Digital BW, The Print

Hi Bob,

 

You might be interested in comparing the water-glycerol dilution v.
viscosity table 1 at http://www.sciencedirect.com/science?_ob=ArticleURL
<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGJ-3YMFMHY-C&_u
ser=4423&_coverDate=03%2F01%2F2000&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c
&_acct=C000059605&_version=1&_urlVersion=0&_userid=4423&md5=898ece7e1b118c51
fcba786501d3424d#sec8>
&_udi=B6TGJ-3YMFMHY-C&_user=4423&_coverDate=03%2F01%2F2000&_rdoc=1&_fmt=&_or
ig=search&_sort=d&view=c&_acct=C000059605&_version=1&_urlVersion=0&_userid=4
423&md5=898ece7e1b118c51fcba786501d3424d#sec8 with the composition of my
simple base at http://home1.gte.net/res09aij/Viscosity_Comparisons.pdf .  My
simple base appears to be close to the 5 mPa-s viscosity limit Epson throws
out in its MSDSs.

 

My "cheap and easy" capillary viscometer is measuring kinematic viscosity as
opposed to dynamic viscosity. Glycerol-water mixes are considered typical
Newtonian fluids.  Dye inks also appear to be Newtonian.  However, pigmented
inks appear to become non-Newtonian, where the shear rate affects the
viscosity.  See, for example,
http://math.berkeley.edu/~sethian/2006/Applications/ViscoElastic/viscoelasti
c.html  This introduces some variables that are beyond what my little
experiments (and brain) can deal with.  I doubt we'll find much willingness
of the large companies to publish their data on the dynamic viscosities of
their non-Newtonian inks and the relationships with increasing frequencies
required for higher speed and higher resolution printing.  However, my guess
is that pigmented inks and these imperatives of competition are on a
collision course.  And I wonder how the Claria inks fit into all this.  Are
they Newtonian?

 

All very interesting.  As a practical matter, the solution for me is to just
shove some UT-R2 inks into a 260 and see what happens.  (Which is exactly
what MIS should be doing about now.)

 

Paul

www.PaulRoark.com <http://www.paulroark.com/>  

 



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