Digital BW, The Print

I'm just getting around to reading this thread, some of which I must admit is both amusing and potentially very important.

First, as to old Eboni -- I understand that companies have a financial incentive to have people buy new ink.  But, I also think there is truth in what MIS says; there may be a risk of clogging.  From what I can tell old inks may tend to clump. ("Floccuation," see http://en.wikipedia.org/wiki/Flocculation, is the more technical term.)  Keeping the particles separated is mostly done these days with a coating that gives the particles an electrostatic repulsion.  I think this coating oxidizes.  I've seen old Eboni bottles pull in slightly, as if air is being sucked out of them.  I think it is.  The coatings (not the carbon) may be oxidizing.  This would mean the particles would not have the electrostatic repulsion needed to keep them from clumping.


The second and potentially interesting (as well as amusing) point relates to the vibrators.

"mrjimbo" <mrjimbo@...> wrote:
>
>... adult toys.. as in vibrators.. 
> I can tape or Velcro it to the ink feed lines on a large format printer that isn't used very much ...It sends it little vibrations across the entire set of lines so the inks in the lines stay suspended...  
> I'm kinda curious to see if this gets ignored a second time... 

Not by me.  I'm sorry I missed it the first time.

I was disappointed when Epson did not address the ink settling issue in the 7800 and newer series of wide format printers via some sort of pulsing of the air and design of the cart so that the inks would be agitated.  This vibrator idea may be a route that we can take to do this.

An initial caveat, however, related to the first point of this post.  Epson may not want to agitate the inks too much.  Their inks are also, I assume, subject to floccuation (clumping) as they get old.  So, agitation of new inks, which they recommend, may be safe, whereas agitation of old inks may cause those clumps to rise off the bottom of the cart and into the heads.  Zeiss once made the point that all pigment inks have what he called "clunkers" in them -- large particles or clumps -- that are best left to settle.  So, the recommendation has been to agitate the inks, but then let them settle for a while before operation of the printer or ink mixing.

The question I'd like to pursue is whether there is a way to use a vibrator to agitate the carts -- with Eboni in wide format carts being my main concern.  If there are small vibrators that we could put under the bags in the carts, we might be able to somewhat automate the agitation and avoid having to pull the carts to do this.

So, are there small vibrators?  (I'm not sure I want to ask my daughters.)  Piezoelectric devices should be able to do this and be small.

Paul
www.PaulRoark.com