ALTANA Auto Film-Applic No2101 - Handbuch (Seite 30)

This instrument has been designed
to draw down sample coatings with
an improved degree of reprodu-
cibility. Manual drawdowns are
often inconsistent, especially
between operators, and this makes
test comparisons between samples
either difficult or unreliable.
The factors affecting the drawn
down coating are the shear rate,
and the weight placed on the
applicator tool. The automatic
applicator employs a precisely
controlled traverse of carriage at a
speed selected to suit the particular
drawdown to be made.
This unit can be used for most
special applicators and wire cators.
A standard applicator is placed in
front of the beam so that, when the
traverse is started, the beam
pushes it along the test surface to
draw down a film. Both shear rate
and the weight placed on the
applicator are constant, so that a
uniform film is produced.
3. System Description
The automatic applicator is
equippped with a vacuum bed. The
vacuum is generateed by a pump
within the instrument itself - an
external vaccum pump is not
required. The vacuum bed is zoned
to accomodate different sizes of test
cards.