Question about pigment settling / intermittent use on 9900 and 9880

[rafaelrojas]

Hi there!

I have had problems with pigment settling on my Epson 9900 and K7 system… due to intermittent use of the printer. This led to big dispersions when linearizing. Then, when I realized the problem, and shook all the cartridges, I realized that the density of the inks had greatly increased, I assumed due to the fact the printer had been draining liquid with less pigments in suspension for some time. I realized this increase of density when trying to linearize my system for piezoDN, where I had to limit standard curves that normally should had worked without limitation…

All these problems made me learn the lesson!

Now, I need to come with a viable solution for intermittent use of the printer so that pigment settling does not occur again. Due to frequent absence from the studio (photographic trips), I can squeeze working sessions with the printer from time to time. I know the best solution might be to load the printers with piezoflush if they are going to be idle for more than 2 or 3 weeks, and I might do so from now on, putting aside a few weeks for heavy printing, and then loading them with piezoflush again. But, as an alternative that allows me to make use of the days I am at the studio, I am also considering coming with a protocol of “shaking” in order to be able to work on those intermittent periods when I am home again.

I must note that when I am leaving the printers at the studio, they are running automatically one nozzle test per day (I use the software Harvey Head cleaner). This might help keep the printer head from clogging? But I assume it does not do anything against pigment settling, due to the small amount of ink that is circulating…

What I would like to ask you is the recommended practice to avoid pigment settling depending on the time the printer is going to be left aside. I would like to hear what other users of printers that work intermittently do to avoid problems, and what you do at Inkjetmall to avoid problems when using yours…which are the different actions to use from lesser to greater effect? Which one to use depending on the time the printer is left idle? I guess that even you at Inkjetmall leave on holidays and leave your printers idle?

For what I know (please complete or rectify if I am wrong), some typical actions to avoid pigment settling might be, from lesser to greater effect:

a) Shaking the whole printer: How you do that to make it work? Do you need to leave the inks sit for some time before use after shaking the printer?

b) Shaking each cartridge: Which is the recommended way to do this? Do you need to leave the inks sit for some time before use? How to avoid introducing air into the system? Do you need to purge the cartridges with a syringe after shaking? I have noticed the introduction of air already when doing this…

c) Running cleaning cycles to circulate ink: Do you perform cleanings after shaking cartridges, etc? Which kind of cleaning do you use on 9900 and 9880 printers and how many times? - power cleanings, init fill, CL3 cleanings… ?

d) Filling the printer with piezoflush: When the printer has been previously left idle for a certain time, would you perform two init charges or just one init charge of piezoflush ?

The second part of question would be to know which one of the last actions mentioned (or others recommended that I might have missed) are to be applied in relation to how long the printer has been left idle between printing sessions:

If the printer has been left idle for 1 week?

For 2 weeks?

For 3 weeks?

For 1 month?

For 2 or more months?

Thanks so much for your help!

Rafael