

Ink on the bottom of the head can be too much pressure (like a bulk ink set set too high)/(air leaks) or a head that is not firing properly.

Dampers are fairly delicate, and allow a certain amount of degassing, and there is a filter inside each one. If you damage the membrane it can leak ink out or just air in.

 

[Grafix USA]

I had a similar issue when letting it sit too long during a trip. A little eco solvent cleaner (purchased from SignWarehouse) and letting it sit on the pad with solvent cleaner for about 20 minutes and then ran the cleaning process and started printing perfectly.

 

[Biker Scout]

OK, update... no new news.

8 New dampers, no air in the lines. Prints only what looks like about a 50% solid and then fades all the way to nothing after running print after print.

Now what?

 

[SE SignSupply]

OEM Ink?

 

[Biker Scout]

Yes. Even flushed the lines with cleaning solution twice.

 

[SE SignSupply]

So a nozzle check before you start printing yields good results.

If you cancel a job once the printer starts to fade colors, what does this nozzle check look like?

 

[Biker Scout]

missing and faded

 

[SE SignSupply]

It still seems you have an ink delivery problem of some kind. In general, printheads either work, or they don't. Your problem seems more related to how the ink is being delivered to the head.

Have you pulled ink through the head and capping station using a syringe? This is a great way to find an air leak because you can actually hear the air leaking.

When you replaced the printhead did it come with the upper manifold attached (the part the dampers plug into)?

Also, your ink cartridges are plenty full?

Ryan