RE: low viscosity gum combo

Gordon -

Very timely that you would mention this. I recently obtained samples of 3
different gums, tragacanth being one of them. I'll be testing them in a
couple of weeks and I'll post my results. As I understand it, gum
tragacanth is hardly in the same ballpark as gum arabic, viscosity-wise.
Gum tragacanth can have a 1% viscosity of anywhere from 300 cps to 1200 cps,
the average (in the food industry) being about 800 cps. If you made the
most concentrated solution you could of gum Arabic (about 70%) it would only
be about 200 cps. I'm hoping for a breakthrough that will revolutionize
gumprinting!! (and open up a myriad of new paths for failure...)

Keith

-----Original Message-----
From: Gordon J. Holtslander [mailto:holtsg@duke.usask.ca]
Sent: Wednesday, September 07, 2005 9:24 AM
To: alt-photo-process-l@usask.ca
Subject: low viscosity gum combo

Hi:

Was reading up on colloids and came across this:

        A solution of gum tragacanth and gum arabic has a lower viscosity
than either of the gums alone. Gum tragacanth by itself has a higher
viscosity than gum arabic (about 100 times as viscous as gum). Gum arabic
has the lowest viscosity of any of the common gums. Logically the mixture
would have a lower viscosity than any commonly used gum by itself.

Does anyone after a really low viscosity gum want to try this? I don't
know how a mixture would react to a bichromate and exposure. I don't
happen to have any gum tragacanth.

Gum tragacanth is a natural gum. It the gum from the species Astragalus
gummifer, A. adscendens and A. microcephalus found primarily in Iran, but
common in the eastern Mediterranean and southwestern Asia. Its harvested
much like gum arabic is.

Gord

---------------------------------------------------------
Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
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Received on Wed Sep 7 14:20:29 2005