Spongeless cartridge

[ocular]

Got hold off some interesting spongeless refillable Canon BCI3 cartridges. They are completely spongeless and can be easily changed into CIS

They look as though they come from http://www.jetyoung.com/pro-e-refill-cartridge.htm

Unlike the MIS spongeless there is no sponge at the exit port. There is a soft small silastic plunger offset in the exit port. When the cartridge is clipped in the printhead the plunger is pushed up and the ink is then allowed to flow out. Thus the exit port is self sealing when removed from the print head. There is still a clip to go over the exit port for refilling. The refilling process involves removing the black plug from the top of a cartridge. A syringe half full of ink is then pushed into the hole. The tip fits snugly into the hole. The syringe is used to suck air out of the cartridge and then released and ink will be drawn in to replace the air withdrawn. This is repeated a no of times until the cartridge is full. The hole is left unplugged as this is the breathing hole.

Here is a pic of the exit port and you can see the plunger in it. The cartridge is resting on the exit port clip

I haven't worked out the physics of this cartridge but it seems to have lots of different chambers. Along one side there is a clear membrane the covers passages and a filter screen.

As well as being a standalone refillable cartridge it can be used in a CIS. Here is the black cartridge already filled in a CIS for a Canon IP3000

I obtained this setup from www.inkbank.com.au here in Australia - great support from the bloke that runs the show.

 

[Nifty]

That is just incredible. I wonder how well it works as a simple refillable cartridge without a CIS / CFS system. I'm curious what grandad has to say on this one!

 

[BlasterQ]

If there is no problem with printhead clogging and dripping, then this is probably the best refillable cartridge ever! These chinese are really smart! Bad english, but good products!

 

[Grandad35]

Ocular - great photos! Where do you find this stuff?

Nifty-stuff - remember, you asked for this.

Designing a removable ink cartridge may seem to be a simple task, but if you spend some time thinking about what it must do, it is obvious that it is far from a simple design. Given the Canon print head design, the cart must:
1 Tolerate being inserted and removed numerous times without leaking into the printer, onto the floor, etc. There should not be any ink left on the rubber sealing pad in the print head - there should be at most small bubble of ink on top of the ink pickup itself.
2 Automatically and reliably make a fluid connection to the ink pickup in the print head.
3 Provide as much or as little ink as is pulled away by the print head's ink pickup.
4 Be able to tolerate long periods with no ink flow without leaking.
5 Provide the ink at very close to zero pressure. As I understand the print head design, it is only capillary action that feeds ink from the pickup to the nozzles. Positive pressure will cause the print head to leak and a suction will prevent the ink from feeding.
6 Provide a final filtration for the ink.
7 Accommodate any print head requirements that we don't know about.

This spongeless cart is a very interesting concept that is not easily analyzed. If Ocular can't figure it out with the cart in his hands, it will be impossible to figure it out from a distance. There certainly appear to be a number of intricate channels and chambers - this would be in keeping with the requirement to provide zero pressure at the print head pickup.

The old axiom "KISS - Keep It Simple, Stupid" usually applies to most designs. The sponge cart certainly meets this criteria, and it has proven to be a reliable design over an extended time frame. From a prefilled cart manufacturer's point of view, it is close to a perfect design; it meets the design goals and it is low cost, simple, reliable and difficult to refill without degrading the overall performance because of air getting into in the sponge. Also, since Canon designed the sponge cart they were certainly aware of any special design needs for the cart.

Based on Ocular's photos and description, I have the following concerns about the spongeless design:
1 The valve that opens and closes the exit port will probably leave ink on the rubber print head pad and may drop some ink when it is removed. Ink is free to flow as soon as the plunger is activated, so If you have problems locking the cart into its final position you might get an ink spill onto the head.
2 If the design isn't perfect, even a small pressure from the height of the ink in the final chamber of the cart may cause a leak. This is one of things that is difficult to "get right" with a continuous flow system. Neil Slade says in his write-up: "I have tried Continuous Flow systems for Canon printers. Sorry, but I did not have long term success".
3 If the final filtration is only provided by a "screen" filter it will not be nearly as good as the "cigarette" filter in a sponge cart. Unless they are using some exotic metal filter (which would be expensive), single layer wire mesh filters generally only filter down to about 10-20 microns (a human hair is 50-75 microns). Filters such as the "cigarette filter" are easily able to filter down to less than a micron. I don't know the diameter of the nozzles, but a 2 picoliter ink drop is about 15 microns in diameter. You can draw your own conclusion as to which would be the better filter.

