PGI9 ink bag problem Pro9500

[rodbam]

Gday all, I have been emptying the ink out of my PGI9 carts so I can refill them with the new ink formulation from Precision Colors. I used a syringe & the clip adapter to suck the old ink out & was careful not to pull the vacuum too hard but now I have a few carts where the bag inflates on its own even though it's empty.
Does this mean the carts are buggered? I tried sucking the air out of the bag to fill with ink but it inflates too quickly.

 

[jtoolman]

Nope that is entirely normal.
I deviced a method to counteract that problem.
You either aspirate all the air immediately before refilling with either the drip or your method.
Or you can use a somewhat larger syringe such as a 30ml one. Load it with less than the required amount such as 14-15ml ml of ink.
Attach it to the clip adapter and to the cart. Pull back on the syringe to suck out all the air and recollapse the ink bag if needed. Now push the ink in slowly aspirate again if you need to and proceed to inject the required volume. I like to only load about 14 ml and then I finish by dripping in the last few ML to reach the full volume either visually checking till it is nearly full or use a Micro Gram Scale.
I average about 32ml give or take a bit per refilled cart.

Joe

 

[rodbam]

Thanks Jose that's a great relief I thought I was going to have to buy a few new carts. Quite a few of the carts I have emptied have stayed collapsed & 4 or 5 have expanded.
I will try with the 30ml syringe & do it the way you suggest.

 

[jtoolman]

They tend to do that when you remove all of the ink from the ink bag. Mikling can explain it a lot more eloquently than I can.
I just recently discovered that as I was also switching from the older inks to the new ones.
Joe

 

[mikling]

Oooh, sometimes when you see a potential problem that can happen it does. When I watched Joe's video I noticed that he emptied all the carts and in the back of my mind, I said to myself. This is not that good a procedure, sometimes it can cause something to trip. Well what do you know it happened.

Well, here is what is going on. Take a look and review the construction of the PGI-9 for a sec.
http://www.precisioncolors.com/PGI-9_Internals.html
In one of the slides, you'll see the contact pad pulled back. Underneath it is a SS steel mesh screen. One of the key functions of that mesh screen is to stop air from going in. How does it do that? When ink is placed on it, the surface tension of the ink basically makes the screen appear non porous as ink is stretched over it. When this screen is wet, the pressure required to break the film is quite large. Now how does ink go through? The same way water will eventually go through a tent if it pools up enough. The film will hold liquid until there is too much and the excess is easily shed away. The spring exerts enough of a vacuum to pull excess ink away from the mesh but never enough to break the film and let air in. When we fill with the dribble method we are causing an excess buildup of ink on the mesh and the spring just drinks it back in.

When you evacuate the cart and pull pretty much all the ink out, it can leave too little or no ink on the mesh and the spring will pull air through. If this happens....then immediately rewet the mesh/pad after removing the clip to restore the film. Or you can half fill a syringe, attach it to the clip, pull out the air and then inject ink back in to wet it. Since the action of the spring is actually quite slow, you can just squeeze some ink on the pad immediately after removing the evacuation jig.

Purchasers of used PGI-9 and PGI-72 need to take a note of this.

It is also for this reason why PGI-9 and PGI-72 carts should always be stored with the pad on the bottom to ensure that the pads remain wet at all times.

Now I see some are using the injection method to refill. My comment is that while fast...it has some inherent compromises and one is that you are not completely backflushing the cart as in the full dribble would do. The full dribble ends up completely flushing a cart each time it is refilled and keeps everything in tip top shape for a long long time. If you insist on using the fast method, maybe you should alternate fills with the dribble or some combination.

 

[palombian]

Agree with Mike.

I avoid flushing PGI-9 carts as much as possible and refill original empties as is (the only OEM inkt that can dry into a thick paste is yellow).
IMO the color difference by changing ink formulation is less than the dilution by remaining water in the bag (quite visible with yellow).
I even change from manufacturer without clogging or whatsoever until now.

Always drip filling too.

When I have no clip for an empty cart I seal it with tape.

 

[jtoolman]

I tend to fill by dripping as I never really let them get too low to begin with.
I never cease to learn from you guys, specially Mike!
What you said makes total sense. Even though I did manage to get the flushed carts to load without problems, I can see where it could be a problems with some folks who may not understand how the carts actually work internally.
Thanks again!

 

[rodbam]

I had a look at Mikes link & it does explain a lot, thanks Mike. I have printed up quite a few A3+ shots to test out the carts with my old head as I didn't want to risk the new head when it gets here & everything seems to fine. One really good strange happened is my blocked red now gives a good nozzle check. I tried twice to soak & clean the head but the red blockage seemed very stubborn so I thought bugger it & I tried running quite a few reddish looking prints through the printer & it seems to have cleared itself without burning out that channel.
One other strange thing when I was refilling is on one of the carts the refilling was really slow to absorb through the pad, I had to keep stooping until it had absorbed then carry on dripping. I hate it when things don't go normally because it makes me not trust the cart.

 

[websnail]

One other strange thing when I was refilling is on one of the carts the refilling was really slow to absorb through the pad, I had to keep stooping until it had absorbed then carry on dripping. I hate it when things don't go normally because it makes me not trust the cart.

I'd be a bit wary of that cartridge were I you... That sort of behaviour is usually indicative of the sponge and/or mesh starting to clog up and reduce ink flow. Whenever I've had that with PGI-9 or PGI-72 carts, poor ink flow has followed or arrived with it.

It may not be necessary but if you do find that ink flow is being impeded then I've found that flushing with a cleaning solution will restore the normal ink flow back and forth. However, worth noting that flushing with ink has not, in my testing, had the same restorative effect.

Just to add to that, as has been discussed elsewhere, if you do flush with a cleaning solution you will get air ingestion into the cartridge so, to restore the ink film and eject the air, you can use a flush clip and syringe with a few millilitres of ink to flush out any remaining cleaning solution, dump the ink you used and then refill properly. As a precaution I'd definitely recommend using scales or do a force fill (with a measured "full" amount of ink) to ensure you have actually filled the cartridge properly and not left an air bolus in the cartridge bag. Wouldn't want to end up blowing the head due to an incomplete fill.

 

[rodbam]

Thanks Martin I will relook at that cart & see if I can fix it.