Roland Print Colour Drop - Weird One...

[Andrew Signs]

Hi All,

Ok, this one has me confused. We just got over our JV33 issue on one of our machines now this.

We run a Roland AJ1000 ecomax inks etc primary used to print mesh. Was perfect a few days ago when it ran a full 50 meters

Few points:

- Test draw is perfect, all nozzles ok etc
- Ink in lines, pulls through file.
- Caps are clean and moist with ink.
- Magenta head is brand new.

Issue:

- We noticed when we went to print mesh (basically all we use it for) that the solid yellow background printed about 15mm(half inch) in the correct colour them proceed to print at an almost half strength yellow
- Thinking is was a yellow issue we replace damper, did full clean and pull through.
- Test draw again and still perfect across all colours
- Set the machine to print another mesh print which was a full background red (deep red).
- It printed the first 200mm approx solid colour them did the same half strength colour.

***Important Note - when it happened the second time the print was half red half, grey and it did it to both colours and it printed across the mesh. Both the red and grey printed full colour then dropped to what I would guess is half?***

So, I'm hoping someone can point me in the direction of what they may think is happening. I have ruled out a range of things as its not isolated to a colour/head and is replicating across different colours. I also don't understand how it can be settings related as it starts fine?


Thanks in advance!

 

[Andrew Signs]

Please also see attached picture. On the right side you will see the first 10-15mm is a heavier colour and correct to what is should be.

Sorry for the average picture, I can likely upload a better one tomorrow

 

[Caw]

Try to pull ink from the dampers. We are literally waiting for parts to fix this exact problem, we had a yellow damper plug up and it will print a couple of inches and then just fade off..turning all my nice reds a lovely pink.

 

[Patentagosse]

'Had the same problem with black few months ago... 'printed fine for the firsts 2" than dropped 50% so black turned gray. 'Had my tech in for diagnostic and to conclude I had to replace the head (replaced 24 months earlier, low volume printing here). Barely 4k later it runs fine 'til yesterday. 'Had 2 backglasses to print, head was freshly cleaned, black cartridge was full and this shit happened. 'Stopped the print, selected another profile, print again... everything was perfect 'til 14" of the end. I can't stand it anymore. I'm in the office for way too many hours every week to burn material / ink / time (money) like that.'Tryied to fix this problem for years and still makes it randomly, techs (many have come here) with no clue. 'Had to send my file to another shop in order to get it printed so I can do my installs today. 'fed up...

 

[Andrew Signs]

Thanks for the replies.

The reason I can't see if being the head is its happening across all colours, and at least one head/damper is literally brand new and still doing it on that.

After further testing we increased the periodic cleaning (by reducing time lapse) and it seems to rectify it.

When a printer generally cleans its pulling ink presumably as it all pressures up. This makes me think on these really heave, full colour prints at 2 meters wide that we are having ink starvation issues? Does anyone agree?

Then the question is, if so, is the only way to rectify to keep the clean period short for big heavy colours to allow it to think and fill etc?

Thanks,