Fuji Acuity Banding Issue

[dethsky]

Hello,

Im new to the world of flatbed printing i have been doing it for about 3 months and i have been learning alot. There is one issue i cant seem to tackle on the Fuji Acuity Advance HSX2. I have been having alot of problems with the print doing what everyone here refers to as banding. about everyone inch there is a dark band in the print, it looks like the printer is overlapping which is making the quality of the print look bad. Im getting good nozzle checks and im keeping the machine clean. I have humidifiers going and there is no static in the substrate. The substrate in the picture is magnet material any help would be greatly appreciated.

 

[artbot]

run it in unidirectional.

see if you can isolate it by trying a few things. uv printers can produce a thing called "cure banding". where in printing bidirectional the printer will dose the ink stronger going left vs right. print a test swatch in unidirectional mode to see if it goes away. if it does then you will want to look at the shutters and make sure they are opening and closing fully and on time. also try different lamp exposure settings to see if this changes the print quality.

if nothing changes when running these tests, then you will move to the next possibility.

 

[StarSign]

Could also be a lamp issue

 

[P Wagner]

run it in unidirectional.

see if you can isolate it by trying a few things. uv printers can produce a thing called "cure banding". where in printing bidirectional the printer will dose the ink stronger going left vs right. print a test swatch in unidirectional mode to see if it goes away. if it does then you will want to look at the shutters and make sure they are opening and closing fully and on time. also try different lamp exposure settings to see if this changes the print quality.

if nothing changes when running these tests, then you will move to the next possibility.

Agreed. This appears to be what i would term 'Chromatic Banding'. It is caused by the inverting of the order of ink application in bi-directional printing. It is often referred to as lawnmower banding, and UV Curing inks can be prone to this. Running the machine in uni-directional mode will diagnose if this is what is happening in this case.

 

[dethsky]

Ok I will try some testing this morning and let you all know if im successful in getting rid of the banding.
Thank you all for your input much appreciated.

 

[dethsky]

Well the results are in. Printing in Uni-Directional Mode helped out quite a bit, I printed the same image multiple times in Uni-mode with all the different lamp settings and they all turned out to be similar. I also changed the lamp settings in Bi-mode as well and it was still having the banding issue. So Uni-Directional mode is certainly the best way to go to help me with this situation. ArtBot you had said something about the shutters, I looked through my settings on the printer and I dont see any where that I can change a setting for them, if there even is a setting that can be changed. Any addition information you have about them would be great! Thanks.

 

[artbot]

on most (maybe every) uv printer there are options to cure directly behind the head or on the way back after the ink has wetted out for a bit. there should be a utility that shows some sort of lamp curing order.

sticky lamps will give off an odd rhythm. one direction will sound different than the other and you might see that there seems to be a bit different light spread on the substrate.

the option isn't to switch to uni mode unless that's a way for the printer to limp until you solve the banding. as one response in this thread states, one lamp may also be older than the other and not curing as rapidly. this would cause banding as well in that the one direction would have higher dot gain than the other.

go through any motor calibrations that you've got as well. you need to make sure that the gantry is stepping perfectly with the print data.

 

[tgrinds]

Issue could also be profile related, media related and/or bi-directional alignments out along with artbot's lamp suggestion. This is common to UV printers, but also can be easily resolved.

 

[dethsky]

Alright, I figured out the problem. My K3 package print head was out of alignment. Which is pretty upsetting because about 3 weeks ago there was a tech out to service my machine for a misaligned black print head.... So after trying everything else first I decided to check the alignment and sure enough it was out of whack. Luckily I watched him when he did the servicing and picked it all up. So needless to say what a ****ty tech. Thanks a bunch for the responses I hope this thread helps someone else.

 

[Bimo]

hello everyone, i just got a fuji acuity advance hs 3545, and currently having this banding issue , can anyone tell me how to align the print head? do I have to replace the head or can i just uninstall and re-install the head. any suggestion will be highly appreciated.

 

[AlsEU]

hello everyone, i just got a fuji acuity advance hs 3545, and currently having this banding issue , can anyone tell me how to align the print head? do I have to replace the head or can i just uninstall and re-install the head. any suggestion will be highly appreciated.

Unfortunately replacement of the heads in HS version is the most tricky of any Advance printers. Sometimes it's necessary to use some small parts called 'shims' to get the proper position of the head, so it's not as easy as in other machines from the Advance range. And without the service key you won't be able to reach the ink filling procedure after the replacement, you can't set voltage and waveform for the new head etc. Honestly, I would recommend to ask a qualified service for the HS printer. Too many thing will go wrong, if you start to play with the heads without knowledge, spare parts and proper calibrations afterwards...