FLUSHING....WHY?

[stratman]

Without getting too complicated,

What is the principle by which ink is drawn into and saturates the sponge? Surface energy?

I experienced this problem twice - on the same day. After further tests, I suspect that the problematic carts were not completely dry on their first fill.

There are reports of bone dry sponges having issues properly absorbing ink. Within those reports are solutions such as wetting the sponge with water or Pharmacist's solution. I have no evidence to the contrary, but, this would seem to contradict your assertion that a wet sponge was preventing proper refilling. Maybe it is the degree of residual water. Maybe something else is in play.

Concerning @pharmacist's conditioning solution for recalcitrant sponges, what physical properties does the solution provide to cure poor ink uptake by the sponge?

I know this is entering the physical chemistry zone, but I would like to understand better.

 

[The Hat]

Do not understand. Please explain further.

I threw that in because we just don’t know how much data is stored on a cart chip and if all of this info on board these chips, can it be influenced, changed or made to react differently the next time a firmware or driver upgrade is applied to that printer ?

We do know that the cart chip and the EPROM do talk because there is some Canon photo software Apps. that won’t work if you have refilled your original cart for instance, how does it know ?

Then there are some who believe that the CLI-8 and CLI-42 carts are different in some way, don’t ask me where there’re suppose to be different but you do have to allow for Muppets from time to time to have their moment in the sun, so I don’t think we should go there..

 

[jnug]

I do wish we could feel comfortable with performing software updates and refilling. Not really happy with having to give up updates as ultimately that can end up getting you in other ways. On the other hand, having an update change your ability to refill is a pretty bad deal.

Arghhhhhhhhhh!!!

 

[turbguy]

Then there are some who believe that the CLI-8 and CLI-42 carts are different in some way, don’t ask me where there’re suppose to be different but you do have to allow for Muppets from time to time to have their moment in the sun, so I don’t think we should go there..

The difference between the BCI-6 carts and BCI-3 carts was the ink...otherwise the carts will interchange quite well. The difference between a CLI-8 and CLI-42 (besides the chip)? Well, at least something is different about the YELLOW ink!

 

[The Hat]

If would seem that the BCl-3 / BCl-6 and CLl-8 / CLl-42 carts had one thing in common, their slight differences in ink.
The new OEM yellow in the CLl-42 cart is only a problem if you want it to be and these 2 CLl carts are still interchangeable even with the BCl carts..

 

[Grandad35]

What is the principle by which ink is drawn into and saturates the sponge? Surface energy?

There are reports of bone dry sponges having issues properly absorbing ink. Within those reports are solutions such as wetting the sponge with water or Pharmacist's solution. I have no evidence to the contrary, but, this would seem to contradict your assertion that a wet sponge was preventing proper refilling. Maybe it is the degree of residual water. Maybe something else is in play.

Concerning @pharmacist's conditioning solution for recalcitrant sponges, what physical properties does the solution provide to cure poor ink uptake by the sponge?

I decided to make the ultimate sacrifice and cut into a perfectly good purged cart to look at the sponge/foam. Boy, am I glad that I used the word "conjecture" in previous posts, as I had it all wrong. The "sponge" appears to be a PP or PET spun bonded needle punched "felt-like" product as shown below:

This is one edge of the top piece, where it was easily split apart in the vertical plane (it won't split in any other plane). There was no apparent orientation of the fibers, so the ink transmission should be about the same in all directions. The bottom part measured 15x40 mm and weighed 0.53 grams (880 gsm). The top part measured 18x40 mm and weighed 0.71 grams (990 gsm). The most interesting observation was that while the ink was readily absorbed, it didn't wet out on the fibers. When a little water was run over the ink, it literally flew off the fibers. On reflection, this shouldn't have been a surprise because both PP and PET are hydrophobic and require significant surface treatment to make them hydrophilic.

Given that we aren't dealing with round voids in a foam, but long parallel passages between overlapping round fibers, the mechanism that pulls ink into the felt would appear to be the same capillary action as that which pulls water up into a tree. This action works even if the liquid doesn't wet out the fibers.

As to why a conditioning solution helps, perhaps it has a lower surface tension than ink, and a higher surface tension in the ink wants to "chase out" the solution, filling the voids in the process?

 

[stratman]

@Grandad35

Thank you for your service in this forum.

I figured that the material would be hydrophobic or else there would be a degree of difficulty in the ink properly leaving the sponge upon printing. What I was unsure of was the counter balance action that drove ink into the sponge. I also suspected capillary action but for some brain fart reason could only think of osmosis (which i knew was wrong). I suppose this means that hygroscopy is not involved as has been mentioned on the forum?

I had read about wetting out, something I was not book-aware but intimately aware from waxing cars, and figured this was not involved either. I enjoyed how you tied Pharmacist's solution with wetting out, though.

My primer on surface energy and wetting out that pretty much covers what you wrote on this: http://www.adhesives.org/adhesives-.../structural-design/surface-energy-and-wetting. Like learning new things!

While I am not fluent or even conversant in this discipline as you, I can be a quick study and appreciate that your post corroborates what I had been thinking for the most part. Thanks.

 

[Emulator]

I use two sets of CLi8, both flushed and treated with pharmacist's solution (using glycerine) and IS inks. I found that on refilling (clearly not dry after the treatment), the ink moved very rapidly up to the top of the absorbent "filling", on the side adjacent to the reservoir, faster than I could fill the reservoir itself, but more reluctantly across the rest, still leaving a white area by the time I put them in storage. Examining them some weeks later they have completely saturated the filling, with no voids, but not entered the capillary vent. One set is in use and performing well.

The use of pharmacist's solution, tends to suggest an entirely different principle of operation.

The weights in grams of the OEM carts (including the orange twist off cap and a short piece of electricians tape) filled with IS ink are as follows:-
Red 30.1
Green 30.25
Black 30.4
Magenta 29.45
Cyan 29.39
P.Magenta 29.01
P Cyan 29.46
Yellow 30.51

An OEM ink filled P Cyan 28.38

I checked the scales calibration with 3 x £1 coins claimed to be 9.5g each = 28.5g. The scale read 28.48g, but the coins had been circulated.

 

[The Hat]

I have known for a very long time that the material inside of the OEM cartridge was not made of sponge and accepted its description because it was as good as the next.

99% of all OEM related cartridge discussions refer to it as “Sponge” so I reckon whatever we do we should continue to call it “Sponge “ because it will confuse the hell out of a lot of guys if we started to say “ Felt“ instead.

 

[PeterBJ]

Yes, the sponge or felt or what we should call it is a fibrous material. I have cut open a PGI-520 and a CLI-521 cartridge that were causing problems. A simple burn test of the fibres suggests that they are made from polypropylene.