Why do inkjet cartridges have those sponges?

Has anyone found out why inkjet cartridges have those sponges
inside, one for each ink? The only advantage I can see is that they
keep ink from spilling all over the place if the cartridge gets
tilted or inverted in transit. Or are they meant to keep the user
from shaking the cartridge and hearing that the ink compartments
start out less than half full? Thanks in advance for any and all
illumination on this mystery!

Adam

On Tue, 20 Jul 2010 18:33:41 -0400, Adam wrote:

Has anyone found out why inkjet cartridges have those sponges
inside, one for each ink? The only advantage I can see is that they
keep ink from spilling all over the place if the cartridge gets
tilted or inverted in transit.

You may be on to something.


Or are they meant to keep the user
from shaking the cartridge and hearing that the ink compartments
start out less than half full? Thanks in advance for any and all
illumination on this mystery!

Adam

Joel wrote:
Has anyone found out why inkjet cartridges have those sponges
inside, one for each ink?

It seems like it's part of the old design and to limit the amount of ink.
The printer manufactures don't see any better reason to go without it as
well as the sponge can limit the number of refill etc. so they continue
using the old design.

Okay, that makes sense. From the printer manufacturer's point of
view, anyway.

The original ink cartridge we have to pump the ink slowly, when the
refillable ink cartridge we use vacuum method and you can fill the cartridge
as fast as the vacuum can vacuum the ink. This is how it works.

Thanks for the very helpful YouTube links!

1. Plug the AIR VENT hole

2. Insert the syringe without needle to the REFILL hole (whre the gentleman
in video inserts the needle), then PULL the syringe to create vacumm, and
the ink will be sucked into cartridge the exact amount of air taking out.

That's it! no need to suck the ink our from bottom. I can also fill the
ink without taking the cartridge off the printer (like CISS), but I always
take them off to check the ink level.

So far I've been using the one-syringe method (inject ink slowly),
but the vacuum method looks good too, as long as one can get a tight
seal around the second syringe. With HP's black plastic cartridges,
there's no easy way to check the ink level, so I'm just going by
what the printer reports, and filling them before they get too low.

I also learned that even for cartridges with removable tops (like
I've done to some of my old HP 22s), the needle is still necessary
for refilling to prevent cross-contamination.

Adam

On 07/20/2010 06:33 PM, Adam wrote:
Has anyone found out why inkjet cartridges have those sponges inside,
one for each ink? The only advantage I can see is that they keep ink
from spilling all over the place if the cartridge gets tilted or
inverted in transit. Or are they meant to keep the user from shaking the
cartridge and hearing that the ink compartments start out less than half
full? Thanks in advance for any and all illumination on this mystery!

Just my own speculation, but I think you may have the main idea when you
talk of spilling. But not just in transit. Since these are tricolor
cartridges, the sponges may be there to reduce sloshing and potential
cross-contamination during high-speed printing. It's true that that
problem could be eliminated with a cartridge designed to be spongeless,
but this is how they chose to do it.

TJ

--
Life isn't fair. It's not meant to be.
Overcoming the disadvantages we face is what makes us strong.

The use of sponges or other batting (some use a plastic fiber) is
multiple, but is also an older and not as effective method. It is
mainly there to control ink release to the head. The capillary action
of the sponge or batting, helps to keep the ink from leaking out of the
cartridge and through the heads, flooding them. Some heads, like those
on Epson printers are passive, meaning they are always open and can,
through siphon action, spill all the ink out the bottom. The sponge
allows the ink to hold. Also, with the heads moving back and forth
relatively rapidly, it keep the ink from splashing up the cartridge and
out the air vent.

The other advantage for the manufacturer, is it makes the cartridge more
difficult to refill will air pockets developing during refilling, In
fact, some manufacturers add a foaming agent which creates a dense
soap-like foam into the sponge, making it much more difficult to get the
refill ink into place. Depending upon the ink, one way to get around
this, besides the vacuum refill method, is using a small amount of
isopropyl alcohol injected into the cartridge, swishing it around before
adding ink. The alcohol breaks down the soap foam bubbles.

The problems with this system are that it wastes a lot of ink in the
sponge, (and some of the components of the ink are considered
environmentally hazardous), the ink has more chance of oxidizing due to
direct air exposure, and the ink distribution to the head is not well
regulated which can lead to skipping ink output, the surface of the
sponge can dry out, the sponge can break down chemically, etc.

Many newer cartridges use no sponge. Instead they use a complex
labyrinth of channels and air exchange filters, and valves to control
the ink flow, control air contact, etc. They also are even more
difficult to refill ;-)

Art

If you are interested in issues surrounding e-waste,
I invite you to enter the discussion at my blog:

http://e-trashtalk.spaces.live.com/

TJ wrote:
On 07/20/2010 06:33 PM, Adam wrote:
Has anyone found out why inkjet cartridges have those sponges inside,
one for each ink? The only advantage I can see is that they keep ink
from spilling all over the place if the cartridge gets tilted or
inverted in transit. Or are they meant to keep the user from shaking the
cartridge and hearing that the ink compartments start out less than half
full? Thanks in advance for any and all illumination on this mystery!

