Overspray on HP9000

[dbot]

Hi Everyone.

im busy printing high quality paper posters. I usually print these on 16pass. I am however now getting an over spray on colors. Mainly Magenta and Cyan.

Im really unhappy with the print quality. Does anyone have any suggesting why it is doing this?

Also if you look closely on the fisrt pass of each colour you see tiny vertical lines. Im not sure if this is a diffusion technique or the way it prints 16 pass.

BTW im running Flexi 10 Pro.

 

[4R Graphics]

Post a pic it would really help.

As for overspray on my JV3 it usually means a nozzle or nozzles are deflecting sometimes a good cleaning will fix it. Also it can sometimes be that something has shifted and the alignment is off but this is usually shown as over spray to one direction only. Magenta and cyan always standout quickly when they are off (out of alignment or deflected nozzles).

 

[dbot]

Hi

here with the pic.

It prints without overspray for the first 1/2mt and then the overspray starts. Where you see it very bad on the black was just after i paused the machine for 1min. it was over-spraying a bit then i thought let me pause and see what happens. it then got even worse. then i paused it again for a bit longer then the over-spray improved a bit.

It also starts loosing nozzles on various colours. Magenta and Cyan mainly.

We have done the following to the machine so far.
Replaced Capping Stations
Replaced Wiper Blade and Wiper Sponge Assembly
Replaced 1 x Primer Pump for magenta
Replaced Dampers on all colours.
We havent replaced any o rings though.
Made sure head height is low
Droped down side guards to their lowest.
Left it in wash Print head mode overnight
Done a head clean with the pad overnight.

we feel we are so close to getting this right as it prints perfectly for as much as 1-2 mts and then it starts to go. We are just trying everything possible under the sun before we replace heads. it just doesnt make sense that its a head because when you do an iq test or nozzle check all nozzles are in.

Machine has only printed 5000mts.

 

[sowinski_t]

It's possible the problem is static charge. I would try to increase the humidity in your print area to at least 50% and ideally about 60-70%. This should bring down the static a lot and maybe fix (or improve) the situtation.

 

[HulkSmash]

static, or you have some fuzz stuck on your heads.

 

[Aqua5]

To me that looks like you have some dust/dirt/debris on your printheads. I'd do a soak for no less than 4 hours and see if that doesn't remove the debris.

 

[sfd2122]

Soak them overnight for at least 8 hours with the printhead cleaning pads and the wiper solution. Then in the morning run a strong printhead recovery on them and try another test print.

 

[Quix]

I used to have one 9000, and this overspray could be:
1- The ink you are using is too dense or expired. Maybe it's very sensitive to temperature changes
2- Te environmental temperature is low. I was using toyo inks which only printed great above 24°C in the room.
3- Check the input voltage: Some technicnians recommend to raise the PH Voltage, and this helps a lot; but you should check FIRST that the voltage the printer is receiving is not low. If this happens, the voltage in all printheads is also low (even though it's filtered in many regulators inside the machine). You should notice more overspray in the heavier inks, such as black.
I had endless problems with this overspray. I did all of the above, getting slight imporvements. Only when I installed the printer to 220V with a BIG regulator I saw significant changes.
I hope this helps