Get Ink Out Of Air lines: CET Color Flatbed Printer

[phillipcc210]

Quick question.
How do I Get Ink Out Of Air lines from my CET Color Flatbed Printer, and what needs to be replaced?

 

[artbot]

generally lines from the secondary to the head can introduce air into the lines. are you getting air in all of them? or just one head keeps giving you issues? is there a thin layer of ink pooling at the bottom of any of the heads?

 

[phillipcc210]

No Pooling.

generally lines from the secondary to the head can introduce air into the lines. are you getting air in all of them? or just one head keeps giving you issues? is there a thin layer of ink pooling at the bottom of any of the heads?

 

[phillipcc210]

Yet!

Yet!

View attachment 99963

 

[artbot]

i'm not at all a guru with flatbed printers. i have one right now, had a CET fk512 previously. that's the disclaimer in case i am completely wrong here.

this photo looks like ink pumps and negative air pump parts. air does not get into your lines at these points. the secondary tank has an air space at the top of it that has a mild/adjustable negative air pressure inside of it. this reduces the weight of the ink coming down the lines. which without it would just drip out under its own weight. these tanks also act as a damper of sorts (as on an epson solvent printer) to catch air and keep it away from the heads.

so air getting in the heads happens after the secondary tanks. do you have the little clasps on the unions from fittings to lines? i've seen those quickly get rid of a tiny leak that is pulling air into the lines.

 

[phillipcc210]

Thanks for your support

Thanks for your support

 

[Nameci]

Ink would get into the air lines if there is excessive negative pressure on the system. Check your system, the ink overflow tank should be able to hold the ink. Do you happen to turn your machine off at night or on the weekends? If the machine is turned off, the battery powers on the negative pressure system but there is no way it would be cut if the ink goes into the ink overflow tank.My suggestion is if the machine is needed to be turned off, then unplugged the negative pressure pump, otherwise leave the printer turned on always.

 

[MrNick86]

So, could the negative pressure system have play in why I drop out with high ink demands, in particular magenta? Yesterday, as well as the last time I ran this job, I drop out about every 12 inches of rich red on a full 96 inch sheet. I jacked the negative pressure way up to 4.5 and it made it about 24 inches. That was with a 3 extract. I have struggled with figuring out why the FK512x drops out all the time.

Please help...

If you look into some of my previous posts, I have modified the negative pressure manifold to have high quality metal piston valves, I have capped one of the two inlet/outlets that go into the heads from the secondary's, eliminating the bleed tubes. I have also replaced all of the crappy plastic tube fittings with stainless ones and Teflon taped anything that could be taped. I basically have done everything possible to eliminate air from entering the system, it is completely sealed. I have had a fairly stable system until I have high ink demand. It is almost like the ink cannot keep a steady flow to the heads, especially quickly enough.

A couple other observations I have made are that I notice the negative pressure slowly increases throughout the day, even when I come in the morning and fire it up, it will be higher then I left it. Also, when I open a valve on the manifold and attempt to manually purge, the pressure cannot push ink through the heads unless I drop the negative pressure to the point where it would drop anyways. That pump has been replaced, no difference. Many parts and filters have all been replaced and I have seen zero improvement with these faults.

Ideas???