Just my own speculation, but I think you may have the main idea when you
talk of spilling. But not just in transit. Since these are tricolor
cartridges, the sponges may be there to reduce sloshing and potential
cross-contamination during high-speed printing. It's true that that
problem could be eliminated with a cartridge designed to be spongeless,
but this is how they chose to do it.

TJ

The use of sponges or other batting (some use a plastic fiber) is
multiple, but is also an older and not as effective method. It is mainly
there to control ink release to the head. The capillary action of the
sponge or batting, helps to keep the ink from leaking out of the cartridge
and through the heads, flooding them.

Yes, the sponges are used to retain the ink. It's the simpliest method. I
don't see any drawback of using sponges.


The problems with this system are that it wastes a lot of ink in the
sponge, (and some of the components of the ink are considered
environmentally hazardous), the ink has more chance of oxidizing due to
direct air exposure, and the ink distribution to the head is not well
regulated which can lead to skipping ink output, the surface of the sponge
can dry out, the sponge can break down chemically, etc.

I don't think the sponges waste ink. For example a normal black cartridge
could contain 15ml of ink and after it runs out contains only 1ml residue
ink.
The surface of the sponge doesn't dry, because of the usually long breathing
channel. I have cartrides wihch work even 10 years later.

"Adam" wrote in message
...
Has anyone found out why inkjet cartridges have those sponges inside, one
for each ink? The only advantage I can see is that they keep ink from
spilling all over the place if the cartridge gets tilted or inverted in
transit.

Without foam or some other method to hold the ink in the ink would freely
dribble out the bottom of the cartridge.

Regards,
Bob Headrick, MS MVP Printing/Imaging

Well, that's what some people may think. Now you can try for yourself.

1. Fill a bottle with water with a big hole at bottom.

2. Put a sponge in the bottle then put the bottle on top of your monitor
or
laptop (if you have one).

Then tell me that the sponge will hold the water.


Take a full ink cartridge, remove the top label and turn it upside down. Do
you notice any spill of ink?

There are some methods to hold the ink inside. Of course "no sponge" are
some other methods. Sponge method another. May companies take advantage of
the sponge to make the refilling more difficult (there are many different
methods for this too). But STILL the sponge retains the ink!!!

Inkjet cartridges with sponges DO have a hole drilled in them, at the
top, Joel, or a vacuum would develops which would not allow the ink out.

They usually had a pull tab you have to pull off before installing the
cartridge to open that hole.

It is that vacuum that keeps the water in the bottle without the drilled
hole. In order for the water to leave, air needs to replace it, or the
sides of the container need to collapse. f the hole is large enough at
the bottom, air comes it part of the hole while the water escapes from
the other part.


Art

If you are interested in issues surrounding e-waste,
I invite you to enter the discussion at my blog:

http://e-trashtalk.spaces.live.com/

Joel wrote:
"Yianni" wrote:

The use of sponges or other batting (some use a plastic fiber) is
multiple, but is also an older and not as effective method. It is mainly
there to control ink release to the head. The capillary action of the
sponge or batting, helps to keep the ink from leaking out of the cartridge
and through the heads, flooding them.
Yes, the sponges are used to retain the ink. It's the simpliest method. I
don't see any drawback of using sponges.

Well, that's what some people may think. Now you can try for yourself.

1. Fill a bottle with water with a big hole at bottom.

2. Put a sponge in the bottle then put the bottle on top of your monitor or
laptop (if you have one).

Then tell me that the sponge will hold the water.

Now,

1. Fill the plastic soda bottle with water. Don't drill any hole on this
one

2. Now turn the bottle upsidedown see if any water will spill out.

These I learned from junior high school over 60 years ago. And I don't
know if they still teaching this old laws of physics or not, but they still
seem to work quite well on my new catridge with no sponge and 2 big holes on
top of cartridge. And a big hole at the bottom with the rubber to make the
hole smaller and longer as a small tube,. as well as some special design
around the bottom hole. Remember that Epson cartridge has no printhead.

The problems with this system are that it wastes a lot of ink in the
sponge, (and some of the components of the ink are considered
environmentally hazardous), the ink has more chance of oxidizing due to
direct air exposure, and the ink distribution to the head is not well
regulated which can lead to skipping ink output, the surface of the sponge
can dry out, the sponge can break down chemically, etc.
I don't think the sponges waste ink. For example a normal black cartridge
could contain 15ml of ink and after it runs out contains only 1ml residue
ink.
The surface of the sponge doesn't dry, because of the usually long breathing
channel. I have cartrides wihch work even 10 years later.

Arthur Entlich wrote:
It is mainly there to control ink release to the head.
[...]
The other advantage for the manufacturer, is it makes the cartridge more
difficult to refill will air pockets developing during refilling,

Thanks, Arthur and EVERYONE, for all your very informative replies!
I'd never expected my question to generate this much discussion.

As I mentioned, I'm playing around with one HP22 cartridge where I
pried off the top and removed the sponges. If anyone else ever
wants to try that, at least make sure you reseal the top back on
thoroughly. Otherwise ink does tend to splash around and escape
from the cartridge, even in normal use.

Thanks again, everyone!

Adam