Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "erikhuneker" 
<erik.huneker@p...> wrote:
 Part of 
my 
> background is in flexo printing (the 50" web, 800 ft/min, 8-colors 
> CMYK, $5 million dollar type of machines)

Oh yeah, you mean the web press stuff. Good gosh I at one point 
briefly prepared plates for a 6 color web. Huge monsters. Never ran 
the darn thing though, yikes. I like keeping all my fingers.
 Would the inks be similar then?

 as well as chemistry, 
> amateur photograph and for 3 mths proud owner of a Canon S800 to get 
> started in digital printing.


Yes, but the Canon uses different technology, not Piezo but some form 
of thermal I think- the ink would be way less viscous I imagine.

> 
> The inks we use in flexo printing are somewhat similar to the stuff 
> used for inkjets (some solvent, water, carrier and pigments etc...).

like Epson or more like Canon or HP tho...maybe they're all 
reasonable close when it comes to chemical makeup?
 
> In my opinion, you certainly do NOT want to use the clear ink. It 
> contains the carrier(or base) with the solvents but no pigments, and 
> that carrier will dry and stick to the pad and to the printhead. Not 
> good...

Then the mechanism is if I have a puddle of clear ink base, the 
solvent will evaporate out leaving the carrier which will gunk up. If 
this is the case, if I now take a drop of MIS pigment ink and put a 
puddle down, I'll be left with the carrier and the pigment as gunk. 
Wouldn't this happen if a person did too many cleaning cycles and 
overwhelmed the vacuum pump hooked under the parking pad?
Just thinking out loud...

> 
> Jim, your comments were absolutely correct on acetone, water, 
> solvents evaporating etc...

hhmmm..ok. Looong time ago I studied that stuff.<g> 

 Most solvents that dissolve the 
> base/pigment combination (non-polar) do evaporate.

i.e. water-based solvents.


 Some that do not 
> are oils (as in olive oil, kitchen oils or motor oil). But they do 
> not have a good dissolving power, and if a liquid does not 
evaporate, 
> I am fairly sure that there will be some sticking to the printhead 
> and causing trouble printing.


to make it clear to a gearhead...are you saying I want to put on the 
little parking pad a water-based solvent that will evaporate 
completely, but slowly? Or do I misunderstand?

Since Fantastik is for cleaning kitchen grease, it is then a polar 
solvent? This can't be true, as I can spray it on dried ink and it 
disloves/dilutes it.

> 
> Try to go for the solvents that do evaporate the slowest, and for 
> that the glycols are the best option. Careful not to smell them too 
> much though, some are toxic...

Well, I was thinking the clear Epson base had di-ethylene glycol in 
it. But maybe that's the solvent, and there's also a killer carrier 
mixed in.

If I restricted to Windex, Fantastik, or alcohol, I think I would then 
remove alcohol from the list, as I think it evaporates faster than the 
other two mixtures. I think this may leave me with Fantastik as being 
the better solvent with a slow evaporation rate.

Perhaps you can suggest a glycol that would be relatively safe to 
handle and easy to obtain. Di-ethylene glycol didn't look exactly 
harmless, but what do I know?

> 
> Hope this helped,

Yes it did, although as you see, it raised more questions. Where I 
came from, that was usually a good sign tho<g>.
Jim H.
> Erik.
>
> --- In DigitalBlackandWhiteThePrint@y..., "jimhayes361" 
> <jimhayes@j...> wrote:
> > --- In DigitalBlackandWhiteThePrint@y..., Todd Flashner 
> <tflash@e...> 
> > wrote:
> > > on 3/6/02 11:39 AM, jimhayes361 wrote:
> > > 
> > > > Therefore, a solvent that not only would dissolve
> > > > clogs but not evaporate quickly or leave a harmful residue 
(say 
> a
> > > > perfume) on pad would be desirable.
> > >