Digital BW, The Print

Op 15-1-2011 0:42, Mark schreef:
> Ernst,
>
> Oops, I forgot one variable in my list.  It's a biggie, too. The
> manufacturers can also add anti-oxidants. In fact anti-oxidant
> technology was first deployed to solve the early PE cracking issue in
> RC prints. In the early days, field failures tipped the RC paper
> manufacturers off to a problem that was caused by the switch to TiO2
> whiteners.  When exposed to light TiO2 can generate free radicals
> that leads to peroxide formation and subsequent
> embrittlement/cracking of the PE layers (as well as severe silver
> tarnish in silver gelatin RC B&W prints. Anti-oxidants greatly
> reduced these problems, and I believe anti oxidants were once again
> enlisted to help control the ozone attack of the dyes in microporous
> inkjet papers (recall, the Epson 1270 era "orange fade" problem).
>
> Your spectral plot database is growing!  Very cool.
>
> kind regards, Mark

What I recollect of that problem was a switch to a different structure
of TiO2 rutile>anatase or the other way around.to get better results
with TiO2 whitened polyethylene barriers.. And the addition of extra
plasticisers in the paperbase that could migrate to the barriers in time
to compensate their structural hardening . Anti-oxidants fit in well but
I wonder whether the construction of the paper hasn't changed more
since, the TiO2 whiteners added to the base and the polyethylene (more
complex polymers now) kept transparent.

I am reading again parts of Wilhelm's book  The Permanence .... and it
is fantastic in its totality and detail but gas fading has escaped his
attention more or less. There are tests and results that could be better
explained with gas fading than what was seen as the cause and effect then.

-- 
Met vriendelijke groeten,   Ernst

Try: http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/

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