INTRODUCTION
Printing inks used in ceramics are constituted of inorganic pigments dispersed in a
serigraphic liquid. This liquid gives to the ink some rheological properties necessary
for the printing process (with a screen or a flexographic roll).
A good stability of ink, at rest or in use, is essential because pigments tend to settle
and to aggregate. The aggregation can be reversible or not because of chemical
interactions between the pigment and the serigraphic liquid. This instability leads to
evolutions of the rheological properties of the product, which can make the
application difficult or even impossible, and provoke defects in the printing.
For a given pigment, it is necessary to study the stability of the ink as a function of
the different serigraphic liquid available in the market.
The Turbiscan Classic enables to study the stability of formulated inks and compare
their stabilities :
• If the pigment settles quickly it is not redispersible, the use of
the ink is not recommended.
• If the migration rate of the pigment is low but the sediment is
not redispersible, the ink as to be used quickly.
• Finally, if the sedimentation is low and the pigment is
redispersible, the using time is long enough and the product
can be stored for the future.
