To sponge or not to sponge - renew or remove "porous pads"?

[martin0reg]

After grabbing two old classic printers on ebay I wonder what sponges are good for.

First is a R800, seems to be in really good condition, especially the printhead, after some maintenance. As I had other r800 (and gave them away), I knew that the purge pad mostly is totally smeared up with ink, particular with matte black. I think that happens when this photo printer was (ab)used mainly for office printing, text and grafics on plain paper = matte black. So I had to literally scrape the tar from the sponge of the purge pad... and flooding with hot cleaning solution.. until finally the pump would succeed again in absorbing the ink. Now it looks like this:

..and seem to work okay, although the sponge feels very soft and muddy when I touch and press it with a screwdriver or q-tip.

The sponge in the printing area was missing when I got the printer, I ordered new one... although this sponge might not be needed at all, because the absorbing material underneath will take the ink in the end, not the sponge. And so the overspray would flow direcctly through the holes of the plastic:

While this thin sponge in the printing area might be not needed (perhaps only to avoid the dirty look of ink drops, I wonder how important the absorbing material of the purge pad really is. You can't order it for cheap price (like the printing area sponge, which costs 3€) instead you have to renew the whole purging unit (for about 50€).

The second inkjet classic which I got for bargain is a stylus photo 950/960, with roll paper, auto cutter and a manual straight feed from the front for hard media, many options for different media:
http://ixbtlabs.com/articles/epsonphoto950/
And in this printer I discovered something interesting: a purge pad like a drain, without sponge!

The sponge in the printing area is crumbly and I will remove it completly... and will see how important it really was - or not..

But after having seen the spongeless drain at the 950's purging pad
- I wonder if I should try to remove the absorbing inlay oof the r800's purge pad too...!?


Here is what the service manual of 950/960 says regarding the spongeless purging pad:
2.2.4.2 Capping Mechanism
The capping mechanism covers the printheads with the cap holder to prevent the nozzle from increasing viscosity when the printer is in stand- by mode or when the printer is off.
...
The CR moves to left side of the Cap assembly and the pump absorbs the ink inside the cap.
...
2.Previously the sponge was provided to prevent frothing during cleaning.
3.Now, since the shape of new cap prevents frothing by its- self, it is not necessary to attach a sponge on the cap.


To summarize my question regarding those crumbled "oldies but goodies"
- sponge material on top of the printing area may be needless if it has become crumbly, the overspray will flow directly through holes and gaps into the waste ink
- if the absorbing material of the capping station / purge pad has become crumbly or is smeared up with matte pigment ink, so that the pump would not succeed to clean it from waste ink puddle - should I remove it too??

 

[websnail]

Honestly?

My considered opinion would be... "Meh! What the heck... Let's find out"

The critical bit is the skirt more than anything else.. If that's damaged you'll lose suction from the pump. My guess is that the sponge dissipates the vacuum so that there isn't a central pull that sucks from the nozzles closest to the waste tube connection but that's nothing but a guess.

 

[martin0reg]

That's my idea too and I will give it a try with the one printer I haven't give (or thrown) away.

By the way, I have learned a bit while looking at the process of purging and reading the explanation from 2002 about the purging process (what then was new now probably is standard).
Here is the complete quote from the service manual (2002 !!):
"The capping mechanism covers the printheads with the cap holder to prevent the nozzle from increasing viscosity when the printer is in stand- by mode or when the printer is off. This product has valveless cap system.
Air valve function used for the previous models pumps and ejects ink only inside the cap by absorbing ink with the valve open. By opening the Air valve, the negative pressure is decreased and only the ink inside the cap is ejected. (the ink is not absorbed from Ink cartridge or head cavity.)
But, valveless cap system, this operation is done out side of the capping area. The CR moves to left side of the Cap assembly and the pump absorbs the ink inside the cap."

What I see when observing a cleaning cycle is the following:
First the PH is on the sealed cap, the pump sucks ink (well I guess it's the pump..)
Then the PH moves a bit to the left and the pump tries to empty the pad - which is more or less wet or even filled up with ink.
Looking at this second step I can see that the printer with the crumbled pad now is able to empty the puddle (which wasn't the case when I received it all smeared up).
But nevertheless this crumbled muddy pad may be needless or even counterproductive... so I will try make a clean drain and see what happens..

 

[martin0reg]

Now that was a surgery.
You have to cut the "sponge". Because this layer of absorbing material is hold by the tiny silver rectangle, which you can see also on the photo above. Now it lies down on the ground... but the ground is not the clean drain I expected, there are further absorbing layers.

Anyway cleaning cycles seems to work fine.
So if you got a r800 or other old epson, which purge pad is all smeared up from printing with MK and then dried out from standing idle for years: You might cut and remove the whole upper layer instead of trying to dissolve the tarby soaking and cleaning for days

PS: In canon home printers (like pixma 4500) the inlay of the purge pad seems to be a porous, but hard material. So there are different solutions for draining: soft absorbing inlay, becoming crumbly after years (epson), hard absorbing inlay (canon), no inlay (early epson 950)

 

[websnail]

Looks good... There may be a replacement part for those sponge pads so as you're looking at service manuals anyway I'd take a gander and see if you can find a reference. If there is one I can query a supplier to see if they still exist at all.

 

[martin0reg]

The reason for this dirty action: there is no such replacement part, only the whole cleaning unit.
I know this from a german supplier "Gedat", where you can find the most of the epson parts.
And now I know why: you would not get this sponge layer underneath the tiny silver grid, because by removing I have to cut it in pieces..

 

[websnail]

The reason for this dirty action: there is no such replacement part, only the whole cleaning unit.
I know this from a german supplier "Gedat", where you can find the most of the epson parts.
And now I know why: you would not get this sponge layer underneath the tiny silver grid, because by removing I have to cut it in pieces..

Had a feeling that might be the case, still worth asking to be sure.

Ah well... Plan Z?

 

[palombian]

I lost once the purge pad sponge in a Canon printer.
Tried different absorbing materials, but they caused ink contamination between the colors.

It is indeed not a sponge, but a porous ceramic material. In an old Epson I saw a metal mesh.
The major function is maybe only to keep some distance from the rubber bottom of the pad so that ink can be sucked.

As replacement for the sponge in the printing area, I cut small slices from a household sponge, much stronger, I can rinse them under the tap and reuse.