As they say, "The proof is in the pudding". In the final analysis, all that matters is whether it works. If it works, nothing else matters. Hopefully, Ocular will give us a field report, keeping in mind the various design needs listed above.

 

[Nifty]

Very excellent points. I think the biggest issue is #3, to "Provide as much or as little ink as is pulled away by the print head's ink pickup."

Now that I think of it we should have waited to post our comments until Ocular was done testing and playing with the cartridges... now he's going to be too scared to use them!

 

[BlasterQ]

i think ocular will test them. i'll do if i have those stuff. if this carts performs well, then it is well worth the risk. if it doesn't, it is still worth the risk, we get to eliminate another cartridge and add it to our 'not recommended' list.

 

[ocular]

Thanks for all those comments. I'll take courage in hand and try out the black cartridge over the weekend as a standalone refillable unit and then later as part of a CIS/CFS.

It is hard to imagine how the necessary resistance to outflow can be provided like a sponge cartridge. Though the resistance to outflow is more when the sponge cartridge is not in contact with the printhead. When the sponge cartridge is in contact with the printhead then there is a wick effect and the outflow of ink is probably limited by the air breather maze. In some non genuine sponge cartridges this can just be a crude hole with minimal resistance.

There is a clear membrane on one side of the cartridge - this may be an area of weakness long term with constant refilling.

Yes the physics of ink flow changes with CIS/CFS- there is probably an increased resistance to outflow as the tanks are lower than the cartridge (other wise the ink would siphon out).

Watch this space.

 

[Nifty]

Subscription to this page has been checked and double checked! Thanks ocular!

 

[ocular]

Well, I went thru the process of filling a virgin cartridge. I put 20 mls of ink in a 60ml syringe. Fitted the end neatly into the hole on top of the cartridge and did what I call withdraw/suck technique. Watching the ink initially whiz around the maze of tracks and compartments was entertaining.

I weighed the empty cartridge and measured the ink. Followed the refilling instructions. Withdrew and sucked 3-4 times and didn't seem to be getting anymore ink into the cartridge. Only had 15 mls in the cartridge at this stage. Emailed Jetyoung and got a prompt reply but was just a repeat of the technique I was using.

So I decided to try inverting the cartridgeand was able to get more air in and more ink out. Total of 25mls ( Sponge black cartridges take about 28mls I think.) The picture below gives an idea of all the chambers and connections.

The next pic shows the darker channels that are just covered by a transparent membrane. Note that most chambers are full except for one the bottom right one.

This is the otherside of the filled cartridge - notice the ink ingrained finger- sign of a true refiller!.

I then placed the filled cartridge in the printer and did some nozzle checks and test prints. everythings seems to work well. This is a new bulk ink I am trying and the black text is nice and dark and crisp.

The concern I have using this cartridge as a standalone refillable is the useful amount of ink between refills. Interestingly there is a prism on the bottom of the front chamber so presumably the cartridge low warning works with these.

One way of working out the useful amount of ink a cartridge can supply is to weigh the cartridge when full and then when it is empty. A perceived limited amount of ink with this spongless cartridge may not be the case as the end point of when to fillup a sponge cartridge is ill defined as we know if you let the cartridge become completely empty then the life of the cartridge is shortened- something that is not the case with a spongeless cartridge.

May be all refillable cartridges can be graded on cost, ease of refill ( including sealability), durability( no of refills before discard), performance( leaking/blockages).

I will continue to use this spongeless cartridge to see if I have any leakage/bockage problems. And will try and document amount of ink used between refills. I have emailed jetyoung and asked them how much ink they expect a virgin black cartridge is expected to hold.

 

[Nifty]

Excellent post! Please keep us posted on the amount of ink that is used before you are required to refill.

ocular, did you mention how you are sealing the refill hole / port on this cartridge?

I wish you had a digital video camera to show us all the process of the black ink shooting through that crazy maze... that would be a fun sight!