HP Scitex FB500 - clogged nozzles

[FrankW]

Because of a repair which have taken a few days because of haven't found the problem immediately and time for delivery of spare parts, a FB500 of one of my customers haven't cleaned correctly during some days. Nearly every nozzle was clogged, but while the CMYK-Nozzles are working fine again after a little work, the white nozzles (Lc- and Lm-heads) seems to be permanently clogged.

Are there any ideas of cleaning that heads successfully even if the inks have dryed in the nozzles?

Thank you very much.

 

[ColoPrinthead]

That sounds horrible, and the waiting on parts all too familiar. You might try soaking the heads with flush over night.

 

[Jayefkay531]

This may be a stupid question - but has he tried a performance purge and several recovery jet patterns (the big black bar print)? I had a few clogged nozzles and after a few printhead cleanings, purges, and recover jet patterns, I had most restored to good use. Then mapped the jets for replacement and it looks good now. If he's tried this, I would complain with HP that the service technicians didn't properly prepare for extended downtime of the printheads

 

[johnnysigns]

This using OEM inks?

 

[LarryB]

Whenever I have had clogged heads I did a head soak by cutting a piece of coroplast and put the wipes on it soaked with flush. Tape the coroplast underneath to the heads. Let it soak for a couple hours. This has worked for me.

 

[FrankW]

Thanks for the answers.

It wasn't possible to prepare the print heads for the

 

[FrankW]

Thank you for the replies. Yes, a Performance Purge was done several times, thats why the CMYK-Heads are working good until now. And they are using original inks.

Good idea to put something soaked with flush below the print heads. I know that from filling cap tops with flush on Rolands and Mutohs, but this machine haven't caps.

 

[bottomsignco]

Whenever I have had clogged heads I did a head soak by cutting a piece of coroplast and put the wipes on it soaked with flush. Tape the coroplast underneath to the heads. Let it soak for a couple hours. This has worked for me.

Hi, hopefully someone can still help with this. Did you have any issues with the ink not sticking to substrate after using this method? We have done multiple purges after and still the ink is cracking and has no adhesion or cure to it. Good news is the black definitely looks better than it did before. Any help is greatly appreciated.

 

[johnny kelly]

Because of a repair which have taken a few days because of haven't found the problem immediately and time for delivery of spare parts, a FB500 of one of my customers haven't cleaned correctly during some days. Nearly every nozzle was clogged, but while the CMYK-Nozzles are working fine again after a little work, the white nozzles (Lc- and Lm-heads) seems to be permanently clogged.

Are there any ideas of cleaning that heads successfully even if the inks have dryed in the nozzles?

Thank you very much.

I am really late on this. But I am seeing it now and maybe offer some help to someone in the future.
I had the same issue and here is what I did. Ultrasonic cleaner, fill the bottom with flush. Hang the head to just below the surface, MAKE SURE THE SIDE OF THE HEAD IS TOUCHING THE SIDE OF THE CLEANER. THIS IS KEY.) Keep a firm hold on the ribbon and make sure the head does not go past the black plastic. Run for 10 or 15 minutes. GENTLY squeeze flush into each side. take it and lay it on its side and let is sit over night. you can even put flush on the face of the print head. Do the same thing the next day. put it in the machine and fill. Run a print bar test. if it didnt work, do it again. Its worth it.

 

[netsol]

Frank, is the FB500 chemistry something that would respond well to being "whacked" with 5%-10% acetone??
or MEK?

of course you would need to flush the acetone out of the system, completely

 

[netsol]

do you have access to a printhead doctor?
we have a chinese knockoff,

 

[netsol]

didn't realize how old a post this was