Eleanora Eden on mon 1 oct 07
Here is the 911 on all the veegums from Insight materials information.
Eleanora
Veegum is not a 'gum', rather it is a fine particle mineral called
'smectite' (bentonite and hectorite are similar minerals). It is a
complex colloidal and extremely plastic magnesium aluminum silicate.
It is an off-white insoluble flake magnesium aluminum silicate that
swells to many times its original volume when added to water. Its
aqueous dispersions are thus high viscosity thixotropic gels at low
solids. Veegum is not subject to attack by microorganisms. Various
grades are classified according to viscosity and ratio of aluminum to
magnesium content.
Density (Mg/m3): 2.6
Viscosity (after shear mixing, 5% dispersion): 250 cps +/- 25%
Moisture: 8% max
Bacterial Count: less than 1000 per gram. No E. coli, S. aureus,
Salmonella sp., P. aeruginosa at time of shipment.
Veegum T is used as an in-mix suspending agent and surface hardener
for glazes. It is also suitable for use as a spray-on surface
hardener before decorating (mix it with water and put a light layer
on dried ware).
VGT is employed as a plasticizing agent for nonplastic formulations
such as high alumina or zirconia bodies, and as a nonmigrating binder
in extruded bodies. The material is clean and therefore does not
affect fired whiteness.
VGT has a high pH of 8.5 and yet acts as a flocculant, contributing
to the workability of porcelain. 1.5-2.0% added to a porcelain, that
is otherwise a little to short for modeling or throwing, will
transform it into a plastic material.
Veegum CER is a mixture of Veegum T and medium viscosity sodium
carboxymethylcellulose that gives optimum surface hardening of
unfired ceramic glazes for safe handling of the ware. It serves as
hardener, suspending agent and viscosity stabilizer in glazes.
Veegum Pro is Veegum treated with amine to improve dispersability.
Veegum Pro hydrates readily in hot or cold water to form high
viscosity dispersions. Recommended for use where a minimum amount of
water is required and/or only slow type mixers are available.
--
Bellows Falls Vermont
www.eleanoraeden.com
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